Behavioural and neurophysiological correlates of human cataplexy: a video-polygraphic study.
OBJECTIVE
To investigate the behavioural and neurophysiological pattern of cataplexy.


METHODS
Seven narcolepsy with cataplexy patients underwent daytime videopolygraphy using humorous movies or/and jokes to trigger cataplectic attacks.


RESULTS
During segmental cataplectic attacks, EMG showed brief and irregular periods of silencing focally involving facial, neck, axial or limb muscles, sometimes coinciding with bursts of rapid eye movements. All patients enacted intentional movements in response to these segmental postural lapses. During global cataplectic attacks, EMG showed suppression of activity alternated with patterned enhancement, enhanced EMG activity in neck muscles preceding that of other cranial, axial and lower limb muscles. This waxing and waning EMG pattern ended with a complete body collapse and persistent muscle atonia. Breathing irregularities, heart rate (HR) instability and EEG desynchronization were observed during global cataplectic attacks without any appreciable blood pressure changes, but with HR deceleration and silencing of sympathetic skin response while in complete atonia. Patients subjectively perceived the involuntary postural lapses as startling and alarming.


CONCLUSIONS
Cataplexy in our patients showed many of the features of tonic REM sleep.


CONCLUSIONS
Cataplexy can be construed as a "freezing-like" perturbation of the orienting response with transient impairment of posture and movements resulting in a "patchwork-compromise-behaviour".
Vetrugno
Roberto
R
Department of Neurological Sciences, University of Bologna, Bologna, Italy. roberto.vetrugno@unibo.it
D'Angelo
Roberto
R
Moghadam
Keivan Kaveh
KK
Vandi
Stefano
S
Franceschini
Christian
C
Mignot
Emmanuel
E
Montagna
Pasquale
P
Plazzi
Giuseppe
G
D000293:Adolescent; D000328:Adult; D001143:Arousal / Q000502:physiology*; D002385:Cataplexy / Q000175:diagnosis* / Q000503:physiopathology*; D002490:Central Nervous System / Q000503:physiopathology; D002648:Child; D004569:Electroencephalography / Q000379:methods*; D004576:Electromyography / Q000379:methods; D004644:Emotions / Q000502:physiology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009123:Muscle Hypotonia / Q000209:etiology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D009483:Neuropsychological Tests; D009949:Orientation / Q000502:physiology; D010775:Photic Stimulation; D011187:Posture / Q000502:physiology; D056152:Respiratory Rate / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology*; D014741:Video Recording / Q000379:methods*; D055815:Young Adult