Low-frequency transcranial magnetic stimulation for visual spatial neglect: a pilot study

Abstract

Objective: The aims of this study were to investigate the effects of low-frequency repetitive transcranial magnetic stimulation on patients with visual spatial neglect and to explore the potential mechanisms of visual spatial neglect.

Methods: A total of 14 patients with prior stroke and visual spatial neglect were divided into a control group and a treatment group. The treatment group was exposed to low-frequency, repetitive transcranial magnetic stimulation for 2 weeks, twice a day, for 15 min per session. Stimuli were delivered at 0.5 Hz to the left posterior parietal cortex (i.e. position P3 according to 10-20 electroencephalogram co-ordinate systems). All patients performed a battery of tasks, including line bisection and line cancellation tests, 2 weeks before treatment, at the beginning, at the end, and 2 weeks after treatment.

Results: Following low-frequency repetitive transcranial magnetic stimulation, the performance of the patients in the treatment group improved significantly. The behaviour assessment data changed with time; at time-points 2 and 3 the comparison test showed a significant difference in line cancellation and line bisection results (p = 0.003 and p = 0.027, respectively).

Conclusion: This study indicates that low-frequency repetitive transcranial magnetic stimulation of the unimpaired hemisphere might improve visual spatial neglect after stroke and points to the need for further studies. The results support the theory of inter-hemispheric competition in the attentional network.