Chorea-athetosis-like hyperkinetic seizures in temporal lobe epilepsy: insights from stereo-EEG in three patients.

Purpose: To characterize the clinical and electrographic features of temporal lobe epilepsy (TLE) presenting with chorea-athetosis-like hyperkinetic seizures and to delineate the underlying seizure network using stereo-electroencephalography (SEEG). Methods: We retrospectively reviewed 102 consecutive patients with drug-resistant TLE who underwent presurgical SEEG evaluation between January 2021 and October 2024 at a single tertiary epilepsy center. Three patients with brief, stereotyped chorea-athetosis-like movements during seizures were identified. Clinical, neuroimaging, SEEG, surgical, and follow-up data were analyzed, focusing on the seizure-onset zone, early propagation pathways, and the temporal relationship between ictal activity in cortical and deep structures and the emergence of hyperkinetic movements. Results: All three patients had focal seizures with auras and/or impaired awareness accompanied by transient chorea-athetosis-like movements. Structural MRI demonstrated unilateral temporal abnormalities in each patient. [^18F]FDG-PET showed predominantly ipsilateral temporal hypometabolism concordant with the epileptogenic zone and, in one patient, additional contralateral temporal hypometabolism. SEEG demonstrated seizure onset in the ipsilateral temporal pole or mesial temporal structures, with rapid propagation to the insula and posterior orbitofrontal cortex. Hyperkinetic movements invariably followed cortical ictal onset and coincided with widespread high-frequency activity in temporal and insular cortices. In one patient, the caudate head and thalamus were secondarily recruited without evidence of primary deep seizure onset. All patients underwent tailored temporal (± partial insular) resections and achieved Engel class I outcomes with complete resolution of chorea-athetosis-like seizures at 1-2 years. Conclusions: Chorea-athetosis-like hyperkinetic seizures in TLE appear to be cortically driven, with seizures arising from temporal cortex and propagating through a temporo-insular-orbitofrontal network before recruiting basal ganglia-thalamic structures. These findings highlight the importance of adequate SEEG coverage of temporal and insular regions to avoid misdiagnosis and to optimize presurgical evaluation and surgical planning.