Publication

Abstract : A 30-month-old boy presented with global developmental delay and generalized dystonia since infancy. He was born to nonconsanguineous parents at term. He had a history of bilirubin encephalopathy requiring exchange blood transfusion on day 2 of life; maximum documented serum bilirubin was 20 mg/dL. On examination, he was hypotonic with intermittent dystonia involving all 4 limbs. He had a specific gaze restriction (Video; available at www.jpeds.com) that clinched the clinical diagnosis. Neuroimaging revealed bilateral globus pallidus hyperintensities (Figure). Auditory brainstem response revealed prolonged interpeak latencies. The child was managed as evolving cerebral palsy secondary to kernicterus. He was initiated on antidystonia medications and rehabilitative measures. Upgaze palsy is a useful clinical sign and ocular examination may provide important clues to the etiology in early-onset dystonia. Chronic bilirubin encephalopathy or kernicterus is not an uncommon disorder. It can occur in preterm infants, even in the absence of marked hyperbilirubinemia1,2 and the history of neonatal jaundice may not be forthcoming in many instances. Therefore, it poses a diagnostic challenge in such clinical settings. Also, kernicterus is a clinicoradiologic mimicker of many neurometabolic diseases, if bilateral globus pallidus involvement and pseudoregression after the onset of movement disorder is taken into account. Upgaze restriction, enamel hypoplasia, and sensorineural hearing loss can aid in reaching a conclusive diagnosis in cases with a diagnostic dilemma. This can also avoid an unyielding battery of metabolic investigations.