title: Task-dependent modulation of visuospatial exploration by transcutaneous electrical neural stimulation and cyclic pressure application.
abstract: We investigated the effects of one somatosensory stimulation technique, the cyclic pressure application (CPA), and compared them with the effects of left transcutaneous electrical stimulation (TENS) on the expression of left visuospatial exploration deficits in 13 stroke patients, as assessed by four visuospatial exploration tasks. Four treatment conditions were given: TENS, CPA, TENS + CPA, as well as a placebo condition. For each patient, the intensity of the TENS was determined, based on his/her perception threshold of paresthesia for the electrical impulses. The results demonstrated that only TENS stimulation is a sufficient condition to reduce the expression of visuospatial exploration deficits dependent of the task. The point of time at which stimulation had an effect was also dependent of the mode of stimulation and the task. Normal visuomotor integration requires the ability to explore both sides (left and right) of the visual space with egocentric reference to the midsagittal plane of trunk. Unilateral disturbances in visuospatial exploration, often associated with the neurologic syndrome of hemispatial neglect and more frequently observed after right hemisphere damage, refers to the defective ability of patients with unilateral cerebral lesions to explore the side of space contralateral to the lesion. Many quantifiable tests have been developed to assess the expression of visuomotor exploration. These tests differ substantially in their sensitivity, but the Star Cancellation and Line Bisection tasks are cited as the most sensitive measurements of visuospatial exploration.
authors.affiliation: Scientific Unit Rehabilitation Center "Hof ter Schelde", Antwerp;                                      Laboratorium voor Neuropsychologie, Katholieke Universiteit Leuven;                                      Department of Physiotherapy, Free University of Brussels, Belgium.
authors.forename: Christophe
authors.initials: C
authors.lastname: Lafosse
authors.forename: Erik
authors.initials: E
authors.lastname: Kerckhofs
authors.forename: Marc
authors.initials: M
authors.lastname: Troch
authors.forename: Erik
authors.initials: E
authors.lastname: Vandenbussche