Headache

Background: HA is common presenting sx Most causes of HA are benign; however, although representing only 0.5% to 6% of presentations of

acute headache to the ED, the most important and commonly encountered life-threatening cause of severe sudden head pain is subarachnoid hemorrhage (SAH)

o Unfortunately this is missed 25% of the time

Pathophysiology the brain parenchyma is insensitive to pain. The pain-sensitive areas of the head include the meninges,

the arteries and veins supplying the brain, and the various tissues lining the cavities within the skullo most pain assoc w/ HA, particularly w/ vascular headaches and migraines, is mediated through

CNVDifferential Diagnosis

History and Physical Exam determine pattern and onset

o is it similar to prior headaches > marked variation could signal new or serious problem o rapid and severe onset of pain (“thunderclap” headache) assoc w/ serious causes of headache

“Almost all studies dealing with subarachnoid bleeding report that patients moved from the pain-free state to severe pain within seconds to minutes. The thunderclap headache

is common in acute presentations of SAH but is not highly specific. If the patient with moderate or severe headache can indicate the precise activity in which he or she was engaging at the time of the onset of the headache, the suddenness of onset warrants consideration of SAH. Careful questioning about the onset of headache may lead to the correct diagnosis of SAH, even if the pain is improving at the time of evaluation.” Rosens

determine the pt’s activity at onset of pain o HA that come on during exertion have a relationship to vascular bleeding

additionally, although the syndrome of postcoital headache is well known, coitus is also recognized as an activity associated with SAH, so a pattern of previous postcoital headache is key, as is understanding whether the current headache fits that pattern

hx of trauma? o Ddx switches markedly toward epidural and subdural hematoma, traumatic SAH, or

intraparenchymal hemorrhage, skull fracture and closed head injury (concussion, diffuse axonal injury)

Intensityo Pain scale might help differentiate patients intitially > has more value in monitoring response to

therapy Character of pain (ie, throbbing, pressure) may be helpful to describe and for billing but doesn’t help

differentiate the underlying diagnosis Location of head pain – at onset and as the pain progresses > helps examiner look for external casues

of pain. o Unilateral pain is more suggestive of migraine or localized inflammatory process in skull (sinus,

TMJ) or soft tissue (TA, dental infection)o Muscle tension usually starts at the base of the skill and can extend over the entire head

(following occipital-frontal aponeurosis) Exacerbating or alleviating factors

o Do headaches occur only when patient goes to a certain area? (ie. Basement workshop) > could be CO

Signs High yield physical exam findings

o CN III, IV, and VI defecits > mass lesion or IIHo Headache + red eye >> acute angle glaucoma > investigate intraocular pressure

Ancillary testings: A CT scan performed within 6 hours of onset of headache has been shown to be sufficiently sensitive to

exclude the diagnosis of SAH when using a third-generation CT scanner

Diagnostic Algorithm

Indications of patients at higher risk for serious cause of headache who are candidates for more comprehensive evaluation include (1) sudden onset of headache, (2) patient description of the headache as “the worst ever,” (3) altered mental status, (4) meningismus, (5) unexplained fever, (6) focal neurological deficit on examination, (7) symptoms refractory to appropriate treatment or worsening despite treatment, (8) onset of headache during exertion, (9) history of immunosuppression, or (10) pregnancy or peripartum state.

Empiric Management

Break HA into two categories:

o w/ AMS assume brain tissue is compromised

principles of cerebral resuscitation address the seven major causes of evolving brain injury

o lack of substrate (glucose, O2)o cerebral edemao intracranial lesiono endogenous or exogenous toxino metabolic alteration (fever, seizure)o ischemiao elevated ICP

recall: ICP = MAP - CCPo w/o AMSo opioids are not first-line for any time of headache, except when ICH (including SAH) is thought

to be presento empiric tx does not precede diagnostic studies except when suspect meningitis

Disposition pts who are not thought to have a serious cause for their head pain requiring hospitalization but who

are w/o a specific diagnosis are provided with appropriate return precautions and recommendations for follow-up care

can suggest pts start headache journal to bring to outpatient follow up

Idiopathic Intracranial Hypertension Principles

o Also called “Pseudotumor cerebri” or benign intracranial HTN (but don’t be fooled, this is not benign > can causes permanent vision loss)

Other risk factors: antibiotics (tetracyclines mc), vitamin A, retinoids, and human growth hormone

Epidemiologyo Incidence:

1-2/100,000 people Higher incidence in obese women btw 15-44: 4-21/100,000

Highest incidence ws reported in Ireland (28/100,000)o Risk Factors:

Mc seen in young obese women of childbearing age In a prospective study of 50 consecutively diagnosed IIH patients, 92 percent

were women with a mean age of 31 years (range 11 to 58 years), and 94 percent were obese [10].

o Wall, M George D. Brain. “Idiopathic intracranial hypertension. A prospective study of 50 patients.” 1991. Dept of Neuro, Tulane

Other case series in different geographic areas and ethnic groups report consistent findings (see UTD)

However, IIH can also occur in males, elderly, kids as young as 4mths, and normal weight patients

However, work up for secondary causes is even more important in these pts

One study showed that in orlder pts (44-88) w/ IIH were more often male and less often obese

Recent wt gain is a risk factor > one case-control series showed there was an average 1.8kg wt gain over 2mth preceding sx onset. Another showed an average wt gain of 10lbs in preceding year

Idiopathic Intracranial Hypertension Treatment Trial (IIHTT), 5 percent of patients reported a family history of IIH > suggesting genetic component

Medications Growth hormone

o 2007 study estimated incidenc of IIH in kids tx w/ growth hormone to be 27.7 per 100,000 treatment years

usually presents w/I one year of tx initiation stopping or resuming a lower dose often stops IIH

Tetracyclines (including minocycline and doxycycline)o Onset usually w/I few weeks to months after onset of txo Usually goes away with drug withdrawal

Hypervitaminosis A from excessive dietary intake Derm retinoids (all-trans retinoic acid, isotretinoin, retinol, and tretinoin) Other anecdotal evidence

o Thyroid replacemento Corticodsteroid withdrawalo Lithiumo Nalidixic acido Nitrofurantoin

Other systemic illness assoc w/ IIH besides obesity Addison disease Hypoparathyroidism Anemia, usually severe Sleep apnea Systemic lupus erythematosus (SLE) Behçet syndrome Polycystic ovary syndrome Coagulation disorders Uremia

Pathogenesis o not well well understood. Theories:

imbalance of CSF production and reabsorption [Rosen’s] cerebral venous outflow abnormalities (ie. Venous stenosis or venous HTN) increased CSF outflow resistance at level of arachnoid granulations or CSF lymphatic

drainage sites obesity-related increased abdominal and intracranial venous pressure altered sodium and water retention mechanisms abnormalities of vitamin A metabolism

o intracranial venous hypertension Elevated intracranial venous pressure is postulated both as a primary mechanism and as

a "final common pathway" for IIH. This theory is supported by the similar clinical appearances of IIH and secondary intracranial hypertension due to cerebral venous

thrombosis and other causes of obstructed venous outflow. Some patients thought to have IIH have been later discovered to have one of these conditions

Clinical features

o o sx:

HA is usually gradual in onset and moderate in intensity (occurs in 84-92% of pts per UTD)

sometimes headache is worsened by eye movement can be constant of come in waves may awaken pt from sleep increases when pt bends forward or Valsalva maneuver (both impede cerebral

venous return) kids are less likely to present with HA (one study showed 29% of kids did not

have HA) visual complaints are common

pts may complain of transient visual obscurations (TVOs) (68-72% of pts per UTD or 2/3 of pts with papilledema)> momentary blackouts of vision most likely due to temporary disruption of microcirculation to optic nerve head

o usually occur with postural changes > do not predict vision loss diplopia 18-38% - usually caused by unilateral or bilateral 6th CN palsey or

divergence insufficiency from increased ICP retrobulbar pain 44% photopsia (brief sparkles or flashes of light) 48-54%

Intracranial noises (pulsatile tinnitus or rushing of wind/water) occurs in 52-60% n/v, dizziness and pulsatile tinnitus

o Physical Exam 50% of pts will have papilledema and visual field deficits on occasion, 6th n palsey is noted (false lateralizing sign) papilledema

fundoscope > graded by Frisen scale > the more severe the higher risk of permanent vision loss

vision loss visual field loss occurs before changes in visual acuity visual field loss usually peripheral

DDxo CVT, mass lesions, obstructive hydrocephalus, and leptomeningeal infiltration by neoplastic or

infectious processo UTD :

Intracranial mass lesions (tumors, abscess) Obstruction of venous outflow, ie (venous sinus thrombosis, jugular vein compression,

neck surgery) Obstructive hydrocephalus Decreased CSF absorption (ie. Arachnoid granulation adhesions after bacterial or other

infectious meningitis, subarachnoid hemorrhage) Increased CSF production (ie. Choroid plexus papilloma) Malignant systemic HTN

Diagnostic Testingo MRI w/ MRV is preferred modality for diagnosis b/c is detects mass lesions and hydrocephalus,

as well as cerebral venous thrombosis or meningeal processeso If neuroimaging is normal, doctor should get LP in lateral decubitus position to measure CSF

opening pressure and get CSF studies (cell count, protein, glucose, cultures, and cytology) Opening pressure of >/= 250mmH2O (normal is 70-180) is needed to make diagnosis

[Rosens] Traditionally, the ULN is 200mmHg but obese pts may have a higher ULN, with

opening pressures that may normally approach 250mmHg (UTD) In young children <8yrs), they seem to have an a higher ULN. Dx based on 90th

percentile to be > 250-280mmHg in kids not sedated or obeseo Also order ophtho consult for detailed visual field testing

Management o Patients that present w/o vision loss, sx therapy is all that is necessaryo Weight loss

Low-Na+ weight reduction program > some might need surgical intervention for morbid obesity

However, medications are generally given at the same time as weight loss since it takes awhile to lose weight

o Removal of a large amount of CSF (>20mL) to decrease CSF pressure to relieve that patient’s HAis recommended in all tx guidelines for IHH

Avoid serial lumbar punctures CSF re-accumulates w/I 6hrs so has short effect LPs are uncomfortable and painful to many There are complications with LPs (low pressure HA, CSF leak, CSF infxn,

intraspinal epidermoid tumors) In obese pts, LPs are difficult

However, can use serial LPs as a temporizing measure before surgery or in pregnany patietns who wish to avoid therapy

o If has sx vision loss, tx with meds to lower ICP Acetazolamide –> usually started at 500mg BID > advance as tolerated up to 2-4g per

dayo In kids, starting dose is 25mg/kg/day (max dose of 100mg/kg or 2g per

day) MOA: carbonic anhydrase inhibitor > decreased rate of CSF production Average tx duration was 14 months per 1 long term follow up study

SE: digital and oral paresthesias, anorexia, malaise, metallic taste, fatigue, nausea, vomiting, electrolyte changes, mild metabolic acidosis, and kidney stones (usually dose related)

o The IIHTT study found monitoring electrolytes during acetazolamide tx was not necessary if it is the only diuretic used

o Diamoxi sustained release could be used by patients who can’t tolerate generic version but is much more money

o Methazolamide (Neptazane) is another CAinhibitor that can be tried Contraindications:

o sulfa allergy (releative…little clinical or pharm basis for this rec) A true cross-reaction between sulfonamide antimicrobials and the

sulfa moiety in acetazolamide and furosemide is unlikely. Therefore, if no severe reaction, have a risk and benefits discussion with patient.

o Pregnancy (relative contraindication > Class C pregnancy risk) Particularly first 20 weeks Teratogenic effects have been reports in high doses in animals,

and a single case of teratoma was seen in humans Have risk and benefit discussion with patient and Ob/Gyn and

have patient sign informed consent Furosemide

Can be used as an adjunct therapy to acetazolamide in IIHo one report of eight children treated with combined therapy of

acetazolamide and furosemide, all had a rapid clinical response with resolution of papilledema, reduction in the mean CSF pressure after the first week of treatment, and normalization of CSF pressure within six weeks of starting therapy

Dose: o Adults: 20 to 40mg per dayo Kids: 1-2mg/kg/day

Relative Contraindication = hx of sulfa-allergyo Same principle applies as with acetazolamide

Topiramate MOA: anti-seizure drug that inhibits carbonic anhydrase activity

o Its efficacy in the treatment of migraine headaches and its association with weight loss are features that make it an attractive potential therapeutic option in IIH.

o But more studies have to be done before it is considered first-line tx Steroids – should be avoided:

Can cause weight gain Withdrawal can cause severe rebound intracranial HTN assoc w/ marked vision

loss Significant systemic side effects *** can be considered in the settting of acute vision loss as a temporizing

measure prior to surgical intervention o One case series describes successful use of methylprednisolone (250 mg

four times a day for five days followed by an oral taper) in conjunction with acetazolamide in four patients with IIH and severe, acute visual loss

Avoid using too many ibuprofen or Tylenol to prevent analgesic overuse/rebound headaches

o If vision loss and sx do not improve with meds, refer to ophtho for optic nerve sheath decompression or neurosurgery for CSF diversion (lumboperitoneal or ventriculperitoneal shunt)

Prognosis o No large studies have described the natural history of IIH >> protracted course lasting months

to years appears commono Permanent vision loss is major concern

Early, hospital study showed 24% of pts developed (n=57, followed for 5-41yrs) developed blindness

Community and clinic-based studies have found a lower rateo Recurrence: recurrence of symptoms may occur in 8 to 38 percent of patients after

recovery from an episode of IIH or after a prolonged period of stability Weight gain will increase recurrence

Dispositiono Optho and neurology should be involved in patient’s evaluation, tx and dispo from ER since

vision loss can occur early or late in the course of IIH

IIH and US Prior studies have illustrated that optic disc elevation, with a minimum disc height of 0.6 mm, obtained

via ultrasound can be 82% sensitive and 76% specific for papilledema [Teismann] Using invasive intracranial monitoring as a reference standard, previous studies have revealed that an

optic nerve sheath diameter of greater than five mm, measured three mm posterior to the orbit, can be a sensitive (88%) and specific (93%) marker for elevated intracranial pressure of greater than 20 cm H2O [Stone, Kimberly]

REFERENCES

Christopher S. Russi and Laura Walker “Headache.” Ch17. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th edition

Thomas Kwiatkowski and Benjamin W. Friedman. “Headache Disorders.” Ch 93. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th edition

Boyd JS, Rupp JD, Ferre RM. EMERGENCY ULTRASOUND. In: Knoop KJ, Stack LB, Storrow AB, Thurman R. eds. The Atlas of Emergency Medicine, 4e New York, NY: McGraw-Hill; . http://accessmedicine.mhmedical.com/content.aspx?bookid=1763&sectionid=125439068. Accessed April 13, 2020.

John F. Salmon MD. “Neuro-ophthalmology.” Kanski's Clinical Ophthalmology, Chapter 19, 745-825https://www.clinicalkey.com/#!/content/book/3-s2.0-B9780702077111000194?scrollTo=%23hl0003114

Idiopathic intracranial hypertension (pseudotumor cerebri): Epidemiology and pathogenesishttps://www.uptodate.com/contents/idiopathic-intracranial-hypertension-pseudotumor-cerebri-epidemiology-and-pathogenesis?search=idiopathic%20intracranial%20hypertension&source=search_result&selectedTitle=3~150&usage_type=default&display_rank=3

Idiopathic intracranial hypertension (pseudotumor cerebri): Clinical features and diagnosishttps://www.uptodate.com/contents/idiopathic-intracranial-hypertension-pseudotumor-cerebri-clinical-features-and-diagnosis?search=idiopathic%20intracranial%20hypertension&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1

Idiopathic intracranial hypertension (pseudotumor cerebri): Prognosis and treatmenthttps://www.uptodate.com/contents/idiopathic-intracranial-hypertension-pseudotumor-cerebri-prognosis-and-treatment?search=idiopathic%20intracranial%20hypertension&source=search_result&selectedTitle=2~150&usage_type=default&display_rank=2#H1

Stone. “Ultrasound diagnosis of papilledema and increased intracranial pressure in pseudotumor cerebri.” Am J Emerg Med. 2009 March https://www.ncbi.nlm.nih.gov/pubmed/19328404/

Kimberly HH, Shah S, Marill K, et al. Correlation of optic nerve sheath diameter with direct measurement of intracranial pressure. Acad Emerg Med. 2008;15(2):201–4.

Teismann N, Lenaghan P, Nolan R, et al. Point-of-care ocular ultrasound to detect optic disc swelling. Acad Emerg Med. 2013;20(9):920–5. 

Sinnott. “Papilledema: Point-of-Care Ultrasound Diagnosis in the Emergency Department” Clin Pract Cases Emerg Med. 2018 May; 2(2): 125–127. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5965109/#b3-cpcem-02-125

https://www.acep.org/sonoguide/smparts_ocular.html