To describe upper (9-hole peg test (9HPT)) and lower extremity (25-foot walk (25-FW)) function in participants at enrollment as a function of their disability (Extended disability status scale (EDSS))

Few studies have examined concurrent impairment of upper and lower extremity function in multiple sclerosis (MS).  The North American Registry for Care and Research in MS (NARCRMS) is a longitudinal registry studying the course of MS in the disease-modifying era and provided an opportunity to examine motor impairment in large numbers of patients.

Seven hundred and seventy-seven subjects were recruited as of October 16^th, 2020.  Various clinical metrics were collected including motor performance for upper and lower extremities and EDSS scores.

EDSS and 25-FW times were available in 651, and 9-HPT in 647 subjects. Mean walking speed of 4.96 seconds was recorded in patients with EDSS of 0 and progressed to 18.09 seconds with aids by EDSS 6.5.  For the 9-HPT, patients with EDSS of 0 had a mean speed of 19.45 seconds in the dominant and 20.46 seconds in the non-dominant hand. Hand function remained unimpaired until EDSS of 2.0 and progressively worsened with worsening disability, and at EDSS 6.5 speed had declined to 38.43 seconds for the dominant and 50.88 seconds for the non-dominant hand.

A linear correlation of the 25-FW speed to EDSS increases reiterates the commonly held belief that EDSS is a “walking scale”. Decline in hand function at 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, occurring concurrently with decline in lower extremity motor performance, suggests that the 9-HPT is a good marker of declining hand function and should be included in clinical monitoring of patients.