The locations of cerebral infarctions were studied in 14 patients with tuberculous meningitis (TBM) and 173 patients with noninflammatory ischemic stroke (IS). In patients with TBM, 75% of infarctions occurred in the "TB zone" supplied by medial striate and thalamoperforating arteries; only 11% occurred in the "IS zone" supplied by lateral striate, anterior choroidal and thalamogeniculate arteries. In patients with IS, 29% of infarctions occurred in the IS zone, 29% in the subcortical white matter, and 24% in (or involving) the cerebral cortex. Only 11% occurred in the TB zone. Bilaterally symmetrical infarctions of the TB zone were common with TBM (71%) but rare with IS (5%).

Peripheral neuropathy is an important factor of disability in the elderly. In order to learn more on the usefulness of intensive evaluation of patients over 65 years of age with subacute or chronic disabling peripheral neuropathy, we reviewed the clinical and nerve biopsy findings of the last 100 patients of this age group who suffered from a peripheral neuropathy severe enough to justify performance of a nerve biopsy for a diagnostic or prognostic purpose. Normal nerve biopsy findings led to the diagnosis of lower motor neuron disease in three patients and pointed to lesions of the spinal roots in six other patients. Necrotizing arteritis was demonstrated in the biopsy specimens of 23 patients, and non-necrotizing vasculitis in five. In five additional patients the diagnosis of vasculitic neuropathy was kept in spite of non-contributive biopsy findings. In two diabetic patients who had a multifocal neuropathy the biopsy also revealed the presence of vasculitis. Thus 35% of the patients included in this series had one form or another of vasculitic neuropathy. Fourteen patients had a chronic inflammatory demyelinating polyneuropathy. In 11 patients the neuropathy was associated with monoclonal gammopathy, which was benign in nine and associated with malignant plasma cell dyscrasia in two. Among the six patients with diabetes mellitus, two patients who presented with a multifocal neuropathy were found to have vasculitis in the nerve specimen; in the others the biopsy was performed because of uncommonly severe pains or motor involvement due to an extremely severe diabetic neuropathy. Six patients suffered from a long-lasting disability secondary to a drug-induced neuropathy. The remaining 15% had neuropathies of different origin, including amyloidosis, lepromatous leprosy, carcinomatous neuropathy and alcoholic neuropathy. Six patients had a mild, non-progressive or slowly progressive axonopathy of unknown origin, ageing of the peripheral nervous system may have played a role in its development. Our findings show that vasculitis is an important and treatable cause of disabling neuropathy in the elderly and that the proportion of patients with severe neuropathy of unknown origin is small.

1. Interneurones mediating reciprocal inhibition between wrist flexors and extensors in man are characterized using both Renshaw cells and transarticular group I afferent activation. 2. Renshaw cells were activated by reflex discharges evoked by a tendon tap. The tendon tap was applied to the tendon of the muscles from which the Ia fibres responsible for the reciprocal inhibition originated. Contrary to what was observed both in the cat hindlimb and in human elbow muscles, this Renshaw cell activation never resulted in a long depression of the reciprocal inhibition between wrist flexors and extensors. 3. Convergence from group I elbow muscle afferents and antagonistic group I afferents onto interneurones mediating reciprocal inhibition between wrist muscles was revealed in post‐stimulus time histogram (PSTH) experiments using the technique of spatial facilitation. 4. The characteristics of the interneurones mediating reciprocal inhibition between wrist flexors and extensors could therefore be summarized as follows: (a) they are fed by antagonistic group I afferents and group I afferents originating from both flexor and extensor elbow muscles; (b) they are not inhibited by Renshaw cells; (c) they are not excited by low threshold cutaneous afferents; and (d) they are probably interposed in a disynaptic pathway. 5. It is therefore concluded that interneurones mediating reciprocal inhibition between wrist flexors and extensors in man differ both from Ia interneurones and from interneurones interposed in the Ib reflex pathways and these characteristics are related to the complex circumduction movements developed in the wrist.

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High-performance liquid chromatography with electrochemical detection has been employed to analyze ultrafiltrates of cerebrospinal fluid of Parkinson's Disease (PD) patients and age-matched controls for the dopamine (DA) metabolites homovanillic acid (HVA) and 5-S-cysteinyldopamine (5-S-CyS-DA). The mean level of HVA in the CSF of PD patients, measured 5 days after withdrawal from L-DOPA therapy, was significantly lower than that measured in controls. By contrast, mean levels of 5-S-CyS-DA were not significantly different in the CSF of PD patients taking L-DOPA (PD-LT patients) the same patients 5 days after discontinuing this drug (PD-LW patients) or controls. However, the mean 5-S-CyS-DA/HVA concentration ratio was significantly (p < 0.05) higher in the CSF of PD-LW patients compared to controls. Although the PD patient population employed in this study had been diagnosed with the disease several years previously and had been treated with L-DOPA for prolonged periods of time the results of this study suggest that low CSF levels of HVA and a high 5-S-CyS-DA/HVA ratio together might represent useful markers for early diagnosis of PD. The high 5-S-CyS-DA/HVA ratio observed in the CSF of PD-LW patients also provides support for the hypothesis that the translocation of glutathione or L-cysteine into neuromelanin-pigmented dopaminergic cell bodies in the substantia nigra might represent an early event in the pathogenesis of PD.