Hypoxic - ischemic Encephalopathy in Term Infants: Correlation of Neurosonographic Findings in Basal Ganglia and Thalamus with Prognosis

ABSTRACT

PURPOSE: To evaluate abnormal neurosonographic (NSG) findings of thalami and basal ganglia in full term babies with hypoxic-ischemic encephalopathy and to correlate the findings with follow-up studies and prognosis. METHODS: We evaluated 13 full term babies with abnormal NSG findings of thalarni and basal ganglia. NSG was performed within 7 days after clinical abnormalities. Follow-up NSG was done in 11 cases; CT scan in 4 and MRI in 7. We classified NSG findings as diffuse, unilateral, and focal types according to increased echogenicity and evaluated prognosis based on follow-up studies and neurological sequelae. RESULTS: Nine cases of diffuse type had diffuse echogenic changes of bilateral thalami and basal ganglia, slit-like lateral ventricles suggesting cerebral edema, and increased parenchymal echogenicity. In diffuse type, follow-up studies showed more prominent echogencities and ventricular dilatations and cerebromalacia. One case of unilateral type caused by thromboembolism had unilateral echogenicity of right thalamus and basal ganglia with increased echogenicity of the ipsilateral cerebral hemisphere and compression of the lateral ventricle, suggesting cerebral infarction. Follow-up study showed unilateral cystic cerebromalacia. Three cases of focal type had a localized echogenic area in thalamus with lacunar infarction, which decreased in size during follow-up. Among nine cases of diffuse type, one died within 2 days, two were discharged against medical advice, and six had severe neurologic sequelae. One case of unilateral type had a moderate degree of neurologic sequelae. All 3 cases of focal type had normal development. CONCLUSION: Pattems of abnormal echogenicity in thalami and basal ganglia in fullterm infants with hypoxic-ischemic encephalopathy are correlated with the outcome and may be helpful for treatment planning.