Studies in man of phenytoin absorption and its implications.Gibberd, F B; Webley, M
doi: 10.1136/jnnp.38.3.219pmid: 1151402
The absorption of phenytoin was studied in man. It is concluded that phenytoin absorbed from the intestine is recirculated via the bile, so that blood levels do not accurately reflect absorption. Phenytoin is loosely bound to serum proteins and is found in red cells in concentrations similar to those in plasma. It is rapidly lost from the blood stream after intravenous administration, which is an important factor to be considered in the treatment of status epilepticus.
Amphetamines in the treatment of Parkinson's disease.Parkes, J D; Tarsy, D; Marsden, C D; Bovill, K T; Phipps, J A; Rose, P; Asselman, P
doi: 10.1136/jnnp.38.3.232pmid: 1097600
Twenty-two patients with Parkinsonism were treated with levoamphetamine and 12 of these with dextroamphetamine. Levoamphetamine resulted in a significant improvement in disability from Parkinsonism, although the reduction in total disability, tremor, akinesia, and rigidity scores was slight (ca 20 percent). Dextroamphetamine in lower dosage also reduced disability by some 17 percent. The most disabled patients, including those also on levodopa, showed the greatest response to amphetamines. Previously, amphetamines have been reported to be a selective treatment for the oculogyric crises of post-encephalitic Parkinsonism. Amphetamines are thought to cause the release of catecholamines from central neurones. Their action in Parkinson's disease may be limited because of pre-existing striatal dopamine deficiency. Side-effects of amphetamines, anorexia, and CNS stimulation are different from those caused by levodopa in patients with Parkinson's disease.
Pallido-pyramidal syndrome treated with levodopa.Horowitz, G; Greenberg, J
doi: 10.1136/jnnp.38.3.238pmid: 1151403
Two siblings are reported who developed classical signs and symptoms of Parkinsonism in the first decade of life. In addition, they had evidence of cortical spinal tract disease, thus putting them in the category of Davison's pallido-pyramidal syndrome. Both deteriorated to the point of a non-productive existence until the institution of levodopa treatment, at the ages of 18 and 20 years. The response of the extrapyramidal signs plus the lack of response of the pyramidal tract signs demonstrate the specificity of a pharmacological agent in certain areas of the nervous system. The rapid response of the female patient to very low doses of levodopa is unusual in our experience. Both patients have remained well for eight months after initiation of treatment.
Myxoedematous polyneuropathy: a light and electron microscopic study of the peripheral nerve and muscle.Shirabe, T; Tawara, S; Terao, A; Araki, S
doi: 10.1136/jnnp.38.3.241pmid: 168317
Histopathological findings of biopsied peripheral nerve and muscle were studied in a case with myxoedematous polyneuropathy. The most striking findings in the sural nerve were segmental demyelination and onion bulb formation with scanty mucinous deposits in addition to marked loss of large myelinated nerve fibres. The peroneus brevis muscle revealed the association of neuropathic and myopathic changes. It is suggested that myxoedematous polyneuropathy might be intrinsic neuropathy due to metabolic disorder of Schwann cells related to hypothyroidism, resulting in segmental demyelination, not merely compressive neuropathy due to mucinous deposits in the peripheral nerves.
Electrophysiological findings in diphenyl poisoning.Seppäläinen, A M; Häkkinen, I
doi: 10.1136/jnnp.38.3.248pmid: 1151404
The fungistatic agent diphenyl caused fatal poisoning with signs of neurotoxicity in a worker in a Finnish paper mill. This initiated a neurophysiological study of 24 workers occupationally exposed to diphenyl. Ten men showed EEG abnormalities, mainly diffuse or generalized ones. The abnormalities persisted on re-examination one and two years later. Nine subjects had EMG abnormalities; seven also exhibited fibrillations in some muscles. One subject showed a long rhythmic series of fasciculations similar to the spontaneous activity described in infantile spinal muscular atrophy. Nerve conduction velocity, especially that of slower motor fibres, was reduced in several cases. Electroneuromyographic abnormalities also persisted on re-examination. Although diphenyl is considered a comparatively safe chemical, it showed evidence of neurotoxicity when workers were exposed to concentrations in excess of the presently accepted threshold limits. Electrophysiological methods should be applied for the early detection of occupational hazards.
Intention tremor--a method of measurement.Morgan, M H; Hewer, R L; Cooper, R
doi: 10.1136/jnnp.38.3.253pmid: 1151405
A method of measuring and analysing intention tremor using a linear accelerometer is described. Reasons are given for measuring this particular parameter of the tremor, for using this specific energy conversion device, and for employing the particular form of analysis. A comparison of the numerical values obtained for the amount of tremor activity, compared with a corresponding clinical grading, is made for 30 patients with intention tremor due to a variety of pathological causes. It is shown that the method gives clear correlation with the clinical assessments, although certain discrepancies are noted, and their importance discussed.