One session of repeated parietal theta burst stimulation trains induces long-lasting improvement of visual neglect.

Journal article

BACKGROUND AND PURPOSE: Visual neglect is a frequent disability in stroke and adversely affects mobility, discharge destination, and length of hospital stay. It is assumed that its severity is enhanced by a released interhemispheric inhibition from the unaffected toward the affected hemisphere. Continuous theta burst transcranial magnetic stimulation (TBS) is a new inhibitory brain stimulation protocol which has the potential to induce behavioral effects outlasting stimulation. We aimed to test whether parietal TBS over the unaffected hemisphere can induce a long-lasting improvement of visual neglect by reducing the interhemispheric inhibition. METHODS: Eleven patients with left-sided visual neglect attributable to right hemispheric stroke were tested in a visual perception task. To evaluate the specificity of the TBS effect, 3 conditions were tested: 2 TBS trains over the left contralesional posterior parietal cortex, 2 trains of sham stimulation over the contralesional posterior parietal cortex, and a control condition without any intervention. To evaluate the lifetime of repeated trains of TBS in 1 session, 4 trains were applied over the contralesional posterior parietal cortex. RESULTS: Two TBS trains significantly increased the number of perceived left visual targets for up to 8 hours as compared to baseline. No significant improvement was found with sham stimulation or in the control condition without any intervention. The application of 4 TBS trains significantly increased the number of perceived left targets up to 32 hours. CONCLUSIONS: The new approach of repeating TBS at the same day may be promising for therapy of neglect.

Authors: Nyffeler, T; Cazzoli, D; Hess, C; Müri, R

• Journal: Stroke; a journal of cerebral circulation
• Volume: 40
• Issue: 8
• Pages: 2791-2796
• Publication date: 2009-08-01
• DOI: 10.1161/strokeaha.109.552323
• EISSN: 1524-4628
• ISSN: 0039-2499
• Language: English
• Keywords: Visual Perception; Time Factors; Humans; Reaction Time; Parietal Lobe; Transcranial Magnetic Stimulation; Vision Disorders; Middle Aged; Adult; Aged; Theta Rhythm