Late presentation of basilar artery infarct secondary to embolism from a superior left vertebral artery dissection. The patient was initially thought to have had symptoms of dehydration, with stroke not considered as part of the differential diagnosis. This was possibly secondary to the relatively young age of the patient as well as non-specific symptoms. Facial droop and unilateral weakness were very subtle features at the initial presentation. However, symptoms did not improve with intravenous fluids. The patient unfortunately progressed to locked-in syndrome.

CT demonstrates the typical features of acute basilar artery occlusion including the hyperdense vessel sign as well as hypoattenuation. The hyperdense vessel sign is the earliest abnormality identifiable on non-contrast CT and is seen in approximately 50-70% of patients with basilar artery thrombosis ¹.