neurology advanced csf jl sarrazin

Cerebro Spinal Fluid (CSF) Intracranial Hypotension

Idiopathic Intracranial Hypertension JL Sarrazin

Hôpital Américain de Paris, Hôpital de Bicêtre

150 cm3

Cerebro Spinal Fluid (CSF) Locating CSF

Extra axial

In the sub ararachnoid space (SAS) between the arachnoid membran and the pia mater

In the cistern

(encephalic and spinal)

125 cm3

In the Ventricles

25 cm3

DURA MATER

ARACHNOID

PIA MATER

CSF

Sub arachnoid space

Extra axial :

�  Sub arachnoid space

�  Cisterns �  Cisterna Magna

�  Interpeduncular cistern

�  Ambient citern �  Peripontine cistern

�  Pontocerebellar cistern

CSF

CSF

The ventricles

�  V1 and V2 (lateral ventricles) are linked to V3 through the foramen of Monroe

�  V3 is linked to V4 through the mesencephalic aqueduct

�  V4 is linked with the cisterns through �  the Luschka foramens lateraly �  The Magendie foramen

medialy

�  Only meninx : pia mater

Production of CSF 20 cm3/h or 500 à 600 cm3 every 24 hours

CSF is produced:

Mainly in the choroid plexus area

A lesser amount is produced in the capillaries of the spinal and encephalic sub arachnoid space

A small amount starts from the intraparenchymal vessels to join the encephalic sub arachnoid space through the Virchow-Robin perivascular spaces

Production du LCR

H2CO3HCO- CO2

H2OH+

ATP

3’-5’ AMPc

passif

H+

2 Na+3 Na+

2 Na+3 Na+

2 K+

2 K+

H2OH2O

HCO-

Cl-Cl-

AC

Na/KATPaseactif

actif

H2O

Acétazolamine

OuabaïneFibres E-adrénergiques

10

Plexus choroïdes

10

Plexus choroïdes

Choroid epithelium : brush border epithelial cells spread on a basement membrane

The junction between the cells is not a100 % tight and the capillaries are fenestrated : exchanges between blood and interstitial fluid are free

Composition of CSF �  Maintains the physico-chemical environment constant in the

brain

�  Fluid �  Clear, pH = 7,3

�  3 à 5 lymphocytes/cm3

�  The CSF composition is different from that of the plasma.

Plasma CSF

Na+ 150 mmol/l 147 mmol/l

K+ 4,6 mmol/l 2,8 mol/l

Ca++ 1,8 mmol/l 1,1mmol/l

Cl- 115 mmol/l 130 mmol/l

HCO 3- 26 mmol/l 22 mmol/l

pH 7,4 7,3

PCO2 45 mmHg 50 mmHg

Proteins 8g/100ml 0,02 g/100ml

CSF flow

Resorption of CSF �  Passive flow from production area to clearance

area. �  Flowrate: 20 cm3/h.

�  Renewal: 3 times a day.

�  The CSF flows through the dural sinuses, the spinal veins, and in a lesser part in the lymph along the nerves 4/5 of the CSF

�  1/5 is eliminated in the spinal area

Dural Sinuses and Arachnoid granulations (Pacchioni’s granulations) Hernias of the arachnoid in the dural sinuses

Small « safety valves » responds passively by hydrostatic or osmotic pressure difference

ICP>ISP ICP<ISP

Other resorption pathways

Role of CSF

�  Mechanical protection of the brain and the spinal cord

�  +++ Role in cerebral homeostasis by holding a ionic equilibrium, allowing the flow of active molecules and the removal of catabolite

Stories of two women …….

with headaches

Thoracic back pain after heavy weight lifting, 1 week ago. Severe daylies Headaches

29 y.o tall, thin woman.

Global thickening and enhancement of dura mater

Clinical question : Are they orthostatic headaches?

Sub dural fluid collection

Intracranial hypotension

Intracranial hypotension

�  CSF leak, with volume loss of that fluid

�  Monroe Kelly principle : �  Brain vol + Blood vol + CSF vol = constant

�  Decreasing of CSF = Increasing of blood volume

Cerebral and spinal venous congestion

Secondary Intracranial hypotension

Dural breach �  Lumbar punction, spinal anesthesia, myelography

�  Accidental punction of dura mater

�  Medullary or cranial trauma 15% after Traumatic Brachial plexus injury

�  Cranial or spinal surgery

�  Excessive flow rate in derivation

�  Erosive lesions

J Neurosurg / Volume 118 / January 2013 149

J Neurosurg 118:149–154, 2013©AANS, 2013

IN recent years, the syndrome of intracranial hypoten-VLRQ�KDV�EHFRPH�ZHOO�GHÀQHG�DQG�DFFHSWHG��3DWLHQWV�with intracranial hypotension typically present with

SRVWXUDO�KHDGDFKHV�GXH�WR�UHGXFHG�&6)�YROXPH��$�ZLGH�variety of spontaneous, traumatic, and iatrogenic causes affecting the brain and spinal cord leading to CSF hy-SRYROHPLD� KDYH� EHHQ� LGHQWLÀHG�� 6XUSULVLQJO\�� RQO\� ��SDWLHQWV� ZLWK� %3,� UHVXOWLQJ� LQ� &6)� K\SRYROHPLD� DQG�

intracranial hypotension have been reported,12,14 despite the relatively common pattern of injury and its potential RYHUW�VRXUFH�RI�&6)�OHDNDJH��%HFDXVH�WKH�FOLQLFDO�SLFWXUH�RI�%3,� LV�GRPLQDWHG�E\�PRWRU�GHÀFLWV��VHQVRU\�GHÀFLWV��DQG�SDLQ��KHDGDFKHV�PD\�QRW�EH�UHSRUWHG��,W�LV�XQNQRZQ�LI�WKH�SUHYDOHQFH�RI�KHDGDFKH�LQ�SDWLHQWV�ZLWK�%3,�LV�ORZ��or if the headaches are unrecognized by physicians and/RU�SDWLHQWV�EHFDXVH�WKH�IRFXV�RI�FDUH�LV�WKH�DIIHFWHG�OLPE��The aim of this study was to determine the prevalence of ORZ�SUHVVXUH�KHDGDFKHV�LQ�DGXOW�SDWLHQWV�ZLWK�%3,�

&HUHEURVSLQDO�ÁXLG�YROXPH²GHSOHWLRQ�KHDGDFKHV�LQ�SDWLHQWV�with traumatic brachial plexus injury

Clinical articleMARIE-NOËLLE HÉBERT-BLOUIN, M.D.,1 BAHRAM MOKRI, M.D.,2 ALEXANDER Y. SHIN, M.D.,3 ALLEN T. BISHOP, M.D.,3 AND ROBERT J. SPINNER, M.D.1,3

Departments of 1Neurologic Surgery, 2Neurology, and 3Orthopedics, Mayo Clinic, Rochester, Minnesota

Object.� 3DWLHQWV�ZLWK� EUDFKLDO� SOH[XV� LQMXU\� �%3,�� SUHVHQW�ZLWK� D� FRPELQDWLRQ�RI�PRWRU�ZHDNQHVV�SDUDO\VLV��VHQVRU\�GHÀFLWV��DQG�SDLQ��%UDFKLDO�SOH[XV�LQMXU\�LV�JHQHUDOO\�QRW�EHOLHYHG�WR�EH�DVVRFLDWHG�ZLWK�KHDGDFKHV��+RZHYHU��&6)�OHDNV�PD\�EH�DVVRFLDWHG�ZLWK�&6)�YROXPH²GHSOHWLRQ��ORZ�SUHVVXUH��KHDGDFKHV�DQG�FDQ�RFFXU�LQ�%3,�VHFRQGDU\�WR�QHUYH�URRW�DYXOVLRQ��2QO\�D�IHZ�FDVHV�RI�KHDGDFKHV�DVVRFLDWHG�ZLWK�%3,�KDYH�EHHQ�UHSRUWHG��,W�LV�XQNQRZQ�LI�KHDG-DFKHV�LQ�SDWLHQWV�ZLWK�%3,�RFFXU�VR�UDUHO\��RU�LI�WKH\�DUH�MXVW�XQUHFRJQL]HG�E\�SK\VLFLDQV�DQG�RU�SDWLHQWV�LQ�ZKLFK�WKH�IRFXV�RI�DWWHQWLRQ�LV�WKH�DIIHFWHG�OLPE��7KH�DLP�RI�WKLV�VWXG\�ZDV�WR�GHWHUPLQH�WKH�SUHYDOHQFH�RI�&6)�YROXPH²GHSOH-WLRQ�KHDGDFKHV�LQ�SDWLHQWV�ZLWK�%3,�

Methods.�$OO�DGXOW�SDWLHQWV�SUHVHQWLQJ�DW�WKH�0D\R�EUDFKLDO�SOH[XV�FOLQLF�ZLWK�WUDXPDWLF�%3,�ZHUH�DVNHG�WR�FRP-SOHWH�D�TXHVWLRQQDLUH�DGGUHVVLQJ�WKH�SUHVHQFH�DQG�TXDOLW\�RI�KHDGDFKHV�IROORZLQJ�WKHLU�LQMXU\��7KH�SDWLHQWV·�FOLQLFDO��LQMXU\��DQG�LPDJLQJ�FKDUDFWHULVWLFV�ZHUH�VXEVHTXHQWO\�UHYLHZHG�

Results.�%HWZHHQ�'HFHPEHU��DQG�-XO\��SDWLHQWV�FRPSOHWHG�WKH�TXHVWLRQQDLUH��7ZHQW\�WZR�SDWLHQWV�UHSRUWHG�QHZ�RQVHW�KHDGDFKHV�RFFXUULQJ�DIWHU�WKHLU�%3,��(LJKW�RI�WKHVH�SDWLHQWV�H[SHULHQFHG�SRVLWLRQDO�KHDGDFKHV��VXJJHVWLYH�RI�&6)�YROXPH�GHSOHWLRQ��2QH�RI�WKH�SDWLHQWV�ZLWK�RUWKRVWDWLF�KHDGDFKHV�ZDV�H[FOXGHG�EHFDXVH�WKH�KHDG-DFKHV�LPPHGLDWHO\�IROORZHG�D�OXPEDU�SXQFWXUH�IRU�D�P\HORJUDP��6L[�RI�WKH�RWKHU��SDWLHQWV�ZLWK�SRVLWLRQDO�KHDGDFKHV�KDG�D�FOHDU�SUHJDQJOLRQLF�%3,��7KH�DYDLODEOH�LPDJLQJ�VWXGLHV�LQ�WKHVH��SDWLHQWV�UHYHDOHG�HYLGHQFH�RI�&6)�OHDNV��SVHXGRPHQLQJRFHOHV��Q� ��&6)�WUDFNLQJ�LQWR�VRIW�WLVVXHV��Q� ��&6)�WUDFNLQJ�LQWR�WKH�LQWUDVSLQDO�FRPSDUWPHQW��Q� ��&6)�WUDFNLQJ�LQWR�WKH�SOHXUDO�VSDFH��Q� ��DQG�ORZ�SRVLWLRQHG�FHUHEHOODU�WRQVLOV��Q� ��

Conclusions.� ,Q� WKLV� UHWURVSHFWLYH� VWXG\��RI�SDWLHQWV� ��RI��SDWLHQWV��ZLWK� WUDXPDWLF�%3,� VXIIHUHG�IURP�D�QHZ�RQVHW�KHDGDFKH��6HYHQ�RI� WKHVH�SDWLHQWV��H[SHULHQFHG�SRVWXUDO�KHDGDFKHV�FOHDUO\�VXJJHVWLYH�RI�&6)�YROXPH�GHSOHWLRQ�OLNHO\�VHFRQGDU\�WR�D�&6)�OHDN�DVVRFLDWHG�ZLWK�WKH�%3,��ZKHUHDV�WKH�RWKHU��SDWLHQWV��suffered headaches that may have represented a variant of CSF depletion headaches without a postural characteristic RU�D�KHDGDFKH�IURP�DQRWKHU�FDXVH��7KHVH�GDWD�VXJJHVW�WKDW�&6)�YROXPH²GHSOHWLRQ�KHDGDFKHV�RFFXU�LQ�D�VLJQLÀFDQW�SURSRUWLRQ�RI�SDWLHQWV�ZLWK�%3,�DQG�KDYH�EHHQ�XQGHUUHFRJQL]HG�DQG�XQGHUUHSRUWHG�(http://thejns.org/doi/abs/10.3171/2012.9.JNS112368)

KEY WORDS� � � �� LQWUDFUDQLDO�K\SRWHQVLRQ� � � �� FHUHEURVSLQDO�ÁXLG�OHDN� � � �� ORZ�FHUHEURVSLQDO�ÁXLG�SUHVVXUH�KHDGDFKH� � � �� SRVWWUDXPDWLF�KHDGDFKH� � � �� RUWKRVWDWLF�KHDGDFKH� � � �� SHULSKHUDO�QHUYH

149

Abbreviation used in this paper:�%3,� �EUDFKLDO�SOH[XV�LQMXU\�

Idiopathic Hypotension �  Defined 20 years ago. Scarce, but its frequency is under

estimated. Prevalence: 1/500000

�  Slim, tall, young woman �  F/M ratio : 3/1

�  Average age: 37-42 y.o (extreme: from15 to 76) y.o

�  Aetiologies �  Minor trauma (sneezing, coughs, violent sport moves )

�  Pre-existing anomalies: Tarlov cysts, meningeal diverticula

�  Disease of the connective tissue (Marfan type).

The main symptom ORTHOSTATIC headaches

�  Orthostatism : the Headache appears within less than 15 minutes

�  Decubitus : the headache disappears within 30 minutes

Uninterrupted, not pulsating, growing along with orthostatism, with neck pains and feelings of neck and shoulder tensions headaches

Intensifying with head moves, coughing and sneezing shocks . ….Valsalva maneuver

Variable ways to start, mostly in a progressive way, sometimes in a brutal way

Downward shift of cerebral structures causing headaches by the pulling on

anchoring structures in brain’s dura mater

Other clinical symptoms �  Neck stiffness

�  Nausea and vomiting 30%

�  Visual troubles : diplopia mostly through VI (Abducens nerve)

�  Hearing and vestibulary troubles : tinnitus, dizziness (less frequent)

CSF Analysis

�  Decreased pressure < 60 mm of water… sometimes normal

�  Hyper proteinorachia, important sometimes

�  Lymphoticpleocytocis

�  Normal Glycorrhachia

�  this set offers less interest since MRI

DIAGNOSIS

Clinical (orthostatic headaches+++)

+

MRI

Thickening of dura mater �  Thickening and enhancement of dura mater, equally

spread, supra and infra tentorial areas

�  Leptomeninges untouched

�  Might be due to dilation of dura mater veins

Dura mater enhancement Lepto meninx enhancement

Differential diagnosis

�  Post traumatic

�  Infection

Tuberculosis (leptomeninges are often involved)

�  Inflammation

Sarcoidosis, Wegener’s, PR

�  Tumor

Meningiomatosis, metastasis, lymphoma

Dura Mater : Hyper intense on sequence FLAIR

Technical note : Flair always essential sequence 2D or 3D +++

Sub dural collections

Collections and sub-dural hematoma

SDHematoma caused by ripping off of arachnoid granulations («Pacchioni’s granulations »)

Congestion of veins

Pituitary gland and stalk

Retroclival veins

Shifting downward of structures

Chiasma

Cerebellar tonsils Less frequent

ORIGINALRESEARCH

The Venous Distension Sign: A Diagnostic Sign ofIntracranial Hypotension at MR Imaging of theBrain

R.I. FarbR. Forghani

S.K. LeeD.J. Mikulis

R. Agid

BACKGROUND AND PURPOSE: Patients with intracranial hypotension (IH) demonstrate intracranial venousenlargement with a characteristic change in contour of the transverse sinus seen on routine T1-weightedsagittal imaging. In IH, the inferior margin of the midportion of the dominant transverse sinus acquires adistended convex appearance; we have termed this the venous distension sign (VDS). This is distinct fromthe normal appearance of this segment, which usually has a slightly concave or straight lower margin. Thissign is introduced, and its performance as a test for the presence of this disease is evaluated.

MATERIALS AND METHODS: The transverse sinuses on T1-weighted sagittal imaging of 15 patientswith IH and 15 control patients were independently assessed in a blinded fashion by 3 readers for thepresence of a VDS. A present or absent VDS was determined for each patient by each reader, and aconsensus result for each patient was determined by unanimity or majority rule.

RESULTS: Using the VDS, the readers correctly identified 93% (14 of 15) of the IH patients andsimilarly 93% (14 of 15) of the control patients. There was a high rate of agreement among the readersfor the interpretation of the VDS (multirater ! ! 0.82). The overall sensitivity of the VDS for thediagnosis of intracranial hypotension was 94%. Specificity was also 94%.

CONCLUSION: The VDS appears to be an accurate test for the presence or absence of IH and may behelpful in the evaluation of these patients.

Intracranial hypotension (IH) is a syndrome of variable eti-ologies, clinical presentations, and MR imaging appearances

that share a unifying cause of CSF volume depletion and re-sultant low CSF hydrostatic pressure.1-7 The syndrome ofspontaneous IH (SIH) typically presents with orthostaticheadache associated with MR findings and most commonlyresults from spontaneous leak of CSF from the spinal thecalsac. Iatrogenic causes of IH include “over shunting” associatedwith CSF diversion procedures, as well as continued leaks aftersurgical procedures and lumbar punctures. Many characteris-tic MR findings have been associated with IH regardless of itsetiology.1-12

On review of the MR imaging of patients presenting to ourinstitution with IH, we have identified a highly reliable novel im-aging sign for the diagnosis of IH. We have termed this sign the“venous distension sign” (VDS) and evaluated for it on routinenonenhanced sagittal T1-weighted imaging of the brain. In pa-tients with IH, the dural sinuses enlarge as they compensate forthe loss of intracranial CSF volume.2,7,13,14 This phenomenon isnot easily quantified; however, the expansion results in a charac-teristic change in the contour of the dural sinuses. This contourchange is readily appreciated at the level of the transverse sinus onstandard nonenhanced T1-weighted sagittal images of the brain.The presence of this sign can be determined in a binary fashion.Specifically, when visualized in its midportion on sagittal imagesof the brain, the contour of the dominant (larger) transverse sinus

normally has a concave or straight inferior border (Fig 1). In casesof IH, the inferior border acquires a distended appearance with aconvex bulging of its inferior border (a VDS, as in Figs 2 and 3).The purpose of this paper is to report this sign and evaluate itsperformance in a controlled trial for identifying patients with IHand differentiating them from normal age- and sex-matchedcontrol subjects.

Materials and MethodsInstitutional review board approval was obtained for this project.

Patients with IHA retrospective review of clinical and imaging records was carried out toidentify patients evaluated for IH at our institution from February 2001to September 2005. Criteria used in this study to firmly establish thediagnosis of IH were similar to those reported previously for SIH2,15 andinclude the following: diffuse headache that worsens within 15 minutesafter sitting or standing; evidence of low CSF pressure on MR imaging;and spontaneous headache resolution or within several days after epi-dural blood patch (EBP). Fifteen IH patients (IHPs) with complete MRimaging at presentation were identified and included 13 women and 2men with an overall average age of 46 years. Of the 15 patients withconfirmed IH, 12 presented with primary SIH, 2 presented after lumbarpuncture, and 1 after a spinal anesthetic procedure. All 15 of the IHPsprovided the typical clinical presentation of orthostatic headaches, as wellas characteristic findings at gadolinium-enhanced MR imaging of thebrain. Nine of the 15 went on to have EBP treatment, 4 had spontaneousresolution of their symptoms, and 2 were lost to follow-up. Follow-upMR imaging of the brain was available in 10 of the 15 IHPs.

Control PatientsEighty consecutive potential control patients (CPs) were recruitedfrom the population of cancer patients at our institution who wereundergoing screening for intracranial metastatic disease. Thesepatients had no clinical signs or symptoms of neurologic disease.

Received December 5, 2006; accepted after revision January 29, 2007.

From the Department of Medical Imaging (R.I.F., S.K.L., D.J.M., R.A.), Division of Neuro-radiology, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada; andDepartment of Medical Imaging (R.F.), McGill University, Montreal, Quebec, Canada.

This research was supported by the Department of Medical Imaging, University of Toronto.

Please address correspondence to Richard I. Farb, Division of Neuroradiology, Department ofMedical Imaging, University Health Network, Toronto Western Hospital, New East Wing 3MC430, 399 Bathurst St, Toronto, Ontario, M5T 2S8, Canada; e-mail: [email protected]

DOI 10.3174/ajnr.A0621

BRA

INORIGIN

ALRESEARCH

AJNR Am J Neuroradiol 28:1489 –93 ! Sep 2007 ! www.ajnr.org 1489

ORIGINALRESEARCH

The Venous Distension Sign: A Diagnostic Sign ofIntracranial Hypotension at MR Imaging of theBrain

R.I. FarbR. Forghani

S.K. LeeD.J. Mikulis

R. Agid

BACKGROUND AND PURPOSE: Patients with intracranial hypotension (IH) demonstrate intracranial venousenlargement with a characteristic change in contour of the transverse sinus seen on routine T1-weightedsagittal imaging. In IH, the inferior margin of the midportion of the dominant transverse sinus acquires adistended convex appearance; we have termed this the venous distension sign (VDS). This is distinct fromthe normal appearance of this segment, which usually has a slightly concave or straight lower margin. Thissign is introduced, and its performance as a test for the presence of this disease is evaluated.

MATERIALS AND METHODS: The transverse sinuses on T1-weighted sagittal imaging of 15 patientswith IH and 15 control patients were independently assessed in a blinded fashion by 3 readers for thepresence of a VDS. A present or absent VDS was determined for each patient by each reader, and aconsensus result for each patient was determined by unanimity or majority rule.

RESULTS: Using the VDS, the readers correctly identified 93% (14 of 15) of the IH patients andsimilarly 93% (14 of 15) of the control patients. There was a high rate of agreement among the readersfor the interpretation of the VDS (multirater ! ! 0.82). The overall sensitivity of the VDS for thediagnosis of intracranial hypotension was 94%. Specificity was also 94%.

CONCLUSION: The VDS appears to be an accurate test for the presence or absence of IH and may behelpful in the evaluation of these patients.

Intracranial hypotension (IH) is a syndrome of variable eti-ologies, clinical presentations, and MR imaging appearances

that share a unifying cause of CSF volume depletion and re-sultant low CSF hydrostatic pressure.1-7 The syndrome ofspontaneous IH (SIH) typically presents with orthostaticheadache associated with MR findings and most commonlyresults from spontaneous leak of CSF from the spinal thecalsac. Iatrogenic causes of IH include “over shunting” associatedwith CSF diversion procedures, as well as continued leaks aftersurgical procedures and lumbar punctures. Many characteris-tic MR findings have been associated with IH regardless of itsetiology.1-12

On review of the MR imaging of patients presenting to ourinstitution with IH, we have identified a highly reliable novel im-aging sign for the diagnosis of IH. We have termed this sign the“venous distension sign” (VDS) and evaluated for it on routinenonenhanced sagittal T1-weighted imaging of the brain. In pa-tients with IH, the dural sinuses enlarge as they compensate forthe loss of intracranial CSF volume.2,7,13,14 This phenomenon isnot easily quantified; however, the expansion results in a charac-teristic change in the contour of the dural sinuses. This contourchange is readily appreciated at the level of the transverse sinus onstandard nonenhanced T1-weighted sagittal images of the brain.The presence of this sign can be determined in a binary fashion.Specifically, when visualized in its midportion on sagittal imagesof the brain, the contour of the dominant (larger) transverse sinus

normally has a concave or straight inferior border (Fig 1). In casesof IH, the inferior border acquires a distended appearance with aconvex bulging of its inferior border (a VDS, as in Figs 2 and 3).The purpose of this paper is to report this sign and evaluate itsperformance in a controlled trial for identifying patients with IHand differentiating them from normal age- and sex-matchedcontrol subjects.

Materials and MethodsInstitutional review board approval was obtained for this project.

Patients with IHA retrospective review of clinical and imaging records was carried out toidentify patients evaluated for IH at our institution from February 2001to September 2005. Criteria used in this study to firmly establish thediagnosis of IH were similar to those reported previously for SIH2,15 andinclude the following: diffuse headache that worsens within 15 minutesafter sitting or standing; evidence of low CSF pressure on MR imaging;and spontaneous headache resolution or within several days after epi-dural blood patch (EBP). Fifteen IH patients (IHPs) with complete MRimaging at presentation were identified and included 13 women and 2men with an overall average age of 46 years. Of the 15 patients withconfirmed IH, 12 presented with primary SIH, 2 presented after lumbarpuncture, and 1 after a spinal anesthetic procedure. All 15 of the IHPsprovided the typical clinical presentation of orthostatic headaches, as wellas characteristic findings at gadolinium-enhanced MR imaging of thebrain. Nine of the 15 went on to have EBP treatment, 4 had spontaneousresolution of their symptoms, and 2 were lost to follow-up. Follow-upMR imaging of the brain was available in 10 of the 15 IHPs.

Control PatientsEighty consecutive potential control patients (CPs) were recruitedfrom the population of cancer patients at our institution who wereundergoing screening for intracranial metastatic disease. Thesepatients had no clinical signs or symptoms of neurologic disease.


From the Department of Medical Imaging (R.I.F., S.K.L., D.J.M., R.A.), Division of Neuro-radiology, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada; andDepartment of Medical Imaging (R.F.), McGill University, Montreal, Quebec, Canada.

This research was supported by the Department of Medical Imaging, University of Toronto.

Please address correspondence to Richard I. Farb, Division of Neuroradiology, Department ofMedical Imaging, University Health Network, Toronto Western Hospital, New East Wing 3MC430, 399 Bathurst St, Toronto, Ontario, M5T 2S8, Canada; e-mail: [email protected]

DOI 10.3174/ajnr.A0621

BRAINORIGIN

ALRESEARCH

AJNR Am J Neuroradiol 28:1489 –93 ! Sep 2007 ! www.ajnr.org 1489

3D Flair +++

MRI o  Global enhancement of dura mater

o  Sub dural collection

o  Venous congestion Ø  Pituitary gland and pituitary stalk Ø  Retroclival veins

o  Cranio caudal shift Ø  Chiasma, Cerebellar tonsils

Causative investigation �  Cause identified

Lumbar punction, surgical operation

�  « Idiopathic » process •  Minor trauma, sneezing, violent cough, sudden

sports effort •  «Anatomical « fragility » of meninges:

peri radicular cysts , meningeal diverticula,Tarlov cysts, meningocele

•  Inherited/genetic: Marfan, NF1, Ehlers-Danlos…

�  Never (or very scarce) at level of skull base

J Neurosurg 116:749–754, 2012

Causative investigation = Spinal cord exploration �  Isotopic transit

�  Myelo CT

�  Spinal cord MRI Ø  Myelo MR Ø  Axial +/- T2 weighted sequence

ü Spin echo sat fat ü  « T2 » High resolution (Fiesta, CISS, drive) ü 3D FSE T2 Sat Fat

ORIGINALRESEARCH

The Role of MR Myelography with IntrathecalGadolinium in Localization of Spinal CSF Leaksin Patients with Spontaneous IntracranialHypotension

J.J. AkbarP.H. Luetmer

K.M. SchwartzC.H. Hunt

F.E. DiehnL.J. Eckel

BACKGROUND AND PURPOSE: Localization of spinal CSF leaks in CSF hypovolemia is critical indirecting focal therapy. In this retrospective review, our aim was to determine whether GdM washelpful in confirming and localizing spinal CSF leaks in patients in whom no leak was identified on aprior CTM.

MATERIALS AND METHODS: Forty-one symptomatic patients with clinical suspicion of SIH werereferred for GdM after undergoing at least 1 CTM between February 2002 and August 2010. Aretrospective review of the imaging and electronic medical records was performed on each patient.

RESULTS: In 17 of the 41 patients (41%), GdM was performed for follow-up of a previously docu-mented leak at CTM. In the remaining 24 patients (59%), in whom GdM was performed for asuspected CSF leak, which was not identified on CTM, GdM localized the CSF leak in 5 of 24 patients(21%). In 1 of these 5 patients, GdM detected the site of leak despite negative findings on brain MRimaging, spine MR imaging, and CTM of the entire spine. Sixteen of 17 patients with previouslyidentified leaks underwent interval treatment, and leaks were again identified in 12 of 17 (71%).

CONCLUSIONS: GdM is a useful technique in the highly select group of patients who have debilitatingsymptoms of SIH, a high clinical index of suspicion of spinal CSF leak, and no demonstrated leak onconventional CTM. Intrathecal injection of gadolinium contrast remains an off-label use and should bereserved for those patients who fail conventional CTM.

ABBREVIATIONS: CTM ! CT myelography; GdM ! intrathecal gadolinium MR myelography; In111-DTPA ! indium-111 diethylene triamine pentaacetic acid; SIH ! spontaneous intracranial hypoten-sion; SPGR ! spoiled gradient-recalled-echo

SIH is a debilitating syndrome classically characterized byorthostatic headaches, low CSF pressure, and diffuse

pachymeningeal gadolinium enhancement on MR imaging.1

First-line treatment for patients with this condition is conser-vative therapy or large-volume lumbar epidural blood patch.2

Further treatment, however, including targeted epiduralblood patches, fibrin glue injections, and open surgical repairsmay be necessary. Each of these focal therapies requires preciselocalization of the CSF leak. Current standard radiologic tech-niques used to evaluate spinal CSF leaks in these patients in-clude conventional CTM, dynamic CT myelography, radio-nuclide cisternography, and conventional spine MR imaging.GdM has been reported in small series and case reports to be auseful adjunct in localization of CSF leaks in the difficult sub-set of patients with debilitating symptoms of SIH in whom noleak was identified on a prior CTM.3-15 However, the sensitiv-ity of GdM in this subset of patients has not been well studied.Our aim in this study was to perform a retrospective reviewof our experience and to determine and describe the cases inwhich GdM was a helpful adjunct to CTM in localizing spinalCSF leaks.

Materials and MethodsApproval of the institutional review board with waived consent wasobtained for this Health Insurance Portability and AccountabilityAct— compliant retrospective research study. A search of the radiol-ogy information system between February 2002 and August 2010 re-trieved a total of 164 patients who were referred for myelography forevaluation of SIH. Of these, 41 patients underwent GdM after under-going at least 1 CTM. If "1 GdM was performed on a single patient,only the first examination was evaluated in our study. No other caseswere excluded.

Imaging examinations reviewed included prior brain MR imag-ing, spine MR imaging, CTM (standard or dynamic16), nuclear med-icine In111-DTPA cisternography, and GdM. All imaging studies andreports were reviewed by a neuroradiologist (J.J.A.), and all GdM, by2 neuroradiologists with consensus agreement (J.J.A. and P.H.L.). Foreach brain MR imaging, the presence or absence of diffuse pachyme-ningeal gadolinium enhancement, subdural fluid collections, andsagging of the brain was recorded. “Brain sagging” was defined as thesubjective observation of inferior descent of the optic chiasm, mid-brain, pons, or cerebellar tonsils with effacement of the suprasellar orprepontine cisterns on sagittal T1 images. Brain MR imaging wasgraded as “classic” if both pachymeningeal enhancement and saggingof the brain were present (Fig 1). Brain MR imaging was graded as“equivocal” if pachymeningeal enhancement without “brain sag” or“brain sag” without pachymeningeal enhancement was noted. BrainMR imaging was graded as negative if neither pachymeningeal en-hancement nor sagging brain was present. For each spine MR imag-ing, the presence or absence of extradural fluid was recorded. For each

Received May 10, 2011; accepted after revision June 25.

From the Department of Neuroradiology, Mayo Clinic, Rochester, Minnesota.

Paper previously presented at: 49th Annual Meeting of the American Society of Neurora-diology, June 4 –9, 2011; Seattle, Washington.

Please address correspondence to Patrick H. Luetmer, MD, Department of Neuroradiology,Mayo Clinic, 200 1st St SW, Rochester, MN 55905; e-mail: [email protected]

http://dx.doi.org/10.3174/ajnr.A2815

SPINE

ORIGINAL

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AJNR Am J Neuroradiol 33:535– 40 ! Mar 2012 ! www.ajnr.org 535

ORIGINALRESEARCH

The Role of MR Myelography with IntrathecalGadolinium in Localization of Spinal CSF Leaksin Patients with Spontaneous IntracranialHypotension

J.J. AkbarP.H. Luetmer

K.M. SchwartzC.H. Hunt

F.E. DiehnL.J. Eckel

BACKGROUND AND PURPOSE: Localization of spinal CSF leaks in CSF hypovolemia is critical indirecting focal therapy. In this retrospective review, our aim was to determine whether GdM washelpful in confirming and localizing spinal CSF leaks in patients in whom no leak was identified on aprior CTM.

MATERIALS AND METHODS: Forty-one symptomatic patients with clinical suspicion of SIH werereferred for GdM after undergoing at least 1 CTM between February 2002 and August 2010. Aretrospective review of the imaging and electronic medical records was performed on each patient.

RESULTS: In 17 of the 41 patients (41%), GdM was performed for follow-up of a previously docu-mented leak at CTM. In the remaining 24 patients (59%), in whom GdM was performed for asuspected CSF leak, which was not identified on CTM, GdM localized the CSF leak in 5 of 24 patients(21%). In 1 of these 5 patients, GdM detected the site of leak despite negative findings on brain MRimaging, spine MR imaging, and CTM of the entire spine. Sixteen of 17 patients with previouslyidentified leaks underwent interval treatment, and leaks were again identified in 12 of 17 (71%).

CONCLUSIONS: GdM is a useful technique in the highly select group of patients who have debilitatingsymptoms of SIH, a high clinical index of suspicion of spinal CSF leak, and no demonstrated leak onconventional CTM. Intrathecal injection of gadolinium contrast remains an off-label use and should bereserved for those patients who fail conventional CTM.

ABBREVIATIONS: CTM ! CT myelography; GdM ! intrathecal gadolinium MR myelography; In111-DTPA ! indium-111 diethylene triamine pentaacetic acid; SIH ! spontaneous intracranial hypoten-sion; SPGR ! spoiled gradient-recalled-echo

SIH is a debilitating syndrome classically characterized byorthostatic headaches, low CSF pressure, and diffuse

pachymeningeal gadolinium enhancement on MR imaging.1

First-line treatment for patients with this condition is conser-vative therapy or large-volume lumbar epidural blood patch.2

Further treatment, however, including targeted epiduralblood patches, fibrin glue injections, and open surgical repairsmay be necessary. Each of these focal therapies requires preciselocalization of the CSF leak. Current standard radiologic tech-niques used to evaluate spinal CSF leaks in these patients in-clude conventional CTM, dynamic CT myelography, radio-nuclide cisternography, and conventional spine MR imaging.GdM has been reported in small series and case reports to be auseful adjunct in localization of CSF leaks in the difficult sub-set of patients with debilitating symptoms of SIH in whom noleak was identified on a prior CTM.3-15 However, the sensitiv-ity of GdM in this subset of patients has not been well studied.Our aim in this study was to perform a retrospective reviewof our experience and to determine and describe the cases inwhich GdM was a helpful adjunct to CTM in localizing spinalCSF leaks.

Materials and MethodsApproval of the institutional review board with waived consent wasobtained for this Health Insurance Portability and AccountabilityAct— compliant retrospective research study. A search of the radiol-ogy information system between February 2002 and August 2010 re-trieved a total of 164 patients who were referred for myelography forevaluation of SIH. Of these, 41 patients underwent GdM after under-going at least 1 CTM. If "1 GdM was performed on a single patient,only the first examination was evaluated in our study. No other caseswere excluded.

Imaging examinations reviewed included prior brain MR imag-ing, spine MR imaging, CTM (standard or dynamic16), nuclear med-icine In111-DTPA cisternography, and GdM. All imaging studies andreports were reviewed by a neuroradiologist (J.J.A.), and all GdM, by2 neuroradiologists with consensus agreement (J.J.A. and P.H.L.). Foreach brain MR imaging, the presence or absence of diffuse pachyme-ningeal gadolinium enhancement, subdural fluid collections, andsagging of the brain was recorded. “Brain sagging” was defined as thesubjective observation of inferior descent of the optic chiasm, mid-brain, pons, or cerebellar tonsils with effacement of the suprasellar orprepontine cisterns on sagittal T1 images. Brain MR imaging wasgraded as “classic” if both pachymeningeal enhancement and saggingof the brain were present (Fig 1). Brain MR imaging was graded as“equivocal” if pachymeningeal enhancement without “brain sag” or“brain sag” without pachymeningeal enhancement was noted. BrainMR imaging was graded as negative if neither pachymeningeal en-hancement nor sagging brain was present. For each spine MR imag-ing, the presence or absence of extradural fluid was recorded. For each

Received May 10, 2011; accepted after revision June 25.

From the Department of Neuroradiology, Mayo Clinic, Rochester, Minnesota.


Please address correspondence to Patrick H. Luetmer, MD, Department of Neuroradiology,Mayo Clinic, 200 1st St SW, Rochester, MN 55905; e-mail: [email protected]


SPINE

ORIGINAL

RESEARCH

AJNR Am J Neuroradiol 33:535– 40 ! Mar 2012 ! www.ajnr.org 535INTERVENTIONAL NEURORADIOLOGY

Detection and treatment of spinal CSF leaks in idiopathicintracranial hypotension

G. Albes & H. Weng & D. Horvath & C. Musahl &H. Bäzner & H. Henkes

Received: 11 March 2012 /Accepted: 8 June 2012 /Published online: 6 July 2012# Springer-Verlag 2012

AbstractIntroduction This study aimed to evaluate the diagnosticimaging findings and treatment results of patients with idi-opathic intracranial hypotension (IIH) due to cerebrospinalfluid (CSF) leaks.Methods Between February 2009 and April 2012, 26 IIHpatients (15 men, median age 49 years) presenting withorthostatic headache (n020) and/or with spontaneous sub-dural effusions or subarachnoid hemorrhage (n019) wereenrolled. Twenty-three patients underwent a whole spine CTand MRI myelography, starting 45 min after the intrathecalinjection of 9 cc of iomeprol (Imeron 300 M) and 1 cc ofgadobutrolum (Gadovist). Three patients only underwentMR myelography after intrathecal gadobutrolum injection.

Adjacent to the level(s) of the detected CSF leak(s) alongthe nerve roots, 20 cc of fresh venous blood with 0.5 ccGadovist was injected epidurally (blood patch, BP). Thedistribution of the BP was visualized by MRI the followingday. Treatment results were evaluated clinically and bymyelography 2 weeks after the application of the BP.Retreatment was offered to patients with persistent symp-toms and continued CSF leakage.Results CSF leaks were detected at the cervical (n012),thoracic (n025), or lumbar (n021) spine. In 23 patients,more than one spinal segment was affected. One patientrefused treatment. BP were applied in one (n09) or several(n016) levels. Clinical and/or radiological improvementwas achieved after one (n016), two (n05), three (n03), orfive (n01) BPs.Conclusion CT and MRI myelography allow the reliable de-tection of spinal CSF leaks. The targeted and eventually repeat-ed epidural BP procedure is a safe and efficacious treatment.

Keywords Idiopathic intracranial hypotension . Orthostaticheadache . SAH . Spinal CSF leak . Epidural blood patch

Introduction

Orthostatic headache (i.e., postural headache that improves insupine position) is the key symptom of idiopathic intracranialhypotension (IIH). Further signs and symptoms of IIH includemeningism, nausea, vomiting, tinnitus, hypacusis, cranial nervepalsy, and disturbance of memory and consciousness [1–5].The underlying cause of IIH is a spinal leakage of cerebrospinalfluid (CSF) of unknown nature. The CSF leak reduces theintracranial CSF pressure and may cause a venous dilatation(Monro–Kellie hypothesis) which is considered to cause head-aches via meningeal traction and subdural effusions [6] or

Presented in part at the Annual Meeting of the Deutsche Gesellschaftfür Neuroradiologie (DGNR) Cologne 2011.

G. Albes :D. Horvath :H. Henkes (*)Klinik für Neuroradiologie, Klinikum Stuttgart,Kriegsbergstrasse 60,70174 Stuttgart, Germanye-mail: [email protected]

H. WengKlinik für Anästhesiologie und operative Intensivmedizin,Klinikum Stuttgart,Stuttgart, Germany

C. MusahlKlinik für Neurochirurgie, Klinikum Stuttgart,Stuttgart, Germany

H. BäznerKlinik für Neurologie, Klinikum Stuttgart,Stuttgart, Germany

H. HenkesMedizinische Fakultät der Universität Duisburg-Essen,Essen, Germany

Neuroradiology (2012) 54:1367–1373DOI 10.1007/s00234-012-1055-3

INTERVENTIONAL NEURORADIOLOGY

Detection and treatment of spinal CSF leaks in idiopathicintracranial hypotension

G. Albes & H. Weng & D. Horvath & C. Musahl &H. Bäzner & H. Henkes

Received: 11 March 2012 /Accepted: 8 June 2012 /Published online: 6 July 2012# Springer-Verlag 2012

AbstractIntroduction This study aimed to evaluate the diagnosticimaging findings and treatment results of patients with idi-opathic intracranial hypotension (IIH) due to cerebrospinalfluid (CSF) leaks.Methods Between February 2009 and April 2012, 26 IIHpatients (15 men, median age 49 years) presenting withorthostatic headache (n020) and/or with spontaneous sub-dural effusions or subarachnoid hemorrhage (n019) wereenrolled. Twenty-three patients underwent a whole spine CTand MRI myelography, starting 45 min after the intrathecalinjection of 9 cc of iomeprol (Imeron 300 M) and 1 cc ofgadobutrolum (Gadovist). Three patients only underwentMR myelography after intrathecal gadobutrolum injection.

Adjacent to the level(s) of the detected CSF leak(s) alongthe nerve roots, 20 cc of fresh venous blood with 0.5 ccGadovist was injected epidurally (blood patch, BP). Thedistribution of the BP was visualized by MRI the followingday. Treatment results were evaluated clinically and bymyelography 2 weeks after the application of the BP.Retreatment was offered to patients with persistent symp-toms and continued CSF leakage.Results CSF leaks were detected at the cervical (n012),thoracic (n025), or lumbar (n021) spine. In 23 patients,more than one spinal segment was affected. One patientrefused treatment. BP were applied in one (n09) or several(n016) levels. Clinical and/or radiological improvementwas achieved after one (n016), two (n05), three (n03), orfive (n01) BPs.Conclusion CT and MRI myelography allow the reliable de-tection of spinal CSF leaks. The targeted and eventually repeat-ed epidural BP procedure is a safe and efficacious treatment.

Keywords Idiopathic intracranial hypotension . Orthostaticheadache . SAH . Spinal CSF leak . Epidural blood patch

Introduction

Orthostatic headache (i.e., postural headache that improves insupine position) is the key symptom of idiopathic intracranialhypotension (IIH). Further signs and symptoms of IIH includemeningism, nausea, vomiting, tinnitus, hypacusis, cranial nervepalsy, and disturbance of memory and consciousness [1–5].The underlying cause of IIH is a spinal leakage of cerebrospinalfluid (CSF) of unknown nature. The CSF leak reduces theintracranial CSF pressure and may cause a venous dilatation(Monro–Kellie hypothesis) which is considered to cause head-aches via meningeal traction and subdural effusions [6] or

Presented in part at the Annual Meeting of the Deutsche Gesellschaftfür Neuroradiologie (DGNR) Cologne 2011.

G. Albes :D. Horvath :H. Henkes (*)Klinik für Neuroradiologie, Klinikum Stuttgart,Kriegsbergstrasse 60,70174 Stuttgart, Germanye-mail: [email protected]

H. WengKlinik für Anästhesiologie und operative Intensivmedizin,Klinikum Stuttgart,Stuttgart, Germany

C. MusahlKlinik für Neurochirurgie, Klinikum Stuttgart,Stuttgart, Germany

H. BäznerKlinik für Neurologie, Klinikum Stuttgart,Stuttgart, Germany

H. HenkesMedizinische Fakultät der Universität Duisburg-Essen,Essen, Germany


3D FSE T2 sat fat

Spinal cord MRI Causative investigation

Meningeal diverticula . ..

Level of leakage

Congestion of venous plexuses Fluid collection in the epidural space Collapsing of dural sac

AJNR Am J Neuroradiol 23:618–621, April 2002

Complications

�  Subdural hematoma

�  Thrombophlebitis

�  Intracranial hypertension

TREATMENT Decubitus, hydratation, abdominal strapping

Blood patch

Standard practice : in L3L4 or L4L5

Or at the breach level if location of breach can be seen or known

Injection of 10 to 40 ml (incurring low back pain)

Decubitus for two hours, no forceful exercise for 3 weeks

Way of working

Initial mass effect (immediate effect), vasoconstrictor effect

Fibrin clot plugs up the breach

Results

56% success rate after 2 blood patches

MG Bousser 33 patients

90% immediate efficiency: , 57% sustainable effect for 1 BP, 77% for 2 BP.s’

Empty sella Thin Ventricles

Tortuous optic nerves

Enlargement of

peri optic sub archnoid spaces

Enlargement of



41 y.o woman. Headache. Bilateral pulsatile tinnitus.

Idiopathic intra cranial Hypertension

Empty sella Thin Ventricles


Enlargement of


Enlargement of



Idiopathic (« benign ») intracranial hypertension

Idiopathic intracranial Hypertension

Dandy (1937) Pseudo tumor cerebri ü  Rise of intracranial pressure ü  Normal composition of CSF ü  No tumor

Current criteria

�  1 patient fully aware ü  with a normal neurological examination or ü  Papilledema ü  Widening of blind spot ü  Decreasing of visual field ü  Paralysis of VI

�  2 Rise of pressure of CSF > 200 mmH2O (205 in obese patients). Normal (lateral decubitus) 100 à 200 mmH2O

�  3 Normal composition of CSF (minor hyperproteinorachia may happen)

�  4 No intracranial or medullar (tumoral) pathology

�  5 No metabolic, toxic, or hormonal cause

Epidemiology

�  Sex ratio: Female >>> Male

�  Frequency ü 0,034/100.000 men/year

ü 2,7/100.000 women/year ü  21,4/100.000 obese women/year

�  May happen but scarce in children

Etiological factors

Toxic drugs Endocrinology Haematology Various factors

Tetracycline Pregnancy Anemia Lupus

Doxycycline Infertility Hypercoagulability Behçet’s disease

Nitrofurantoin Oral contraceptives Thrombocytopenia Lyme disease

Penicillin Turner’s syndrome Myeloma Respiratory Insufficiency

Corticoids Obesity High Blood Pressure

Lithium Hypo/hypervitaminosis A

insecticides

Amiodarone Hypo/hyper thyroidism

Tobacco smoking

Tamoxifen Hyperaldosteronism Sleeping apnea

Clinical features Not always conclusive

Unspecified headaches (90-94%)

Sometimes with nausea and vomiting Ophtalmological clues (68-85%)

Weakening of visual acuity (Edema of optic disk, edema of fundus)

Impairments of visual field

Dizziness, pulsatile tinnitus (60%) Obesity: risk factor

MRI

Ruling out tumor pathology

�  Median line: sagittal T1

�  Ventricles: axial or frontal T2/Flair

�  Orbits : optic nerves : T2W sequence HR or 3D FSE T2

�  Veins : venous MR Angiography

Confirming diagnosis: etiologic investigation

�  Flair

�  T2*

�  Diffusion

�  +/- injection

(

MRI

Sagittal T1w sequence (the first sequence for all (or almost) Brain MRI)

-Empty (or partially empty) sella : longstanding effects - downward displacement of chiasma and/or cerebellar tonsils (20%)

ORIGINALRESEARCH

Incidence of Cerebellar Tonsillar Ectopia inIdiopathic Intracranial Hypertension: A Mimic ofthe Chiari I Malformation

A.H. AikenJ.A. Hoots

A.M. SaindaneP.A. Hudgins

BACKGROUND AND PURPOSE: IIH is a syndrome of elevated intracranial pressure without hydroceph-alus, mass, or identifiable cause. Diagnosis is made by clinical presentation, intracranial pressuremeasurement, and supportive imaging findings. A subset of patients with IIH may have tonsillarectopia, meeting the criteria for Chiari malformation type I but not responding to surgical decompres-sion for Chiari I. The purpose of this study was to determine the incidence and morphology ofcerebellar tonsillar ectopia in patients with IIH.

MATERIALS AND METHODS: Forty-three patients with clinically confirmed IIH and 44 age-matchedcontrols were included. Two neuroradiologists with CAQs reviewed sagittal T1-weighted MRI in ablinded fashion and measured cerebellar tonsil and obex positions relative to the foramen magnum andprepontine cistern width at the level of the midpons.

RESULTS: Nine of 43 patients with IIH and 1/44 controls had cerebellar tonsillar ectopia of !5 mm. Fiveof 9 of patients with IIH with ectopia of !5 mm also had a “peglike” tonsil configuration. Patients withIIH had a significantly lower tonsillar position (2.1 ! 2.8 mm) than age-matched controls (0.7 !1.9 mm,P " .05). The obex position was significantly lower in patients with IIH versus controls (#7.9 mm[above the FM] versus #9.4 mm [above the FM], P " .05). The prepontine width was not significantlydifferent between the groups.

CONCLUSIONS: Cerebellar tonsil position in patients with IIH was significantly lower than that inage-matched controls, often times peglike, mimicking Chiari I. A significantly lower obex positionsuggests an inferiorly displaced brain stem and cerebellum. When tonsillar ectopia of $5 mm isidentified, imaging and clinical consideration of IIH are warranted to avoid misdiagnosis as Chiari I.

ABBREVIATIONS: CAQ % Certificate of Added Qualification; CM % Chiari malformation; FM %foramen magnum; ICP % intracranial pressure; IIH % idiopathic intracranial hypertension

IIH, previously known as pseudotumor cerebri, is a syn-drome characterized by elevated ICP with normal CSF com-

position and no other identifiable cause.1 It has been proposedthat the elevated ICP may be related to decreased CSF resorp-tion due to impaired venous outflow and elevated venouspressure; however, controversy still surrounds the significanceof venous sinus stenosis in IIH as the cause or the result ofelevated ICP.2 IIH predominantly affects young overweight(body mass index $25) women with a reported incidence of19/100,000 in this population.2,3 Patients with IIH most com-monly present with headaches, occurring in 68%–98%.2,4

Other clinical features include pain, pulsatile tinnitus, and vi-sual disturbance, which can lead to blindness.2,5 Treatmentconsists of weight reduction, acetazolamide, and surgical in-tervention, including CSF shunt surgery.6-8

Although IIH is a clinical diagnosis based on normal CSFcomposition with an elevated opening pressure ($20 cm H2Oin nonobese patients and $25 cm H2O in obese patients withbody mass index $30), supportive neuroimaging findings

have been described. These include flattening of the posteriorsclera, tortuosity of the optic nerve sheath, empty sella syn-drome, and stenosis of the transverse venous sinuses.9,10

Therefore, imaging can aid in making or supporting the clin-ical diagnosis in some cases, especially if clinicians are not asfamiliar with the diagnosis. The incidence and morphology ofcerebellar tonsillar ectopia in IIH has not been previously de-scribed in the radiology literature, to our knowledge. Whenpresent, tonsillar ectopia in IIH may confuse the radiographicpicture and mimic other entities more commonly associatedwith tonsillar ectopia, such as Chiari I malformation andspontaneous intracranial hypotension.

Chiari I malformation is characterized by caudal protru-sion of “peg-shaped” cerebellar tonsils below the foramen.11,12

Chiari I malformation is defined radiographically as an infe-rior displacement of the cerebellar tonsils of !5 mm belowthe opisthion-basion line.13,14 In the healthy adult, cerebellartonsils are rarely $3 mm below the foramen magnum. Pa-tients with the radiographic appearance of Chiari I malforma-tion can be asymptomatic, but the most common clinicalsymptoms include headache, neck pain, vertigo, sensorychanges, and poor coordination. Therefore, clinical symptomsmay overlap IIH.11 Chiari I malformation is also associatedwith abnormal CSF flow, which can lead to syringomyelia.Treatment of Chiari I consists primarily of surgical hindbraindecompression with suboccipital craniectomy to restore nor-mal flow at the foramen magnum.15

Previous studies in the surgical literature describe a subset


From the Department of Radiology and Imaging Sciences, Emory University, Atlanta,Georgia.


Please address correspondence to Ashley H. Aiken, MD, Radiology Department, EmoryUniversity Hospital, 1364 Clifton Rd, Suite BG 26, Atlanta, GA 30322; e-mail:[email protected]


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AJNR Am J Neuroradiol 33:1901– 06 ! Nov 2012 ! www.ajnr.org 1901

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ORIGINALRESEARCH























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MRI Axial FLAIR

Thin ventricles


MRI

Axial (or frontal) T2w : orbital exploration +++

�  Tortuous optic nerves (> 7O%)

�  Enlargement of peri optic subarachnoid space (70%)

�  Flattening of posterior globe (45%)

3D FSE T2

Empty sella

Enlargement of



Time : 3’30

Enlargement of


Enlargement of

Trijeminale cavum

Enlargement of sub archnoid spaces peri oculo motor nerve

IIH and Veins

41 y.o woman. Headache. Bilateral pulsatile tinnitus.

Old venous Thrombosis

Technical note MR venography

= Angio 3D with injection or Angio 4D (TRICKS, TWIST)

Technical note CT venography = excellent tool for vessels exploration

AngioMR veineuse

Suspicion de sténoses serrées courtes des sinus transverse droit et gauche

Imagerie complémentaire ?

AngioMR veineuse

Suspicion de sténoses serrées courtes des sinus transverse droit et gauche

Imagerie complémentaire ?

Stenosis : Cause or effect of IIH ??

If suspicion of IIH, MR Venography is required +++

DIAGNOSTIC NEURORADIOLOGY

The relationship of transverse sinus stenosis to bony groovedimensions provides an insight into the aetiologyof idiopathic intracranial hypertension

S. E. J. Connor & M. A. Siddiqui & V. R. Stewart &E. A. M. O’Flynn

Received: 20 March 2008 /Accepted: 25 June 2008 / Published online: 12 July 2008# Springer-Verlag 2008

AbstractIntroduction Transverse sinus tapered narrowings are fre-quently identified in patients with idiopathic intracranialhypertension (IIH); however, it remains unclear whetherthey are primary stenoses or whether they occur secondaryto raised cerebrospinal fluid pressure. Computed tomo-graphic venography demonstrates both the morphology ofthe venous system and the adjacent bony grooves so it mayprovide an insight into the aetiology of these transversesinus stenoses.Materials and methods Tapered transverse sinus narrow-ings (>50%) were studied in 19 patients without IIH and 14patients with IIH. Computed tomography vascular studieswere reviewed and the dimensions of the venous sinusesand bony grooves at the sites of maximum and minimumtransverse sinus area dimensions were recorded.Results There was demonstrated to be a strong correlationof bony groove height with venous sinus height at thelargest portions of the transverse sinus in both IIH patientsand non-IIH subjects as well as at the transverse sinusnarrowing in non-IIH subjects. There was a discordantrelationship between bony groove height and venous sinusheight at the site of transverse sinus stenoses in IIHpatients. In 5/23 IIH transverse sinus stenoses, the bonygroove height was proportionate to that seen in non-IIH

subjects. There were a further 8/23 cases where the small orabsent sinus was associated with an absent bony groove.Conclusion Transverse sinus tapered narrowings in subjectswithout IIH and in the majority of patients with IIH wereassociated with proportionately small or absent grooves,and these are postulated to be primary or fixed. Somepatients with IIH demonstrate tapered transverse sinusstenoses with disproportionately large bony grooves,suggesting a secondary or acquired narrowing. This impliesa varied aetiology for the transverse sinus stenoses of IIH.

Keywords Idiopathic intracranial hypertension . Computedtomographic venography . Venous sinus . Vascular stenosis

Introduction

Bilateral transverse sinus stenoses are detected on neuro-imaging studies in the majority of patients with idiopathicintracranial hypertension (IIH) [1–4]. Whether these stenosesare the cause or effect of raised cerebrospinal fluid (CSF)pressure remains controversial. Some investigators haveproposed that primary fixed transverse sinus stenoses resultin venous hypertension [4–6], increased resistance to CSFabsorption and hence increased CSF pressure [4,7]. This hasled to the application of intravascular venous stenting inpatients with intractable IIH when a pressure gradient hasbeen demonstrated across such stenoses [8–10]. Otherauthors suggest that transverse sinus narrowing is morelikely a secondary phenomenon due to the raised intracranialpressure and resulting expansion of CSF and parenchymalcompartments. This is supported by studies which haverecorded a reversal of the pressure gradient or the stenosisfollowing lumbar puncture or CSF diversion [6, 11–15]. It isargued that patients with transverse sinus stenoses that


S. E. J. Connor (*) :V. R. Stewart : E. A. M. O’FlynnNeuroradiology Department, Ruskin Wing,King’s College Hospital,Denmark Hill,London SE5 9RS, UKe-mail: [email protected]

M. A. SiddiquiInstitute of Neurological Sciences, Southern General Hospital,Glasgow G51 4TF, Scotland

DIAGNOSTIC NEURORADIOLOGY

The relationship of transverse sinus stenosis to bony groovedimensions provides an insight into the aetiologyof idiopathic intracranial hypertension

S. E. J. Connor & M. A. Siddiqui & V. R. Stewart &E. A. M. O’Flynn

Received: 20 March 2008 /Accepted: 25 June 2008 / Published online: 12 July 2008# Springer-Verlag 2008

AbstractIntroduction Transverse sinus tapered narrowings are fre-quently identified in patients with idiopathic intracranialhypertension (IIH); however, it remains unclear whetherthey are primary stenoses or whether they occur secondaryto raised cerebrospinal fluid pressure. Computed tomo-graphic venography demonstrates both the morphology ofthe venous system and the adjacent bony grooves so it mayprovide an insight into the aetiology of these transversesinus stenoses.Materials and methods Tapered transverse sinus narrow-ings (>50%) were studied in 19 patients without IIH and 14patients with IIH. Computed tomography vascular studieswere reviewed and the dimensions of the venous sinusesand bony grooves at the sites of maximum and minimumtransverse sinus area dimensions were recorded.Results There was demonstrated to be a strong correlationof bony groove height with venous sinus height at thelargest portions of the transverse sinus in both IIH patientsand non-IIH subjects as well as at the transverse sinusnarrowing in non-IIH subjects. There was a discordantrelationship between bony groove height and venous sinusheight at the site of transverse sinus stenoses in IIHpatients. In 5/23 IIH transverse sinus stenoses, the bonygroove height was proportionate to that seen in non-IIH

subjects. There were a further 8/23 cases where the small orabsent sinus was associated with an absent bony groove.Conclusion Transverse sinus tapered narrowings in subjectswithout IIH and in the majority of patients with IIH wereassociated with proportionately small or absent grooves,and these are postulated to be primary or fixed. Somepatients with IIH demonstrate tapered transverse sinusstenoses with disproportionately large bony grooves,suggesting a secondary or acquired narrowing. This impliesa varied aetiology for the transverse sinus stenoses of IIH.

Keywords Idiopathic intracranial hypertension . Computedtomographic venography . Venous sinus . Vascular stenosis

Introduction

Bilateral transverse sinus stenoses are detected on neuro-imaging studies in the majority of patients with idiopathicintracranial hypertension (IIH) [1–4]. Whether these stenosesare the cause or effect of raised cerebrospinal fluid (CSF)pressure remains controversial. Some investigators haveproposed that primary fixed transverse sinus stenoses resultin venous hypertension [4–6], increased resistance to CSFabsorption and hence increased CSF pressure [4,7]. This hasled to the application of intravascular venous stenting inpatients with intractable IIH when a pressure gradient hasbeen demonstrated across such stenoses [8–10]. Otherauthors suggest that transverse sinus narrowing is morelikely a secondary phenomenon due to the raised intracranialpressure and resulting expansion of CSF and parenchymalcompartments. This is supported by studies which haverecorded a reversal of the pressure gradient or the stenosisfollowing lumbar puncture or CSF diversion [6, 11–15]. It isargued that patients with transverse sinus stenoses that


S. E. J. Connor (*) :V. R. Stewart : E. A. M. O’FlynnNeuroradiology Department, Ruskin Wing,King’s College Hospital,Denmark Hill,London SE5 9RS, UKe-mail: [email protected]

M. A. SiddiquiInstitute of Neurological Sciences, Southern General Hospital,Glasgow G51 4TF, Scotland

further 8/23 cases where the small or absent sinus wasassociated with an absent bony groove. It is of note thatvenous sinuses stenoses have only previously been studiedat the time of clinical presentation or following interventionsuch as CSF drainage. It is possible that the observed“reversibility” of stenoses by lowering intracranial pressure

actually represents an expected increase in size of a primarynarrowing as per the Monro–Kellie hypothesis. Studyingthe adjacent bony groove may provide further insight intothe pre-morbid venous sinus appearances in such cases.

The study may be criticised since observers were notblinded with respect to the identification of IIH and non-IIHdata. The non-IIH subjects could be recognised since CTAstudies were used for the analysis. CTVs could not be usedfor the non-IIH data due to the potential high rate ofassociated venous pathology. In addition, non-IIH patientswere not an ideal “control” group since they were beinginvestigated for neurological complaints; however, thesepatients were considered to have a low likelihood of venous

Table 1 Heightbone/heightsinus for the areamin points in IIH patients.

Heightbone/heightsinus forthe IIH areamin points

Number of sinuses

0–indeterminate small ratio 8−3 absent groove–small sinus−5 absent groove–absent sinus(aplastic segment)

Ratio 1.02–1.5 (rangefor non-IIH subjects)

5

Ratio >1.5 8−4 cases demonstrated true

disproportionately large bony grooves−4 cases discordance could be explained

by the presence of associated drainingcortical veins or arachnoidgranulations

Indeterminate large ratio 2 large bony groove–absent sinus(aplastic segment)

Fig. 6 a Reformatted image perpendicular to the occipital bone in anIIH subject at areamin demonstrates narrowing with a heightbone toheightsinus ratio of 2.2. b, c Reformatted images perpendicular to the

occipital bone in an IIH subject at areamin demonstrates narrowingwith a heightbone to heightsinus ratio of 1.6

Fig. 7 Reformatted image perpendicular to the occipital bone in anIIH subjects at areamin. An arachnoid granulations resulting insuperimposed “intraluminal” narrowing (arrowhead) was not sus-pected when selecting the areamin from the MIP image. It appearslikely to contribute to the increased heightbone to heightsinus ratio onreviewing the reformatted image

Neuroradiology (2008) 50:999–1004 1003

3D Phase Contraste 3D Phase Contraste

Angio 3D with injection

Diagnosis Clinical diagnosis

+

MRI ST1, AFlair, AT2, FrT2 or 3DFSET2

Venous MRA

+

Measuring inner cranium pressure

Pronostic �  No lethal threat.

�  Visual functions threatened.

�  Headaches, Tinnitus…

Treatment �  Medical

�  Weight loss �  Corticosteroids in acute phase : ? �  Acetazolamide

�  Improvement of headaches, tinnitus

�  Iterative Lumbar puncture : ?

�  If weakening of visual acuity persists: �  Drains of CSF �  Fenestration of the optic nerve sheath.

�  Interventional Vascular Therapy �  Transverse sinuses angioplasty

Intravenous pressure measurements with abrupt pressure gradient > 10 mmHg

Angiographie veineuse cérébrale

Æ Gradient de pression trans- sténotique de 35mmHg à droite

Angioplastie de la sténose droite au ballon

Sténoses serrées des sinus transverses droit et gauche

Conclusion (1) IC Hypotension

�  Orthostatic Headache

�  Global and diffuse enhancement of dura mater

Venous congestion

�  TTT : blood patch

IIC

�  Headache, visual troubles, tinnitus

�  Empty sellae, enlargment of CSF resorption ways (peri optic)

�  TTT to preserve visual functions

Conclusion (2) Technical Notes

IC Hypotension IIC

Sagittal T1W

3D FSE T2 sat fat

MR Myelography ???

MR venography

3D Flair

neurology advanced csf jl sarrazin

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