Yl Yu

N-hexane neuropathy in offset printers.

In an offset printing factory with 56 workers, 20 (36%) developed symptomatic peripheral neuropathy due to exposure to n-hexane. Another 26 workers (46%) were found to have subclinical neuropathy. The initial change in the nerve conduction study was reduced amplitude of the sensory action potentials, followed by reduced amplitude of the motor action potentials, reduction in motor conduction velocities and increase in distal latencies. These changes indicate primary axonal degeneration with secondary demyelination. Sural nerve biopsy in a severe case showed giant axonal swellings due to accumulation of 10nm neurofilaments, myelin sheath attenuation and widening of nodal gaps. The development of neuropathy bore no direct relationship to the duration of exposure, hence factors such as individual susceptibility may be important. Optic neuropathy and CNS involvement were uncommon and autonomic neuropathy was not encountered.

Herpes zoster and its neurological complications.

Ninety-three Chinese patients with cutaneous herpes zoster were seen during a 4-year period. Thoracic zoster occurred most commonly, followed by ophthalmic, cervical and lumbosacral zoster. Neurological complications were present in eleven patients (11.8%), the commonest being Ramsay-Hunt syndrome and segmental limb paresis. The clinical picture, pathogenesis, treatment and outcome of segmental limb paresis, myelitis and delayed contralateral hemiparesis following zoster ophthalmicus are discussed. Nine immunocompromised patients received intravenous adenine arabinoside (vidarabine) or acycloguanosine (acyclovir), and no cutaneous or visceral spread occurred in these patients.

Encephalopathy and neuropathy following ingestion of a Chinese herbal broth containing podophyllin

Two patients developed podophyllin intoxication following ingestion of a broth of the Chinese herb guijiu. The neurological manifestations are described and the pathology of the peripheral neuropathy is fully documented with ultrastructural and quantitative studies.

Huntington's disease in Chinese: a hypothesis of its origin.

The period prevalence (1984-91) of Huntingtons disease (HD) in Hong Kong Chinese was 3.7 per million population. HD patients in Mainland China and Hong Kong showed similar hereditary pattern, clinical and pathological features as in the West. Chinese HD patients were male predominant with a younger age of onset and death. Their ancestral origin could be traced mostly to the coastal provinces of China. It is proposed that Chinese HD patients may have a European origin and share the same gene pool as their white counterparts.

Cerebral radionecrosis: is surgery necessary?

Seven patients with cerebral necrosis after radiotherapy for carcinoma of the nasopharynx are presented. The clinical features included seizures and a varying degree of intellectual impairment. In spite of significant mass effect on CT scan, the patients remained alert, ambulatory and independent. We believe that some cases of cerebral necrosis following radiotherapy for extra-cranial neoplasms present in a more benign fashion than has been portrayed in the literature, and in the absence of clinical evidence of raised intracranial pressure, surgical intervention is unnecessary. The importance of careful fractionation of an optimum radiation dose as a preventive measure is emphasised.

High dose ketoconazole in the treatment of cerebral aspergilloma

A 32-year-old Chinese woman with bilateral occipital aspergilloma was treated successfully with high dose ketoconazole (1200 mg/day) for six months in conjunction with amphotericin B and 5-fluorocytosine. No unacceptable side effects occurred. The use of high dose ketoconazole could be considered in CNS aspergillosis unresponsive to conventional anti-fungal therapy.

Lacunar syndromes due to brainstem infarct and haemorrhage.

Nine patients with brainstem infarct and two with brainstem haemorrhage presented with pure motor stroke, pure supranuclear facial palsy, sensorimotor stroke or ataxic hemiparesis. Despite the clinical similarity with hemispheric lacunes, brainstem infarcts causing lacunar syndromes probably have a greater tendency to progress. Small brainstem haemorrhages should also be considered as a cause of lacunar syndromes and the difficulty in differentiating them from small infarcts without CT is emphasised.

No apparent association between HLA and multiple sclerosis in southern Chinese.

HLA-A, -B and -DR antigens have been studied in 34 Chinese patients with multiple sclerosis and 100 normal healthy controls. Unlike patients of other ethnic groups in whom multiple sclerosis is associated with HLA-DR2, there was no obvious association with any HLA antigen in the Chinese patients, although the overall distribution of antigens did not appear typical of the southern Chinese population from which the patients were drawn.

Interaction between carbamazepine and dextropropoxyphene.

Serious side effects may result from the concurrent administration of the usual dosage of carbamazepine and dextropropoxyphene. Three cases are reported and the mechanisms and implications discussed.

Fatal bilateral vertebral artery dissection in a patient with cystic medial necrosis

A 38-year-old man experienced severe neck pain while playing badminton. This was followed by symptoms of vertebrobasilar ischaemia, seizure and coma. Autopsy showed bilateral vertebral artery dissection and cystic medial necrosis.