The acoustic startle reflex in stiff-man syndrome.
We studied the EMG response to loud noise in eight patients with stiff-man syndrome (SMS). Audiogenic muscle jerks originated in the acoustic startle reflex. Patients demonstrated excessive, poorly habituating motor activity predominantly in axial and leg muscles. Exaggerated startle in SMS probably reflects segmental hyperexcitability of axial and lumbar spinal motor neurons.
Matsumoto
J Y
JY
Department of Neurology, Mayo Clinic and Foundation, Rochester, MN 55905.
Caviness
J N
JN
McEvoy
K M
KM
D000328:Adult; D004576:Electromyography; D005121:Extremities; D005152:Facial Muscles / Q000502:physiology; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D011930:Reaction Time; D012022:Reflex, Acoustic / Q000502:physiology*; D013216:Reflex, Startle / Q000502:physiology*; D016750:Stiff-Person Syndrome / Q000503:physiopathology*