Tonic and phasic inhibition indices are constant among nights: new indices for evaluating the degree of the two types of motor inhibition during REM sleep.
BACKGROUND
Tonic inhibition index (TII) and phasic inhibition index (PII) were proposed as indices for evaluating the degree of two types of motor inhibition activity during rapid eye movement (REM) sleep.


METHODS
In the present study, therefore, six healthy men underwent two consecutive all-night polysomnography, and reproducibility of TII and PII was evaluated.


RESULTS
TII was 0.85+/-0.07 (mean+/-SD) on the first night and 0.88+/-0.08 on the second; and PII was 3.4+/-2.1 on the first night and 4.9+/-1.8 on the second. Neither TII nor PII was significantly different between the two nights.


CONCLUSIONS
One night sleep study is considered sufficient for using TII and PII as a tool for evaluating motor inhibition activity during REM sleep in adults.
Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan. kaku@df6.so-net.ne.jp
K
K
Kimura
N
N
Tachibana
J
J
Kohyama
M
M
Taniguchi
H
H
Shibasaki