Pirgit Meritam1, Elena Gardella2, Jørgen Alving3, Daniella Terney1, Melita Cacic Hribljan4, Sándor Beniczky5. 1. Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark. 2. Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark; University of Southern Denmark, Odense, Denmark. 3. Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark; Department of Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark. 4. Department of Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark. 5. Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark; Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark. Electronic address: sbz@filadelfia.dk.
Abstract
OBJECTIVE: To investigate whether Posterior Dominant Rhythm (PDR) can be reliably assessed in sleep-EEG recordings and to investigate the diagnostic yield of standard-wake and sleep-recordings. METHODS: EEG recordings of 303 consecutive patients aged 18-88 years were analyzed. All patients had both standard-wake and sleep-recordings, including patients who had abnormal standard recordings. Melatonin was used in 6% of sleep EEGs, and sleep deprivation in 94%. The mean duration of sleep was 41 min. We measured the PDR frequency in standard and sleep-recordings, both before and after sleep. We compared the diagnostic yield of standard-wake and sleep EEG recordings. RESULTS: Compared to standard EEG, sleep-recordings showed a significantly lower PDR frequency, both when measured before and after sleep (p < 0.001). One-hundred-fifty-six patients (51%) had normal standard recordings, and 35 of them (22%) had abnormal findings in the sleep-recording. One-hundred-forty-seven patients had abnormal standard recordings and in 16 of them (11%) these abnormalities were not present in sleep-recording. CONCLUSIONS: PDR is significantly slower in the wake periods of sleep-recordings, compared to standard wake recordings. SIGNIFICANCE: Sleep and standard wake recordings are complementary.
OBJECTIVE: To investigate whether Posterior Dominant Rhythm (PDR) can be reliably assessed in sleep-EEG recordings and to investigate the diagnostic yield of standard-wake and sleep-recordings. METHODS: EEG recordings of 303 consecutive patients aged 18-88 years were analyzed. All patients had both standard-wake and sleep-recordings, including patients who had abnormal standard recordings. Melatonin was used in 6% of sleep EEGs, and sleep deprivation in 94%. The mean duration of sleep was 41 min. We measured the PDR frequency in standard and sleep-recordings, both before and after sleep. We compared the diagnostic yield of standard-wake and sleep EEG recordings. RESULTS: Compared to standard EEG, sleep-recordings showed a significantly lower PDR frequency, both when measured before and after sleep (p < 0.001). One-hundred-fifty-six patients (51%) had normal standard recordings, and 35 of them (22%) had abnormal findings in the sleep-recording. One-hundred-forty-seven patients had abnormal standard recordings and in 16 of them (11%) these abnormalities were not present in sleep-recording. CONCLUSIONS: PDR is significantly slower in the wake periods of sleep-recordings, compared to standard wake recordings. SIGNIFICANCE: Sleep and standard wake recordings are complementary.