Resuming the obsolete term "small head": when microcephaly occurs without cognitive impairment

Area of Science:

• Pediatrics
• Neonatology
• Medical Diagnostics

Background:

• Microcephaly is clinically defined by head circumference measurements 2 or 3 standard deviations below the mean for age and sex.
• A cutoff of -3 standard deviations is more strongly associated with cognitive impairment compared to -2 standard deviations.
• Prenatal ultrasound and newborn assessments can identify infants with head circumference measurements near the microcephaly cutoff.

Purpose of the Study:

• To evaluate the clinical relevance of different standard deviation cutoffs for microcephaly diagnosis.
• To explore alternative terminology for infants with borderline head circumference measurements and no cognitive delay.

Main Methods:

• Review of clinical definitions and diagnostic criteria for microcephaly.
• Analysis of the association between head circumference measurements and cognitive outcomes.
• Consideration of the psychological impact of microcephaly diagnosis on families.

Main Results:

• Infants with head circumference between -2 and -3 standard deviations, without anomalous clinical signs, may not exhibit cognitive delay.
• Labeling such infants as having microcephaly can cause unnecessary distress to parents and caregivers.
• Ultrasound findings of borderline head circumference do not always predict subsequent cognitive impairment.

Conclusions:

• The distinction between -2 and -3 standard deviations is crucial in clinical practice.
• Alternative terminology, such as "small head," may be more suitable for infants with borderline measurements and normal development.
• This approach can mitigate parental anxiety and improve the patient-caregiver experience.