Author: Jaclyn Tencer, MD; Sonika Agarwal, MBBS, MD, Children’s Hospital of Philadelphia 
Reviewed: April 2021 

SUMMARY

In porencephaly (or cystic encephalomalacia), a fluid-filled cyst develops in brain tissue. The fluid consists of cerebrospinal fluid (CSF). CSF is the clear fluid that normally bathes the central nervous system. The central nervous system is made up of the brain and the spinal cord. CSF helps cushion these important parts of our body. It can prevent injury to them. It also helps provide nutrients to the brain and clear its waste products.  

Porencephaly is a structural abnormality of the brain. It may manifest before or after birth. It has many causes. For instance, it can appear after a brain injury. Stroke, bleeding, or infection can cause the brain injury. In porencephaly, CSF fills the injured area. This creates the fluid-filled cyst.  

These cysts may also appear due to abnormal brain development. Abnormal brain development may have no clear cause. However, on rare occasions, it can be related to an inherited genetic condition. 

Disorder Overview

SIGNS AND SYMPTOMS

Symptoms of porencephaly vary widely. An individual with porencephaly may be asymptomatic. Some patients with very mild or no symptoms are not even diagnosed. Other patients may have severe symptoms. Those with severe symptoms are often diagnosed soon after birth. 

Symptom severity depends on a few factors. First, the location and size of the porencephalic cyst matters. A cyst that disrupts normal brain functions will likely cause symptoms. Different areas of the brain control different parts of the body. Therefore, a cyst affecting one area of the brain will cause symptoms in the corresponding part of the body.  

Symptom severity also depends on whether the porencephaly is associated with prior brain injury or with developmental abnormalities.  

Symptoms in one individual may be very different from those in another individual. The spectrum varies widely for each child. 

DIAGNOSIS 

Porencephaly can be diagnosed during or after pregnancy. During pregnancy, it is diagnosed through one of two types of neuroimaging. The first option is an ultrasound. The second option is magnetic resonance imaging (MRI). Neuroimaging can look at the developing brain of a baby in the womb.  

Porencephaly can also be diagnosed in the first few years of life. Sometimes a primary care physician refers a baby with suspected neurological problems to a specialist. This specialist will likely be a child neurologist. Some child neurologists focus on babies with brain-related diseases.  

This specialist will check if the baby is meeting developmental milestones. Such milestones include sitting, crawling, walking, or speaking. The specialist will do a neurologic examination and look at the baby’s muscle tone, strength, reflexes, and more. After that, the specialist may order neuroimaging. The specialist may also order blood tests or refer the baby to other specialists. 

CAUSES

Porencephaly has a wide range of causes. Some of them can be identified. Many others remain unknown. Generally, however, prior injury to the brain causes porencephaly. These injuries are usually caused by blood clots, bleeding or abnormal vessel formation. The injuries can stem from either a medical condition or a genetic difference. 

LABORATORY INVESTIGATIONS

Porencephaly is most commonly identified through brain imaging. Brain imaging methods include CT scans, ultrasounds, or MRIs. These tests are usually ordered after symptoms are first noticed. 

Once it is identified with imaging, doctors can evaluate the causes of the disease. These evaluations will take different forms depending on a patient’s symptoms. Following are two common routes for investigation. 

If There Is a Clear Cause… 

Sometimes, there is a clear cause of brain injury. This might include maternal physical trauma during pregnancy. Or it might include maternal drug use. In these cases, further evaluation of the cause may not be needed.  

TREATMENT AND THERAPIES

There is no clear cure for porencephaly. This structural abnormality cannot be reversed. However, there are treatments that can help with symptoms arising in the aftermath of porencephaly. 

Symptoms and Available Treatments 

• Cognitive, speech, language, or motor delays. Physical therapy, occupational therapy, special instruction, and speech therapy can be very effective. 
• Learning challenges. Working closely with school systems to generate individualized educational plans and support can be helpful. Special education programs can also help. 
• Seizures. Various medications can be used to treat seizures. There may be dietary and surgical options as well 
• Spasticity. Medications can manage high tone or stiffness in muscles. For instance, injections of botulinum toxin can help loosen muscles or medications such as baclofen are commonly used.  
• Adaptive equipment. Braces and adaptive equipment can significantly improve a child’s functioning and quality of life. 
• Hydrocephalus. This is increased pressure in the brain. Depending on the specific location of the porencephaly, a resection or surgical shunt can relieve this pressure. 

EARLY INTERVENTION

OUTLOOK

Outcomes can vary widely depending on the size and location of the fluid-filled cysts. Some children have mild or no symptoms. They may not even be diagnosed.  

Others may have some mild learning challenges. They may have treatable seizures or motor tone abnormalities. Children in this moderate category do very well with supportive treatment.   

Still others may have more severe secondary symptoms. They may have larger cysts. Their cysts may be in problematic brain locations. These children may have been diagnosed soon after birth. Supportive care, therapies, and special education programs can go a long way. They can improve the long-term outcomes of these children.  

Supports at school or in community settings may be available. They will likely be based on the abilities of an individual child. Therapies are likewise individualized. 

RELATED DISORDERS

The following disorders can have features that overlap with porencephaly: 

Research 

ClincalTrials.gov for porencephaly (birth to 17 years) are clinical trials that are recruiting or will be recruiting. Updates are made daily, so you are encouraged to check back frequently.  

ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world. This is a resource provided by the U.S. National Library of Medicine (NLM), which is an institute within the National Institutes of Health (NIH). Listing a study does not mean it has been evaluated by the U.S. Federal Government. Please read the NLM disclaimer for details.   

Before participating in a study, you are encouraged to talk to your health care provider and learn about the risks and potential benefits.  

The information in the CNF Child Neurology Disorder Directory is not intended to provide diagnosis, treatment, or medical advice and should not be considered a substitute for advice from a healthcare professional. Content provided is for informational purposes only.  CNF is not responsible for actions taken based on the information included on this webpage. Please consult with a physician or other healthcare professional regarding any medical or health related diagnosis or treatment options. 

1. National Institutes of Health,“Porecenphaly Information Page”
https://www.ninds.nih.gov/Disorders/All-Disorders/Porencephaly-Information-Page 

2. National Organization for Rare Disorders,“Sporadic Porecenphal”
https://rarediseases.org/rare-diseases/sporadic-porencephaly/  

3. Orphanet, “Porencephaly”
https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=2940