A 57-year-old man with a history of hypertension was well until he noticed right-handed clumsiness. One year later he was evaluated for slowly progressive right hemiparesis. He had no history of transient ischemic attacks or stroke. On examination he was alert and oriented. The pupils were equal and reactive to light; eye movement was full and smooth. There was no ptosis or facial palsy; his speech was fluent. The soft palate moved symmetrically. The tongue was deviated to the left on protrusion, with atrophy and fasciculation on its left side noted. He had hemiparesis, hyperreflexia, and extensor plantar reflex on the right. Proprioception and vibratory sense were impaired on the right side, but pain and temperature sensations were intact. There was no sign of cerebellar ataxia. These neurological findings constituted the medial medullary syndrome of Déjérine. A contrast-enhanced computed tomographic scan revealed a large calcified mass in the posterior fossa and dorsally displaced vertebral artery trunk compressing the cerebellum and the lower part of the brainstem (Figure 1A, arrow). Magnetic resonance imaging was not useful owing to artifact caused by his denture. Left vertebral angiogram demonstrated irregularly shaped fusiform dilatation and marked posterior dislocation of the vertebral artery (Figure 1B, arrowheads), confirming the diagnosis of dissecting aneurysm. He was treated conservatively with antihypertension drugs and has been neurologically stable for 7 years. A recent computed tomographic scan showed no further enlargement of the aneurysm.
Kurita H, Kawamoto S, Ueki K, Kirino T. Déjérine Syndrome Caused by an Aneurysmal Compression. Arch Neurol. 2000;57(11):1639-1640. doi:10.1001/archneur.57.11.1639