Cyclic Alternating Pattern as a Provocative Factor in Nocturnal Paroxysmal Dystonia

• Published in: Epilepsia (Copenhagen) Vol. 38; no. 9; pp. 1015 - 1025
• Main Authors: Terzano, Mario Giovanni, Monge‐Straws, Marie‐France, Mikol, Francois, Spaggiari, Maria Cristina, Parrino, Liborio
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.1997; Blackwell
• Subjects: Adolescent; Adult; Arousals; Biological and medical sciences; Cyclic alternating pattern; Diseases of striated muscles. Neuromuscular diseases; Dystonia - diagnosis; Dystonia - physiopathology; Electroencephalography; Epilepsy; Female; Humans; Male; Medical sciences; Middle Aged; Motor Activity - physiology; Movement Disorders - diagnosis; Movement Disorders - physiopathology; Neurology; Nocturnal paroxysmal dystonia; Periodicity; Polysomnography - statistics & numerical data; Sleep; Sleep Stages - physiology; Sleep Wake Disorders - diagnosis; Sleep Wake Disorders - physiopathology; Stereotypic Movement Disorder - diagnosis; Stereotypic Movement Disorder - physiopathology; Human; Nervous system diseases; Sleep stage; Pathophysiology; Epilepsy; Periodicity; Exploration; Electroencephalography; Polysomnography; Cerebral disorder; Involuntary movement; Electrodiagnosis; Striated muscle disease; Sleep; Central nervous system disease; Arousal; Dystonia; Neurological disorder; Extrapyramidal syndrome; Dyskinesia
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1111/j.1528-1157.1997.tb01485.x

Purpose: We made a polygraphic study of 6 patients with nocturnal paroxysmal dystonia (NPD) in which the cyclic alternating pattern (CAP) parameters were compared with those of a group of age‐ and sex‐matched controls. Methods: All patients met the requirements for NPD diagnosis, characterized by generalized stereotyped movements (dystonic‐dyskinetic), with a 1‐min centered duration but with no clear evidence of epileptic abnormalities in the waking EEG and during nocturnal recordings. Results: Besides the major events, the NPD polysomnograms also showed shorter, repeated episodes of shorter duration (generally <20 s) consisting of abrupt movements involving one or more body segments. Overall, the motor events in patients with NPD were closely related to periods of unstable non‐REM (NREM) sleep, as evidenced by the sequences of CAP, and began during an A phase. According to the conventional scoring parameters, NPD and controls differed only in sleep latency (+14 min in the NPD patients: p < 0.04). However, the architecture of sleep in the group with NPD was characterized by prolonged and irregular NREMREM cycles. In addition, the NPD recordings showed significantly higher values of CAP rate (p < 0.0001). When major motor attacks were suppressed by medication, sleep was characterized by a decrease in the excessive amounts of CAP rate and by a more regular architecture. Conclusions: The modulatory role of CAP on nocturnal motor events is reported.