J Korean Neurol Assoc.  2006 Feb;24(1):51-57.

Electrophysiological Characteristics of Genetically Confirmed Charcot-Marie-Tooth 1A

• Lee MH
• Sunwoo IN
• Choi BO
• Suh BC
• Cho JH
• Kim SM

Abstract

BACKGROUND: Charcot-Marie-Tooth (CMT) disease is pathologically divided into the following two types: demyelinating type and axonal type. This study aimed to analyze the results of the electrophysiological studies of CMT1A and to reevaluate the clinical significance of nerve conduction studies (NCS).
METHODS
The subjects of the study were 18 patients with genetically confirmed CMT1A during the period of 1995. 1.-2004. 8. The NCS data from 22 family members of the patients were also included. The nerve conduction velocities, conduction blocks and compound muscle action potentials were analyzed.
RESULTS
The subjects were composed of 19 males and 21 females. The mean NCV was 21.70 m/s in the median nerve, and the conduction block was observed in 13 patients (32.5%). The NCV was uniformly slow. The intrafamilial variation of NCVs between parents and their children were analyzed in 30 patients from 11 families. The mean velocity was 24.44+/-3.67 m/s in parents and 19.53+/-5.37m/s in their children.
CONCLUSIONS
The CMT1A showed the slowness in NCV, one of the characteristics of demyelinating neuropathy, and this slowing had a uniform pattern. Nerve conduction block was also frequently observed, the pattern of which was diffuse without dispersion, and non segmental. Because the NCV of the children tended to be slower than that of the parents, CMT1A may not be a simple progressive disease. The onset and progression of CMT1A may be determined by other genetic and environmental factors.

Keyword

Chracot-Marie-Tooth 1A; Nerve conduction study; Conduction block

MeSH Terms

Action Potentials
Axons
Child
Female
Humans
Male
Median Nerve
Neural Conduction
Parents