Pulsatile Culprits: Two Cases of Vertebral Artery Medullary Compression Syndrome

Vertebral artery medullary compression syndrome (VAMCS) is an uncommon neurovascular condition caused by tortuous or ectatic vertebral arteries producing focal compression of the medulla oblongata or cervicomedullary junction. Clinical manifestations are heterogeneous and may include vertigo, imbalance, ataxia, dysphagia, dysarthria, pyramidal tract signs, sensory disturbances, and limb weakness, depending on the site and severity of compression. Because vertebral artery indentation of the medulla may also occur incidentally in asymptomatic individuals, diagnosis requires clinical correlation and exclusion of alternative pathologies. We present two cases demonstrating different scenarios of VAMCS. The first case involved a 77-year-old woman presenting with acute left-sided hemiparesis. MRI demonstrated acute infarcts involving the right insular and occipital cortex and right corona radiata, along with chronic ischemic changes. Additional imaging revealed a tortuous and mildly ectatic dominant left vertebral artery, causing focal compression of the left anterolateral medulla. The coexistence of ischemic infarcts represented a confounding factor in differentiating symptomatic neurovascular compression from concurrent cerebrovascular disease. The second case involved a 46-year-old man presenting with chronic right-sided limb weakness, imbalance, and ataxia. MRI demonstrated focal compression of the medulla by a prominent left vertebral artery and posterior inferior cerebellar artery branch without associated intrinsic medullary signal abnormality. No acute infarct or alternative posterior fossa pathology was identified. In the absence of competing structural lesions, the findings were considered consistent with isolated symptomatic VAMCS. These cases emphasize the importance of evaluation of the cervicomedullary junction on MRI, especially in patients with unexplained posterior fossa or pyramidal tract symptoms. High-resolution MRI and MR angiography play a critical role in demonstrating neurovascular compression and excluding alternative diagnoses. Greater awareness of this uncommon entity may help improve recognition and avoid underdiagnosis.