An initial exploration of the perceptual threshold test using electrical stimulation to measure arm sensation following stroke

Objective: To explore the viability of the perceptual threshold test using electrical stimulation to measure light touch sensation in the hands of stroke survivors.

Design: Descriptive study.

Setting: University research laboratory.

Subjects: Twenty-nine adult community-dwelling chronic stroke survivors.

Main measure(s): Perceptual threshold test using electrical stimulation, stroke rehabilitation assessment of movement, Nottingham sensory assessment for stereognosis, action research arm test, Fugl-Meyer assessment of sensation and motor activity log 14.

Results: Perceptual threshold test using electrical stimulation mean threshold values were 1.23 (0.6) milliamperes (range 0.5–3.5) for the uninvolved side and 1.68 (0.91) milliamperes (range 0.5–4.5) for the involved side. The perceptual threshold test using electrical stimulation demonstrated excellent intra-rater reliability (intraclass correlation coefficient = 0.896 – uninvolved; 0.829 – involved). There was a statistically significant difference between the perceptual threshold test using electrical stimulation mean threshold values for the uninvolved and involved arms (P = 0.003), but this significance did not hold for subjects who had normal sensation as measured by the Fugl-Meyer assessment of sensation (P = 0.083). Low to nonexistent correlations were found between the perceptual threshold test using electrical stimulation and other measures of sensation, arm movement, activity and participation.

Conclusions: The perceptual threshold test using electrical stimulation is a reliable and clinically feasible test with the potential to identify sensory capacity in stroke survivors with substantial sensory loss. Electrical sensory thresholds do not reflect overall sensory function or motor capabilities in stroke survivors.