Porencephalic cysts are cavities seen in the cerebral hemispheres, that may arise due to past hypoxia-ischemia, vascular occlusion (stroke), haemorrhage, or infection. These cysts may co-exist with other structural sequelae of the original cerebral insult or with hippocampal sclerosis.
The clinical presentation of a porencephalic cyst relates to the location of the cyst and to the antecedent insult. Seizure onset can occur from birth, or later, but is usually in the first decade of life. Individuals may have motor impairment (such as hemiparesis), developmental impairment and/or cognitive impairment.
CAUTION developmental and cognitive outcome may be worse in children with uncontrolled seizures in early life, especially if epileptic spasms or generalized seizure types appear, therefore proactive seizure control, which may include consideration of epilepsy surgery, is important in these patients.