Microcephaly Associated With Significant Developmental Deficits
Infants with postnatal etiology showed worse developmental deficits across all domains.
VANCOUVER – Infants with microcephaly face a significant risk of developmental delays and long-term disability, including intellectual disability and cerebral palsy, according to data from a retrospective review presented at the 2016 Child Neurology Society Annual Meeting, October 26-29, 2016 in Vancouver, British Columbia.
With microcephaly top of mind with the emergence of Zika virus, researchers led by Eliza Gordon-Lipkin, MD, of the Kennedy Krieger Institute and Johns Hopkins University School of Medicine in Baltimore, Maryland, sought to better understand the etiologies of microcephaly and its impact on developmental outcomes.
The study included data from 22 infants diagnosed with microcephaly (59.1% female; mean gestational age= 33.79 weeks) from 2006 to 2016. Data from prenatal, perinatal, and neonatal courses as well as NICU follow-up assessments were included in the analysis to yield developmental quotients (DQ). DQs were age-adjusted up to 2 years, with delay defined at DQ<70.
Among the cohort, 55% of infants were preterm, and 41% were characterized as intrauterine growth restricted/ small for gestational age. Approximately 33% had microcephaly at birth (based on data from 12 infants with documented head circumference at birth). Twenty-three percent of etiologies were unknown, while 23% were related to hypoxic-ischemic encephalopathy (HIE); 14% were intracranial hemorrhage (ICH); 14% were structural anomalies; 9% were syndromes; and 5% were related to cytomegalovirus (CMV), herpes simplex virus (HSV) plus hemorrhage, hydrocephalus without hemorrhage, and infart each, respectively.
At follow-up (mean 26.8 months), 73% of infants had delays in one or more areas of development, including gross motor (65%; mean DQ 58.4), fine motor (59%; mean DQ 63.2), and language (59%; mean DQ 65.4), while 45% of infants had delays across all domains. Notably, those with postnatal onset had worse mean DQs across all domains compared to infants with congenital or unknown onsets.
“We don't know why the pathophysiology of one may be better than the other, but I think that is definitely a future direction to look into,” Dr Gordon-Lipkin told Neurology Advisor, noting that advances in neuroimaging and genetic testing may help to identify unknown etiologies in future studies.
“This diagnosis is remerging, but in terms of applying this to Zika virus, it is good to understand the spectrum of microcephaly, what these infants will be presenting with, and what their outcomes will be,” she said.
Gordon-Lipkin E, Gentner M, Leppert M. Neurodevelopmental Outcomes in Infants with Microcephaly. Presented at: 2016 Child Neurology Society Annual Meeting. October 26-29, 2016; Vancouver, BC. Abstract 188.