What is hydranencephaly?
Hydranencephaly is a rare condition in which the brain's cerebral hemispheres are absent and replaced by sacs filled with cerebrospinal fluid. An infant's head size and spontaneous reflexes such as sucking, swallowing, crying, and moving the arms and legs may all seem to be okay. However, after a few weeks the infant usually becomes irritable and has increased muscle tone. After a few months of life, seizures and hydrocephalus (excessive accumulation of cerebrospinal fluid in the brain) may develop. Other symptoms may include:
- Visual impairment
- Lack of growth
- Spastic quadriparesis (paralysis)
- Intellectual deficits
Hydranencephaly is considered to be an extreme form of porencephaly (a rare disorder characterized by a cyst or cavity in the cerebral hemispheres) and may be caused by vascular infections or traumatic disorders after the 12th week of pregnancy.
Diagnosis may be delayed for several months because early behavior appears to be relatively typical. Some infants may have additional abnormalities at birth including seizures, myoclonus (spasm or twitching of a muscle or group of muscles), and respiratory problems.
How can I or my loved one help improve care for people with hydranencephaly?
Hydranencephaly is considered a rare disease, which often means there is not much information known about it. This is usually the case because doctors and researchers do not see many people with hydranencephaly, which makes it hard to learn from them through observations or large studies.
Consider participating in a clinical trial so clinicians and scientists can learn more about hydranencephaly and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.
All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.
For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with hydranencephaly at Clinicaltrials.gov.
Where can I find more information about hydranencephaly?
Information may be available from the following resources:
Genetic and Rare Diseases (GARD) Information Center
March of Dimes
National Organization for Rare Disorders (NORD)
Phone: 203-744-0100 or 800-999-6673; 844-259-7178 Spanish