Vertebral artery dissection induced lateral medullary syndrome characterized with severe bradycardia: a case report and review of the literature

Abstract

Lateral medullary syndrome is the most common type of brainstem infarction. Lateral medullary syndrome results in damage to the corresponding cranial nerve nuclei and the nucleus tractus solitarius, with vertigo, ipsilateral ataxia, crossed sensory disturbances, Horner's sign, bulbar palsy, and other underlying symptoms or signs. However, cases with cardiac arrhythmia and other autonomic dysfunctions as the primary manifestations are less common. Clinically, sudden death occasionally occurs in patients with lateral medullary syndrome, which may be associated with severe cardiac arrhythmia. These patients may suffer in life-threatening arrhythmia and even cardiac arrest, and vital signs should be closely monitored to prevent sudden death. In younger patients, vertebral artery dissection is the most common cause. Here, we present a case of lateral medullary syndrome caused by vertebral artery dissection with severe bradycardia. The patient was a 49-year-old man who was admitted with "sudden onset of numbness in the left limbs and right side of the face for 1 hour". Electrocardiogram (ECG) monitoring showed a repeated heart rate decrease to as low as 23 beats/min, followed by a gradual increase in heart rate to 35-55 beats/min after 2-3 seconds. Head magnetic resonance imaging (MRI) examination revealed right dorsolateral cerebral infarction of the medulla oblongata. Digital subtraction angiography (DSA) revealed a right vertebral artery dissecting aneurysm. We performed an emergency placement of a temporary pacemaker, followed by conservative treatment with platelet aggregation inhibitors, vascular softening agents and improved collateral circulation. Elective spring coil embolization of the vertebral artery dissecting aneurysm and stent implantation were performed. At outpatient follow-up, the patient had a good prognosis. Clinical management of patients with lateral medullary syndrome should be prioritized, with close cardiac monitoring at the early stages of observation and pacemaker placement and tracheal intubation as required to prevent adverse events.