Chronic meningitis in Thailand. Clinical characteristics, laboratory data and outcome in patients with specific reference to tuberculosis and cryptococcosis.

The charts of 114 consecutive patients with chronic meningitis admitted to a general hospital in Bangkok, Thailand, between 1993 and 1999 were retrospectively reviewed. The most common causative agents were Cryptococcus neoformans (54%) and Mycobacterium tuberculosis (37%). HIV and other underlying diseases had a major impact on the presentation of chronic cryptococcal meningitis patients. Compared to HIV-negative cryptococcal meningitis patients (21%), HIV-positives (79%) had a significantly lower incidence of focal signs (p = 0.02), hydrocephalus (p = 0.03) and seizures (p = 0.001) during hospital stay, furthermore, a lower leucocyte level, a significantly higher glucose level (p = 0.02) and a lower protein level (p = 0.03) in the first cerebrospinal fluid examination. Of the 43 patients with chronic tuberculous meningitis, only 3 were HIV positive. Focal neurologic deficits were found more frequently in tuberculous meningitis patients (p = 0.001) when compared to cryptococcal meningitis patients without HIV. Cerebral infarction on cerebral CT was indicative of tuberculous meningitis. Cryptococcal meningitis patients with HIV infection had a worse outcome compared to non-AIDS patients. Advanced stage of the disease on admission, decreased level of consciousness prior to and on the admission day and raised intracranial pressure above 40 cm H(2)O at any given time were predictive of a poor outcome in tuberculous meningitis patients.

Long-term follow-up of myasthenia gravis patients with hyperthyroidism.

OBJECTIVE: To access clinical characteristics and treatment outcome of myasthenia gravis (MG) patients with hyperthyroidism (HT). MATERIALS AND METHODS: The clinical characteristics of 51 MG patients with HT were studied. The treatment outcome was analysed in 34 patients, comparing high-dosage prednisolone (HDP) (group IS), HDP and/or immunosuppressants with antithyroid drugs (group IS + antiHThyr), antithyroid drugs (group antiHThyr), and thymectomy. RESULTS: The prevalence of HT in MG was 17.5%. Group IS showed higher remission of both diseases compared with group antiHThyr, but not with group IS + antiHThyr. Remission of HT and relapse of both diseases showed no difference among the three groups. Ten patients who had thymectomies had a lower relapse of MG but not of HT, whilst remission of both diseases was no different to 24 non-thymectomy patients. CONCLUSION: This study showed a high prevalence of HT in Thai MG. HDP alone can induce remission of both diseases without difference in relapse. Thymectomy lowers MG relapse further but has no influence on HT.

Regional curare test in the study of neuromuscular transmission in hyperthyroidism.

The findings in this study suggest that there is defect in the neuromuscular transmission in hyperthyroidism. This abnormality was detected in 62 per cent of the patients and did not directly correlate with proximal muscle weakness present in most of the patients. It seems that the weakness in hyperthyroidism is the result of myopathy as well as neuromuscular transmission both of which might be due to the same metabolic derangement but are not directly related. After treatment, the muscle power became normal in all of the patients and the neuromuscular transmission was normalized in most but not all of them. It is possible that this transmission defect may be due to other mechanisms apart from the hormonal disorder e.g. the same processes as that which occurs in myasthenia gravis. The underlying pathophysiology is worth further exploration.

Rapid diagnosis of rabies and post-vaccinal encephalitides.

In an attempt to establish the diagnoses of rabies post-vaccinal encephalitis (PVE) and early rabies encephalitis, paired serum and CSF levels of rabies neutralizing antibody (Rab) and rabies specific-IgM (RIgM) were compared in 12 PVE, 10 rabies and five control patients with similar presenting clinical features. Rapid methods of rabies antigen detection were evaluated in 17 patients. All 12 PVE patients had Rab in their serum and in eight it was also present in the CSF. These same eight had RIgM in the serum, and in seven also in the CSF. The CSF antibodies may have originated in the plasma since six patients had a high albumin quotient indicating leakage across the blood-brain barrier. Among the rabies patients, only the two vaccinated ones had serum Rab; this was also detected in the CSF of one and RIgM was in the CSF of the other. A raised IgG Index, indicating intrathecal synthesis of IgG was seen in five of 12 PVE patients. This did not correlate with the presence of CSF rabies antibody, suggesting production of antibody to other vaccine antigens of neural origin. The diagnosis of rabies encephalitis in life was made by antigen detection in a skin biopsy. No false positive results occurred and the method was as efficient as immunofluorescence of a post-mortem brain biopsy.

Parasitic diseases of the nervous system in Thailand.

In Thailand there are 3 parasites that commonly cause neurological diseases in man. 1) In gnathostomiasis man becomes an accidental host by eating infected under-cooked fresh water fish. The tissue nematode involved, Gnathostoma spinigerum, because of its high motility, may cause widespread damage in the spinal cord and brain stem. The common presenting neurological symptoms are severe nerve root pain, paralysis of limbs and urinary retention. Less frequently seen are cranial nerve palsies and symptoms of subarachnoid haemorrhage. The disease has significant morbidity and mortality. 2) Eosinophilic meningitis caused by Angiostrongylus cantonensis, the lungworm of rats, has a more benign, self limiting course. It occurs in Thai people of lower socio-economic groups who acquire the parasite by eating infected raw Pila snails. 3) Cysticercus cellulosae, caused by Taenia solium, commonly results in epilepsy, and sometimes increased intracranial pressure from intraventricular obstruction or from basal arachnoiditis. Spinal cord and cauda equina involvement occurs much less frequently. Cysticercus complement fixation tests on the CSF and computerised axial tomography have been found to be of great diagnostic value.