Clinical and experimental neurology最新文献

Isaac's syndrome is an uncommon, but distressing, condition of spontaneous abnormal muscle activity caused by neuronal hyperexcitability possibly due to damage to slow potassium channels. The underlying aetiology may be peripheral nerve damage from a wide variety of causes, including autoimmune disease. We report a case that failed to respond to carbamazepine or phenytoin but responded dramatically to valproic acid. Thus, valproic acid may be an effective treatment for Isaac's syndrome where these other drugs have failed.

Two cases of rhinocerebral mucormycosis in elderly, non-ketotic diabetics who were initially diagnosed and treated for bacterial periorbital cellulitis are reported. Both presented with a short history of periorbital pain and swelling followed rapidly by complete ophthalmoplegia and blindness. By the time of correct diagnosis, both cases were advanced with lower cranial nerve involvement, CT evidence of ophthalmic artery and cavernous sinus thrombosis and, in one, internal carotid artery invasion (demonstrated on MR angiography) with resultant cerebral infarction. One patient was treated with intravenous amphotericin B but died within a few days. The second patient had aggressive surgical resection and survived with significant residual morbidity. These cases illustrate that mucormycosis should be excluded in any diabetic patient presenting with orbital cellulitis, especially when there is early visual loss. Early aggressive treatment with surgery and antifungal agents is often successful whereas the outcome is almost universally fatal when the diagnosis is delayed.

The incidence of Alzheimer's disease has been suggested to be low in Chinese but there have been few histological studies of the disease and of Alzheimer-related changes in Chinese. In this study, brains from 8 cases of Alzheimer's disease and 27 non-demented elderly Chinese individuals were examined comprehensively. Dementia was excluded in the latter by careful retrospective interviews with relatives. Histological sections were taken from standardised areas and quantitative analysis of neuritic plaques, neurofibrillary tangles and diffuse plaques was carried out with 3 histological methods: microwave modification of Bielschowsky, Bodian and beta A4 protein immunostaining. There were conspicuous differences in the amounts of neurofibrillary tangles and neuritic plaques seen between the demented and non-demented groups. In the latter, the amount of Alzheimer-related changes appeared to be much smaller than in corresponding studies among Western populations. Diffuse plaques were not found to be a good histological marker for dementia.

The central and peripheral nervous systems do not require insulin for glucose uptake. However, insulin receptors have been detected in these regions. The aim of this study was to examine peripheral sensory nerve function and its dependence on insulin using healthy non-diabetic control subjects, obese individuals, and diabetic (insulin dependent and non-insulin dependent diabetes mellitus) subjects. The results revealed that the warm and cold perception thresholds, reflecting the functional states of unmyelinated C-fibres and A-delta fibres respectively, increased with reduced insulin sensitivity and with increased fasting insulin concentrations. From such data in non-diabetic subjects with measured insulin sensitivity, it appeared that sensory nerve function was disturbed in normoglycemic but insulin resistant states, suggesting that insulin has an action on nervous tissue in addition to its effects on glucose metabolism. The mechanisms of this action remain to be elucidated.

The phenomena of epilepsy have been known for at least 3000 years, the earliest recorded account being in an Akkadian text called the Sakikku (written around 1067-1046 BC). Over nearly all the subsequent centuries the popular belief has been that epilepsy is a disorder of supernatural origin, and to some extent such ideas have carried over into medical thought. In Western civilisation, the long dominant belief was that epilepsy was due to possession by a devil or a demon, an interpretation given authoritative support by the miracle story of the cure of the epileptic child which is recorded in all three synoptic Gospels. However, there have been many other interpretations e.g. epilepsy as a consequence of wrong doing or of lunar or magical influences. Such ideas began to die out only in the past 200 years. From Hippocrates (c. 400 BC) onwards, there has been a continuing line of thought that considered epilepsy a medical condition due to natural causes. The hypotheses concerning its pathogenesis have ranged from excess phlegm in the brain, through boiling up of the vital spirits in the brain (Paracelsus), explosion of the animal spirits in the centre of the brain (Willis), heightened reflex activity at a spinal (Marshall Hall) or medullary level (Brown Séquard), to Hughlings Jackson's notion of an occasional, an excessive, and a disorderly discharge' in part of the cerebral cortex. Among thinking men, epileptology in the past century has proved largely to be a matter of exploring the ramifications of Jackson's concepts.

Lamotrigine (LTG) has recently been approved for marketing in Australia as add-on therapy in resistant partial seizure disorders. Early reports cited a therapeutic blood level for LTG of 1-3 mg/L (4-12 mumol/L). Aspects of routine patient care with LTG, devoid of the restrictions of trial protocols, are discussed. Forty-five patients commenced therapy but 15 discontinued LTG. Of the remaining 30 patients, 9 became seizure free, 3 from the de novo trial in focal epilepsy and 6 with generalised epilepsy. Global evaluation of patients showed mild to moderate improvement for those with focal epilepsy and moderate to marked improvement for those with generalised epilepsy. Blood levels of LTG did not provide clinically useful information.

Twenty patients with Parkinson's disease were studied during the early phase of L-dopa treatment to clarify the development and progression of Parkinsonian motor fluctuations. Two patients had developed symptomatic motor fluctuations of moderate severity and another 3 had mild fluctuations. Both the initial response to L-dopa and the amplitude of response to a L-dopa test dose after a mean follow up period of 30 months were significantly greater for the fluctuating patients compared with those without fluctuation (p < 0.05). Although severe motor fluctuations do not usually develop until a number of years of L-dopa treatment have elapsed, this study shows that motor fluctuations can be detected quite early in the disease course and tend to appear in those patients who respond best to L-dopa.

In a territory-wide survey of Huntington's disease (HD) in the Chinese population of Hong Kong, 20 patients from 11 families were identified from 1984 to 1991, giving a low period prevalence of 3.7 per 10(6) population. Six patients had died by 1991, hence the point prevalence was even lower, being 2.5 per 10(6) population. The male to female ratio was 3:1. No paternal transmission effect on the age of onset was observed. Apart from these differences, the clinical and pathological features were similar to those seen in the West.