Abstract 1409
Poster Session III, Monday, 5/3 (poster 7)
Linear hyperchogenicity (LHE) within the basal ganglia and thalamus is an uncommon sonographic finding occuring more frequently in term infants and usually identified at birth. Common associations include congenital infections and chromosome anomalies. In preterm infants, LHE is also uncommon and usually evolves late during hospitalization. The significance of this finding remains unclear. Since the basal ganglia and thalamus are integrated centers controlling motor activity, cognition, emotion and behavior, we hypothesized that LHE would be related to abnormal neurodevelopment outcome, i.e., cognitive and behavioral performances. Ten preterm infants 907±224g, GA 28±1.4 wk with LHE identified between January 1995 and December 1996 and 20 comparison (COMP) infants of BW 859±108g, GA 27±1.1 wk with normal sonogram were evaluated in a blind manner at 18 months with Bayley's scale of infant development. Results: Antenatal steroid therapy was more common in LHE vs. COMP infants (90% vs. 45%), p=0.02). The hospital courses were not different between groups with regard to diseases (e.g., RDS, sepsis, NEC), or interventions (e.g., duration of O2 therapy). 4(57%) of 7 infants with LHE evaluated were CMV positive vs. 0/11 COMP infants (p=0.01). 3/10 LHE infants vs. 0/20 COMP infants were hypothyroid requiring replacement therapy (p=0.03). The mental developmental index score and the percentile rank of behavioral scale were significantly lower in infants with LHE vs. COMP, i.e., 73.7±9.7 vs 83.7±9.4 (p=0.01) and 23.7±20.1 vs 43.9±25.4 (p=0.04), respectively. There was no difference in psychomotor developmental score between LHE vs. COMP infants, i.e., 82.4±15.3 vs. 87.5±11.0 (p=0.31); however, they exhibited poorer motor quality, including muscle tone, gross and fine motor movement, i.e., 22.8±20.5 vs 55.7±37.4 (p=0.02). Emotional regulation score was less in LHE vs. COMP infants, i.e., 25.7±16.1 vs. 42.3±24.0 (p=0.06). Conclusion: Preterm infants with LHE are at increased risk for advanced neurodevelopmental outcome and, in particular, cognitive and behavior function. The sonographic evolution of LHE may be a marker of a more diffuse insult to the brain since factors/events known to effect brain development, i.e., steroid therapy, CMV infection and hypothyroidism, were more commonly noted in these infants. Additional studies are critical to clarify these issues.
