COMORBIDITY IN CHARCOT‐MARIE‐TOOTH DISEASE

Gemignani F., Inglese C., Alfieri S., Melli G., Marbini A. Istituto di Neurologia, Università di Parma—Parma Phenotypic expression of Charcot‐Marie‐Tooth disease (CMT) is widely variable, and possibly conditioned by other factors in addition to genotype. In a series of 53 CMT patients we considered the occurrence of comorbidity to evaluate its influence on the manifestations of the disease. Twenty patients (11 women, 9 men) from 15 families were classified as having CMT1, and 33 (13 women, 20 men) from 29 families were classified as having CMT2. Superimposed factors of neuropathic damage were present in 18 patients (4 with CMT1 and 14 with CMT2), including diabetes (4 patients), glucose intolerance (3 patients), cryoglobulinemia (3 patients), lumbal stenosis (3 patients), chronic obstructive lung disease (2 patients), monoclonal gammopathy IgM‐k (1 patient), previous alcohol abuse (1 patient), and hypothyroidism (1 patient). Positive sensory symptoms were significantly more frequent in CMT patients with comorbidity (14/18 vs 14 / 35; p=0.02). Measures of impairment were similarly affected in the two groups: Rankin score was>1 in 11/ 18 patients with comorbidity and in 20 / 35 without, motor action potentials were absent in 5 / 18 and 13 /  33, respectively, and sensory action potentials were absent in 8  /  18 vs 20  /  35. Sural nerve biopsy was performed in five patients with comorbidity, showing features not different from usual aspects in CMT1 and CMT2; however, in a CMT2 patient with associated cryoglobulinemia, striking aspects of regenerative clusters were seen. In this series, superimposed factors of nerve damage seem to not significantly affect clinical manifestations and quality of life in CMT, apart from the frequent occurrence of sensory symptoms, possibly through interference in regenerative processes.