Imaging technologies such as ultrasound, x-ray computerized tomography, and magnetic resonance imaging (MRI ) can diagnose porencephaly before or after birth

Most persons with porencephaly die before reaching adulthood. Each individual's prognosis will depend on the location and severity of the lesions on their cerebrum.

Porencephaly cysts can be a dangerous problem. These types of cysts often cause small neurological damage where they exist. This damage can become extensive.

Persons with porencephaly may suffer early death, epilepsy , moderate or severe mental retardation , blindness, epilepsy, rigidity, and paralysis.

A 1984 study of 18,000 patients with seizure disorder or retarded neural development that 11 had porencephaly, a rate of 1:1650 in that abnormal population.