Testing overwork weakness in Charcot-Marie-tooth disease: Is it true or false?

Area of Science:

• Neurology
• Clinical Neuroscience
• Musculoskeletal Disorders

Background:

• The existence of overwork weakness (OW) in Charcot-Marie-tooth (CMT) disease, particularly in the hands, remains a subject of debate.
• Previous studies yielded conflicting results, potentially due to variations in muscle groups and assessment tools.

Purpose of the Study:

• To investigate the occurrence of overwork weakness (OW) in the upper limbs (UL) of Charcot-Marie-tooth (CMT) patients.
• To evaluate hand strength, opposition ability, and overall hand function using objective measures.

Main Methods:

• Recruited 120 participants (60 CMT patients, 60 controls).
• Assessed hand-grip strength and tripod pinch strength using a dynamometer.
• Measured opposition ability with the thumb opposition test (TOT).
• Utilized a sensor engineered glove test (SEGT) for instrumental hand function assessment.

Main Results:

• CMT patients showed significantly higher TOT scores in the non-dominant hand (NDH) versus the dominant hand (DH).
• Hand strength was slightly, though not significantly, better in the NDH compared to the DH for CMT patients.
• SEGT results indicated similar performance between NDH and DH in CMT patients, unlike controls where the DH performed better.

Conclusions:

• This study provides evidence supporting the existence of overwork weakness (OW) in Charcot-Marie-tooth (CMT) disease.
• Hand dexterity and overall function may be more impaired in the dominant hand of CMT patients due to opposition deficits.
• Findings underscore the importance of avoiding supramaximal exercises and educating patients on proper movement to prevent overexertion.