Microcephaly Definition

Microcephaly is a neurodevelopmental disease characterized by significantly smaller-than-normal size of head of sufferers for their age and sex, on the basis of standardized charts [1].

Microcephaly Epidemiology

The disease affects 2-2.5% of the entire population. It annually affects over 25,000 infants in the U.S. It is far more common than other popular conditions like Autism [2].

Microcephaly Types

Based on its onset, Microcephaly is categorized into the two following types:

  • Congenital
  • Postnatal onset

Microcephaly Etiology

The disorder usually occurs due to abnormal brain development in the congenital or infantile stage [3]. It may be caused by conditions that affect brain growth, such as:

  1. Infections
  2. Severe malnutrition
  3. Genetic disorders

These include:

  • Cri du chat syndrome
  • Cornelia de Lange syndrome
  • Rubinstein-Taybi syndrome
  • Down syndrome
  • Trisomy 18
  • Trisomy 21
  • Seckel syndrome
  • Smith-Lemli-Opitz syndrome
  1. Indirect factors

These include:

  • Congenital rubella
  • Congenital toxoplasmosis
  • Methylmercury poisoning
  • Congenital cytomegalovirus (CMV)
  • Uncontrolled phenylketonuria (PKU) in the mother
  • Use of certain substances during pregnancy, especially phenytoin and alcohol

Microcephaly Risk Factors

Babies of women who expose themselves to alcohol, drugs or toxic chemicals during pregnancy are at great risk. Infants suffering from severe malnutrition during pregnancy are also susceptible. Babies with family history of certain genetic disorders are also at risk.

Microcephaly Symptoms

The signs and symptoms include [4]:

  • Much smaller head size and circumference (primary sign) at birth
  • Seizures
  • Hyperactivity
  • Abnormal facial features (facial distortions)
  • Poor feeding
  • Mental retardation
  • High-pitched cry
  • Convulsions
  • Dwarfism or short stature
  • Developmental delays
  • Delayed motor functions and speech
  • Difficulties with coordination and balance
  • Greater movement of the limbs (Spasticity)
  • Brain or neurological abnormalities
  • Backward sloping forehead (in severe cases)

Later problems may also include:

  • Underweight body
  • Receding forehead
  • Loose, often wrinkled scalp
  • Disproportionately large face as compared to skull

Some children with microcephaly might have an enlarging head, with normal intelligence although below the normal growth curves compared to head circumference.

Microcephaly Diagnosis

The disease can be diagnosed by prenatal ultrasound before birth. In many cases, ultrasound exams may not help detect it until the third trimester. After birth, diagnosis may involve:

  • Analysis of complete prenatal and birth history of baby
  • Complete physical examination, to check for obvious signs like small head size
  • MRI or CT scans, to detect the underlying cause of developmental delays (in later stages)

Microcephaly Differential Diagnosis

This includes distinguishing the symptoms from those of other disorders like [5]:

  1. Infections (Encephalitis, Meningitis etc.)
  2. Congenital Infections

These include:

  • CMV
  • Rubella
  • Toxoplasmosis
  • Varicella
  1. Autosomal Recessive (Familial) disorders
  2. Autosomal Dominant disorders
  3. Syndromes

These involve:

  • Trisomy 13
  • Trisomy 18
  • Trisomy 21
  • Aicardi Syndrome
  • Beckwith-Wiedemann Syndrome
  • Bloom Syndrome
  • Cornelia de Lange
  • Cohen Syndrome
  • Dubowitz Syndrome
  • Cri-du-chat (5p-)
  • Xeroderma Pigmentosum
  • Rubinstein-Taybi Syndrome
  • Smith-Lemli-Opitz Syndrome
  1. Congenital CNS Anomalies

These include:

Microcephaly Treatment

Apart from surgery, there is usually no treatment measure to reverse the signs or enlarge the head size [6]. Early treatment options include:

  • Physical therapy
  • Speech therapy
  • Occupational therapy

Some complications, like hyperactivity or seizures, may be cured with medicines.

Microcephaly Prognosis

The life expectancy is usually reduced and brain function is poor in children and adults. The outcome varies on the basis of the presence of related abnormalities. The life expectancy is usually low (around 20 years) although lifespan actually depends on the presence of related abnormalities.

Microcephaly Complications

The complications include [7]:

  • Seizures
  • Hyperactivity
  • Facial distortions
  • Mental retardation
  • Behavior problems (later stage)
  • Dwarfism or short stature
  • Difficulties with coordination and balance
  • Permanently small head size for age and sex
  • Developmental delays, such as in speech and movement

Microcephaly Prevention

There is no specific way for prevention as the exact causes are usually unavoidable. Consulting genetic experts before planning pregnancy may be useful. Severe malnutrition can be avoided by proper nutrition of mother during pregnancy. Exposure to alcohol and other toxic materials should also be avoided.

Microcephaly Foundation

Parents of children diagnosed with Microcephaly may contact [8]:

Foundation for Children with Microcephaly

PO Box 12134

Glendale, AZ 85318

Ph. (Toll-free): (877)-476-5503/ (623)-476-7494

Fax: / (623)-241-4543

Microcephaly Pictures

These photos and images would give you an exact view of the physical appearance of Microcephaly sufferers.

Picture 1 – Microcephaly

Picture 2 – Microcephaly Image

Microcephaly ICD9 Code

The ICD9 Code for this disorder is 742.1.


Leave a Reply