. Motor learning and memory consolidation require the contribution of different cortices. For motor sequence learning, the primary motor cortex is involved primarily in its acquisition. Premotor areas might be important for consolidation. In accordance, modulation of cortical excitability via transcranial DC stimulation (tDCS) during learning affects performance when applied to the primary motor cortex, but not premotor cortex. We aimed to explore whether premotor tDCS influences task performance during motor memory consolidation. The impact of excitability-enhancing, -diminishing, or placebo premotor tDCS during rapid eye movement (REM) sleep on recall in the serial reaction time task (SRTT) was explored in healthy humans. The motor task was learned in the evening. Recall was performed immediately after tDCS or the following morning. In two separate control experiments, excitability-enhancing premotor tDCS was performed 4 h after task learning during daytime or immediately before conduction of a simple reaction time task. Excitability-enhancing tDCS performed during REM sleep increased recall of the learned movement sequences, when tested immediately after stimulation. REM density was enhanced by excitability-increasing tDCS and reduced by inhibitory tDCS, but did not correlate with task performance. In the control experiments, tDCS did not improve performance. We conclude that the premotor cortex is involved in motor memory consolidation during REM sleep.

Question of the Study The aim of the study was to ascertain the connection between sleep respiratory disturbances and interictal epileptiform patterns in patients with obstructive sleep apnoea syndrome (OSAS) and epilepsy. Patients and Methods A total of 17 patients (4 women, 13 men) with OSAS and epilepsy underwent nocturnal polysomnography. The patients' mean age was 38.5 years (range: 18-60 years). At least two nocturnal generalized tonic-clonic seizures during the night were established from their personal history. The mean treatment duration of antiepileptic therapy was 11 years (range: 3-24 years). Results All patients had polysomnographically established very poor sleep architecture with multiple arousal reactions or awakenings, reduced slow-wave sleep and REM sleep reduction, and highly significantly represented wakefulness. A total of seven patients (mean apnoea-hypopnoea index was 15, ranging from 8 to 31) had an interictal epileptiform pattern per polysomnography recording. Twenty-four per cent of the 6435 recorded interictal epileptiform discharges (IEDs) was in connection with respiratory disturbances. In 87 % (675) of respiratory disturbances, interictal epileptiform patterns were recorded. Furthermore, a significant difference in the number of IEDs between respiratory disturbance (RD) intervals and control intervals was established. Conclusions These findings support the hypothesis that RD during sleep might trigger interictal epileptiform EEG symptoms.Keywords OSAS -epilepsy -interictal epileptiform discharges. ZusammenfassungEinfü hrung Ziel war die Darstellung eines Zusammenhangs zwischen schlafbezogenen Atmungsstö rungen und interiktalen epileptiformen Mustern bei Patienten mit OSAS und Epilepsie. Patienten und Methodik Bei insgesamt 17 Patienten (4 Frauen, 13 Männer) mit OSAS und Epilepsie wurde eine nächtliche Polysomnographie durchgefü hrt. Die Patienten waren im Mittel 38,5 Jahre alt (range: 18-60). Bei den Patienten waren mindestens zwei nächtliche generalisierte tonisch klonische Anfälle bekannt. Die Behandlungsdauer mit antikonvulsiven Medikamenten betrug im Mittel 11 Jahre (zwischen 3 und 24 Jahre). Ergebnisse Bei allen Patienten zeigten die Schlafableitungen eine schwache Schlafarchitektur mit multiplen Arousalreaktionen oder häufigem Erwachen mit reduziertem Deltaund REM-Schlaf sowie mit hoch signifikant präsentiertem Wachsein. Bei insgesamt 7 Patienten (AHI im Mittel 15, zwischen 8 und 31) zeigten die polysomnographischen Aufzeichnungen interiktale epileptiforme Muster. 24 % der 6435 registrierten interiktalen epileptiformen Entladungen (IEDs) standen in zeitlicher Verbindung zu Stö rungen der Atmung. Bei 87 % (675) der Atmungsstö rungen wurden interiktale epileptiforme Muster Somnologie 7: 97-100, 2003 registriert, darü ber hinaus wurden signifikante Unterschiede in der Anzahl der IEDs in den Intervallphasen respiratorischer Stö rungen und Kontrollen nachgewiesen. Schlussfolgerung Die Ergebnisse unterstü tzen die Annahme, dass schlafbezogene Atmungsstö rungen interiktale epileptifor...