Locked-in Syndrome as the Presenting Manifestation of Acute Vertebrobasilar Ischemic Stroke in a Previously Healthy 23-Year-Old Man

Background.Locked-in syndrome (LIS) is a rare state of near-complete voluntary motor paralysis with preserved consciousness and vertical oculomotor function, most often produced by ventral pontine infarction after acute basilar artery occlusion.Historical series reported mortality approaching 60% and severe residual disability among survivors.Contemporary endovascular recanalization has substantially altered this natural history.Case presentation.We describe a previously healthy 23-year--old man who first presented with sudden headache, unsteadiness, and presyncope, recovered, and was discharged.Hours later he developed diplopia, generalized weakness, and a rapidly declining level of responsiveness.Examination showed a Glasgow Coma Scale score of 5, anarthria, preserved vertical eye movements and blinking, tetraplegia, and spasticity (NIHSS 36).Vascular imaging demonstrated extensive thrombus from the V4 segment of the left vertebral artery through the proximal two-thirds of the basilar artery.Combined intravenous fibrinolysis and mechanical thrombectomy achieved complete recanalization (TICI 3).After extubation the patient reported having been fully conscious throughout the episode.Extensive etiological work-up identified only a patent foramen ovale with a mild right-to-left shunt; TOAST classification remained undetermined.At discharge NIHSS was 3 and modified Rankin Scale 1. Conclusions.Classic LIS may be the presenting phenotype of acute vertebrobasilar occlusion even in a young adult without vascular risk factors.Early recognition-particularly after a stuttering "pontine warning" prodrome-and immediate reperfusion can convert a historically catastrophic syndrome into near-complete functional recovery.