Sixteen cases of vascular headache of the migraine type are referred in whom marked neurological manifestations occurred in a unilateral distribution as part of a migraine attack ("complicated migraine"). The neurologic disorders observed, in order of frequency, include 10 cases of motor hemiparesis, 3 cases of unilateral cerebellar syndrome, 1 case of sensory-motor hemiparesis and 1 case showing signs of the involvement of the motor nuclei of the bulb. The recovery of the motor, sensory, cerebellar and brainstem defects was very slow (average duration: 44.25 days; mode: 14 days) in twelve cases. Two patients showed residual neurological signs respectively after 1 and 7 years from the migraine attack. The patients histories indicate classic or common migraine with a relatively high frequency (80% of the patients experienced one or more crises per month). The most of cases (75%) were female patients. The patients, at time of the attack of complicated migraine, had a mean age years of 32. In ten cases first-grade relatives suffered from classic or common migraine; in no case was there any report of associated or complicated migraine among the relatives. In 4 of the 16 cases the CT scan showed an area of hypodensity consistent to the region of the brain expected to be suffering in view of the clinical type of neurological defect. The Authors take into consideration the controversial relation between complicated migraine with slow or incomplete resolution of neurologic signs and focal brain ischemia due to atherothrombotic infarct, pointing out that the present state of knowledge prevents the reaching of final conclusions.(ABSTRACT TRUNCATED AT 250 WORDS)
Electrophysiological findings in 14 patients with non-Friedreich early onset cerebellar ataxia are reported. Nerve conduction studies showed reduction of sensory action potential amplitudes in 7 cases associated in 3 with a decrease of sensory conduction velocities. Six subjects also exhibited a chronic neurogenic pattern to standard needle electromyography. Motor conduction velocities were normal in all cases; only two cases showed an increase in distal motor latencies. Short-latency somatosensory evoked potentials following median nerve stimulation revealed a prolonged central conduction time (N13-N20 interpeak latency) in 7 cases, compatible with supraspinal damage of the somatosensory pathways. These electrophysiological data are compared with those obtained in two reference groups of patients, respectively affected by Friedreich's ataxia and olivo-ponto-cerebellar atrophy.
The aim of the present study was to investigate the effects of spinal recurrent inhibition on human motoneurone discharge patterns. The tonic discharge activity of motor unit pairs was recorded in the extensor carpi radialis (ECR) and abductor digiti minimi (ADM) muscles during voluntary isometric contraction. While undergoing continuous intravenous saline (NaCl 0.9 %) perfusion, the subjects were given a short lasting injection of L-acetylcarnitine (L-Ac), which has been found to potentiate recurrent inhibition in humans. The variability, synchronization and coherence of the motor unit discharges were analysed during four successive test periods (lasting 2-3 min each). A significant decrease in the inter-spike interval (ISI) coefficient of variation was observed in the discharge patterns of the motor units tested in the ECR and not in the ADM, which were not accompanied by any consistent changes in the mean ISIs of the motor unit activity in either muscle. The L-Ac injection also led to a significant increase in the synchronization in half of the motor unit pairs tested in the ECR muscle (n = 29), whereas no consistent changes were observed with the ADM motor units (n = 25). However, coherence analysis failed to reveal any consistent differences in the incidence of significant values of coherence spectrum between the pre-injection and injection periods among the motor unit pairs tested with either saline or L-Ac injections, in either the ECR or ADM muscles. The contrasting effects on the variability and the synchronization of the motor unit discharges observed with ECR motoneurones known to undergo recurrent inhibition and with ADM motoneurones known to lack recurrent inhibition suggest that the drug may have specific effects which are mediated by an enhancement of the Renshaw cell activity. The decrease in the ISI variability is in line with the hypothesis that recurrent inhibition may contribute along with the post-spike after-hyperpolarization to limiting the influence of the synaptic noise on the firing times of steadily discharging motoneurones. The present data, which suggest that recurrent inhibition plays a synchronizing rather than a desynchronizing role, are in keeping with the fact that the Renshaw cells may provide an important source of common inhibitory inputs.
