Overwork weakness in Charcot-Marie-Tooth disease.

Area of Science:

• Neurology
• Clinical Medicine
• Rehabilitation Science

Background:

• Charcot-Marie-Tooth disease (CMT) is a progressive, inherited neurological disorder affecting peripheral nerves.
• Muscle weakness is a primary symptom, impacting daily activities and quality of life.
• The phenomenon of overwork weakness, where overexertion exacerbates muscle deficits, is a potential concern in neuromuscular conditions.

Purpose of the Study:

• To investigate the incidence and characteristics of overwork weakness in individuals diagnosed with Charcot-Marie-Tooth disease.
• To compare hand muscle strength between dominant and non-dominant sides in CMT patients and healthy controls.

Main Methods:

• A prospective survey design was employed, recruiting 106 outpatients with CMT and 48 healthy volunteers.
• Hand muscle strength of the abductor pollicis brevis (APB) and first dorsal interosseous was assessed using manual muscle testing and the modified Medical Research Council (MRC) Scale.
• Key outcome measures included the side with stronger muscles and the strength difference between the non-dominant and dominant hands.

Main Results:

• A significant difference in muscle strength distribution was observed between CMT patients and controls.
• In CMT patients, muscles were more frequently stronger on the non-dominant side (65.57%) compared to controls (1.04%).
• Conversely, muscles were predominantly stronger on the dominant side in controls (84.38%) but rarely in CMT patients (0.94%).

Conclusions:

• Charcot-Marie-Tooth disease patients exhibit reduced muscle strength in their dominant hand compared to their non-dominant hand.
• This asymmetry in strength suggests that overwork weakness may play a role in the pathophysiology and progression of muscle deficits in CMT.
• Further research is warranted to explore the implications of overwork weakness for rehabilitation strategies in CMT.