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Show ABSTRACTS: AUSTRALIAN ASSOCIATION OF NEUI?DLOGISTS 125 comparing the evoked responses to dvn,lInic random dot sten.'ogr,lms in till' two Ill'misplll'res. Recordings were Ill<lde from Intl'rn,ltion,ll 10-20 scalp sites 02, P-I, Tb, T-I, ,1Ild homotopic sitl's llVl'r the left hemisphere. Strokl' p,ltil'nts with unilatl'r,ll lesions, 13 Il'ft-hemisplll'rl' ,1Ild 13 right-hemisphere caSl'S, Wl're Sl'll'l'll'd on till' b'lsis of s,ltisfactory performance on ocul,H sl'rl'l'ning ll'sls ,1Ild on clinical and. or objective indications th'lt dl'menti,l was ,lbsent. Inll'rgroup nllnparisons Wl'rl' madl' on the full clinical groups ,1Ild on eight patients from each group WillI g,H"l' valid repllrts of the stimulus and eight normal nllltrois ("pl'rceivers"). The stereopsis ll'st schedule included left, right, and center field presentatilllls of 30 arc min disparities. The dot densit~· of the disparitv, relative to that of the remainder llf the random dot field, was manipulated to provide a full-contrast stimulus and a no-contrast. uniform field stimulus; thus varying the availability of monllcular cues provided bv the contrast stimulus. The evoked potentials in the stroke patients were in general noisier and of lower amplitude than in controls. In all 16 of the stroke group "perceivers," an evoked response to the stimulus was identifiable. In the no-contrast condition, however, the response was of low amplitude and poor definition in comparison with the healthy controls. Although there were some differences in waveform morphology in the two clinical groups, analyses of variance carried out on the amplitude and latency data did not reveal a differential between-hemispheres response to left l'l'YSIIS right visual field stimulation (no-contrast condition). The stroke groups were nearly equal in the number of patients able to perceive and correctly locate the stimulus. No evidence was found of preferential unilateral hemisphere control or organizational mechanisms for stereopsis. It was suggested that the techniques used in experiments by other researchers who have argued for the existence of such mechanism may not have been adequate for the study of the questions involved. • 9. Drs. I. M. Williams, P. Dickinson, and Mr. A. Sum presented The Edrophollilll/1 Test ill Myasthellia: Quantitative Oculography, in which they reported that the response of eye movements to edrophonium is easily missed by clinical obsl'rvation alone. They used infrared oculography to examine the response to edrophonium of binocular horizontal 10 degree saccades both before and after fatigue in 26 patients with diplopia or ptosis of uncertain etiology. In this series the most reliable criterion of a positive response was an increase in the amplitude of the saccades of the fixating eye by 10% or more after each of several injections of dilute edrophonium. The response was pllsitive in 13 patients, in 10 of whom the diagnosis was subse-quently confirmed. The response was negative in 13 patients, in to of whom the cause of the diplopia or ptosis was established. Unequivocal responses of the sacca des to edrophonium were found to be difficult to observe clinically when the responses of the saccades of the eyes moving conjugately were unequal and when the patient presenll'd with ptosis and no diplopia. The authors concluded the edrophonium test with infrared oculography is helpful in identifying a neuromuscular junction defect. 10. Drs. K. J. Abbott, G. N. Thompson, A. Poulos, A. C. Pollard, and D. M. Howard noted in Addisoll- Schilder's Disease Rel'isited: Expressioll of a LOllg-Chaill Falll{ Acid Storage Disorder With ill a Killship that X-linked adrenomyeloneuropathy and childhood adrenoleukodystrophy are both associated with accumulation of long-chain fatty acids in plasma, cultured skin fibroblasts, and various tissues. They stated isolated reports have described their coexistence within kinships. The authors described three males and one carrier female. An 8-year-old boy presented with progressive dementia, ataxia, bipyramidal signs and visual loss, suggesting adrenoleukodystrophy. Longchain fatty acids (C2,,1C22 and C2./C22 ratios) were elevated in plasma and skin fibroblasts; no evidence of adrenal insufficiencv. or brain demv-elin-ation on CT scan was found. His mother had mild leg spasticity and long-chain fatty acid values consistent with heterozygosity. The maternal uncle (aged 33) complained of recurrent gynecomastia and recent gait disorder; he had spastic paraparesis, recent skin pigmentation, and subtotal alopecia from early childhood. His long-chain fatty acids were elevated, and other studies indicated primary adrenal insufficiency hypogonadism and peripheral neuropathy. A maternal cousin had presented at the age of 12 years with melanoderma and adrenal failure; at age 27, he was reported to be neurologically normal and had fathered two children. The authors reported adrenomyeloneuropathy and adrenoleukodystrophy are phenotypic variants of a storage disorder, probablv resulting from deficient enzymatic degradation of long-chain fatty acids. Males may present with childhood deml'ntia, spastic paraparesis, or endocrine dysfunction; carrier females may have neurologic signs. A con natal form results in neonatal seizures and rapid deterioration. Long-chain fatty acid studies enable carrier detection and prenatal diagnosis. NOTES • Paper to bl' published in lull in Clillica/ Illld Expcrimelltlll Nellr%xy Volume 22. t Paper to be published in iull in journals elsewhere. J Clill N('lIro-ol'lttltallllol, Vol. 6, No.2, 1986 |