Neuroanatomical correlates of stroke-related dizziness and vertigo: secondary analysis from the INSPiRE-TMS trial.

Dizziness and vertigo are common and debilitating neurological symptoms among patients visiting the emergency department (ED). Possibly because the symptoms are not captured by standard stroke severity tools such as the NIHSS (National Institutes of Health Stroke Scale), their network-level neuroanatomical correlates-particularly potential supratentorial contributions-remain incompletely characterized. Therefore, we aim to investigate the neuroanatomical substrates of post-stroke dizziness and vertigo. This retrospective analysis included patients with acute ischemic stroke from the randomized controlled INSPiRE-TMS trial. Each patient underwent MRI within seven days of symptom onset, and stroke severity was assessed using the NIHSS at hospital admission. Patients were assessed for broadly defined new-onset dizziness/vertigo associated with the acute cerebrovascular event. Lesion symptom mapping (LSM) and lesion network mapping (LNM) were used to investigate associations between lesion location, functional connectivity, and dizziness/vertigo. Among 484 patients, 32% (n = 157) reported dizziness at stroke onset. Notably, dizziness was reported in 22% (77/347) of patients with supratentorial lesions, compared with 58% (80/137) of those with infratentorial lesions. Patients with dizziness were more often female (36.9% vs. 27.8%, p = 0.042) and more frequently had hemianopia (35.1% vs. 15.6%, p < 0.0001). LSM identified cerebellar clusters (left lobules VI, Crus I-II, VIIb, VIIIa, and bilateral lobule IX with the vermis) associated with visuospatial and multisensory processing. LNM revealed a dizziness network involving left-dominant cerebellar regions, the brainstem, and higher-order visual areas, including the occipital pole, lingual gyrus, and fusiform gyrus. This network remained robust across subgroups stratified by lesion location (supra- vs. infratentorial) and after adjusting for age, sex, lesion volume, and hemianopia. Exploratory subtype comparisons suggested that lesions associated with vertigo showed relatively stronger connectivity to midline cerebellar structures (vermis), whereas those associated with swaying dizziness involved broader cerebellar hemispheres, although the overall network pattern was spatially similar and centered on the cerebellum. In conclusion, broadly defined post-stroke dizziness/vertigo symptoms were associated with a consistent lesion network involving cerebellar and occipital regions, suggesting involvement of distributed visual, vestibular, and multisensory brain systems. These findings may help guide future studies aimed at improving diagnostic evaluation and treatment of affected patients. ClinicalTrials.gov (NCT01586702; https://clinicaltrials.gov/ct2/show/NCT01586702 ); first registry in April 2012; first patient recruitment: September 2011.