Isodense cerebellar hematoma

One week after chiropractic manipulations, a 60-year-old normotensive man suffered acute onset of vertigo, ataxia, and dysarthria. CT disclosed an isodense mass of the posterior fossa. Vertebral arteriography showed that the avascular mass arose from the right cerebellar hemisphere. Hydrocephalus developed, and suboccipital craniotomy revealed a large cerebellar hematoma due to a small arteriovenous malformation. A similar episode occurred 2 months later. CT isodense cerebellar hematomas should be considered before giving anticoagulant therapy.