Hemichorea in a patient with ipsilateral cortical infarction: a case report

BACKGROUND: Hemichorea is usually caused by contralateral deep structures of brain. It rarely results from acute cortical ischemic stroke and that caused by ipsilateral brain lesions is even rarer. CASE PRESENTATION: A 64-year-old female presented with acute obtuseness and left-sided hemichorea. She had a history of right frontal lobe surgery and radiotherapy due to brain metastasis from lung cancer 8 years ago. MRI revealed acute left frontal lobe infarction in addition to an old right frontal lobe lesion. 18FDG PET-CT showed hypometabolism in the left frontal lobe and hypermetabolism in the right basal ganglia region and central sulcus. The choreatic movement remitted after antipsychotic treatment. CONCLUSION: The mechanism of hemichorea after ipsilateral cortical infarction is poorly understood. We assume both previous contralateral brain lesion and recent ipsilateral ischemic stroke contributed to the strange manifestation in this case. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12883-021-02420-4.