New Functional Outcome Measure for Charcot-Marie-Tooth Disease

The Charcot-Marie-Tooth Functional Outcome Measure (CMT-FOM) is a new performance-based measure designed to assess functional abilities in adults with CMT that has now been shown to be well tolerated with no floor or ceiling effect in an adult cohort matched to those likely to enter upcoming clinical trials.(Neurology:September 19, 2018) 

In a study designed to test feasibility, reliability, and convergent validity CMT-FOM, 43 adults with CMT type 1A (CMT1A) (70% women; mean age 41) were assessed with the CMT-FOM, CMT Exam Score (CMTES), and a symptom report. Results for each patient were tested for intraclass correlation, internal consistency, and validity compared with convergent and known-groups. In this analysis, CMT-FOM discriminated between patients with mild versus moderate to severe CMT1a with reliability (intraclass correlation coefficient = .92) and consistency (Cronbach alpha = .81) Patients’ mean score on the CMT-FOM (25.3 +/- 8.7; range 12-44 of 52) correlated moderately with the CMTES (P < .0001) and patients with mildest CMT1A symptoms who had a floor effect on CMTES did show functional limitations on the CMT-FOM. 

The authors conclude that the CMT-FOM appears reliable with convergent and known-groups validity in adults with CMT1A and also note that further longitudinal studies of CMT-FOM and its responsiveness to clinical change are needed before it can be applied in clinical trials.