Movement-related desynchronization-synchronization (ERD/ERS) in patients with Unverricht-Lundborg disease.
We studied changes in event-related desynchronization/synchronization (ERD/ERS) patterns in patients with Unverricht-Lundborg disease (ULD), presenting with prominent action myoclonus. We analyzed the movement-related ERD/ERS in alpha and beta frequency bands in 15 patients using self-paced finger extension as a motor paradigm and we compared the results with those obtained in 12 healthy volunteers. In all ULD patients, alpha- and beta-ERD regularly occurred with onset and location similar to that found in healthy controls, but the desynchronization of alpha activity was significantly greater than in controls (C3: -64.4+/-9.8% vs. -49.7+/-14.8%; p=0.004). Moreover, in the patients, both alpha- and beta-ERD spread toward frontal electrodes. In controls, the post-movement beta-ERS regularly occurred; it was absent in eight patients with severe action myoclonus, while, in seven patients with mild or moderate myoclonus, the beta-peak was significantly smaller with respect to that measured in controls (55.6+/-15.1% vs. 153.9+/-99.8%, p=0.006). The failure of beta-ERS well-correlated with motor impairment resulting from action myoclonus, whereas SSEPs and long-loop reflexes performed to detect signs of cortical hyperexcitability showed inconsistent changes. In ULD patients, ERD/ERS changes indicate an increased activation of motor cortex during movement planning and a great reduction of post-excitatory inhibition of motor cortex. The changes involving beta-ERS had a significant relationship with the functional disability in individual patients and might play a pathogenic role in the motor dysfunction.
Visani
E
E
Department of Neurophysiology; C. Besta National Neurological Institute, Milan, Italy.
Agazzi
P
P
Canafoglia
L
L
Panzica
F
F
Ciano
C
C
Scaioli
V
V
Avanzini
G
G
Franceschetti
S
S
D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D001931:Brain Mapping; D003344:Cortical Synchronization; D004569:Electroencephalography; D004576:Electromyography; D005071:Evoked Potentials / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005260:Female; D005385:Fingers / Q000294:innervation / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology; D009068:Movement / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D009207:Myoclonus / Q000503:physiopathology; D020194:Unverricht-Lundborg Syndrome / Q000188:drug therapy / Q000503:physiopathology*
D000927:Anticonvulsants