Changes in sleep spindle activity of subjects with chronic somatosensitive and sensorial deficits. Preliminary results

We investigated the effects of the somatosensitive and sensory afferent inputs on the thalamic generators of sleep spindles (SS) in adult subjects affected by posterior funiculi lesions (five subjects), deafness (four subjects) or blindness (four subjects). The density, duration and frequency of SS, as well as the index of spindling, were analyzed during stage 2 NREM. The results show that the subjects with somatosensitive and sensorial lesions spent much more time on SS activity than the control group (eight subjects), and had a significantly increased density (<.0001), duration (<.0005) and index of spindling (<.0001). On the other hand, the frequency of spindling was little modified (<.05). Moreover, among the three groups of patients, those with somatosensitive deficits showed the greatest SS activity. In conclusion, our results suggest that the thalamic generators of SS are markedly modulated by peripheral inputs in man.SommarioGli effetti delle afferenze somatosensitive e sensoriali sui generatori talamici dei fusi del sonno sono stati studiati in soggetti adulti con lesioni dei cordoni posteriori (5 soggetti), con cofosi (4 soggetti) e con cecità (4 soggetti). La densità, la durata, la frequenza ed un indice dell'attività fusale sono stati analizzati durante lo stadio 2 NREM. I risultati mostrano che i soggetti con lesioni somatosensitive e sensoriali hanno prodotto un'attività fusale superiore al gruppo di controllo (otto soggetti) con un incremento particolarmente significativo della densità (<.0001) della durata (<.0005) e dell'indice (<.0001) dell'attività fusale. Al contrario la frequenza è stata scarsamente modificata (<.05). Inoltre, fre i tre tipi di pazienti, quelli con deficit somatosensitivi hanno mostrato i valori più elevati di attività fusale. In conclusione i nostri risultati suggeriscono che, nell'uomo, i generatori talamici del sonno sono marcatamente modulati dalle afferenze periferiche.

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