Can the site of brain lesion predict improved motor function after Low-TENS treatment on the post-stroke paretic arm?

Objectives: Previous reports suggest that afferent stimulation improves arm motor function in patients suffering from stroke. The aim of this pilot study was to test the hypothesis that the brain lesion location determines the response to low-frequency (1.7 Hz) transcutaneous electric nerve stimulation (Low-TENS) therapy. Design: Magnetic resonance imaging (MRI) was performed on 14 patients who had previously received Low-TENS on the paretic arm after stroke. Methods: MR images were classified with two different methods. First, lesions in the cortical and the subcortical areas were registered. Secondly, any change in a described periventricular white matter (PVWM) area was recorded. Interactions between the lesion site, as detected by MRI, and response to Low-TENS treatment were analysed. Results: Arm motor function after Low-TENS treatment in relation to lesion in different brain areas showed that absence of lesions in the PVWM area increased the possibility for improved motor capacity after afferent stimulation. Conclusions: The site of lesion may play a role in prognosis/outcome after Low-TENS treatment but this hypothesis should be further tested in a larger prospective study.