Innovative quantitative testing of hand function in Charcot-Marie-Tooth neuropathy

To describe a new test to quantitatively evaluate hand function in patients affected by Charcot-Marie-Tooth neuropathy (CMT). The sensor-engineered glove test (SEGT) was applied to CMT patients (N: 26) and compared with a cohort of healthy controls (HC, N: 26). CMT patients were further divided into subjects with clinically normal (group 1) or impaired hand (group 2) function. The SEGT parameters evaluated were touch duration, inter-tapping interval, and movement rate parameters of two different sequences: finger tapping (FT) and index-medium-ring-little (IMRL) performed at self-paced mode (SPM) and maximum velocity (MV). Hand function and strength were assessed by the 9-hole peg test (9HPT) and dynamometry. Disability of patients was measured by the CMT neuropathy score. CMT patients had significantly worst performances at SEGT than controls regarding the rate of execution of both FT (at MV) and IMRL sequences (at SPM and MV). The rate parameter at MV in IMRL sequence showed a significant trend of decreasing in its average between HC (n: 26, rate = 3.08 ± 0.52 Hz), group 1 (n: 9, rate = 2.64 ± 0.66 Hz) and group 2 (n: 17, rate = 2.19 ± 0.45 Hz) (p for trend <0.001). No correlations were found with either 9HPT, dynamometry, electrophysiology, and the CMT neuropathy score. The SEGT test is sensitive to show hand dysfunction in CMT patients, with and without clinically impaired hands.