doi: 10.1136/jnnp.54.9.822 1991 54: 822-825J Neurol Neurosurg Psychiatry

A Schnider, T Landis and M Regard

encephalitis.Balint's syndrome in subacute HIV

http://jnnp.bmj.com/content/54/9/822Updated information and services can be found at:

These include:

serviceEmail alerting

the box at the top right corner of the online article.Receive free email alerts when new articles cite this article. Sign up in

Notes

http://group.bmj.com/group/rights-licensing/permissionsTo request permissions go to:

http://journals.bmj.com/cgi/reprintformTo order reprints go to:

http://group.bmj.com/subscribe/To subscribe to BMJ go to:

group.bmj.com on November 2, 2013 - Published by jnnp.bmj.comDownloaded from

Journal ofNeurology, Neurosurgery, and Psychiatry 1991;54:822-825

Balint's syndrome in subacute HIV encephalitis

A Schnider, T Landis, M Regard

AbstractA 45 year old patient with AIDS is des-cribed in whom Balint's syndromedeveloped over several days withoutother higher cognitive defects.Radiological findings were typical ofsubacute HIV encephalitis involvingmainly the white matter of the occipitallobes with extension into the parietal andtemporal lobe on the left side and intothe temporal lobe on the right side.While the padent could usually recogniseonly oe single component within her

field, her performance in readingmu-ch imved if she was allowed toobserve -tie examiner wrting. This find-ing is attributed to well preservedmovement perception in our patient,which may have helped her in directingher visual attention. The preservation ofmovement perception despite damage tothe lateral temporo-occipital area maybe due to the distinct pathology ofsubacute HIV encephalitis, which leavesthe cortex and adjacent subcortical whitematter virtually intact and thereforeallows information transfer betweenprimary visual areas in the occipital lobeand movement specific areas in thelateral temporo-occipital area throughU-fibres.

Department ofNeurology,NeuropsychologicalUnit, UniversityHospital, Zurich,SwitzerlandA SchniderT LandisM RegardCorrespondence to:Dr Schnider, Department ofNeurology, UniversityHospital, CH-8091 Zurich,SwitzerlandReceived 22 November 1990.Accepted 24 January 1991

Patients with Balint's syndromel" have a triadof visuo-ocular disturbances: 1) Visual inat-tention which prevents the perception ofseveral simultaneous events in the visual fieldat a time. This disturbance is usually called"simultanagnosia"; 2) Ocular apraxia, that is,an inability to fixate and follow an object withthe eyes;56 3) Optic ataxia, that is, a limbataxia which becomes evident in goal-directedmovements performed under visual controlbut not in movements performed with closedeyes.56 Even though Hecaen7 and Luria6 sug-gested that the whole triad of Balint's syn-drome could be explained in terms of a nar-rowing of visual attention, it seems that thedifferent components of Balint's syndrome areindependent from each other as minor formsof Balint's syndrome have been described inwhich certain elements of the syndrome areless pronounced,7 and all components havebeen described separately.8 Simultanagnosia,can also be of varying degree. In the extremeform of simultanagnosia, the patient's visualattention may be so narrowed that he recog-nizes only one single object within the visual

field.8 This form is always due to bilateralparieto-occipital lesions. In its subtler form,which was originally described by Wolpert,9the patient may not be able to grasp themeaning of a picture despite preserved recog-nition of its elements. This disorder may arisefrom a unilateral left-sided parieto-occipitallesion. 10 1Most patients who have been described

with Balint's syndrome had a vascular lesion.We amined a patient with Balint's syn-drome due to subacute HIV encephalitiswhich was diagnosed from the appearance ofthe MRI.2-'5 The lesions mainly involved theoccipital lobes and extended into the temporaland parietal lobes. In contrast to vascularlesions, this disease involves primarily thewhite matter of the cerebral hemisphereswhile it leaves cortical and adjacent subcor-tical white matter relatively undamaged. Infact, our patient had exceptionally wellpreserved movement perception despiteinvolvement of the lateral occipito-temporalareas.

Case reportThe patient was a 45 year old schoolteacherwith AIDS stage IV who had already sufferedfrom two opportunistic pneumonias a year ago,but who had not previously experienced anyneurological sequelae. She had been infectedthrough unprotected sexual intercourse andhad never used intravenous drugs. Therapywith zidovudine was initiated only ten daysbefore admittance. She was a heavy smokerwith 80 pack-years. She was admitted becauseof visual disturbances.

She had already felt a progressive weaknessof her right arm for three weeks, when shenoticed an inability to perceive the propertiesof standing objects or persons some days beforeadmittance. She had first realised this when sherecognised only moving objects on television.In daily life, she could not distinguish betweenpeople and objects if they did not move.However, she still recognised familiar people,even though she was puzzled by not being ableto see specific features, such as the colour oftheir hair or eyes or hairstyle. She thought sheremembered newly introduced people mainlythrough such hints as their walk or voice. Shewas totally unable to read anything, even largenewspaper headlines. When walking she oftendid not perceive obstacles on either side andrepeatedly walked into them, especially intoglass doors. The patient was able to walkwithout aid but preferred to go along the walls

822

group.bmj.com on November 2, 2013 - Published by jnnp.bmj.comDownloaded from group.bmj.com on November 2, 2013 - Published by jnnp.bmj.comDownloaded from group.bmj.com on November 2, 2013 - Published by jnnp.bmj.comDownloaded from group.bmj.com on November 2, 2013 - Published by jnnp.bmj.comDownloaded from

Balint's syndrome in subacute HIV encephalitis

to orient herself. She found her way around inthe hospital but was unable to find her bedroomas she could not read the room number. Thus aplastic bag was attached to the door which shewould search for. She could eat by herself butcould not cut the food because she could notfind it with the knife. She could pour coffee intoa cup without spilling it but had to adjust thepositions of the cup and the pot carefully withtactile control before pouring.On neurological examination, there was a

right homonymous hemianopia both in theupper and lower quadrant with preserved per-ception of movements of the whole hand of theexaminer, but not offine movements such as thefingers. Her gaze seemed void in that her eyesmoved around in search of eye contact with theexaminer or when trying to fixate an object.Once she had fixed an object, her eyemovements were full and she could smoothlyfollow it with her eyes. However, when tryingto "catch" an object in her visual field with hereyes, the saccades were severely dysmetric toboth sides (ocular apraxia). No other distur-bances of cranial nerves were observed. Therewas a slight weakness of the right arm, both forproximal and distal muscles. Sensibility of theright arm and especially the right hand wasdiminished for all qualities, and she did notrecognise objects put into her right hand.There was no upper limb ataxia on either sidein the finger-to-nose trial with closed eyes.However, with visual control, she displayedsevere ataxia of both arms when trying to pointto an object with her index finger (optic ataxia).With both arms, this was more pronounced inthe right hemispace. Muscular strength andsensibility of the legs were intact. Tendonreflexes were normal and symmetrical, and theplantar response was flexor on both sides.On mental status examination this left han-

ded woman was oriented for space and time.Language functions such as spontaneous

Figure 1 Examples of thepatient's visual gnosisperformance. Thedrawings and the patient'scommentaries to them areshown in the same order asduring the examination.The thin lines overlyingsome of the drawings andscripts are trials of thepatient tofollow theiroutlines with a pencil.

// 0/'A straight line' "I don't see anything

coherent. Somethingwith lines'

',-.,

"Unes. It doesn'tmake any sense.'

"A circle' " Two lines" 'A rather short arrow.It lacks the crossbow."

A"Maybe a letter. Mightbe an -R.. don't knowwhere it is precisely."

HA"An -A"" 'No idea what it is!.

speech, auditory comprehension, repetition,word list generation, comprehension of wordsspelled out to her, and naming of environmen-tal sounds were intact. Oral calculations werecorrect. There was no ideomotor apraxia of theface or the arms and no finger agnosia. Verbalimmediate and short term memory were intact.In a line cancellation test, she did not showhemispatial neglect, that is, she succeeded inmarking all lines despite great difficulty inadjusting the position of the pencil to the lines.Her problems were primarily visual: she

wrote with correct sequences of letters withboth her right and left hand but had greatdifficulties in aligning the letters. If she brieflyinterrupted the writing she could not find theend of what she had written previously andtherefore could not keep to one line. There wasno prosopagnosia: the patient knew most of aseries of famous people on photographs andrecognised the examiner after several hourseven though he was wearing different clothesfrom those during the examination and wasneither moving nor speaking. Facial emotionson photographs were recognised. She coulddistinguish, match, and name colours, eventhough sometimes she misjudged their bright-ness.Examples of the patient's visual gnosis per-

formance are given in fig 1. She recogniseddrawings of single thin straight lines or a circle.However, if the drawing consisted of severallines that were crossed or if the lines weredashed (needing mental completion), she wastotally incapable of identifying any form or offollowing it with a pencil.The exceptions were single letters and num-

bers which were usually recognised if presen-ted alone. But iftwo letters were shown at once,neither of them was recognised. The perfor-mance dramatically improved if the patient wasallowed to observe the examiner writing. Shecould then read words of up to seven blockletters and numbers up to three digits long.This enhancement of perception throughobservation was not possible for words writtenin script or for drawings ofabstract figures, suchas a triangle or a cross, or for meaningfuldrawings, such as a head, face, flower or tree.A CT scan revealed a hypodensity in the

parieto-occipital region on the left side withoutcontrast enhancement. In the right hemis-phere, there were small non-enhancing lesionsin the frontal and occipital lobe. An MRIshowed extensive lesions, which involvedmainly the white matter, in the occipital lobeswith extension into the temporal and parietallobe on the left side and into the temporal lobeon the right side (fig 2). Furthermore, a smallsubcortical lesion was seen in the area of theRolandic fissure on the left side.The lumbar tap yielded a slight pleocytosis

with 12 cells per mm3, mainly lymphocytes,while the protein content was normal.Serologic and microbial studies were negativefor cytomegalovirus, toxoplasmosis, cryp-tococcosis, and mycobacteria.The patient continued to receive zidovudine.

On a follow up examination two months later,her visual perception had significantly

823

Schnider, Landis, Regard

Figure 2 MRI of the patient (T2-weighted) with confluent tesions involving theoccipital lobes on both sides that extend into the temporal and parietal lobe on the leftside and into the temporal lobe on the right side. The left side of the images corresponds tothe right side of the brain.

improved and she was now able to recognisecorrectly all the items displayed in fig 1. Herability to read was still much impaired but shesucceeded in reading in a letter-by-letterfashion a whole text. Further follow up was notpossible.

DiscussionThis patient with AIDS stage IV presentedwith Balint's syndrome as the first neurologicalmanifestation of the disease. The simultanag-nosia was of an extreme degree and allowed herto perceive only the one component within hervisual field which she was fixating. In line-drawings, she could not identify objects madeup of several lines or dashed lines and she couldnot follow the outlines of such drawings. Thisextreme form ofpiecemeal perception is alwaysdue to bilateral parieto-occipital lesions4 asopposed to milder forms of simultanagnosiawhich may be seenr in unilateral left-sidedlesions.'"" In our patient, the lesion involvedthe occipital lobes on both sides with extensioninto the temporal and parietal lobe on the leftside and into the temporal lobe on the rightside. As evident from the MRI, the disease ofour patient consisted of bilateral confluent

lesions that were mainly limited to the deepwhite matter and spared the cortex andadjacent subcortical matter. Even though abiopsy was not performed, the MRIappearance"5 and the clinical course withresponsiveness to zidovudine make a diagnosisof subacute encephalitis due to HIV mostlikely."2"4While some patients with Balint's syndrome

experience difficulties in perceivingmovements,4 16 our patient was able to perceivemovements and this enabled her to distinguishbetween objects and people. In addition toshowing that disturbances of movement per-ception are coincident with rather than essen-tial to Balint's syndrome, this pecularity in ourpatient deserves discussion. Isolated defectivemovement perception has been reported in apatient with bilateral vascular lesions affectingthe lateral occipito-temporal cortex andunderlying white matter.'7 Because of theextension of our patient's lesions into thetemporo-occipital junction on both sides, animpairment of movement perception mighthave been expected. But unlike vascularlesions, our patient's disease mainly spares thecortex and adjacent subcortical matter with theU-fibres.'4 It has been shown that the informa-tion transfer from the primary visual areas inthe striate cortex to the higher visual areas inthe occipito-temporal junction and the tem-poral lobe takes place through U-fibres ratherthan through deep white matter pathways.'8 Itis therefore not surprising that certain visualproperties were preserved in our patient, forexample, movement perception, which isknown to follow a functionally andanatomically distinct pathway. '"Form discrimination by our patient

improved with the aid of motion not only indaily life but also in the test situation whenasked to read. While she was otherwise onlyable to recognise single letters or numbers, shecould read whole words and 3-digit numbers ifshe was allowed to observe the examiner writ-ing. It is possible that additional kinestheticinformation obtained from ocular movementsby observing the examiner's hand might con-tribute to her perception. This kind ofcompen-sation for impaired visual recognition wasdescribed by Goldstein and Gelb20 and byLandis et al2' in patients who "traced" thevisually seen contours by hand or headmovements and thus became able to "read" atext. In our patient, however, this explanation(that is, recognition through kinesthetic media-tion), cannot account for the relative modalityspecificity of the ensuing improvement. Thiswas limited to the perception of words andnumbers, while the perception of abstractdrawings such as a cross or a triangle, or ofmeaningful drawings such as a head, face, ortree, was unaffected. It is known that visualattention in normal subjects can be attracted bymotion.22 The observation of the examinerwriting may have attracted our patient's visualattention, thus resolving an otherwise incom-prehensible array of visual components thatcould only be read in isolation if there was nomovement. The fact that this compensation

824

Balint's syndrome in subacute HIV encephalitis

was possible only for block writing but not forscript lends further support to this explanation.Such an interpretation implies that the visualdisturbance in Balint's syndrome is due to adisorder of the spatial distribution of visualattention, as suggested by H&aen7 and Luria.6

1 Balint R. Seelenlahmung des "Schauens", optische Ataxie,raumliche Storung der Aufmerksamkeit. Monatschr PsychNeuro 1909;25:51-71.

2 Potzl 0. Die optisch-agnostischen Storungen (Die ver-schiedenen Formen der Seelenblindheit). Leipzig, Deuticke1928.

3 De Renzi E. Disorders of space exploration and cognition.New York: John Wiley, 1982.

4 Damasio AR. Disorders of complex visual processing:agnosias, achromatopsia, Balint's syndrome, and relateddifficulties of orientation and construction. In: MesulamMM, ed. Principles of behavioral neurology. Philadelphia:FA Davies, 1985:259-88.

5 Holmes G. Disturbances of visual orientation. Br J Ophthal-mol 1918;2:449-68, 506-16.

6 Luria AR, Pravdina-Vinarskaya EN, Yarbuss Al. Disordersof ocular movement in a case of simultanagnosia. Brain1963;86:219-28.

7 Hecaen H, Ajuriaguerra J. Balint's syndrome (psychicparalysis of visual fixation) and its minor forms. Brain1954;77:373-400.

8 De Renzi E. Disorders of spatial orientation. In: Vinken PJ,Bruyn GW, Klawans HL, Frederiks JAM, eds. Handbookof clinical neurology, vol 45: Clinical neuropsychology.Amsterdam: Elsevier Science, 1982:405-22.

9 Wolpert I. Die Simultanagnosie- Storung der Gesamtauf-fassung. Zges Neurol Psychiat 1924;93:397-415.

10 Kinsbourne M, Warrington EK. A disorder of simultaneousform perception. Brain 1962;85:461-86.

11 Kinsbourne M, Warrington EK. The localizing significanceof limited simultaneous visual form perception. Brain1963;86:697-702.

12 Kleihues P, Lang W, Burger PC, et al. Progressive diffuseleukoencephalopathy in patients with acquired immunedeficiency syndrome (AIDS). Acta Neuropathol (Berlin)1985;68:333-9.

13 Petito CK, Cho ES, Lehmann W, Navia BA, Price RW.Neuropathology ofacquired immunodeficiency syndrome(AIDS): an autopsy review. J Neuropath Exp Neurol1986;45:635-46.

14 Gray F, Gherardi R, Scaravilli F. The neuropathology oftheacquired immune deficiency syndrome. A review. Brain1988;1 11:245-66.

15 Jarvik JG, Hesselink JR, Kennedy C, et al. Acquiredimmunodeficiency syndrome. Magnetic resonance pat-terns of brain involvement with pathologic correlation.Arch Neurol 1988;45:731-6.

16 Girotti F, Milanese C, Casazza M, Allegranza A, CorridoriF, Avanzini G. Oculomotor disturbances in Balint'ssyndrome: anatomoclinical findings and electrooculogra-phic analysis in a case. Cortex 1982;18:603-14.

17 Zihl J, Von Cramon D, Mai N. Selective disturbance ofmovement vision after bilateral brain damage. Brain1983;106:313-40.

18 Tusa RJ, Ungerleider LG. The inferior longitudinal fas-ciculus: a reexamination in humans and monkeys. AnnNeurol 1985;18:583-91.

19 Livingstone M, Hubel D. Psychophysical evidence forseparate channels for the perception of form, color,movement, and depth. J Neurosci 1987;7:3416-68.

20 Goldstein K, Gelb A. Psychologische Analysen hirnpatho-logischer Falle auf Grund von Untersuchungen Hirn-verletzter. Z ges Neurol Psych 1918;41:1-142.

21 Landis T, Graves R, Benson DF, Hebben N. Visualrecognition through kinaesthetic mediation. Psychol Med1982;12:515-31.

22 McLeod P, Driver J, Crisp J. Visual search for a conjunctionof movement and form is parallel (Letter). Nature 1988;332:154-5.

825