Somatosensory evoked potential recovery in kii amyotrophic lateral sclerosis/parkinsonism-dementia complex (kii AlS/PDC).
OBJECTIVE
To evaluate the recovery function of the sensory cortex in patients with Kii amyotrophic lateral sclerosis/parkinsonism-dementia complex (Kii ALS/PDC) using somatosensory evoked potentials (SEPs) elicited by paired stimuli of the median nerve at the wrist.


METHODS
Five patients with Kii ALS/PDC were compared with 5 patients with classical ALS, 5 with Parkinson's disease (PD), and 7 healthy normal volunteers. SEPs were recorded from the hand sensory area contralateral to the side of stimulation. Recovery functions of N20-P25 and P25-N33 components were evaluated by comparing the second SEPs elicited by paired pulse stimuli at various interstimulus intervals (ISIs, 20-300 ms) with the SEPs elicited by single stimuli.


RESULTS
Conventional SEPs to a single stimulus had a normal latency and size in all patients. The recovery function of the N20-P25 and P25-N33 components showed significantly less suppression at short ISIs without any facilitation at long ISIs in Kii ALS/PDC patients than in normal subjects, classical ALS or PD patients.


CONCLUSIONS
In Kii ALS/PDC, the sensory cortex is disinhibited or hyperexcitable. These abnormalities may reflect cortical pathology in the sensory cortex and may be partly due to a secondary effect on the sensory cortex from the primary parkinsonian pathological changes.
Machii
Katsuyuki
K
Department of Neurology, School of Medicine, Mie University, 2-174 Edobashi, Tsu Mie, 514-8507, Japan. machan@be.mbn.or.jp
Ugawa
Yoshikazu
Y
Kokubo
Yasumasa
Y
Sasaki
Ryogen
R
Kuzuhara
Shigeki
S
D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000503:physiopathology*; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000502:physiology; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology; D013003:Somatosensory Cortex / Q000503:physiopathology