Figure 5: (a) Basal sympathetic drive is high. Rise in BPM after IHG in 1^st min rises by 5 to 8 beats - significant sympathetic impairment, (b) follow-up shows a still high basal sympathetic drive of around 80 with rise in BPM after IHG of 10–12 beats in 1^st min suggesting some improvement, (c) another patient with grossly affected IHG test and mild improvement in follow-up period (d). BPM - Betas per minute; IHG - Isometric Handgrip Test