Porencephaly is a rare disorder of the central nervous system. It involves cysts or cavities in a cerebral hemisphere. The cysts or cavities are usually the remnants of destructive lesions. These are due to stroke or infection. But they are sometimes the result of abnormal development. The disorder can occur before or after birth. Most infants show symptoms shortly after birth. Diagnosis is usually made before age 1.


Signs may include:

  • Delayed growth and development.

  • Slight or incomplete paralysis (spastic hemiplegia).

  • Low muscle tone (hypotonia).

  • Seizures. These are often infantile spasms.

  • Large head (macrocephaly).

  • Small head (microcephaly).

Individuals with this disorder may have:

  • Poor or absent speech development.

  • Epilepsy.

  • Hydrocephalus.

  • Spastic contractures. This is shrinkage or shortening of a muscle.

  • Mental retardation.


Treatment may include:

  • Physical therapy.

  • Medication for seizure disorders.

  • A shunt for hydrocephalus.