Device for quantifying tactile neglect in stroke patients

Perceptual problems such as tactile neglect are important features of stroke and strong predictors of a poor outcome. Although new methods of treatment have been described, documentation of the effects of such treatment is inadequate, mainly because satisfactory methods of quantifying tactile neglect are unavailable. We describe a device for quantifying neglect based upon the principle of the Bender test which uses double or simultaneous bilateral stimulation to determine neglect. The device, which is computer driven to ensure uniformity of test protocols, determines the cutaneous perceptual threshold to controlled-current electrical stimulation using surface electrodes. The effect of rival contralateral stimulation on the perceptual thresholds on the affected side of the patient's body is a quantitative measure of tactile neglect. The device was evaluated in normal young and neurologically normal elderly subjects and in stroke patients with clinical evidence of tactile neglect. It was shown to distinguish reliably between normal subjects and those who had tactile neglect. The device will be suitable for use in trials of treatments for tactile neglect and in tracking the natural history of this symptom.