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Show f. Clill. NClIro-o/,Iltlla!lI/o!, 5: 55-56, 19H5, Editorial Comment Whence Pseudotumor Cerebri? In this issue llf the 111urn,1!. Drs, B,lker ,1I1d Buncic repurt l)n thrl'e p,ltil'nts with pselldl1tllnlOr cerebri ,1nd describe tr,lnsient l'I'rt,t'II! l1cular de\' i,ltil1l1S ,1S ,bsllci,lll'd findings If line rec,ll1s the d,bsic c~iteria fllr the di,lP1~)sis l1f pseudl1tumor cerebri I - ,1S seen in T,lbk I, lH1l' might Cl1l1sider this ,1S ,1 heretic,ll suggestil1n, T,''d'LL 1 Dand" Criteria ior the Diagnosis oi Pseudotumor Cerebri (\Iodiiiedl 1 ~I::-:n .....11'"11..1 ... ,n1ptl..)nb \.),. lIlCrl',bl'd Intr.lcf.llll,ll prl'~surl' I ht',hi.h:hl'.... 1l,1U .... t·,1 \ l.)nlltln~, tr,ln .... lt'nt llb~(ur,ltIt.Hb ut \ I'h.\fl ~""l~"ldlt·J.l'nl.l) ""\ \.1. 1 11.)\.'.lIILln~ nt'url..llll~l( .... I~n .... llthl'f\'"bt'. With the ....Ingle ,'\(et'tl,'n betn~ unJiJrer,ll ur bJi,lter,ll VI n,'n',' pJr,'''' Lerebr,"ptnJI tluld "hlc'h (In "h"" tn(fe,bt'd pre"ure, but \\ lth nl l (~·tl)lllhl( l)r (henlIC..1! abnurnl.llities uthenvise ~ ",'rmJI te, ,mJII ,\mnwtn(JI \ entndes must be demun' trJted \,'n~lnJllt required \t'ntn(uiL)~rJph\', but nut\' d,'m,'n'trJted b\ ",'mputed t<,mu~rJph\') Huwen'r, if one looks at the article by Drs, Baker and Buncic more cluselv, some additional points can be made, Their first patient was a 15year- old girl with a 25-diopter esotropia due to bilateral lateral rectus weakness, They stated: 'When the horizontal deviation was neutralized a smal!. but definite incumitant vertical deviation was present as well: a right hypertropia of 1PO 111 left gaze, and a left hypertropia of 1PO in right gaze which 1I1creased to 2PD in gaze dl1wn and right and disappeared in gaze up and right, simulating the pattern seen with inferior oblique overaction," One distinguished strabismus expert who reviewed this paper suggested that this sentence be deleted because the pattern of inferior ublique uveractiun increases in up gaze, and is less on down gaze, which is the oppusite of the findings noted in this case. However, the puint that is being emphasized here is that the authors describe a vertical deviation of I-prism diopter in eccentric positions of up gaze and 2-prism dil1pters of left hyperdeviation in gaze down and right. It should be emphasized that it is difficult to see deviations of less than 2-3 diopters on cardul objective examinations, and many examiners will not find a devia tion of 1-2 diopters except by careful subjective tests, The point being made March 1985 here is that the vertical deviations seen in this (,lSl' were ll1inull' in amount, Dr. Walsh used tll ll'1l me that one could accept up tll 2-3 prism diopters llf a vertical deviation with a VI nerve palsy alone, but that any amount Il1llrl' than that was significant. I believe a pertinent quote from the classic text' by Dr. Alfred Kestenbaum, Clillit'al Methods of Neuro-ophthalIlIolo:\ ic Exall/illatioll, should be mentioned here: "Vertical diplopia ill abducells paresis. In abducens paresis a vertical component is sometimes found in the distance between the images." (Kestenbaum then describes the red glass test results as follows:) "For example, in gaze to the left, the white image (the image belonging to the left eye) stands farther to the left, indicating a left abducens paresis. In gaze up and to the left, the white image stands not only farther to the left but also lower, 'less peripheral.' In gaze down and to the left, the white image stands to the left and higher than the red one. Such behavior would suggest that in addition to the left abducens paresis, muscles of the right eye are involved, since the red images stand more 'peripheral' in vertical directions. The elevated red image in gaze up and to the left, and the depressed red image in gaze down and to the left, would indicate additional paresis of the right inferior oblique and the right superior oblique, respectively. Such a triple combination seems strange, and yet this syndrome is not too rare. This phenomenon may be explained as follows: "The left lateral rectus nl1rmally causes a certain mechanical inhibition llf l'Ievatio'n and depression in abduction. In paresis uf this muscle, the evein gaze to the left-can be elevait'd ,1I1d depressed more than normal; a hypermotility of the left eve upwards and downwards is present. This hvpermotility of the leit eye, in gaze to the leit, causes a dipillpia imitating a hypomotility of the right eye due to a paresis of the right inferior oblique and the right superior llblique. Thereiore, a slight vertical distance between the images on gaze upwards or downwards within the field of action of the paretic lateral rectus is to be neglected and is not to be used for diagnosis of an additional paresis of a vertical motor muscle of the other eye." What is Dr. Kestenbaum really saying here? On page 229, he states: "The lateral rectus ... is mainly an abductor. In addition, it has a slight 55 Editllri,11 Cllllllllcnt: l'scudlltUlllllr Cl'rl'Dri inhibiturv dicct un vertical muvements uf the eve." In 'utlll'r words, if all of the extraocular nluscles ad in CUIlL'ert and each une has a stabiIi/ ing dfcd lll1 mutions of the globe, it can be ,1pprcciall'd th,1t in ,1 signific,1I1t Iall'ral rectus wc,1I--ness, the glube l',m "slip" up or down a little bit when it gues intu abduction, and this associ,1ll'd slight vertic,11 cumponent can be up to 3 diupll'rs bdurl' une l-,1I1 trulv call ,mother vertical musclc as being invulved pathulogically. I think it is Impurt,1I1t to re,11i/e this 3-prism vertical slip phenumenun with abducens weakness, and the ,1I11llunt of vertical deviation reported in Drs. Bal--er ,1I1d Buncic's first case, is within the limits of this phenumenon. Their secund case is a bit more difficult to assess. A 5-year-old girl with apparent "otitic hvdwcephalus" syndrome had bilateral papilledema and a V-pattern esotropia, as had been noted in the first patient. However, 2 weeks later, the patient had a "large" left hypertropia with relative inability to depress the left eye at all. Three weeks after a lumboperitoneal shunt, the vertical eve movements were normal, but at a 4year follow-up, the patient has 20/20 acuity in each eve, a normal horizontal, and vertical ocular motilit~y findings. A follow-up high-resolution computed tomographic brain scan with emphasis on posterior fossa would be of interest in this patient, but it is still an important and welldocumented case to this point. The third case was a 7-year-old boy with bilateral sixth nerve palsies and one must presume to have associated papilledema, although no mention of the optic discs in this case is given. Again the magnitude of the right hypertropia in diopters was not given (as in case 2), and the patient was treated with Decadron, and 2 months later, was said to have normal ocular motilitv. The followup was said to be a "neurosurgica( examination," which may not have meticulouslv assessed the presence of a small vertical deviation, and the authors admit in their paper that they did not see this patient, but got the information from his chart. With only a 2-month follow-up, the final report on this patient may not vet be in. It is important to fullow patients with pseudotumor cerebri as carefully as if they had a known intracranial neoplasm, ~for many experienced clinicians have encountered patients with a diagnusis of "pseudotumor" that years later were subsequently found to have what Dr. Noble David calls "tumo'r vera." One way that this can occur is for a small mass lesion to invade or compress the lateral or 56 straight sinuses, or even the torcula, and thus produce the picture of a great venous sinus occlusion. Such an uccurrence is, fortunately, less commonly missed now with the availability of cranial compull'd tomography than in the days when this was not available. One might wonder why, therefore, we published this paper in the light of the above considerations First of all, the paper was reviewed by three eminent uutside consultants and all of these thought that it should definitely be published! One of them did admit that he had difficulty interpreting Hess screen charts (since Hess screen testing is not performed in his institution and he had to luul-- up the answer in Worth and Chavasse to understand the figures). Another thing that prompted publication of this paper is that in a 1984 editIOn of an outstanding neurology textbook: a table was given listing over 35 entities and 10 subgroups under the heading of "benign intracranial hypertension," and it was thought that some of the points in this editorial would, therefore, merit reemphasis to the clinician. Finallv, it is hoped that Drs Baker and Buncic's report will stimulate further analysis of subtle verticle deviations in patients with pseudotumor cerebri. It should be stressed, however, that one should not abandon the classic Dandy criteria for the diagnosis of this clinical situation, for to do so may well open Pandora's box from the diagnostic point of view. Let us examine carefullY and proceed with caution' FinallY, Kestenbaum:s observations published nearly aquarter of a century ago merit reappraisal by the neuro-ophthalmic communitv. J. L. Smith, M.D. References Smith, J.L Pseudotumllr eerebri. TrailS. Am. Acad. 1l1'Iztllalllllli. Ottl !.ln/Il'\tl l. 62: 432-440,1958. 2 O,md\' \\'T. Intraer'ani,11 pressure without brain tllmllr: Oh1gnl1sls and treatment. AIlIl. Slag. 106: 4ll 2-5D,lll.3; .3 "eslt'nballm. A.. CIIIlIC,11 Aletlll1ds of Neuro-ophthalIlllll''',\ It' EX'IIIIII/'lIlt>1l (2nd ed.). Grune & Stratton, New 1llrk 1llt> L pp. 229-259 4. Fishman. R.A: Mcrritt's Textrook of Neurology (7th cd). L. r Rlnv!and, Ed. Lea & Febiger, Philadelphia, Ill1\4. p 211. Journal of Clinical Neuro-ophthalmology |
