Joachim Bas1, Emilien Delmont2, Farzad Fatehi1, Emmanuelle Salort-Campana3, Annie Verschueren1, Jean Pouget3, Marie-Noëlle Lefebvre4, Aude-Marie Grapperon1, Shahram Attarian5. 1. Referral Center for Neuromuscular Diseases and ALS, La Timone University Hospital, Aix-Marseille University, Marseille, France. 2. Referral Center for Neuromuscular Diseases and ALS, La Timone University Hospital, Aix-Marseille University, Marseille, France; Aix-Marseille University, UMR 7286, Medicine Faculty, Marseille, France. 3. Referral Center for Neuromuscular Diseases and ALS, La Timone University Hospital, Aix-Marseille University, Marseille, France; Aix-Marseille University, Inserm, GMGF, Marseille, France. 4. CIC-CPCET, La Timone University Hospital, Aix-Marseille University, Marseille, France. 5. Referral Center for Neuromuscular Diseases and ALS, La Timone University Hospital, Aix-Marseille University, Marseille, France; Aix-Marseille University, Inserm, GMGF, Marseille, France. Electronic address: sattarian@ap-hm.fr.
Abstract
OBJECTIVE: The aim of this study was to assess the usefulness of motor unit number index (MUNIX) technique in Charcot-Marie-Tooth disease and test the correlation between MUNIX and clinical impairment. METHODS: MUNIX technique was performed in the abductor pollicis brevis (APB), the abductor digiti minimi (ADM) and the tibialis anterior (TA) muscles in the nondominant side. A MUNIX sum score was calculated by adding the MUNIX of these 3 muscles. Muscle strength was measured using the MRC (medical research council) scale. Disability was evaluated using several functional scales, including CMT neuropathy score version 2 (CMTNSv2) and overall neuropathy limitation scale (ONLS). RESULTS: A total of 56 CMT patients were enrolled. The MUNIX scores of the ADM, APB and TA muscles correlated with the MRC score of the corresponding muscle (p < 0.01). The MUNIX sum score correlated with the clinical scales CMTNSv2 (r = -0.65, p < 0.01) and ONLS (r = -0.57, p < 0.01). CONCLUSION: MUNIX correlates with muscle strength and clinical measurements of disability in patients with CMT disease. SIGNIFICANCE: The MUNIX technique evaluates motor axonal loss and correlates with disability. The MUNIX sum score may be a useful outcome measure of disease progression in CMT.
OBJECTIVE: The aim of this study was to assess the usefulness of motor unit number index (MUNIX) technique in Charcot-Marie-Tooth disease and test the correlation between MUNIX and clinical impairment. METHODS: MUNIX technique was performed in the abductor pollicis brevis (APB), the abductor digiti minimi (ADM) and the tibialis anterior (TA) muscles in the nondominant side. A MUNIX sum score was calculated by adding the MUNIX of these 3 muscles. Muscle strength was measured using the MRC (medical research council) scale. Disability was evaluated using several functional scales, including CMT neuropathy score version 2 (CMTNSv2) and overall neuropathy limitation scale (ONLS). RESULTS: A total of 56 CMTpatients were enrolled. The MUNIX scores of the ADM, APB and TA muscles correlated with the MRC score of the corresponding muscle (p < 0.01). The MUNIX sum score correlated with the clinical scales CMTNSv2 (r = -0.65, p < 0.01) and ONLS (r = -0.57, p < 0.01). CONCLUSION: MUNIX correlates with muscle strength and clinical measurements of disability in patients with CMT disease. SIGNIFICANCE: The MUNIX technique evaluates motor axonal loss and correlates with disability. The MUNIX sum score may be a useful outcome measure of disease progression in CMT.