No Difference Between Noxious and Innocuous Thermal Stimulation on Motor Recovery of Upper Extremity in Patients With Acute Stroke: A Randomized Controlled Trial With 6-Month Follow-up

Abstract Background Thermal stimulation (TS) has been developed and incorporated into stroke rehabilitation. However, whether noxious and innocuous TS induce the same effects on motor function recovery after stroke is still unknown. A comparative study of different temperature combination regimens is needed. Objective To compare the short- and long-term effectiveness between noxious and innocuous TS on motor recovery of upper extremity in patients with acute stroke. Design Randomized, controlled trial with concealed allocation, intention-to-treat analysis and blinded outcome assessors. Setting A university hospital rehabilitation department in Taiwan. Participants A total of 79 patients with acute ischemic stroke were recruited. The majority had moderate to severe motor impairment of the upper extremity (UE). Intervention In addition to traditional rehabilitation, the experimental group (n = 39) underwent noxious TS (heat pain 46-47°C/cold pain 7-8°C), and the control group (n = 40) received innocuous TS (heat 40-41°C/cold 20-21°C). TS intervention was applied for 30 minutes once per day and for a total of 20-24 times during hospital stay. A custom-made TS instrument, comprising 2 thermal stimulators and their respective thermal pads constructed in a closed-loop system, was used. Outcomes The Fugl-Meyer upper extremity score (the primary outcome), Action Research Arm Test, Motricity Index, Barthel Index, and modified Ashworth scale (the secondary outcomes) were administered by a blinded assessor at baseline, post–12th TS, post-intervention, 1-month, and 6-month follow-ups. Results No significant differences between groups were found on the primary outcome at postintervention and follow-up assessments. At 1-month follow-up, the innocuous group showed a small effect (partial η 2 = 0.02) that was greater than that of the noxious group, but that effect was eliminated at 6 months. Both groups presented significant within-group improvements over time (both P Conclusions Combining noxious TS with traditional rehabilitation did not yield better short-term or long-term results than combining innocuous TS with traditional rehabilitation on UE functional recovery for individuals with acute stroke. Level of Evidence II