Theta-burst transcranial magnetic stimulation for the treatment of unilateral neglect in stroke patients: A systematic review and best evidence synthesis

BACKGROUND: Unilateral neglect (UN) is a common and disabling disorder after stroke. UN is a strong and negative predictor of functional rehabilitative outcome. Non-invasive brain stimulation, such as theta-burst transcranial magnetic stimulation (TBS), is a promising rehabilitation technique for treating stroke-induced UN. OBJECTIVE: To systematically review the available literature, researching whether TBS of the contra-lesional hemisphere is more effective than standard rehabilitation in improving symptoms of UN in patients with right hemisphere stroke. REVIEW METHODS: A systematic review was conducted to retrieve randomized controlled trials (RCTs) that were relevant to the objective of this review. PubMed, Ovid and Cochrane Library electronic databases were comprehensively searched from inception up to February 2021. Of the included studies, methodological quality was assessed using the PEDro scale, whereafter a best evidence synthesis (BES) was conducted to summarize the results. RESULTS: Nine RCTs investigating the effects of TBS on stroke-induced UN symptoms were included in this review. Seven studies assessing continuous TBS (cTBS) found significantly greater amelioration of UN symptoms in the TBS intervention group when compared to the control group; one study assessing cTBS found no such significant difference. One study assessing intermittent TBS (iTBS) found significant between-group differences in favor of the intervention. The BES yielded strong evidence in favor of cTBS, and limited evidence in favor of iTBS. CONCLUSIONS: The included studies in the present review allow the conclusion that TBS can have favorable effects on UN recovery in stroke patients. Its clinical use is recommended in conjunction with cognitive rehabilitation and occupational or physical rehabilitation as needed. However, many aspects for optimal usage of TBS therapy in clinical settings, such as exact TBS protocols, number of sessions, and treatment duration, are not clear.