1,721,026 research outputs found
Malattia del motoneurone
No full textPer Malattia del Motoneurone (MN) s’intende un insieme eterogeneo di patologie caratterizzate da una degenerazione primaria, con andamento progressivo, del I neurone di moto (centrale) e/o del II (periferico). Possono essere individuate 4 forme di MN: la sclerosi laterale amiotrofica (SLA), la sclerosi laterale primaria, l’atrofia muscolare progressiva e la paralisi bulbare progressiva. Nella SLA si verifica il coinvolgimento contemporaneo del I e II motoneurone. Le altre forme prevedono il coinvolgimento di un solo MN, superiore o inferiore (sclerosi laterale primaria o atrofia muscolare progressiva rispettivamente)
Reciprocal inhibition in co-contracting forearm muscles during suppression of motor cortical output: evidence suggesting that the central command for decreased reciprocal inhibition is uncoupled from motor cortical activity
No full textELECTROMYOGRAPHIC SILENT PERIOD AFTER TRANSCRANIAL BRAIN-STIMULATION IN HUNTINGTONS-DISEASE
No full textThe silent period evoked by transcranial (TCS) and nerve stimulation was studied in the hand muscles in 13 patients with Huntington's disease and in 11 normal subjects. The duration of the silent period after TCS was longer in patients and correlated significantly with the severity of chorea; in contrast, the duration of the silent period after nerve stimulation was similar in patients and controls. The prolongation of the cortical silent period suggests that the duration of the silent period is a functional correlate reflecting basal ganglia influence over the motor cortex
THE EFFECT OF HYPERVENTILATION ON MOTOR CORTICAL INHIBITION IN HUMANS - A STUDY OF THE ELECTROMYOGRAPHIC SILENT PERIOD EVOKED BY TRANSCRANIAL BRAIN-STIMULATION
No full textWe studied the effects of hyperventilation under control of the end-tidal PCO2, on the electromyographic silent period evoked by transcranial magnetic brain stimulation and by peripheral nerve stimulation. We also studied the effects of hyperventilation on the threshold, latency and amplitude of motor potentials. Hyperventilation significantly reduced the duration of the cortical silent period, but did not affect the length of the peripheral silent period. Neither did it alter the latency, amplitude or threshold of the motor potentials. These findings suggest that hyperventilation selectively depresses motor cortical inhibition in humans
MOTOR CORTICAL INHIBITION AND THE DOPAMINERGIC SYSTEM - PHARMACOLOGICAL CHANGES IN THE SILENT PERIOD AFTER TRANSCRANIAL BRAIN-STIMULATION IN NORMAL SUBJECTS, PATIENTS WITH PARKINSONS-DISEASE AND DRUG-INDUCED PARKINSONISM
No full textThe silent period after contralateral and ipsilateral transcranial magnetic brain stimulation was studied in patients with Parkinson's disease before and after dopaminergic and anticholinergic therapy; in normal subjects before and after L-dopa administration and in patients with drug-induced parkinsonism. inpatients and normal subjects the silent period was also studied after peripheral nerve stimulation. The silent period after transcranial cortical stimulation was shorter in Parkinson's disease patients than in normal subjects. inpatients with Parkinson's disease L-dopa prolonged the silent period after transcranial brain stimulation and after ipsilateral cortical stimulation. Biperiden prolonged the silent period after transcranial brain stimulation. rn normal subjects, L-dopa produced similar but smaller changes. In the patients with drug-induced parkinsonism the silent period after transcranial magnetic stimulation was shorter than normal subjects. The peripheral silent period was similar in normal subjects and in patients and did not change after drug administration. In conclusion cortical silent period is abnormal in patients with Parkinson's disease and drug-induced parkinsonism. Dopaminergic drugs modulate the duration of the cortical silent periods in patients and in normal subjects, through mechanisms acting mainly at basal ganglia and possibly also directly at cortical level
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