HLA-DRB1 and multiple sclerosis in Malta.

BACKGROUND: By comparison with the neighboring island of Sicily, the frequency of multiple sclerosis (MS) in Malta is remarkably low. METHODS: To explore whether the relative rarity of MS in Malta might be the result of lower population frequencies of major histocompatibility complex susceptibility alleles, we genotyped the HLA-DRB1 locus in 77 Maltese-born patients (97% of the prevalent unrelated native cases) and 206 Maltese controls. We made comparisons with previously published data for Sicily and other European countries. RESULTS: The anticipated association with HLA-DRB1*15, the main susceptibility allele in most other populations, was confirmed (p(c) = 0.009) but, in addition, we also observed an equally strong, and apparently protective, effect of the HLA-DRB1*11 allele (p(c) = 0.016). In comparison with previously published data from Sicily, we found that all HLA-DRB1 risk alleles were more common in Malta, whereas HLA-DRB1*11 was slightly less common. CONCLUSIONS: The difference in prevalence seen between the neighboring islands of Malta and Sicily cannot be explained by differences in background HLA-DRB1 population allele frequencies, which if anything would predict a higher rate of disease in Malta than in Sicily.

Carbon monoxide poisoning: easy to treat but difficult to recognise.

Carbon monoxide (CO) poisoning is a common medical emergency and a frequent cause of deliberate or accidental death. It can cause acute and chronic central nervous system damage which may be minimised by prompt treatment with 100% oxygen or hyperbaric oxygen therapy. However, recognition of this intoxication can be difficult. Failure to diagnose it may have disastrous effects on the patient, and other members of the household who could subsequently become intoxicated. Guidance on the correct diagnosis of this condition is provided in the light of a number of studies screening emergency room populations. Guidelines for treatment with hyperbaric oxygen therapy are also reviewed.

Stimulus-sensitive spinal myoclonus.

Two cases of spinal myoclonus are described; in both patients myoclonus was responsive to stimuli and absent during sleep. The first patient was considered to have viral neuronitis and the condition resolved spontaneously. The second patient had spinal cord ischaemia; there was electro-physiological evidence of abnormal alpha motor neurone activity and histological study of the spinal cord revealed a severe reduction in small and intermediate neurones. This supports the theory that spinal myoclonus may result from abnormal activity of alpha motor neurones released from control by spinal internuncial neurones.

Plasma DOPA levels and growth hormone response to levodopa in parkinsomism.

It has been suggested that the therapeutic response to levodopa in patients with Parkinson's disease may be related to changes in plasma growth hormone concentration. In order to examine this problem, we have determined plasma DOPA and growth hormone levels after a standard oral levodopa load in 32 patients with Parkinson's disease. Levodopa caused an increase in plasma growth hormone concentration in 30 subjects. The magnitude and timing of this growth hormone response was not related to the clinical response, the presence or absence of response swings, or the occurrence of dyskinesias. The growth hormone response to levodopa is normal in patients with Parkinson's disease and not altered by long-term levodopa treatment.

Bromocriptine treatment in Parkinson's disease.

Thirty-one patients with Parkinson's disease were treated with the ergot alkaloid bromocriptine, a drug which stimulates dopamine receptors. Bromocriptine had a slight therapeutic effect in patients on no other treatment and an additional effect in patients on levodopa. The mean optimum dosage of bromocriptine, established over a 12 week period, was 26 mg daily. In 20 patients bromocriptine was compared with placebo in a double-blind controlled trial. Active treatment caused a significant (P less than 0.02) reduction in total disability and akinesia scores. The least disabled patients showed the greatest response. Side-effects of bromocriptine--nausea, vomiting, hallucinations, and abnormal involuntary movements--were similar to nature to those of levodopa. In most normal subjects, bromocriptine causes an increase in plasma growth hormone concentration. This was determined in 20 patients with Parkinson's disease after 1-15 mg bromocriptine. Only a single patient showed an obvious increase up to 120 minutes after dosage. Bromocriptine was not effective treatment in two patients who had not previously responded to levodopa and replacement of this drug by bromocriptine in patients with end-of-dose akinesia after chronic levodopa treatment did not totally abolish response swings.