rTMS reduces cortical imbalance associated with visual hallucinations after occipital stroke

To investigate the efficacy of multiday repetitive transcranial magnetic stimulation (rTMS) to the occipital cortex in a patient with continuous visual phosphene hallucinations for more than 2 years following occipital stroke.

Low-frequency rTMS (1 Hz) was applied to the lesion site for 30 minutes daily over 5 consecutive days. Functional MRI (fMRI) was performed before and after rTMS treatment.

Increased application of rTMS corresponded with a reduction in intensity of visual phosphene hallucinations and was reflected in altered blood oxygen level-dependent signal. fMRI revealed focal excitatory discharges at the border of the lesion, highlighting the origin of phosphenes. Post-rTMS, rTMS did not simply suppress activity in the patient but rather redistributed the previously imbalanced cortical activity not only at the stimulation site but in remote cortical regions so that it more closely resembled that of controls.

This case is rare in its presentation of chronic continuous visual phosphene hallucinations following occipital stroke. We present a case of multiday application of rTMS to visual cortex and demonstrate that rTMS provides a valuable therapeutic intervention in modulating visual hallucinations following occipital damage.

This study provides Class IV evidence in a single-case report that multiday rTMS reduces intrahemispheric and interhemispheric imbalance and associated visual phosphene hallucinations following occipital stroke.