How to estimate head size
Head circumference is measured with a measuring tape at the widest part - above the eyebrows and through the occipital protuberance. The result is plotted on a centile graph corresponding to the age, gender and date of birth of the child. Microcephaly is spoken of when the rate is significantly below the average for this age. Much more important than the figure obtained once is how the indicator changes over time: if the head grows parallel to the schedule, and the child develops normally, we are often talking about a constitutional feature. The parents' heads must also be measured.
- Measurement at the widest circumference of the head
- Score using centile tables for age and gender
- Accounting for the date of birth in premature infants
- Dynamics over several months is required
- Measuring parents' head circumference
- Comparison with the height and weight of the child
Reasons
Congenital microcephaly is most often associated with genetic disorders and intrauterine exposures. Among the infections, cytomegalovirus, toxoplasmosis, rubella, herpes and Zika virus are important. A separate group of causes are alcohol, drugs and certain medications taken during pregnancy, as well as severe malnutrition and uncontrolled phenylketonuria in the mother. The acquired form develops after severe hypoxia during childbirth, meningitis, encephalitis, traumatic brain injury, or against the background of hereditary metabolic diseases. Sometimes the cause cannot be determined.
- Genetic syndromes and chromosomal disorders
- Intrauterine infections: CMV, toxoplasmosis, rubella, Zika
- Alcohol and drugs during pregnancy
- Severe hypoxia and cerebral ischemia during childbirth
- Past meningitis or encephalitis
- Hereditary metabolic diseases
- Family (constitutional) small head
How does this affect development?
The range is very wide. In the familial form, a child with a small head develops completely normally, learns on par with peers and does not need treatment. With microcephaly associated with brain damage, speech and motor delays, learning difficulties, epilepsy, visual and hearing impairment, and changes in muscle tone are possible. The prognosis is determined not by a centimeter of circumference, but by MRI data and the child’s actual skills. Therefore, it is important for parents not to look for the answer in one number, but to observe and work with the child.
- Family form - development is normal
- Delayed motor and speech development due to brain damage
- Epileptic seizures
- Spasticity or decreased muscle tone
- Learning and behavioral difficulties
- Visual and hearing impairment
Survey
The examination begins with detailed collection of information about pregnancy, childbirth and family, examination by a pediatrician and neurologist. Neurosonography through the fontanel is available and safe for infants and shows gross malformations of the brain and calcifications characteristic of congenital infections. MRI of the brain provides the most accurate picture of the structure of the cortex and white matter. Testing for congenital infections is especially important in the first months of life. If a hereditary cause is suspected, karyotyping and modern genetic tests are prescribed, and an EEG is needed for seizures and freezing.
- Examination by a pediatrician and pediatric neurologist
- Neurosonography through the large fontanel
- MRI of the brain
- EEG for suspected seizures
- Screening for congenital infections
- Karyotyping and genetic counseling
- Vision and hearing tests
What can you do
There are no drugs that would increase brain volume, and promises of this kind should be alarming. Real help consists of treatment of the identified cause, control of seizures, good nutrition and early intervention: classes with a speech therapist and speech pathologist, physical therapy, work with an occupational therapist. The earlier developmental activities begin, the better the child uses the available opportunities. The family benefits from genetic counseling when planning the next pregnancy, and during pregnancy, prevention of infections, taking folic acid and completely abstaining from alcohol.
- Treatment of an established cause
- Anticonvulsant therapy as prescribed by a neurologist
- Early developmental intervention and sessions with specialists
- Physical therapy and motor skills work
- Monitoring nutrition and weight gain
- Family genetic counseling
- Preventing infections and avoiding alcohol during pregnancy