Excessive daytime sleepiness (EDS) is, in its consequences, a major
problem for the patient and for the society. EDS is mainly caused by night-time sleep disorders, in particular: the sleep apnoea syndrome (SAS) and periodic limb movements in sleep (PLMS). Our study was designed for finding out a) if there is a correlation between the gravity of the two conditions and the degree of EDS in patients with SAS and those with SAS and PLMS combined, and b) if EDS in the SAS+PLMS group is greater than in patients with the SAS alone. 35 patients with SAS and 10 with SAS+PLMS were examined using nocturnal polysomnography (PSG) and the multiple sleep latency test (MSLT).
As for SAS, no correlation was found between EDS and the gravity of the condition. On the other hand, PLMS was found correlated to the mean sleep latency value. A correlation between the gravity of the disease and the reduced TST, SE and the sleep stages under study was corroborated for both groups. In addition, both conditions were found to interfere with the sleep architecture more than the SAS alone. This noctural sleep disturbance, though, would stop short of raising the mean sleep latency tested in the MLST. Correlations were found in SAS between the age and 2NREM latency and between the latter and average sleep latency. In the MSLT, the groups showed no difference as to the mean sleep latencies.