NREM arousal parasomnias and their distinction from nocturnal frontal lobe epilepsy: a video EEG analysis.
OBJECTIVE
To describe the semiological features of NREM arousal parasomnias in detail and identify features that can be used to reliably distinguish parasomnias from nocturnal frontal lobe epilepsy (NFLE).


METHODS
Systematic semiologial evaluation of parasomnias and NFLE seizures recorded on video-EEG monitoring.


METHODS
120 events (57 parasomnias, 63 NFLE seizures) from 44 subjects (14 males). Interventions. The presence or absence of 68 elemental clinical features was determined in parasomnias and NFLE seizures. Qualitative analysis of behavior patterns and ictal EEG was undertaken. Statistical analysis was undertaken using established techniques.


RESULTS
Elemental clinical features strongly favoring parasomnias included: interactive behavior, failure to wake after event, and indistinct offset (all P < 0.001). Cluster analysis confirmed differences in both the frequency and combination of elemental features in parasomnias and NFLE. A diagnostic decision tree generated from these data correctly classified 94% of events. While sleep stage at onset was discriminatory (82% of seizures occurred during stage 1 or 2 sleep, with 100% of parasomnias occurring from stage 3 or 4 sleep), ictal EEG features were less useful. Video analysis of parasomnias identified three principal behavioral patterns: arousal behavior (92% of events); non-agitated motor behavior (72%); distressed emotional behavior (51%).


CONCLUSIONS
Our results broadly support the concept of confusion arousals, somnambulism and night terrors as prototypical behavior patterns of NREM parasomnias, but as a hierarchical continuum rather than distinct entities. Our observations provide an evidence base to assist in the clinical diagnosis of NREM parasomnias, and their distinction from NFLE seizures, on semiological grounds.
Derry
Christopher P
CP
Epilepsy Research Centre, Department of Medicine, University of Melbourne, Victoria, Australia. cderry@nhs.net
Harvey
A Simon
AS
Walker
Matthew C
MC
Duncan
John S
JS
Berkovic
Samuel F
SF
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D016000:Cluster Analysis; D003937:Diagnosis, Differential; D004569:Electroencephalography / Q000379:methods*; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020921:Sleep Arousal Disorders / Q000175:diagnosis*; D012894:Sleep Stages; D014741:Video Recording / Q000379:methods*; D055815:Young Adult