Electrical Somatosensory Stimulation in Early Rehabilitation of Arm Paresis After Stroke: A Randomized Controlled Trial

Abstract

Background. Arm paresis is present in 48% to 77% of acute stroke patients. Complete functional recovery is reported in only 12% to 34%. Although the arm recovery is most pronounced during the first 4 weeks poststroke, few studies examined the effect of upper extremity interventions during this period. Objective. To investigate the effect of electrical somatosensory stimulation (ESS) delivered during early stroke rehabilitation on the recovery of arm functioning. Methods. A total of 102 patients with arm paresis were randomized to a high-dose or a low-dose ESS group within 7 days poststroke according to our sample size estimation. The high-dose group received 1-hour ESS to the paretic arm daily during hospitalization immediately followed by minimum 15-minute task-oriented arm training that was considered a component of the usual rehabilitation. The low-dose group received a placebo ESS followed by identical training. Primary outcome-Box and Block Test (BBT); secondary outcomes-Fugl-Meyer Assessment (FMA), grip strength, pinch strength, perceptual threshold of touch, pain, and modified Rankin Scale (mRS); all recorded at baseline, postintervention and at 6 months poststroke. Results. There were no differences between the high-dose and the low-dose groups for any outcome measures at any time points. Improvements ⩾ minimal clinically important difference were observed for FMA, hand grip strength, and mRS in both groups. Conclusions. Providing the present ESS protocol prior to arm training was equally beneficial as arm training alone. These results are valid for patients with mild-to-moderate stroke and moderate arm impairments. We cannot exclude benefits in patients with other characteristics, in other time intervals poststroke or using a different ESS protocol. Trial Registration. ClinicalTrials.gov (NCT02250365).

To stimulate or not to stimulate? A rapid systematic review of repetitive sensory stimulation for the upper-limb following stroke

“…Three of four studies in the acute and subacute periods [11,13,31] reported some significant differences in impairments (grip strength, hand function and sensation) to control participants but no changes in wider function of the upper-limb. The fourth study [10] undertaken in the acute period after stroke found no differences to control participants.…”

“…Four studies were conducted in the chronic stage of stroke (Table 1) [22]. From the others, two were in the early subacute stage [11,31], a third was in the acute period after stroke [10] whilst another crossed two time periods (early subacute/late subacute) [13].…”

“…Similarly, two studies [31,32] used a very low/no current during sham stimulation. Only one study used the same intensity of stimulation for experimental and sham interventions, but used a stimulation cycle that meant the sham group received only 2% of the active treatment provided in the experimental group [10].…”

“…It is often delivered to the skin via pads or embedded in a glove [5,8]. This type of sensory stimulation has also been referred to as electrical somatosensory stimulation (ESS) [9,10], repetitive peripheral sensory stimulation (RPSS) [8,11], peripheral nerve stimulation (PNS) [12] and peripheral sensory stimulation (PSS) [13] but is distinct from functional electrical stimulation which requires provision of the electrical stimulation alongside an attempted movement [14]. It is hypothesized that RSS may promote motor function by inducing cortical plasticity [15], including both functional changes in neurons and synapses, and structural changes such as changes in synapse formation, elimination, and morphology [16].…”

Easily Conducted Tests During the First Week Post-stroke Can Aid the Prediction of Arm Functioning at 6 Months

“…The ESS trial demonstrated no difference between the intervention and the control group (42), making it possible to merge the two cohorts for the purpose of the present study. Detailed information on the type and amount of delivered rehabilitation in the ESS trial is available elsewhere (42).…”