A 4-day-old term neonate with untreated severe unconjugated hyperbilirubinemia becomes lethargic with a high-pitched cry and poor feeding. Over the next two days he develops retrocollis, opisthotonus, and fever. Which structure bears the greatest burden of bilirubin deposition responsible for these findings?

• A Globus pallidus and subthalamic nuclei ✓
• B Cerebellar vermis
• C Spinal anterior horn cells
• D Occipital cortex

Explanation

Acute bilirubin encephalopathy progresses from lethargy, poor feeding, and a high-pitched cry to retrocollis, opisthotonus, and fever. Unconjugated bilirubin selectively stains the basal ganglia, especially the globus pallidus and subthalamic nuclei, along with the hippocampus and brainstem nuclei such as the oculomotor and vestibular nuclei. Survivors develop chronic kernicterus with athetoid cerebral palsy, sensorineural deafness, and gaze palsies.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.