Relationships between Chalder's fatigue scale score and autonomic nerve activities. Autonomic nerve activities were evaluated using the % low-frequency power (%LF; a), % high-frequency power (%HF; b), and LF/HF ratio (c) obtained on R-R wave interval analyses using electrocardiography. Linear regression lines, Pearson's correlation coefficients (R), and P values are shown.
Tanaka et al. Behavioral and Brain Functions 2011 7:46 doi:10.1186/1744-9081-7-46