Pressure from supratentorial hematomas and the accompanying edema may cause transtentorial herniation, compressing the brain stem and often causing secondary hemorrhages in the midbrain and pons. If the hemorrhage ruptures into the ventricular system, blood may reach the subarachnoid space. Cerebellar hematomas can expand to block the ventricular system, causing acute hydrocephalus, or dissect into the brain stem. Either course can produce stupor or coma. Symptoms and Signs Symptoms typically begin abruptly with headache, followed by steadily increasing neurologic deficits.
Loss of consciousness is common, occurring within a few minutes after onset or developing gradually.
Nausea, vomiting, delirium, and focal or generalized seizures are also common. In survivors, consciousness returns and neurologic deficits gradually diminish as the extravasated blood is resorbed. Some degree of impairment usually remains, including some dysphasia if the dominant hemisphere was affected, but many patients make a reasonable functional recovery, especially from hemorrhages in silent areas. Small hemorrhages cause focal deficits like those in ischemic stroke. CT is the procedure of choice because hemorrhage is so easily seen as hyperintensity.