Microcephaly

Microcephaly is a neurological disorder in which the head circumference is smaller than normal. This condition can be congenital and present at birth or develop during the first years of a child’s life. It may also appear alone or in combination with other major congenital defects. It is a rare disorder.

Symptoms

In addition to a small head size, microcephaly may be accompanied by other symptoms:

• High-pitched crying.
• Feeding difficulties.
• Seizures.
• Spasticity: permanent muscle contraction.
• Hyperactivity.
• Delayed motor and language development.
• Hearing or vision problems.
• Intellectual disability.

As the child grows, they develop a disproportionately long face, as it continues to grow while the skull does not. A receding or sunken forehead and loose, wrinkled scalp may also be observed. The rest of the body is usually underweight and smaller in size.

Causes

Microcephaly is generally due to a total or partial reduction in brain growth. The interruption of fetal brain development can be caused by:

• Genetic disorders, such as Down syndrome, Cri du Chat syndrome, trisomy 13, and trisomy 18.
• Intrauterine viral infections, such as rubella, varicella, toxoplasmosis, cytomegalovirus, or Zika virus.
• Maternal consumption of medications, alcohol, or drugs.
• Exposure to chemicals or toxic substances, such as radiation, arsenic, or mercury.
• Severe maternal malnutrition.
• Untreated maternal phenylketonuria: this genetic disorder hinders the breakdown of phenylalanine, an amino acid, and can affect fetal development.
• Craniosynostosis: premature fusion of the joints or sutures between the skull’s bony plates, preventing brain growth.
• Hereditary metabolic disorders, such as diabetes.

Acquired microcephaly after birth may also result from:

• Lack of oxygen (cerebral anoxia) during birth.
• Infections.

Primary autosomal recessive microcephaly is a hereditary form of the disorder caused by mutations in several genes, most commonly in the ASPM gene.

Risk Factors

The main factors that increase the likelihood of a baby developing microcephaly include:

• Family history.
• Risk behaviors during pregnancy: exposure to toxins, inadequate or insufficient diet, and alcohol or drug consumption.
• Complications during birth.

Complications

Although a percentage of children with microcephaly have normal intellectual development, most cases are associated with some degree of developmental delay and intellectual disability, as well as a reduced life expectancy. Additionally, microcephaly can lead to severe long-term disorders, such as cerebral palsy.

Prevention

The risk of a baby developing microcephaly can be reduced by taking the following measures during pregnancy:

• Avoid alcohol and drug consumption.
• Limit medication use.
• Stay up to date with vaccinations.
• Practice safe sex using condoms.
• Avoid consuming raw or undercooked meat.
• Avoid handling cat feces or litter boxes.
• Wash hands frequently.
• If you have phenylketonuria, follow the prescribed treatment.
• Use gloves and a mask when handling chemical substances.

What Specialist Treats Microcephaly?

Microcephaly is evaluated and treated by specialists in pediatric neurology and neurosurgery.