Brain Networks Tied to Post-Stroke Dizziness

TOPLINEDizziness after ischemic stroke was associated with a consistent brain network involving cerebellar and occipital cortical regions, a study showed. This network remained stable across both infratentorial and supratentorial lesions and across different dizziness subtypes, suggesting the involvement of distributed visual, vestibular, and multisensory systems.METHODOLOGYA secondary analysis of the multicenter randomized INSPiRE-TMS trial included 484 patients (mean age, 67.3 years; 30.8% women) with acute ischemic stroke who had visible lesions on MRI within 7 days of symptom onset and documented assessment of dizziness at admission.Researchers performed lesion symptom mapping (LSM) and lesion network mapping (LNM) to identify brain regions and networks associated with dizziness, using a normative connectome from 1000 healthy participants.Patients were included from stroke units across Germany; median National Institutes of Health Stroke Scale score at admission was 2, and median diffusion-weighted imaging lesion volume was 0.96 mL.Patients were stratified by lesion location (supratentorial vs infratentorial) and by dizziness phenotype (vertigo vs swaying dizziness) to assess network consistency.Spatial similarity analysis compared the dizziness-related network with established vestibular cortex maps from the Julich-Brain and Brainnetome atlases.TAKEAWAYDizziness was reported in 32.4% of patients at admission and was more common in those with infratentorial lesions (51.0% vs 17.4%, P < .0001) and in women (36.9% vs 27.8%, P = .042). Patients with dizziness had significantly higher rates of hemianopia than those without dizziness (35.1% vs 15.6%; P < .0001).LSM identified significant clusters in the left cerebellar lobules VI, Crus I–II, VIIb, and VIIIa, as well as the bilateral lobule IX and the vermis, which showed positive functional connectivity with occipital cortical regions including the lateral occipital cortex, occipital pole, occipital fusiform gyrus, and lingual gyrus.LNM revealed a consistent dizziness-related network involving cerebellar and occipital regions (P = .015). The infratentorial and supratentorial dizziness-related networks showed partial spatial overlap with each other, and each was significantly similar to the dizziness-related network derived from the whole cohort.In exploratory subtype analyses, the vertigo-related and swaying dizziness-related networks were spatially similar to each other and to the whole-cohort network ( all P < .001). Vertigo was more strongly associated with the cerebellar vermis; swaying dizziness was linked to broader cerebellar hemispheres.IN PRACTICE"These findings provide network-level correlates of post-stroke dizziness and offer a framework for future studies incorporating detailed vestibular phenotyping and individualized functional imaging. Improved characterization of these network correlates may contribute to better recognition of post-stroke dizziness and inform future diagnostic and therapeutic strategies," the authors wrote.SOURCEThe study was led by Yunyou Tang, Charité–Universitätsmedizin Berlin, Berlin, Germany. It was published online on August 12 in the Journal of Neurology.LIMITATIONSDizziness assessment relied on patient-reporting, and was susceptible to misclassification. Some patients may have reported pre-existing or chronic symptoms rather than new ones, and the study couldn't systematically distinguish spontaneously reported from elicited symptoms. There was no systematic oto-neurological examination, so dizziness could only be classified from patient report and routine clinical documentation.DISCLOSURESThe study was funded by a Project of the Collaborative Research Center ReTune Transregional Collaborative Research Centre. Several authors reported having financial relationships with various organizations. Details are provided in the original article.This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.