Microcephaly is one of the rarer malformations in humans. It is either genetic or acquired and is primarily manifested by a skull circumference that is too small. Children born with microcephaly often also have a smaller brain and show other physical and mental developmental abnormalities. However, there are also cases of microcephaly in which young patients develop normally cognitively despite their smaller brain size.
What is microcephaly?
Microcephaly (MCPH) is a malformation of the human skull: it is too small relative to that of other people of the same sex and age. At birth, microcephaly is usually not yet so noticeable. The developmental disorder becomes clearly visible later, when the circumference of the head does not “grow” with the child. It can then be more than 30 percent smaller than in other people of the same age. Microcephaly is usually associated with cognitive impairment and other limitations. As a rule, the children also have a brain that is too small for their age. The intellectual deficit is mild to moderate. Microcephaly occurs in a ratio of 1.6:1000. Primary microcephaly is usually inherited in an autosomal recessive manner. The secondary form results, for example, from infections and brain injuries to which the embryo is exposed in the womb.
Causes
Microcephaly can have many causes. The main cause is dyscephaly: the child’s brain grows too slowly in the womb due to insufficient pressure. As a result, the skull cannot expand to the normal extent. As Australian scientists discovered in 2012, a gene called TUBB5 is responsible for the impaired brain growth. TUBB5 produces a protein called tubulin, which is important for cell assembly. If TUBB5 mutates, the embryo‘s brain continues to grow much more slowly. If craniostenosis is present, the cranial sutures close prematurely, preventing the brain from continuing to grow. They can be separated surgically if the craniostenosis is detected in time. Other causes are gene mutations: MICPCH syndrome (a form of microcephaly) occurs when the CASK gene located on the X chromosomes mutates. Infections of the expectant mother with rubella, cytomegalovirus, chickenpox or toxoplasmosis can also lead to microcephaly. In addition, alcohol or drug abuse by the pregnant woman can have such an unfavorable effect on the child. The same is true if she is exposed to radiation (cancer treatment). Untreated phenylketonuria (PKU) and cerebral anoxia (the brain receives too little oxygen) can also cause the developmental disorder in the unborn child.
Symptoms, complaints, and signs
The clearest sign of microcephaly is that the head circumference is too small compared to children of the same age. The bridge and cerebellum are retarded in their development. Cognitive and motor retardation can also be observed. Language development is delayed. As a result of swallowing disorders, they have difficulty ingesting food and are therefore often up to 30 percent underweight and also too small. Some of them have balance disorders. Many microcephaly children are hyperactive and show involuntary movements (hyperkinesias). About ten percent of them suffer from epileptic seizures. Because of their lower defenses, they have an increased tendency to infectious diseases, which can have a negative impact on their life expectancy. Characteristic of microcephaly patients with hypotonia (too little muscle tension) is their curved back. They also have a four-finger groove on their palm, a sandal gap, and twin teeth.
Diagnosis and course of the disease
Whether a fetus has microcephaly can be determined with the help of prenatal ultrasound only after 32 weeks of pregnancy. In most cases, however, the developmental disorder is not detected until much later. The specialist measures his head circumference and compares it using head circumference tables. There is also the possibility of X-ray, CT scan and MRI. The CT scan is preferable to the X-ray because of its greater accuracy. On an MRI image, the features that cause the mutation of the CASK gene can be easily seen: a slightly smaller brain that looks essentially normal and differs only in terms of a somewhat simplified brain-wire pattern.However, parents have final certainty only after a blood and urine test.
Complications
Microcephaly primarily leads to a restriction of mental and motor development in affected individuals. Especially for children, severe discomfort occurs, so that they are usually dependent on the help of other people in later life. Furthermore, speech defects and swallowing difficulties also occur, so that those affected cannot take in food on their own. There are also disturbances of balance or epileptic seizures. It is not uncommon for those affected to also suffer from reduced muscle tone and various malformations on the body. Parents or relatives may also suffer psychologically or be affected by depression due to the disease. The affected children are not infrequently hyperactive and thus unable to follow lessons. As a rule, they therefore require special instruction. With the help of various therapies, the symptoms of microcephaly can be limited. However, a complete cure of this disorder is not possible, so that patients are usually dependent on the help of other people for the rest of their lives. Convulsions can be limited with the help of medication. No particular complications occur during treatment of this disease.
When should you go to the doctor?
Microcephaly is usually not recognized immediately. Affected children initially make a healthy impression. However, within the first few months of life, it becomes very apparent that the head circumference is smaller than that of peers. Unless the treating pediatrician makes the diagnosis on his or her own during routine examinations, parents should definitely consult a doctor if microcephaly is suspected. The condition should be treated as early as possible. The sooner the affected child receives appropriate therapy, the better his or her chances of a longer life expectancy. It is important to start with physiotherapy, occupational therapy and speech therapy as early as possible, since the child can gain a certain independence through intensive support and the parents can thus be relieved. Especially in case of repeated seizures, the pediatrician or a specialist should be consulted. In such cases, rapid drug treatment is needed.
Treatment and therapy
There is no complete cure for people with microcephaly. However, with the help of appropriate therapies, parents can increase their child’s life expectancy and give him or her more joy in life. The earlier the child receives the appropriate treatment, the better his or her chances later on. Although the head circumference can no longer be corrected, parents can ensure that their child regularly participates in physiotherapy as well as occupational and speech therapies. It is also important to promote the independence of the disabled child and to strengthen his self-confidence. Regular checks of head circumference and general growth help to intervene more quickly in case of difficulties. Symptoms such as hyperactivity and seizures can be easily treated with medication.
Outlook and prognosis
Basic statements about the outcome of microcephaly are difficult. Affected individuals must be prepared for lifelong limitations in any case. How severe these turn out to be varies from case to case. In practice, it often proves difficult that too little research has been done on the disease. This means that important knowledge is missing, which is crucial for therapy. Since statistically only 1.6 out of 1,000 children suffer from microcephaly, and since most of these children are in Africa, only a slow improvement in treatment options can be expected. The cranial malformation is diagnosed in young children. The extent to which physical development can contribute to improvement cannot be predicted. In any case, doctors cannot correct the reduced head circumference. Nevertheless, parents should not renounce offered aids. Non-treatment is the worst option. Because at least consequences and accompanying symptoms can be treated. Physiotherapy and speech therapies can help to improve the situation. Many patients suffer from mental or physical disabilities. As a result, they are dependent on aids for the rest of their lives. Life expectancy as a whole need not be limited due to microcephaly.
Prevention
Parents who have a microcephaly child and want more children should definitely try to find out what causes microcephaly. If it is genetic, the only way to help is to see a specialist who can tell them the likelihood that their further offspring will also have the developmental disorder. In the case of autosomal recessive inheritance, the child also has a 25 percent probability of having a reduced skull.
Follow-up
Because microcephaly generally cannot be completely cured, follow-up care focuses on managing the condition well. Affected individuals should try to build a positive outlook on life despite the adversity. Relaxation exercises and meditation can help with this. Affected persons are only able to speak with great delay, so that there are also disturbances and a significant delay in the child development of the affected person. The affected persons usually also suffer from a clear retardation and also from disturbances of the balance, so that it comes to restrictions and to disturbances in the everyday life. Likewise, various malformations or deformities can appear on the body of the affected person, thus also significantly reducing the aesthetics.In addition to therapeutic measures, it is helpful to sensitize the social environment to the disease in order to prevent misunderstandings. Since the symptoms of microcephaly are sometimes severe, this can also lead to depression or other severe psychological upsets in the parents or relatives. It is advisable to clarify this with an experienced psychologist and to weigh up to what extent therapy is appropriate. Contact with similarly ill persons can also help to improve the quality of life.
What you can do yourself
Microcephaly manifests in childhood and is often, though not always, associated with impaired cognitive abilities. Parents who suspect that their child has microcephaly should consult an expert immediately. If the suspicion is confirmed, a thorough clarification of the causes is urgently required in addition to the diagnosis. The latter is particularly important with regard to family planning. Microcephaly can be genetically determined. If this is the case, affected individuals whose family planning has not yet been completed should seek genetic counseling. The support measures indicated for the patients themselves depend on the degree of disability. A learning disability can usually not be completely compensated for by educational and psychotherapeutic care started at an early stage, but it can almost always be mitigated. Occupational therapy and physiotherapy measures can help to counteract the consequences of delayed or disturbed motor development. In the case of speech disorders, a speech therapist should be consulted at an early stage. This can be very stressful for parents. They should therefore seek professional support in caring for their child. It is important to apply for a care level at an early stage. Since children suffering from microcephaly are often unable to attend a normal elementary school and places at special schools are scarce, parents should also make arrangements for school enrollment much earlier than for a healthy child.