mikrocefali

Microcephaly, or mikrocefali, is a medical condition in which a person’s head circumference is smaller than expected for their age and sex. It is commonly defined as more than two standard deviations below the mean, or below the third percentile. Microcephaly can be present at birth (congenital) or develop in infancy (secondary) due to impaired brain growth.

Causes include genetic mutations causing primary microcephaly; syndromic forms with other anomalies; prenatal infections such as Zika, cytomegalovirus, toxoplasmosis, and rubella; exposure to teratogens (including alcohol); nutritional deficiencies; and perinatal brain injury.

Clinical presentation ranges from isolated microcephaly with normal or mild intellectual disability to syndromic cases with significant neurodevelopmental impairment, seizures, and dysmorphic features. Many children have delayed development of motor and language skills.

Diagnosis relies on longitudinal head circumference measurements and growth charts, and neuroimaging (MRI preferred) to assess brain size and structure. Genetic testing (gene panels or exome sequencing) aids in identifying etiologies. Evaluation for prenatal infections and other contributing factors is part of the workup.

Management is supportive and multidisciplinary, focusing on early intervention and therapies for developmental delay, seizure control if present, and management of associated medical problems. Family counseling and regular follow-up are recommended.

Prognosis varies with cause and severity. Isolated cases with mild impairment may have near-normal adaptation, while extensive brain involvement often leads to substantial intellectual and motor disability.

Epidemiology: microcephaly is relatively rare, and prevalence varies by population. Outbreaks such as Zika have increased incidence in affected regions; familial microcephaly occurs in a minority of cases.