Background: Despite its lengthy history, the study of jaundice, hyperbilirubinemia and
kernicterus suffers from a lack of clarity and consistency in the key terms used to describe both the
clinical and pathophysiological nature of these conditions. For example, the term Bilirubin-induced
Neurological Dysfunction (BIND) has been used to refer to all neurological sequelae caused by exposure
to high levels of bilirubin, to only mild neurological sequelae, or to scoring systems that
quantitate the progressive stages of Acute Bilirubin Encephalopathy (ABE).
Objective: We seek to clarify and simplify terminology by introducing, defining, and proposing
new terms and diagnostic criteria for kernicterus.
Methods: We propose a systematic nomenclature based on pathophysiological and clinical criteria,
presenting a logical argument for each term. Acknowledging observations that kernicterus is symptomatically
broad and diverse, we propose the use of the overarching term Kernicterus Spectrum
Disorders (KSDs) to encompass all the neurological sequelae of bilirubin neurotoxicity including
Acute Bilirubin Neurotoxicity (ABE). We further suggest subclassification of KSDs based on the
principal disabling features of kernicterus (motor, auditory). Finally, we suggest the term subtle
KSD to designate a child with a history of significant bilirubin neurotoxicity with mild or subtle
Results and Conclusion: We conclude with a brief description of the limited treatments currently
available for KSD, thereby underscoring the importance of further research. We believe that adopting
a systematic nomenclature for the spectrum of clinical consequences of hyperbilirubinemia will
help unify the field and promote more effective research in both prevention and treatment of KSDs.