Trinucleotide repeat analysis of spinocerebellar ataxia patients in Oman.

OBJECTIVE: To explore the profile of cytosine/adenine/guanine (CAG) repeat expansion in Omani spinocerebellar ataxia (SCA) patients. METHODS: Ten SCA patients attending the Sultan Qaboos University Hospital Neurologic clinics, Al-Khoud, Oman in the 3 years starting from January 2000 were recruited for this study. Genomic DNA was extracted from peripheral blood samples and CAG repeat expansion analysis was carried out by polymerase chain reaction and sequencing, when required. RESULTS: The CAG triplet repeats leading to polyglutamine expansion and neurodegeneration are seen in spinocerebellar ataxias 1, 2, 3, 6, 7 and 17. By using primers for SCA 1, 2, 3 and 7, we found the repeats were in the normal range and triplet repeats do not seem to be a common cause for ataxia in Oman. CONCLUSION: Spinocerebellar ataxia in Oman has the normal range of CAG repeats for the commonly found SCA1, SCA2, SCA3 and SCA7.

A syndrome of olivopontocerebellar atrophy and deafness with onset in infancy.

Olivopontocerebellar atrophy (OPCA) is rare in childhood and onset in infancy is uncommon. We encountered 11 consecutive children with clinical and radiological features of OPCA which started in infancy. In addition to cerebellar ataxia, these children also had sensorineural deafness and speech impairment. Of the present cases, 8 were sporadic and the pedigree patterns in 3 (with a sibling also involved) point to an AR inheritance. The CT scan showed varying degrees of cerebellar and pontine atrophy. The underlying genetic and neurochemical substrates of this syndrome await further study.

Cognitive evoked potential (P300): a metric for cerebral concussion.

Cognitive impairment has been reported to occur in minor head injury (concussion). The value of the P300 evoked potential as a measure of cerebral concussion was studied in 20 patients with minor head injury and compared with the data from 20 normal subjects. Significant abnormalities of the P300 latency and amplitude were noted in these patients in the post-concussion period. The abnormalities improved completely on repeat testing. The correlation of the P300 to other parameters of head injury is discussed. The P300 constitutes a simple laboratory test that is sensitive measure of cerebral dysfunction in concussive head injuries.

Ipsilateral motor seizures.

A patient presented with elementary partial motor seizures on the same side as the cerebral lesion. A cerebral computerised tomographic scan showed a right medial frontal atrophic lesion and an electroencephalogram showed seizure discharges from the same region. The clinical significance and pathophysiology of ipsilateral seizures are discussed.

Bruxism: its significance in coma.

Bruxism, the phenomenon of non-functional grinding of the teeth has been ascribed to various causes. Twenty patients with coma from different causes who displayed bruxism were studied with an attempt to correlate the phenomenon to the level of consciousness, eye movements, respiration, cold caloric test, motor deficits and sleep wake cycles. Bruxism was seen to appear at different levels of consciousness, but to disappear only after a significant improvement in the level of consciousness. A relationship with the appearance of sleep wake cycles was also seen.