Fig. 1

Results of diffusion tensor tractography (DTT) for the ascending reticular activating system (ARAS). a T2-weighted brain magnetic resonance images at the time of diffusion tensor imaging scanning in representative subjects of patient subgroup A (71-year-old female), patient subgroup B (33-year-old male), and the control group (50-year-old female). b Results of DTT for the lower dorsal ARAS. Narrowing (yellow arrows) is observed in both lower dorsal ARAS in patient subgroup A compared to that in patient subgroup B and the control group. c Results of DTT for the upper ARAS. A decreased neural tract (green arrows) is observed in both upper ARAS in patient subgroup A compared with that in patient subgroup B and the control group