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To the Editor We read with interest the article by Lee et al1 describing hereditary motor and sensory neuropathy with proximal dominance, a rare type of autosomal dominant adult-onset Charcot-Marie-Tooth disease (CMT). It is indicated that detailed magnetic resonance imaging analysis revealed a distinct pattern of muscular involvement consisting of marked hyperintense signal changes in the hip muscles compared with those in the thigh or the leg muscles. According to the authors, these signal changes are different from the ones in patients with CMT with length-dependent neuropathy.2,3 Although accepting this position, we wish to draw attention to the fact that, late in the clinical course, a small subset of patients with CMT type 1A (CMT1A), the most common form of CMT, may exhibit florid involvement of thigh and pelvic musculature.4,5 One of our patients with CMT1A, aged 53 years, was serially evaluated over 3 decades. Initial examination at age 23 years showed mild phenotype including pes cavus, areflexia, stocking hypoesthesia, and nerve enlargement.4 At age 34 years and throughout the subsequent 4 years, she developed gradually progressive and symmetric leg amyotrophy and weakness, obliging her to use foot orthotics. As of age 43 years, she developed progressive deterioration of gait, her walk becoming ungainly and waddling with bilateral steppage obliging her to continuously use a cane. At her last examination, her stance was wide based and also possible only with support (see Figure 1 in the article by Berciano et al4), and there was positive Gowers maneuver in getting up from a chair. At that time, magnetic resonance imaging of the pelvic, thigh, and calf musculature showed extensive fatty muscle atrophy comparable with that illustrated by Lee et al1 (Figure 2I-P). Worthy of note is the fact that marked fatty atrophy of gluteus medius and minimus muscles was an outstanding finding in both studies,1,4 accounting for the observed waddling gait. In short, involvement of pelvic and thigh musculature, which is a characteristically inaugural manifestation of hereditary motor and sensory neuropathy with proximal dominance, may exceptionally occur late in the clinical course of CMT1A.
Berciano J, Gallardo E. Proximal Lower-Limb Weakness in Charcot-Marie-Tooth Disease. JAMA Neurol. 2013;70(12):1587. doi:10.1001/jamaneurol.2013.4662