Diffuse basal ganglia or thalamus hyperechogenicity in preterm infants

Objective: To determine the incidence and factors associated with diffuse basal ganglia or thalamus hyperechogenicity (BGTH) in preterm infants. Study design: (1) Review of serial neurosonograms among neonates with gestational age (GA) <34 weeks born at Weiler Hospital during a 21-month period; (2) Color Doppler flow imaging; (3) Case -control study using GA group-matched controls; and (4) Blind reading of CT scans or MRIs in patients with BGTH. Results: Among 289 infants, 24 (8.3%) had diffuse BGTH. Color Doppler flow imaging was normal in nine patients. The incidence of diffuse BGTH was inversely related to GA (P<0.01). Logistic regression (n =96) showed that diffuse BGTH was significantly associated with requirement of high-frequency oscillation (HFO) (P =0.031), severe intraventricular hemorrhage (IVH) (P =0.004), hypotension requiring vasopressors (P =0.040), hypoglycemia (P =0.031) and male gender (P =0.014). Most patients with diffuse BGTH had normal basal ganglia and thalamus on CT/MRI, one had a hemorrhage, and one had an ischemic infarction. Conclusions: In our series, diffuse BGTH occurred in 8.3%, and was associated with factors similar to those previously reported. In contrast, several series have reported almost exclusively linear or punctuate hyperechoic foci, corresponding to hyperechogenicity of the lenticulostriate vessels. Our data provide further evidence to suggest that diffuse BGTH and hyperechogenicity of the lenticulostriate vessels are two different entities. Additional studies are required to determine the long-term significance of diffuse BGTH.