Table 2.

Comparison of hand muscles’ strength and ulnar and median nerve conduction studies between dominant and non-dominant hands.

	Dominant hand	95% CI	Non-dominant hand	95% CI	P value
Mean score FDIO	3.78	3.56, 4.00	4.00	3.80, 4.00	<0.0001
Mean score APB	3.38	3.02, 3.75	3.69	3.35, 4.02	0.0001
CMAP median (APB, mV)	2.03	0.96, 3.10	3.03	2.13, 3.93	0.02
CMAP ulnar (ADM, mV)	4.70	3.15, 6.25	4.86	3.48, 6.24	0.89

Patients with CMT1X have a higher mean MRC strength score for the first dorsal interosseous (FDIO) muscle and the abductor pollicis brevis (APB) muscle in non-dominant hands compared to dominant hands. Median nerve compound motor action potentials (CMAP) (measured on APB) were larger in non-dominant hands whereas ulnar nerve CMAPs (measured on abductor digiti minimi, ADM) were similar between hands. Mean values with 95% confidence interval are shown.