Comparison between clinical disabilities and electrophysiological values in Charcot-Marie-Tooth 1A patients with PMP22 duplication.
OBJECTIVE
Charcot-Marie-Tooth disease (CMT) type 1A (CMT1A) is the demyelinating form of CMT that is significantly associated with PMP22 duplication. Some studies have found that the disease-related disabilities of these patients are correlated with their compound muscle action potentials (CMAPs), while others have suggested that they are related to the nerve conduction velocities. In the present study, we investigated the correlations between the disease-related disabilities and the electrophysiological values in a large cohort of Korean CMT1A patients.


METHODS
We analyzed 167 CMT1A patients of Korean origin with PMP22 duplication using clinical and electrophysiological assessments, including the CMT neuropathy score and the functional disability scale.


RESULTS
Clinical motor disabilities were significantly correlated with the CMAPs but not the motor nerve conduction velocities (MNCVs). Moreover, the observed sensory impairments matched the corresponding reductions in the sensory nerve action potentials (SNAPs) but not with slowing of the sensory nerve conduction velocities (SNCVs). In addition, CMAPs were strongly correlated with the disease duration but not with the age at onset. The terminal latency index did not differ between CMT1A patients and healthy controls.


CONCLUSIONS
In CMT1A patients, disease-related disabilities such as muscle wasting and sensory impairment were strongly correlated with CMAPs and SNAPs but not with the MNCVs or SNCVs. Therefore, we suggest that the clinical disabilities of CMT patients are determined by the extent of axonal dysfunction.
Department of Neurology, Ewha Womans University School of Medicine, Seoul, Korea.
Young Hwa
YH
Kim
Hwa Kyung
HK
Chung
Kee Duk
KD
Park
Kyoung-Gyu
KG
Choi
Seung-Min
SM
Kim
Il-Nam
IN
Sunwoo
Young-Chul
YC
Choi
Jeong-Geun
JG
Lim
Kwang Woo
KW
Lee
Kwang-Kuk
KK
Kim
Dong Kuk
DK
Lee
In Soo
IS
Joo
Ki-Han
KH
Kwon
Seok Beom
SB
Gwon
Jae Hyeon
JH
Park
Dae-Seong
DS
Kim
Seung Hyun
SH
Kim
Woo-Kyung
WK
Kim
Bum Chun
BC
Suh
Sang-Beom
SB
Kim
Nam-Hee
NH
Kim
Eun Hee
EH
Sohn
Ok-Joon
OJ
Kim
Hyun Sook
HS
Kim
Jung Hee
JH
Cho
Sa-Yoon
SY
Kang
Chan-Ik
CI
Park
Jiyoung
J
Oh
Jong Hyu
JH
Shin
Ki Wha
KW
Chung
Byung-Ok
BO
Choi