Source: Leong A, Floer A, Kirton A, et al. Head circumference trajectory in children with perinatal stroke [published online ahead of print March 8, 2021]. J Child Neurol. doi:10.1177/0883073821996103Investigators from Alberta Children’s Hospital, Calgary, Canada, conducted a retrospective cohort study to evaluate longitudinal head growth in children with perinatal stroke. Children with perinatal stroke were identified through a population-based research cohort of children with MRI-confirmed unilateral arterial perinatal stroke and who had follow-up of more than 12 months with the Pediatric Stroke Outcome Measure (PSOM), a validated measure of neurologic deficit and function. Participants included in this current study were ≤18 years old and had no other systemic conditions. Demographics were collected at the time of cohort enrollment.The primary predictor was occipital-frontal head circumference (OFC) as obtained from the medical record. OFC data at different ages from the same participant from birth to 18 years old were included. The primary outcome was neurologic deficit, as measured by the PSOM. The PSOM is scored on a 10-point scale, with higher scores representing worse deficits. Investigators generated sex-segregated OFC plots from birth to 18 years old using the 50th percentile OFC at every 2-week interval between birth and 6 months of age, 1-month intervals from 6 months to 2 years of age, and 6-month intervals from 2 to 18 years of age. Investigators also compared the 50th percentile OFC among participants at each interval to the 50th percentile OFC of healthy American children serving as controls using OFC data obtained from a separate database. Lastly, investigators assessed whether there were more participants with PSOM scores ≥1 who had OFCs at <50th percentile (vs ≥50th percentile).There were 315 OFC measurements from 102 participants with perinatal stroke included in analysis. Overall, 52% participants were male. There was a mean of 2.8 OFC measurements among female participants and 3.2 OFC measurements among male participants. Overall, 28% (N = 29) of participants had a PSOM score of 0.The OFC for female participants followed the OFC for female healthy controls until age 3 months, at which point the 50th percentile OFC for female participants became significantly smaller compared to healthy controls. This effect also was observed for male participants, but the divergence occurred later at 18 months. There were significantly more participants with an OFC <50th percentile (vs ≥50th percentile) who had PSOM scores ≥1 (87% vs 52%; P = 0.004).Investigators conclude that there is a deceleration in head growth in children with perinatal stroke and worse neurological outcomes among those with an OFC <50th percentile.Dr Candee has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.Perinatal stroke is the most common cause of hemiplegic cerebral palsy, occurring in roughly 1/2,300 term births and 7/1,000 preterm births.1 It is most often the result of ischemic injury to brain tissue, which then leads to encephalomalacia, volume loss, and a decrease in OFC.2 Although acquired microcephaly has been shown to be associated with poor neurologic development across a variety of conditions, the current investigators are the first to look specifically at the impact of head growth (using OFC trajectory as a surrogate) on neurologic development in children with a history of perinatal stroke.3The results of the current study confirm the suspected hypothesis of the investigators, namely that head growth deceleration occurs in children with perinatal stroke, and that OFC <50th percentile is associated with a worse neurological outcome (as measured by PSOM). Interestingly, the timing of OFC divergence between the study population and healthy controls occurred much earlier for girls (eg, 3 months, vs 1 year for boys). The study findings are strengthened by the exclusion of “higher-risk” children with systemic conditions or other non-stroke neurologic diagnoses. They potentially are limited in that the collective data could be biased by over-representation of the more severely affected patients (who may have had more measurements).Perinatal stroke often goes unnoticed until 4-6 months of life, when motor asymmetry, early hand preference, or seizures become evident.1 While OFC is only a rough estimate of head size in a mobile infant and therefore highly subject to measurement error, it is an inexpensive, noninvasive tool that can enable primary care providers to detect perinatal stroke or its complications (eg, infantile spasms or cerebral palsy) sooner. OFC measurements also potentially could facilitate the connection of infants with earlier individualized support or therapeutic interventions for optimizing development.Head growth deceleration in children with perinatal stroke is associated with poor developmental outcome.Hats off to research with results that underscore the continued value of physical examination rather than newer health care technology.