Hypersynchronous delta sleep EEG activity and sudden arousals from slow-wave sleep in adults without a history of parasomnias: clinical and forensic implications.
OBJECTIVE
To determine the frequency of classical markers of non-rapid eye movement (NREM) parasomnias--hypersynchronous delta sleep (HSD) electroencephalogram waves and sudden arousals from slow-wave sleep (SWS)--in patients without histories of somnambulism or other NREM parasomnias.


METHODS
Retrospective review.


METHODS
Sleep disorders center laboratory.


METHODS
82 consecutive patients without a history of parasomnias who underwent diagnostic polysomnograms; 57 men and 25 women, mean age 48+/-13.3 years, were included without regard to diagnosis or findings. All patients had at least 30 seconds of stage 3 or 4 sleep during the polysomnogram.


RESULTS
The primary diagnosis of all but 4 patients was obstructive sleep apnea (mean respiratory disturbance index, 30 +/- 23.6 [range, 2.7-117] per hour of sleep). Polysomnograms were then reviewed for the presence of HSD and SWS arousals. A total of 235 arousals (mean, 2.9 +/- 2.7; range, 0-14) from stage 3 or 4 sleep were noted. Eight-five percent of all patients had at least 1 SWS arousal and 45% had 3 or more SWS arousals; 85.1% of all arousals from SWS were secondary to sleep-disordered breathing, and 5.9% were secondary to leg movements. At least 1 episode of HSD (mean, 1.4 +/- 1.6; range, 0-9) was noted in 65.8% of patients.


CONCLUSIONS
HSD and SWS arousals were a common finding in patients without clinical histories of sleepwalking or other parasomnias but who were found to have frequent respiratory-related arousals during sleep. HSD and SWS arousals thus have a low specificity for NREM parasomnias and, without further research, are not useful for the objective confirmation of parasomnias in clinical evaluations and in the forensic evaluation of sleepwalking as a legal defense.
Sleep Medicine Services, Division of Pulmonary and Critical Care Medicine, Department of Medicine, The Lankenau Hospital and Medical Research Center, Wynnewood, Pennsylvania, USA. pressmanm@mlhs.org
Mark R
MR
Pressman
D001143:Arousal / Q000502:physiology*; D003344:Cortical Synchronization / Q000295:instrumentation; D003700:Delta Rhythm; D004569:Electroencephalography; D004576:Electromyography; D005260:Female; D005555:Forensic Psychiatry; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012189:Retrospective Studies; D012890:Sleep / Q000502:physiology*; D012891:Sleep Apnea Syndromes / Q000175:diagnosis