PMID- 8913199
OWN - NLM
STAT- MEDLINE
DCOM- 19961220
LR  - 20191210
IS  - 0013-4694 (Print)
IS  - 0013-4694 (Linking)
VI  - 101
IP  - 5
DP  - 1996 Oct
TI  - Effect of photic conditioning on blink reflex recovery function in blepharospasm.
PG  - 446-52
AB  - Patients with blepharospasm may have selective sensitivity to photic stimuli, for 
      their symptoms are often aggravated after exposure to brightness. To investigate 
      the pathophysiology underlying this phenomenon, we compared the effects of 
      electric and photic conditioning on electrically-evoked blink reflex in 21 
      patients with blepharospasm and 11 age-matched control subjects. With electric 
      conditioning, R1 was facilitated at inter-stimulus intervals (ISIs) of up to 100 
      ms in both groups. R2 was inhibited at all ISIs longer than 20 ms in the normals, 
      but to a much lesser extent in the patients, suggesting increased excitability of 
      the multi-synaptic reflex pathway. Compared to electric conditioning, photic 
      conditioning was less potent in inhibiting R2 in the normals. In contrast, photic 
      conditioning in the patients produced R2 inhibition as powerful as electric 
      conditioning. These findings indicate that, in patients with blepharospasm, 
      photic input has a relatively more profound inhibitory effect on the test blink 
      reflex than electric conditioning as compared with normal subjects. The greater 
      susceptibility of the brainstem interneurons to photic conditioning in 
      blepharospasm may be related to the clinically-observed light sensitivity.
FAU - Katayama, M
AU  - Katayama M
AD  - Department of Neurology, Kyoto University Hospital, Japan.
FAU - Kohara, N
AU  - Kohara N
FAU - Kaji, R
AU  - Kaji R
FAU - Kojima, Y
AU  - Kojima Y
FAU - Shibasaki, H
AU  - Shibasaki H
FAU - Kimura, J
AU  - Kimura J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Ireland
TA  - Electroencephalogr Clin Neurophysiol
JT  - Electroencephalography and clinical neurophysiology
JID - 0375035
SB  - IM
MH  - Adult
MH  - Aged
MH  - Blepharospasm/*physiopathology
MH  - Blinking/*physiology
MH  - Conditioning, Psychological/*physiology
MH  - Electric Stimulation
MH  - Female
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Photic Stimulation
EDAT- 1996/10/01 00:00
MHDA- 1996/10/01 00:01
CRDT- 1996/10/01 00:00
PHST- 1996/10/01 00:00 [pubmed]
PHST- 1996/10/01 00:01 [medline]
PHST- 1996/10/01 00:00 [entrez]
PST - ppublish
SO  - Electroencephalogr Clin Neurophysiol. 1996 Oct;101(5):446-52.