27 - Hyperbilirubinemia and kernicterus

Summary

Introduction

The term kernicterus was originally used to describe the deposition of bilirubin in the basal ganglia. It was first described in 1903 by Schmorl. More recently, the term has also been used in reference to the chronic and permanent clinical sequelae of bilirubin toxicity. For the acute manifestations of bilirubin toxicity, the term acute bilirubin encephalopathy or ABE has been adopted. Another acronym, BIND, has been adopted to describe any bilirubin-induced neurologic dysfunction. Although technically the diagnosis of kernicterus can only be confirmed at autopsy, brain magnetic resonance imaging (MRI) studies may now aid in the confirmation of the diagnosis in a living child with severe jaundice. The MRI signature for kernicterus includes high signal intensity on T1-weighted (T1W) images in the globus pallidus, internal capsule, thalamus, and hippocampi (Fig. 27.1). The associated T2W images have abnormal increased signal in the globus pallidus and thalamus in the same regions as the high signal on the T1W images (Fig. 27.2). Loss of demarcation between globus pallidus, internal capsule, and the anterior thalamus was the major finding. The source of these abnormal signals has not been definitively identified, and therefore the MRI findings should not be considered diagnostic in themselves, but only consistent with the diagnosis of kernicterus in the context of severe neonatal jaundice and the acute and chronic clinical features of bilirubin toxicity (Table 27.1).