The Effect of Low-frequency Repetitive Transcranial Magnetic Stimulation (rTMS) on Unilateral Spatial Neglect and Changes in Regional Cerebral Blood Flow (rCBF) / The Japanese Journal of Rehabilitation Medicine

ABSTRACT

Objective: To describe the effect of low-frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) on unilateral spatial neglect (USN) in 22 right-handed stroke patients with right hemispheric damage and the corresponding change of regional cerebral blood flow (rCBF) before and after rTMS, speculating on the neural basis for recovery from USN. Methods: The time of onset to the initiation of rTMS was 70 to 220 days (mean 128.3 days), on chronic stage in all patients. The therapeutic schedule consisted of 7 sessions of 1 Hz-rTMS delivered every other day for two weeks, with 14 sessions in two patients. Each session consisted of one train of 500 pulses applied over P5 (10/20 EEG system) at 90% motor threshold using a figure-eight-shaped coil. Assessment was made using the Japanese edition of the Behavioural Inattention Test (BIT) and a computed visual search task at four times as well as a cold-xenon CT (Xe-CT) at two times. Results: rTMS induced a significant improvement of USN patient performance in cancellation tasks and the BIT figure copy task as well as in visual search reaction time, an improvement which lasted 2 weeks after rTMS. Xe-CT showed a significant increase in rCBF in the right cerebellum after rTMS. Conclusions: It is conceivable that low-frequency rTMS may be useful for improving USN and it is a promising therapeutic tool. Also, the cerebellum, by forming a neural network with the parietal and frontal lobe, may play an important role in patient recovery from spatial neglect.