Nerve conduction velocity distribution (CVD) study is a newly-developed electrodiagnostic method for detecting alterations in the composition of nerve fibres according to their conduction velocity. The presence of subclinical neuropathy was evaluated in 138 diabetic patients by CVD study of four motor nerves (external popliteal and ulnar nerves bilaterally) and two sensory nerves (median nerve bilaterally), and the data obtained were compared with standard electrophysiological parameters in the same nerve segments. CVD studies revealed an altered distribution pattern in 106 of 129 evaluable patients for motor nerves (82%) and in 67 of 115 evaluable patients for sensory nerves (58%), while standard examination gave abnormal findings in 92 of 137 patients (67%) and in 33 of 118 patients (11%), respectively. Of the patients adequately evaluated by both techniques, 21 of 129 patients (16%) revealed altered CVD data unaccompanied by slowing of maximum nerve conduction velocity, and 37 patients of 101 (37%) showed similar findings for sensory nerves. Subclinical alterations of motor and sensory nerve CVD were not significantly related to age or to metabolic control expressed as glycated haemoglobin levels; a significantly longer duration of disease was found in patients with motor and mixed subclinical neuropathy with respect to non-neuropathic patients. The CVD study allowed us to detect subclinical abnormalities of motor and sensory nerve fibres; often this is a more sensitive method than the standard electrodiagnostic study. This method can be very useful as a diagnostic tool and in research in the study of the progression of diabetic neuropathy.

The sympathetic skin response (SSR), evoked from the middle finger of both hands by electrical stimuli to the median nerve (MN) at the wrist, was studied in 21 patients with bilateral carpal tunnel syndrome (CTS) and in 16 patients with monolateral CTS (14 at the right and 2 at the left side) without clinical signs of autonomic involvement. In monolateral and bilateral CTS there was a decrease in the SSR areas of both sides. In monolateral CTS the decrease was greater contralaterally to the lesion. A decrease in the SSR in CTS generally indicates a local blockade of sympathetic nerve excitability due to MN entrapment. Contralateral reduction of the sympathetic response suggests an involvement of the efferent pathway of the autonomic reflex far from the lesion at the wrist. However, dispersion of the excitement over a long distance and throughout numerous synaptic connections may affect contralateral more than homolateral SSR excitability. Finally, sympathetic damage in CTS is in accord with the anatomofunctional correlation (in the peripheral nerve and ganglia) between somatic sensory, which were most markedly involved in our patients, and sympathetic afferent nerve fibers.

Asymptomatic cysts of the pineal region are common incidental findings in adults. In contrast, symptomatic pineal cysts are rare and their management is not well defined. We present the case of a 39-year-old woman suffering from intracranial hypertension, with visual disturbance and mild papilledema. The MR images showed a voluminous cyst of the pineal region responsible for an obstructive hydrocephalus. Endoscopic treatment with the aid of computerized neuronavigation consisting in third ventriculostomy and fenestration of the cyst was performed. Intracranial hypertension symptoms resolved in 24 hours. The one year follow-up cerebral MR images demonstrated the normalization of ventricular size with patency of the aqueduct of Sylvius. Reviewing the literature demonstrates that the endoscopic approach represents a minimally invasive and safe procedure in the treatment of symptomatic pineal cysts.

The case of a patient who had a relapse of cerebral Whipple's disease (WD) one year after discontinuation of a two-years' antibiotic treatment is reported. Neither the clinical course nor the results of magnetic resonance imaging (MRI) and routine examination of the cerebrospinal fluid (CSF) allowed the caring physician to predict the relapse. Retrospective analysis of serial specimens of CSF showed that slight CSF leucocytosis and intrathecal synthesis of IgA might have suggested persistence of infection. The decision to stop antibiotic therapy in cerebral WD is difficult, but evaluation of cell counts and of intrathecal synthesis of IgA may help in the decision. Some patients may need to take treatment indefinitely.

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