Sleep structure and nocturnal disordered breathing in familial dysautonomia

In 13 patients with familial dysautonomia sleep recordings were obtained to investigate the possibility that autonomic nervous system dysfunction plays a role in disordered breathing during sleep. Sleep structure in some of our patients was abnormal, showing decreased amount of REM sleep and increased REM latencies. All patients showed breathing disorders in sleep. The average number of apneic spells was 73.4 per night; 77% of the patients had more than 50 apneic spells per night. Abnormal breathing patterns were not uniform and were independent of patient's primary complaints. Typically, even severe respiratory irregularities were not associated with the usual cardiac response, indicating that our patients had "cardiac dysautonomia".