Virtual Charcot-Marie-Tooth Examination Score: A Validated Virtual Evaluation for People With Charcot-Marie-Tooth...

The Charcot-Marie-Tooth Examination Score (CMTES) has been used since 2005 in clinics to measure impairment in patients with CMT and has provided natural history data for patients with CMT1A, CMT1B, CMTX1, CMT2A, and many other subtypes. However, the CMTES requires an in-person visit, and many individuals are unable to travel to CMT centers because of the distance from the clinic or physical disability or more recently because of COVID-19 restrictions. We therefore developed the virtual CMTES (vCMTES) as outlined below. The aim of this study is to create a remote clinical outcome assessment to measure impairment in patients with CMT.

We modified the CMTESv2 replacing the pinprick and vibration items with light touch and position sense, which can be performed remotely by the patient or the patient with an assistant while being observed by the clinic evaluator. Motor evaluations were performed similar to CMTESv2 by the assistant or the patient, while being observed remotely. We developed a standardized protocol to be used with Zoom or a similar format, a training and certification program, and enabled the vCMTES data to be housed in the Inherited Neuropathy Consortium databases. Patients were evaluated in person and remotely for interexaminer and intraexaminer studies.

Sixty-four patients with genetically confirmed CMT were evaluated by vCMTES and CMTESv2; 53 patients were evaluated virtually 3 weeks after their initial examination. Ten patients were evaluated with the vCMTES by different examiners 5 days apart. CMTESv2 correlates strongly with the vCMTES in person and virtually (p < 0.0001). There was a strong correlation between the vCMTES made in person and virtually (p < 0.0001). Similar results were obtained comparing symptoms score items, sensory items, and motor items. Interclass correlation coefficients (ICCs) were ≥0.92.

Statistical analyses demonstrated that the vCMTES was reproducible and reliable as a clinical outcome assessment for CMT. Further studies are needed to test responsiveness to change and progression in different subtypes. The vCMTES also offers the potential to reach diverse populations that do not have access to CMT centers.