Multidimensional evaluation is necessary to assess hand function in patients with Charcot-Marie-Tooth disease type 1A

Abstract

Background: Charcot-Marie-Tooth (CMT) disease type 1A (CMT1A) is the most common hereditary neuropathy. Several studies have assessed the relation between axonal loss and grip strength; however, the functional impact on dexterity and health-related quality of life (HRQoL) is unknown. We hypothesized that the severity of axonal loss will be correlated with loss of function and HRQoL.

Objective: The purpose of this study was to evaluate the relation between severity of electroneuromyography impairment and its impact on function and HRQoL in adults with CMT1A.

Methods: Grip and lateral pinch strength were evaluated with specific dynamometers: the Jamar and the Pinch Gauge. Dexterity was explored with the Sollerman, Jebsen, and Nine-hole Peg tests. The CMT impact on well-being was assessed by the validated Medical Outcomes Study Short Form 36 (SF-36), Beck Depression Inventory, and Fatigue Severity Scale, and disease severity by the CMT neuropathy score and Inflammatory Neuropathy Cause and Treatment sensory sum score. Finally, axonal loss and demyelination process was assessed by electroneuromyography.

Results: We included 33 participants with CMT1A (23 females, mean [SD] age 47.0 [4.7] years). We found lack of correlation between severe electroneuromyography impairment (frequency of abnormal results >80%), significant distal amyotrophy (70%) and quality of life (mean [SD] scores for physical and mental SF-36 36.4 [10.0] and 48.4 [11.5]), autonomy for activities of daily living, and hand function that remains relatively preserved. We found a correlation between lateral pinch and dexterity according to the Sollerman test (r=0.52, p<0.05) but a lack of correlation among the other parameters.

Conclusions: Electrophysiological follow-up seems to be of little relevance to follow HRQoL in individuals with CMT1A and manual function related to functional objectives for everyday physical medicine and rehabilitation practice. The manual function is complex and requires an overall, quantitative, qualitative and multidisciplinary assessment. Each tool (Pinch Gauge, Jamar, Sollerman, Jebsen, Nine-hole Peg) measures a specific element of manual function and is necessary when performing a grip function analysis.

Keywords: Axonal loss; Charcot-Marie-Tooth disease; Grip strength; Jebsen; Lateral pinch strength; Nine-hole Peg test; Sollerman.