Long-term effect of low-frequency repetitive transcranial magnetic stimulation over the unaffected posterior parietal cortex in patients with unilateral spatial neglect

Objective: To explore long-term effects on unilateral spatial neglect of low-frequency repetitive transcranial magnetic stimulation (rTMS) over the unaffected posterior parietal cortex. Design: Uncontrolled pilot study. Subjects: Two chronic-phase patients with left-sided unilateral spatial neglect from cerebral infarction. Methods: Six rTMS sessions were undertaken for 2 weeks. Each session included 900 stimuli applied over P5 at an intensity of 95% motor thresholds and a frequency of 0.9 Hz. The Behavioural Inattention Test, either the Mini-Mental State Examination or the Revised Hasegawa Dementia Scale, Brunnstrom Recovery Stage, and Barthel Index were evaluated at 2-week intervals until 6 weeks after rTMS sessions. Single-photon emission computed tomography was performed 2 weeks before and after rTMS. Results: Behavioural Inattention Test scores improved remarkably, especially from 2 to 4 weeks after rTMS sessions. At 6 weeks, Behavioural Inattention Test scores still remained above pre-rTMS levels. Other clinical evaluations as well as single-photon emission computed tomography showed no significant change during the study. Conclusion: In this small pilot study, low-frequency rTMS over the unaffected posterior parietal cortex decreased unilateral spatial neglect for at least 6 weeks.