NARCRMS is a longitudinal registry studying the course of MS in the disease-modifying era.
To examine motor performance metrics of upper and lower extremity function in NARCRMS participants at enrollment, using the Expanded Disability Status Scale (EDSS) and 25-foot walk times.
Recruitment began in 2016 and by April 30, 2021, 855 patients were enrolled at 26 MS sites across the US and Canada. People with any sub type of MS within 15 years of disease onset and an EDSS of up to 6.5 are eligible for enrollment. Various clinical metrics are collected including motor performance for upper and lower extremities. Our initial observations about EDSS, 25-foot timed walk and the 9-hole peg test are reported below.
EDSS and 25-foot walk times were available in 692 patients while EDSS and upper extremity functions were available in 676 patients. A mean walking speed of 4.92 seconds was recorded in patients with an EDSS of 0 (n=113). 5.09 was the mean speed until an EDSS of 3.0 (n=44) where a mean speed of 5.56 seconds was recorded. Walking truly became affected at an EDSS of 3.5 (n=31) where a mean speed of 6.56 seconds was recorded. Thereafter mean speed progressively declined at nearly every EDSS increase. For an EDSS of 4.0 (n=30) mean speed was 8.3 seconds; for an EDSS of 4.5 (n=7), mean speed was 8.64 seconds and continued to increase until an EDSS of 6.5 (n=12) where mean speed was 17.0 seconds. For the 9-hole peg test, patients with an EDSS of 0 (n=107) had a mean speed of 19.44 seconds in the dominant and 20.59 seconds in the non-dominant hand. Hand function remained unimpaired until an EDSS of 2.0 and significant slowing occurred in patients with EDSS ranging from 2.5 to 6.5. For an EDSS of 2.5 (n=48), mean speed was 24.53 seconds in the dominant and 23.57 seconds in the non-dominant hand. For an EDSS of 4.0 (n=31), mean speed was 26.18 seconds in the dominant and 26.19 seconds in the non-dominant hand. For an EDSS of 6.5 (n=16), hand function had declined to a mean speed of 37.59 seconds for the dominant and 48.19 seconds for the non-dominant hand.
A linear correlation of the 25-foot walk speed to EDSS increases was remarkable, reiterating the commonly held belief that the EDSS is a walking scale. Decline in hand function at an EDSS of 2.5 was unexpected since hands are often perceived to be unaffected early in MS and seldom observed as impaired by patients. Progressive decline of hand function at every EDSS increase would suggest that the 9-HP test is a good marker of declining hand function and should be included in clinical monitoring of patients.