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Show ,. Cli,l. NC'urlHlplltllldnltll. S: fl7-69. 1985. Abstracts Australian Association of Neurologists' Annual Scientific Meeting-1984 ISLA M. WILLIAMS. M.D. The Annual Scientific Mt't'ting of the Australian :\sS\.l\.;atilm llf :\jeuwlll~ists-1984. was held in Mt'Ibl'ume. Vit'tllria. Australia. Ten papers were of interest ti' neunl-llphthalmillogists and will be reviewed briet1\'. !. Drs.:"I:. Griffiths and D. G. Milder. in their paper Cll-t'.n~/t'''/ Tl"l'~a-HIII// SIII/linlmt' allti #dill/,all/if l"rlammall'''Y Or/>i/al P~t'uljtltunJllur. rt'portt'd a 57war- old woman who prt'St'ntt'd with pain and paraesthesiat' ct'ntt'rt'd about tht' It'ft t'yt' for tht' prt'\;ous 12 months. and diplopia for tht' prt'vious 3 months. Sht' was known to sufft'r from idiopathiC thrombocytopenic purpura and rht'umatic mitral stt'nosis. E,amination rewalt'd a left proptosis and It'ft partial ptosis. Visual acuitit's and fundal appearances wt'rt' normal. Tht' It'ft pupil was smaJlt'r than tht' right and rt'sponded sluggishly to dirKt illumination. A paralysis of movt'mt'nts subst?rvt'd by tht' It'ft superior. medial. and inft'rior rt'ctus muscles was t'vident. The left globe retractt'd on abduction. The left comt'al responst' was subjectively diminisht'd. A diminisht'd response to pinprick. temperaturt'. and touch st'nsation was prest'nt in tht' ophthalmic division of tht' left tri~eminal nt'rve. and a diminisht'd sensation to pinprick in tht' maxillarv division. The remainin~ neurologic t'xaminati~n was normal. A full blood count rt'vt'alt'd a leucocytosis. Tht' ESR was 46 mOll hour. Serum biochemistry was normal. The antinuclear factor was positive in a dilution of 1 in 40 and DNA binding levels wen~ normal. A CT scan of the brain was normal. A CT scan of the orbits revt'alt'd a localized thickeninK of the left ml-dial rKtus muscle and a soft tissue density in thl' Il'ft postt'rior orbit contiguous with the optic nerve. A diagnosis of Tolosa-Hunt syndrome and idiopathic inflammatory orbital pseudotumo.r. was madt'o Tht' coexistt'nct' of these two condltillns. thought to represent a spectrum of anatomic involvement. was discusst'd. 2. Drs. A. Fisher and W. Knezevic presented a papt'r entitlt'd Ocular al/d Ocular MIIII,r ASI'I'Cls tlf Primary Thalamic Hac'nJllrrl/aXI'. As part of a correla- March 1985 tive study of the neuro-ophthalmological abnormalities in thalamic hemorrhage. tht'y reported preliminary findings in six patit'nts with this condition diagnost'd by clinical and computerizt'd tomographic brain examinations. Fivt' patit'nts were middlt' agt'd and hypertt'nsivt'. Two had Homer's syndrome. and thrt't' anisocoria. Thrt't' patients had prominent mesencephalic dysfunction. There was pathological confirmation of the lesion in one case. The basis of the signs of midbrain disturbanct' in tht'St' patients is unct'rtain. but may comprise pressurt'. traction. or hypoxia. separatt'ly or in combination. Tht're was no positive corrt'lation betwt't'n the t'Stimatt'd size of the demonstratt'd hemorrhage and the severity of the neuro-ophthalmological abnormality. • 3. Drs. S. S. Gubbay and D. Chin rt'portt'd a study in Myasll/fJIia Grat.is i" TIJru Familit~. Six patit'nts sufft'ring from familial myasthenia gravis (MG) belonging to thrt't' different families were described. The thrt't' brothers in the first family were considered to be suffering from familial Iimb~ irdll' MG bet'ause IIf an onset awund the a~e l,f 13 years. no involvement l,f l"ular l'r bulb.n muScles. and Jl'Sp'-IOSt.' to antichl,lint'litl'raS\.' dru~s. Thl' Sl'Cond and third familil's \n-re di.l~nllSt.'d .lS suffl'rin~ from fclmilial wn~enital m~·astheni.l Kravis bl"cclUSl' llf the prl'Sl'nl'e l,f s~'mrtl'ms bl'fore 2 yedrs of a~e. rwminent in\'l,I\'t.'ment llf the l"tral"ular muscll'S with rl'lativl'ly mild ~enerali'- l-d wl'al..ness. and rt'li~'1llOSl' to ,mtit'hillint.'stt.'raSl'S. Thl'n' Wl'rl' nil 1·.lSl'S llf thl' h\'ll lltht.'r dt.'sl'ribl'd \·.lril'lil~ IIf famili.ll MG. n.lml'lv nt.'lIOatal MG whkh 01.1\' bl' .1sSlII:iall'd with tr.lnsient 1."tr, ll""ular musdl' \\'l'.ll..nl'ss. .lnd f.lmili.ll infantilt.' MG which is fh.lr.ll'leri/l'd b~' inll'rmittt.'nt respir. ltl,ry .md fl'l-din~ difficulty withllut e'trall\.'1Jlar mUSl'II' invllln'ml'nt. Thl' tlL-A .mti~en pdttems were dl'SlTibl"d in thl'St' t'dSl~. Type' II muscll' fiber atmphy was IIbserved in edt'h familv. The .lbsent'e IIf antibodii'S indudin~ anti-at'l'tykholine rt.'ct.'ptor antibody 67 in Ihl'Sl' l..lSl·S shuws Ih,ll immunulu~ical ml'chanisms du nul Sl'l'm lu pl,ly ,1 pari in p'llhu~l'nl'~is. TIll'v pWh,lhlv n'sull fwm ~l'nl'lk ur cun~""'.tal dd,;els whidl e,m hl' l'ithl'r prl" ur postsynaptic 4. Pro K. B. Silhl'rstl'in ,md Miss Ain,l Pun' pn's,'ntl'd ,1 p,lpl'r l'nlilll'd rrt'qlll'lIn/ Clllmldl'ris/!CS (It .VislI, d/l/ f".,kl'" SII'IIIIIi SIIIII' PilIi'll I Ials. A slllusuidally \,.lrvin~ vislJ.l1 sli'mulus l'volwd sinusoidal fortkal p,'tl'nti."s ,lt till' stimulus fn'qul'ncy or It~ harn"' nks. TIll'sl' ,Ul' known as ·stl·ady-statl' visually l'\'I,kl'd pull·nti...b" (SSVEP). Thl' m...);nitudl' .of Ihl' SSVEP is slrllll);lv influl'nn'd by thl' ..pallal ch.u",cIl·ristics uf thl' stimulus a.. wdl as its tl'mpl'r... 1 frl'qul'ncy. Thl'Y rl'cordl'd th~ .SSVEP l'vukl'd bv ,1 flkkl'rin~ Ii~ht sourcl' Cllnslslln~ of a du...1 .ur,lv of Ii~hh'mittin~ diodl's. Thl'sl' Wl'rl' vil'\\'l'd Ihwu~h c1osl'd l'ydids. Thl' Ii~hl sourcl' W,lS simultanl'ously altl'rnatin~ at thrl'l' frl'qul'neil'S diffl'rin~ by I liz (l'.g.. 14 Hz. 15 Hz. ~nd 16 liz). Thl' rangl' of frequencies presl'nted III one recording sl'ssion varied from 4 Hz to 60 Hz. Bolh the frl'quency and duration of stimulation were under computer control. Silver/silver chloride electrodes were used to record the SSVEP from sites Oz and pz with respect to linked earlobes. The magnitude and relative phase of the SSVEP was determined by the use of a novel computer-based multifrequency Fourier analysis technique. The magnitude of the SSVEP showed distinct peaks at approximately 10Hz. 18Hz. and 35Hz. The apparent latency of the SSVEP at different stimulus frequencies was calculated from a plot of SSVEP phase shift versus stimulus frequency. They suggested that these results are most rea~i1~ interpreted in terms of a ·parallel processlll~ model for the generation of the SSVEP. t 5. Drs. S. R. Hammond, C. Yiannikas. and J. G. Mcleod reported on Tllf VER: A Comparison 'lf F'lllfal and Full Fifld Stimulation in Il2 Patients wil1l Multiple SderllSis (MS). The visual field defect in optic neuritis is most commonly a central scotoma reflecting the predilection with which fibl'rs subserving central vision are involved in this condition. Modification of the standard VER bv stimulatin~ the foveal region to specifically l',amine these fibers might be expected to increase the sensitivity of lesion detection. The paper reportl'd their rl'sults frum a Cllmparison of fowal with full fidd stimulation in normal contfllls and a gfllUp of 112 patil'nts with MS. 114 ·dl'finitl'" ...nd 211 ·pfllbabll'.· usin~ thl' critl'ria of Rosl' l'l al. II W.lS fdt that thl' Il'chniqul's would bl' bl'st cump n·d in patil'nts with mild oVl'rall and mild. if n~'. visual disability. Thl' ·ddinitl'· gfllUp h...d ... ml·...n Kurtzkl' disabilitv scall' (0-10) of 2.1 and thl' ·prubabll'" ~ruup of 1.7. Only si\ of thl' wholl' );WUP had a visual acuity of Il'ss th.m 20/40 in onl' or both l·yl'S. Thl' full fidd n'sptlllsl' was ubtainl'd hy p...ttl·rn n'vl'rsal stimulation of a 320 diJml'll'r fidd usin~ Chl'l'ks suhll'ndin); ,m an);'" of 55'; for thl' fuw," n'sponsl' a 40 di,lml·tl'r fidd ,md l'hl'cks subtl'nd-ing 27' were used. Multichannel recordings w~re performed in each case. In the contr~1 ~puIati?n (24 males. 25 females), statistically slgmflcant dlffl'rl'nct'S were observed between the sexes for both full field and foveal latencies (mean values: mall'..-full field 97.8 msec, foveal 104.1 msec; fl'mall's-full field 94.9 msec., foveal 99.9 msec.) and bl'cause of this separate normal ranges were dl'rivl'd for l'ach Sl'X. Abnormalities (defined by absent or indeterrninatl' responses, and increased absolute or interocular latl'ncy values) were found in 82% of "definitl'" and 71 ('i of ·probable" patients, Analysis bv stimulation modality showed that while 63% had abnormalitil's detected by both techniques in onl' or both eves. 11 c;. had abnormalities detected by full fidd a'nd 15('( by foveal stimulation alone. Abnormal VERs in the absence of a history or clinical findings to support optic neuritis were found in 46('; of the eves at risk in the "definite" and in 52C:( of those' at risk in the ·probable" group. A~ain the majority showed abnormality with both techniques. but 19('( of the eyes were abnormal onlv on full field and BCC only on fowal stimula'tion. These results indicate that full field and fowal stimulation have a complementarv role in this clinical situation. Thus by combining thl' techniques. a higher yield of abnormalities is obtained than by either technique alone. 6. Drs. R. lansek and J. I. Balla. in their paper A Dt'cisillll Anal"'lc Apprtlac1l "l ti,e Role of VER and CSF Al",,'rma;,ties in ti't' Managemt'nt of Singular Spinal Sclt'rIlSIS. assessed the role of visual-evoked responses (VER) and cerebrospinal fluid (CSF) e\aminatillns in the investigation of patients with suspected singular spinal sclerosis with the use of Bayesian decision analytic techniques. An abnormal VER increases the probability of multiple sclefllsis (MS) bv 50CC. An associated CSF abnormality does not affect this probability. In a setting llf a negative VER, CSF abnormalities increase the probc\bility of MS by 27CC. On currently available data. VER should. therefore. be the primary investi~ atilln in patients with suspected singular spinal scll'fllsis. If the result is abnormal myelogr... phy may be l'mitted. CSF e'\aminations are only useful if VER facilities are not available. t 7. Drs. R. Pamphlett and C. Harper presented their p...per L"iS'I's [lis,'ast': ,0\ Caus~ tlf Arttrial HyptrlI ·nsi,'n. It has long been suspected that lesions of the brain stem can cause arterial hypertension. Idl'ntifyin~ thl' damagl'd structures leading to the h~'pl'rtl'nsillll has bel'n difficult. as widespread sc...ttl'rl'd It'silllls have been found at postmortem. AnimJIl'\pl'riments show that lesions of the solit, uy trJct Jnd nucleus (STN) in the medulla cause h\·pl'rtension. The STN is on the pathway of the baroreceptor reflex arc, and suppression of this rl'fle\ causes hypertension. An II-year-old boy had a sudden onset of ful- Journal of Clinical Neuro-ophthalmology min...tin~ h~'~rtl'nsi'In, with blo,l\.t pn'Ssun'S up t" 180/130 mm H~. ht,'nsiw inwsti~,ltiuns f...ilt.'d to r,'\'t'dl .I edUSl'. II,' di"d sudd,'nlv. At pllStm,'rt,'m \\'l'n' bil,lt,'rdl I,'sillns "f L,'i~h'~ dis' t'aSl' in th,' m"dull,l in\'(,lvin~ th,' STN. Th,'n' Wt'fl' no "th,'r dbnorm.lIiti,'S in th,' IWf\',.us sv~· tt'm ,'r in th,' "th,'r ,'r~.ms. . Th,' (indin~s indiedt" th.lt diSt'n'll' bil,tll'r.lll,'Siun~ ,,( tht' m"dull" in th,' n'~i,,,, ,,( th,' STN ,',m ,'dUSt' drtl'ridl hyp..'rt,'nsi,'n in hum.lIls. In uth,'r ,'.1St'S "f It'i~h's diSt'aSl' with h~,~rtl'nsi,,,,, simil...r br"in stl'm ll'Si,,,,s h"n' bt','n (,'und, but in th,'S\' m,'r,' wid,'~pr".ld 1''SI,'ns h.ln' bt','n pn'S\'nt. m.lkin~ it imp,'sslbl,' tl' pinp"lIlt th,' I,'~il.ns n'S~"",sibl,' (ur th,' hvp,'rt,'nsil'n. S. Dn;. M. C. r"ttt'n;,,,,. I. H. Bunet'....nd M. J. Eadit'. in thl'ir p"pt'r Cat'l'r,lI Al's,','ss ill L"lIkal'II/ia: All lblllslI,,1 Pr"s""tath'" ,,( a R"r,' C,m'I"ieatillll. citl'd in(l'.:til'n .1S .I .:,'mnwn ':"USl' ,,( morbidity dnd m"rt.lhty III pdtll'nts sU((l'rin~ (rum ht'matoio~ical mdh~ndn",'S. H,'wl'\'l'r, st'psis involving thl' Cl'ntral nl'f\I'US syst,'m ap~ars r...rl'ly .It Royal Brisbdn,' H,'spttal. Only tw" caSt'S "f el'rl'br...1...bscl'S.'i \\'l'rl' (,'und in .I rt'\'it'w l,f :!80 p'lStmortl'm l'" "mmatil'ns ~r(l'rmt'd on pdtit'nts dying with ht'· matl,I,'gical malignancit's in tht' ~ri,l\.t 1973-1982 indusi\·e. Bt,th patit'nts sufft'red from acute myeIt'gen,' us leukemia. but there the rt'St'mblance ended. The first. a 1b-year-old mall'. prt'St'nted with 'l\"erwhl'lming S\'pticemi.... and an anile Ct'rebral abscl'Ss which was discoverl'd incidt'ntallv at aut"psy The other caS\' was that of a flb-yearllid ~nsi,,,,er. who prt'St'ntl'd with palinopsia. Tht're was neither fever nl'r headache; the onlv localiZing sign was a denS\' left homonymous hemianopia. The diagnosis of cerebral abscess was suggl'Sted by CT scan and subsequently confirmed at autopsy. The authors have been unable to find reports of such a lesion presenting with palinopsia. • 9. Drs. J. D. Blackie. G. Danta. T. Sorrell. and P. Collignon reported the Ophthalmo/l'sical Compli- March 1985 Williams ,'at/lIllS (If Cry,'te'l"IIl"l".lI Ml'Ilillgitis. Two patients with cryptlll'lllxal ml'ningitis who developed lIphthdlmlllll~ical l'llmplications were described, anI' p.lti,'nt d,'wlllp"d a cryptllcoccal fundal lesi'IIl which rl'SlIlwd with cllntinul'd chemother. tpy. Buth pdtil'nt!> hdd vi!>ual fidd def,'Cts asso,' i.lIl'd with l-hronic rdi!>l-d intracranial prl'Ssure. In th,' fir~t pdtil'nt this n'Spllnd'-d tll rl'pt.'ated lumbar punetun'S. Thl' !>l'l'llnd patil'nt responded to optic nl'rv,' d,'n.mpn'Ssilln. In b(lth caSt.'S. CT '>Canning dl'm'IIl~trdt,'d upti.: nl'rw !>welling and in the Sl'wnd pdtient this n'~rl'SSl-d aftl'r dl'ClImpres!>ion, Th,' vdri,·ty and incid,'ncl' lIf the lIphthalmological (l.mpliedtillns uf cryptococcal ml'ningitis were revi,' wt'd. The ri!>k and mana~eml'nt of vi!>ual dis. lbility Wl're discussl'd. '10. Dr. P. A. Sandstrom pre!>ented a paper on the subject Crypton'ceal Illft'l"timl of tile Celltral Nat·( IllS SyMOII. Two patients with cryptococcal infection of the central nervous system were described. The variability in the mode of presentation was emphasized: caS\' 1 presented with a thalamic mass ll'Siun. while case 2 exhibited constitutional symptoms. headaches. and papilledema. Pulmonary ll'Sions were present in both caSt'S. Despite neurological complications and toxicity problems with combination therapy (Amphotericin Band 5·Flucytosine). both patients survived. although casl' 1 has a significant neurological deficit. Particular attention was paid to antifungal therapy and these specific caS\' reports provided a framework within which to discuss the concepts of drug combinations. drug to'dcity. and duration of therapy. Notes • To be published in full in Clillieal a'/Il Expail1lt'lltal Nt'II,,'h'~lI. V'l/. 11. t Tu b~ published in full in juumals ~Isewhere. 69 |