Hemiballismus is an uncommon manifestation of cerebral damage, typically seen in patients with infarcts of the subthalamic nucleus (STN). Cortical hemiballismus is a rare complication of stroke, usually involving the parietal cortex. It is often self-limiting and has a good prognosis. To our knowledge, this is the first reported case of cortical hemiballismus associated with an isolated insular and temporal infarct.

A 67-year-old male exhibited sudden left upper and lower extremity weakness along with right gaze deviation. NIHSS was 5 at admission with right facial droop, left visual field defect, and mild left sided weakness. CT angiogram revealed a distal right inferior M2 thrombus; ASPECTS score was 9. He was within the therapy window, received thrombolysis, and symptoms resolved in the next 6 hours. MRI brain revealed an area of restricted diffusion in the right insula and temporal cortex without any subcortical involvement. Within 48 hours after presentation, he developed left-sided involuntary, irregular, and jerky appendicular flinging movements. EEG did not reveal any epileptiform discharges and toxic metabolic causes were ruled out. Left sided hemiballismus resolved in the next 2 days without intervention and he was discharged without focal neurological deficits.

Here, we present the first documented case of an isolated right insular and temporal lobe infarct, leading to a transient development of hemiballismus. This supports the shifting paradigm that direct thalamic-subthalamic damage is not necessary for the development of hemiballismus. This further suggests that apart from the parietal cortex, the insula may also play in a role in the movement pathway and any disruption in these nearby tracts may result to a spectrum of movement disorders, such as hemiballismus.