Longitudinal studies of the duplication form of Charcot-Marie-Tooth polyneuropathy

Abstract

This study presents a longitudinal comparison of motor nerve conduction velocities (MCVs) in patients with Charcot‐Marie‐Tooth type 1A with proven duplication of a segment of chromosome 17p11.2p12. Results were compared for 8 CMT1A duplication patients from one family whose MCV measurements were taken 22 years apart (1967 and 1989). Measurements from a total of seven median motor and five peroneal motor MCVs were compared. Median MCVs showed a slight reduction that averaged 2.2 m/s, and peroneal MCVs showed an average decrease of 3.0 m/s. In addition, mild objective increase in limb weakness was seen in only 1 of 8 patients and subjective symptoms of gradual worsening of leg strength were noted in half the patients over the same period. In this study of a small group of CMT1A patients with proven segmental duplication of chromosome 17p11.2p12, the motor conduction velocities and clinical motor exam did not change significantly over 22 years. © 1996 John Wiley & Sons, Inc.

Clinical disease severity and axonal dysfunction in hereditary motor and sensory neuropathy Ia

“…The initial dysmyelination and the subsequent cycles of demyelination and remyelination lead to a kind of balance in myelination in the first decade of life. This is supported by human longitudinal electrophysiological studies showing that motor nerve conduction velocity, an electrophysiological marker of myelination, is already abnormal at 2 years of age [11,13], and remains stable from the age of 5 years onwards [20,33].…”

“…There is controversy about the natural course of HMSN Ia in adulthood in the literature. Previous studies have noted clinical deterioration [4,7,14,33,39], whereas this was not found in other studies [16,20]. In HMSN Ia, CMAP amplitude reduction and disease progression have been shown in childhood [2].…”

Overview of Charcot‐Marie‐Tooth Disease Type 1A

“…Although Birouk et al 26 found that CMT1A is a progressive disorder, the situation after the second decade needs to be studied more extensively. Killian et al 29 undertook measurements on eight members of a single family at an interval of 22 years. MNCV showed a reduction of only 2.2 m/sec in the median nerve and 3.0 m/sec in the peroneal nerve.…”

Median nerve motor conduction velocity is concordant with myelin protein zero gene mutation

“…1 Median nerve motor conduction velocities in patients with different MPZ mutations, including patients in this (open squares) and previous (triangles) reportsprevious studies demonstrated that longitudinal changes in MNCVs of CMT1A patients were not significant[32,33], the NCV follow-up of patients with MPZ mutations has only rarely been reported. Bird et al followed the original CMT1B family for over 20 years and found that the NCVs of the affected patients had changed little over time[30].…”