Porencephaly is a very rare form of cephalic disorder that involves encephalomalacia. It is a type of neurological disorder of central nervous system that is characterized with formation of cysts and/or cavities within one’s cerebral hemisphere.
The term “Porencephaly” was first coined by Richard L. Heschl in the year 1859 for describing a cavity present in human brain.
What Happens in Porencephaly?
The cavities and cysts are generally formed as a result of destructive, cystic brain lesions. They can also be formed due to an abnormal development, inflammation, direct damage or hemorrhage of the brain. The cavities and cysts can cause numerous types of physical, neurological and physiological symptoms. In some patients, the disorder may only lead to some minor neurological problems and not cause disruption of intelligence on any way. On the other hand, many others may face serious life-threatening disabilities or even die prior to the 2nd decade of their lifespan. This disorder is usually more common among infants and can develop both prior to or after birth.
Porencephaly is a very rare condition and although the exact rate of prevalence of this cerebral disorder is not known, studies indicate that around 6.8% patients having cerebral palsy and/or 68% patients having epilepsy with congenital vascular hemiparesis are affected by it. Men are more prone to this disorder than women.
The condition results from a number of factors which are often unknown. These include destruction of the brain tissue as well as absence of cerebral development. Limited research in this field has suggested that Porencephaly is most likely caused by disturbances in the blood circulation which ultimately leads to brain damage. Experts believe that multiple factors like damage to brain tissue or abnormal brain development can influence the causation of this disease.
Porencephaly Risk Factors
The following risk factors play an important role in the development cavities and cysts associated with this condition:
- Abdominal traumas
- Chronic lung diseases
- Pathogenic infections
- Maternal cardiac arrest
- Trauma during pregnancy
- Drug abuse of the mother
- Mutations in gene COL4A1
- Mutations in factor V G1691A
- Brain contusion or cerebral injury
- Cystic periventricular leukomalacia
- Multifocal cerebrovascular insufficiency
- Abnormal cerebral development during birth
- Vascular occlusion – blood clotting of the vessels
- Prenatal and postnatal meningitis and encephalitis
- Hemorrhage or blood loss outside the circulatory system
- Vascular thrombosis or formation of blood clots within the blood vessels
- Cerebral degeneration, involving loss of the neuron structure and functions
- Cerebral hypoxia or reduced concentration of oxygen within the blood system
- Cerebral atrophy, involving loss of cerebral mass and decrease in neuron count and size
- Placental bleeding, leading to hindrance of blood and oxygen supply to the brain of an infant
- Internal bleeding caused by lack of sufficient blood and oxygen supply to the brain of an individual
- Maternal toxemia, i.e. brain damage caused when the toxins present within the circulatory system of the mother is transferred to the fetus
Patients diagnosed with this condition may display a wide array of symptoms that may range from mild to severe. Individuals suffering from severe porencephaly generally suffer from developmental delays and epileptic seizures. Mild cases of the disease are characterized by very little to complete absence of seizures and proper, healthy neurodevelopment.
The various signs and symptoms that are commonly associated with this disorder are mentioned below:
- Mental retardation
- Cerebral white-matter lesions
- Epilepsy and epileptic seizures
- Delayed development and growth
- Intellectual and cognitive disabilities
- Absent or poor speech development
- Hypotonia or reduced muscle strength
- Hemiplegia or paralysis of the appendages
- Degenerative or non-degenerative cysts or cavities
- Poor motor control and abnormal movements of the appendages
- Hydrocephalus or accumulation of the cerebrospinal fluid in brain
- Cerebral palsy, a motor condition that causes movement disabilities
- Tetraplegia or paralysis of the limbs leading to the loss of functionality
- Spastic paresis, which involves loss of or weakness in voluntary movement
- Blood vascular diseases like cerebral infarction and intracerebral hemorrhage
- Contractures that involves painful shortening of the muscles which affects motion
Trans-illumination of the skulls of infant patients can help to detect the presence of porencephalic cavities and cysts. This condition is generally diagnosed clinically by studying the medical history of the family history of a patient, conducting clinical observations and noticing certain physiological and neurological features that are characteristic of the disorder.
Medical imaging tests such as ultrasonography, magnetic resonance imaging (MRI) and computed tomography (CT) can be employed to exclude the possibility of presence of other neurological disorders. Diagnosis of porencephaly can be established antenatally using ultrasounds which show intraparenchymal cysts. A single cyst or a multiple number of cysts are observed that communicate with the subarachnoid space or the lateral ventricles. Bilateral clefts are commonly seen in schizencephaly. However, due to near-calvarial reverberation, missing a near-side lesion and making a diagnosis of the isolated unilateral porencephaly is totally possible. There might be consequent ventriculomegaly caused by ventricular communication with marked signs of asymmetric dilatation of lateral ventricles as well as occasional displacement of midline echo.
The clefts and cysts exert no serious pressure on the adjacent structures. Progression of the condition should be monitored by serial scans. Congenital midline porencephaly is diagnosed when a mid-line parietal scalp anomaly or a cephalocele is found along with hydrocephalus as well as a prominent mid-line intracranial cyst. Other assessments include intellect tests, speech tests and memory tests to help further establish the exact diagnosis of the disorder.
Porencephaly Differential Diagnosis
There are a number of health conditions that show signs and symptoms similar to that of Porencephaly. While determining the diagnosis for this disorder, doctors should differentiate against similar-appearing conditions for a better judgment of the medical status of patients. The differential diagnoses of Porencephaly include taking into consideration such conditions as:
- Arachnoid cysts
- Neuroglial cysts
- Interhemispheric cysts
- Obstructive hydrocephaly
- Alobar holoprosencephaly
- Spontaneous Intracranial Hematoma
At present, there is no cure for Porencephaly as the knowledge and resources available for this neurological disorder is very limited. However, there are various treatment options that can be used to manage this condition. These include:
- Physical therapies
- Neurosurgery for removing the cysts
- Medications for seizures or epileptic episodes
- Usage of a shunt to remove the excess fluid from the brain
Depending on the location, the extent of a lesion, the size of cavities as well as the severity of the condition, a combination of various treatment methods can be imposed. In order to control the seizures in Porencephaly patients, various medications such as carbamazepine, valproate and clobazam can be used. Administration of anti-epileptic drugs is another way of treating epileptic tendencies.
The intensity of symptoms associated with this condition varies significantly across affected population and depends on the cyst’s location and the damage it causes to the brain. Some patients of Porencephaly may only experience some minor neurological problems and can live perfectly normal lives. Self-care is possible in cases of low severity. However, lifelong treatment and monitoring is necessary for the most serious cases. For people having severe disability, an early diagnosis should be followed by medication, rehabilitation to restore motor skills as well as speech and communication therapies. These can significantly alleviate the symptoms and help sufferers to have a healthy, normal life. Infants with this condition can display appropriate movement and communication skills when given proper treatment. In the most critical situations, patients die at a very early age.
Serologic testing for the detection of cytomegalovirus should be seriously considered during pregnancy. As there are no reported associations with any chromosomal disorders, it is not necessary to conduct amniocentesis for karyotyping. Genetic counseling can lower the risk of recurrence when associated with familial cases. After labor, the health of a mother should be observed by a team of experts including pediatrics, neurologists and physiotherapists.
These images would give you a more detailed idea as to the nature of this health condition.
Picture 1 – Porencephaly
Picture 2 – Porencephaly Image
As long as Porencephaly is mild, it can be managed with treatment. Severe cases of the condition can be fatal. There is a dearth of information as to the actual nature of this condition, and currently research is being conducted to find out more about this disorder of the brain.