Health & Care Information
Learn all about microhydranencephaly causes, symptoms and treatment. Microhydranencephaly (MHAC) is a severe abnormality of brain development characterized by both microcephaly and hydranencephaly.
Hereditary Microhydranencephaly MHAC is inherited in an autosomal dominant manner. Microhydranencephaly MHAC is characterized by left ventricular hypertrophy in the absence of a predisposing cardiac or cardiovascular condition.
The manifestation of Microhydranencephaly MHAC is extremely variable, even within the same family, and can range from asymptomatic to progressive heart failure. Other features include syncope, presyncope, shortness of breath, chest pain, orthostasis, and palpitations. The onset of Microhydranencephaly MHAC is usually during adolescence or young adulthood; however, it can range from infancy to much later in adult life.
Microhydranencephaly is an extreme form of porencephaly (another rare disorder of the central nervous system which involves the existence of a cyst or cavity within the cerebral hemisphere) in which the cerebral hemispheres are absent and replaced by sacs filled with cerebrospinal fluid and remains the most severe form of bilateral cerebral cortical destruction.
The prevalence of Microhydranencephaly MHAC is approximately 1 in 500 and ~55-70% of cases are caused by a mutation in one of the genes that encode a part of the sarcomere.
What is Microhydranencephaly (MHAC)?
Microhydranencephaly (MHAC) is a severe neurodevelopmental defect characterized by extreme microcephaly, profound motor and mental retardation, spasticity, and incomplete cerebral formation. It is characterized by microcephaly with severe reduction of brain hemispheres and intracranial space filled with cerebrospinal fluid without signs of intracranial hypertension.
Microhydranencephaly Cause
The exact, underlying cause of microhydranencephaly is unknown. There are reports of families in which the condition is caused by changes (mutations) in the NDE1 gene. In these rare cases, more than one family member (often a pair of siblings) had the condition. There is also suspicion that lack of blood flow or oxygen to a developing child could also lead to microhydranencephaly. A traumatic occurrence of sorts, resulting in prenatal stroke, is believed to be the primary cause of hydranencephaly. Some possibilities include: intrauterine infection, environmental exposure to toxins, vascular insult of another nature, and twin-to-twin transfusion. Some researchers have also suggested the possibility of a genetic component, though only one case has been documented in which a family has been presented this diagnosis for more than one child.
Microhydranencephaly Symptoms
Microhydranencephaly symptoms are;
- Impaired vision
- Growth issues (mental / physical)
- Intellectual issues (speech impairment)
- Mental Retardation
- Irritability
- Poor feeding habits
- Seizures (infantile spasms)
- Rigid motion of arms / legs
- Still other infants display no obvious symptoms at birth, going many months without a confirmed diagnosis of hydranencephaly. In some cases a severe hydrocephalus, or other cephalic conditions, diagnosis is misdiagnosed.
Microhydranencephaly Treatment
There is no cure for microhydranencephaly. Treatment is symptomatic; meaning associated conditions are treated to ensure the best quality of life possible. While the inevitable cannot be avoided entirely; with proper management of these associated symptoms and a proactive care team, the ability for the child to thrive is far greater.
Surgery for placement of a shunt, in cases where hydrocephalus (accumulation of excess cerebrospinal fluid) is apparent, is advised. Not only has this proven to reveal a less than terminal alternate diagnosis in rare cases, with the presentation of “simply” hydrocephalus without the lack of cerebral cortex, but also ensures the child is not living in unnecessary discomfort. While hydrocephalus is common amongst children given this diagnosis, several children display as microcephalic (smaller than average cranial circumference) or present as typical in appearance as well.
Hydrocephalus is treatable with surgery (cerebral shunt), this method is to deter the effects of brain swelling which is caused by cerebral fluid retention (fluid buildup). If left untreated the condition will worsen due to the increase of pressure which can crush brain tissue matter (cerebral shunt is connected to the catheter while the other end is place in the peritoneal cavity).
Microhydranencephaly survivors
Six-year-old Kaliyasha Barrett has defied the odds and doctors’ predictions that she would die soon after being born with the upper-most section of her brain, the cerebral cortex, missing. She’s a survivor. Also jaxon with the half part of skull is a survivor.
Jaxon Strong, Baby with Half Skull
Jaxon has reached his second birthday. Jason Buell, aka Jax Strong was born with a defect called Microhydranencephaly, in which he’s missing much of his skull and brain. He wasn’t supposed to survive pregnancy, much less a full year of life. The parents, Brandon and Brittany Buell, were given the option by their doctors to terminate the pregnancy, since they knew what was wrong before Jaxon was born.
They said no. It wasn’t until Jaxon turned one that he was finally diagnosed with a rare, incurable, and often deadly brain malformation called Microhydranencephaly. They get the question all the time if his case is linked to Zika. Doctors have said that it is definitely not Zika-related, but Jaxon does have a similar condition. Microhydranencephaly can cause microcephaly and scalp rugae which mean Jaxon’s head is smaller than normal. It also means his scalp is ridged but that doesn’t stop Jaxon from living life to the full.
