ABSTRACT NUMBER: ESOC2026A2189 CHRONIC DYSAUTONOMIA AS A RARE SEQUELAE OF THALAMIC ISCHEMIC STROKE: A CASE REPORT

Abstract Background and aims To describe a rare but clinically relevant complication of thalamic ischemic stroke: chronic dysautonomia, and to contextualize its infrequency based on current literature. Methods We report the case of a 44-year-old man, smoker and without significant cardiovascular risk factors, admitted for acute right-sided hemisensory symptoms on awakening. Brain MRI revealed an acute ischemic lesion involving the left lateral thalamic nuclei, consistent with a small-vessel thalamic infarction. An extensive etiological work-up was unremarkable; a patent foramen ovale with minimal shunt was closed due to the absence of alternative causes. Neurological recovery was favorable, with mild residual sensory symptoms and minimal gait ataxia (modified Rankin Scale 1–2). In the months following the stroke, the patient developed recurrent presyncopal and syncopal episodes with pallor, diaphoresis, heat sensation, and postural or situational triggers. Autonomic evaluation, including tilt-table testing, demonstrated a marked vasovagal response with severe hypotension, confirming significant autonomic dysfunction consistent with chronic dysautonomia. Results The patient evolved to persistent dysautonomia, refractory to non-pharmacological measures and poorly tolerant to pharmacological treatment. Conclusions Chronic dysautonomia is an infrequent and poorly quantified sequelae of thalamic ischemic stroke. While autonomic dysfunction after stroke is well described, most data focus on acute or subacute phases, and chronic manifestations following isolated thalamic lesions remain exceptionally rare. This case highlights the thalamus’ role in central autonomic networks and highlights the need for longitudinal studies and standardized definitions to better characterize this complication. Conflict of interest Aida Rodriguez Valer: nothing to disclose.