PMID- 1902237
OWN - NLM
STAT- MEDLINE
DCOM- 19910528
LR  - 20191028
IS  - 0736-0258 (Print)
IS  - 0736-0258 (Linking)
VI  - 8
IP  - 1
DP  - 1991 Jan
TI  - Cortical reflex myoclonus. A study of the relationship between giant 
      somatosensory evoked potentials and motor excitability.
PG  - 95-101
AB  - The excitability cycles of the N1-P1-N2 waveforms of the scalp-recorded 
      somatosensory evoked potential (SEP) and of the long-latency, cortical loop 
      reflex electromyographic (EMG) activity were studied in two patients with 
      cortical reflex myoclonus. Long-latency cortical loop reflex EMG activity in the 
      thenar muscles and giant SEPs occurred following median nerve stimulation. The 
      excitability cycle of the EMG paralleled that of the SEP. There was an initial 
      period of attenuation of SEP and EMG amplitude at interstimulus intervals (ISIs) 
      of less than 40 ms followed by a period of amplitude enhancement at an ISI of up 
      to 200 ms followed by a second period of attenuation. The excitability cycle is 
      abnormal and the SEP and EMG amplitude changes parallel each other. It is 
      therefore likely that a common mechanism determines the abnormal excitability 
      cycle. The substrate for this mechanism is unknown and may be diffuse or 
      restricted. Oral 5-hydroxytryptophan (5-HTP) in therapeutic doses altered the SEP 
      excitability cycle. 5-HTP did not attenuate the giant SEPs but did attenuate the 
      long-latency reflex EMG. Therefore, 5-HTP's site of action may be different from 
      the substrate underlying the mechanism that results in the giant SEPs. 
      Additionally, spinal latency reflex EMG activity occurred following treatment 
      with 5-HTP but was absent when the patient discontinued 5-HTP.
FAU - Seyal, M
AU  - Seyal M
AD  - Department of Neurology, University of California, Davis Medical Center, 
      Sacramento 95817.
LA  - eng
PT  - Case Reports
PT  - Journal Article
PL  - United States
TA  - J Clin Neurophysiol
JT  - Journal of clinical neurophysiology : official publication of the American 
      Electroencephalographic Society
JID - 8506708
RN  - C1LJO185Q9 (5-Hydroxytryptophan)
SB  - IM
MH  - 5-Hydroxytryptophan/administration & dosage
MH  - Adult
MH  - Cerebral Cortex/physiopathology
MH  - Electric Stimulation
MH  - Electromyography/drug effects
MH  - Epilepsies, Myoclonic/drug therapy/*physiopathology
MH  - Evoked Potentials, Somatosensory/drug effects/*physiology
MH  - Humans
MH  - Male
MH  - Median Nerve/physiopathology
MH  - Motor Neurons/drug effects/*physiology
MH  - Muscles/*innervation
MH  - Neural Pathways/physiopathology
MH  - Reaction Time/drug effects/physiology
MH  - Reflex/drug effects/*physiology
EDAT- 1991/01/01 00:00
MHDA- 1991/01/01 00:01
CRDT- 1991/01/01 00:00
PHST- 1991/01/01 00:00 [pubmed]
PHST- 1991/01/01 00:01 [medline]
PHST- 1991/01/01 00:00 [entrez]
AID - 10.1097/00004691-199101000-00012 [doi]
PST - ppublish
SO  - J Clin Neurophysiol. 1991 Jan;8(1):95-101. doi: 10.1097/00004691-199101000-00012.