Basilar Invagination Secondary to Atlantoaxial Instability Presenting as Posterior Circulation Stroke in a Young Patient with Short Neck: A Case Report

Basilar Invagination (BI), a type of Craniovertebral Junction (CVJ) anomaly, is usually diagnosed after the patient develops neurological signs of compression of the medulla, upper cervical cord, and lower cranial nerves. The number of patients presenting with posterior circulation ischaemia strokes as a result of BI is small. Thus, it might take longer to reach the correct diagnosis in the younger, vascular-healthy patients. Hereby, the authors present a case report of a 30-year-old male with headache, dizziness, progressive weakness of all limbs, and difficulty swallowing for a week. Neurological exam findings were consistent with spastic quadriparesis. On physical exam, he exhibited signs of skeletal distortion, a short neck, and a hairline much lower than normal. Magnetic Resonance Imaging (MRI) of the brain showed a recent left cerebellar parafalcine infarct, and vertebral artery thrombosis was noted on Magnetic Resonance Angiography (MRA). MRI of the cervical spine revealed associated CVJ anomalies with atlantoaxial dislocation and atlanto-occipital fusion. The present case underscores the importance of looking for external skeletal changes in the evaluation of young stroke patients with unexplained posterior circulation ischemia. In patients presenting with unexplained posterior circulation ischemia, screening for CVJ anomalies should be performed; if identified, this can subsequently provide a timely diagnosis and treatment.