Convulsive-Like Movements in Posterior Circulation Large Vessel Occlusion: Associations With Midbrain Injury and Poor Outcome.

background and purposeConvulsive-like movements are an uncommon and frequently misinterpreted manifestation of posterior circulation stroke. Although they are often regarded as non-epileptic brainstem motor phenomena, their neuroanatomical substrates and prognostic implications in posterior circulation large vessel occlusion (LVO) remain poorly characterized. This study aimed to define the clinical and imaging correlates of convulsive-like movements and to evaluate their association with functional outcomes.

methodsWe performed a retrospective analysis of prospectively collected data from consecutive adults with posterior circulation LVO admitted between June 2017 and June 2025. Clinical and laboratory data were obtained from a prospectively maintained stroke registry. Neuroimaging was reviewed for ischemic topography and network involvement. Ninety-day functional outcomes were assessed using the modified Rankin Scale (mRS). Multivariable logistic regression was used to identify imaging features associated with convulsive-like movements and to assess the relationship between convulsive-like movements and 90-day functional outcome. Sensitivity analyses were performed in patients with complete neuroimaging and in the EVT-treated subgroup.

resultsA total of 269 patients were included (mean age, 62.0 ± 11.8 years; 76.6% male), and convulsive-like movements occurred in 35 patients (13.0%). Compared with patients without such movements, those with convulsive-like movements presented with more severe neurological deficits (median NIHSS score, 38 vs. 20; p < 0.001) and impaired consciousness (median GCS score, 4 vs. 8; p < 0.001). Midbrain infarction was significantly more frequent in patients with convulsive-like movements (46.4% vs. 19.7%; p = 0.001) and remained independently associated with convulsive-like movements in the imaging-complete subgroup (adjusted odds ratio [aOR], 3.61; 95% confidence interval [CI], 1.16-11.22; p = 0.027). Poor 90-day functional outcome occurred in 91.4% of patients with convulsive-like movements, compared with 62.8% of those without (p < 0.001). After adjustment for age, baseline NIHSS score, treatment modality, and basilar artery occlusion segment, convulsive-like movements remained independently associated with poor functional outcome (aOR, 6.38; 95% CI, 1.38-29.44; p = 0.018). In sensitivity analyses restricted to patients with complete neuroimaging and to EVT-treated patients, the direction and magnitude of this association were similar.

conclusionsIn posterior circulation LVO, convulsive-like movements are an underrecognized but clinically important presentation associated with midbrain injury and unfavorable functional outcome. These findings support improved recognition of this presentation and warrant further prospective validation.