Jaundice and kernicterus jaundice
About 60% to 80% of newborn Infants in the United States are jaundiced, that is they look yellow. Jaundice is yellow coloring of the skin and other tissues. Jaundice can often be seen in the sclera, the "whites'' of the eyes, which look yellow. Although many babies look jaundiced, but they are not deeply jaundiced, not jaundiced below the abdomen, and they act OK - they nurse, they aren't too sleepy, they have normal muscle tone, their cry is normal, and they don't arch their backs.
Kernicterus is a form of brain damage caused by excessive jaundice. The substance which causes jaundice, bilirubin, is so high that it can move out of the blood into brain tissue. When babies begin to be affected by excessive jaundice, when they begin to have brain damage, they become excessively lethargic. They are too sleepy, and they are difficult to arouse - either they don't wake up from sleep easily like a normal baby, or they don't wake up fully, or they can't be kept awake. They may have a high-pitched cry, and decreased muscle tone, becoming hypotonic or floppy with episodes of increased muscle tone (hypertonic) and arching of the head and back backwards. As the damage continues they may arch their heads back into a very contorted position known as opisthotonus or retrocollis, they may develop fever, and they may even develop seizures (convulsions).
Kernicterus is from the Greek "kern" or kernel plus "icterus" or yellow. Kernicterus refers to the yellow staining of the deep nuclei (i.e., the kernel) of the brain namely, the basal ganglia. Kernicterus involves a specific part of the basal ganglia, the globus pallidus. It also includes lesions (damage) to brainstem nuclei in auditory (hearing), oculomotor (eye movement), and vestibular (balance) systems and the cerebellum (coordination). Abnormalities of the globus pallidus can be seen on MRI scan of infants with kernicterus.
Clinically, classic kernicterus involves:
Specific movement disorders
Hearing loss or deafness
Impairment of eye movements especially upward gaze
Abnormal staining of the enamel of baby teeth
Children with kernicterus have a "dystonic" or "athetoid" form of cerebral palsy. The "athetoid" form of cerebral palsy is classic and athetosis refers to the slow, writhing involuntary movements that occur. Dystonia, or abnormal muscle tone and position, is more common, and may occur with or without athetosis.
Some children with kernicterus are deaf, some have normal hearing, and some with or without deafness have an auditory processing problem called auditory neuropathy, auditory dys-synchrony or by it’s new name, auditory neuropathy spectrum disorder (ANSD). Auditory brainstem responses, ABRs also known as BAEPs, BAERs or BSERs are often abnormal, whereas other "hearing" tests, such as otoacoustic emissions (OAEs) and cochlear microphonic responses are normal. An abnormal ABR with a normal cochlear microphonic response is the “gold standard” way to diagnose ANSD, and requires recording electrical activity (brain waves) from a few electrodes pasted on the scalp in response to sounds played through insert earphones, usually when the child is asleep or sedated
Kernicterus is fortunately a very rare occurrence. Other forms of more subtle bilirubin-induced neurological damage may exist, including auditory processing problems, one form of which is ANSD, and other problems of sensorimotor integration.
The opinions in this article are solely mine except where I've cited others. I am a child neurologist and medical researcher. I've been studying brain damage due to jaundice since 1982. I care very deeply about preventing brain damage, and kernicterus is a preventable form of brain damage that occurs in newborn infants. There are many well established scientific facts known about how bilirubin toxicity damages the brain, but unfortunately, there is much that is not known. Usually conservative in my clinical practice, in a baby with excessive hyperbilirubinemia I would err on the side of treatment that is more aggressive. For example, if there is a possibility that subtle cognitive processing problems are caused by levels of bilirubin lower than are usually treated, and if it will take time for new studies to resolve this concern, then I'd err on the side of over- treating while there is still uncertainty because the cost of treating is a few days or so of a very safe treatment, whereas the cost of not treating might be a lifetime of a neurological problem.
Our department receives many requests to evaluate patients. I currently see patients in the inpatient and outpatient services of Children's Mercy's Neurology Department. We make and coordinate referrals by email at firstname.lastname@example.org or by phone at (816) 234-9398. You may be seen in consultation with recommendations for treatment to be carried out locally, or you may receive ongoing care at our clinic, or may opt for a combination of the two.
Diagnosis - New patients fill out a questionnaire, and then undergo a carefully history-taking, physical and neurological examination. We review past medical records. Patients are routinely videotaped for documentation of movements.
Testing - A full range of routine and specialty diagnostic testing is available, including MRI and PET scans, evoked potentials (e.g., ABR); EMG, EEG, video EEG, sleep studies, metabolic and genetic testing, auditory, and neuropsychological testing.
Consultations – with experts in Pediatric Movement Disorders, Orthopedics, Neurosurgery, Gastroenterology (GI), Sleep Disorders Specialists, Ophthalmology, Otolaryngology Audiology, Speech and Language Therapy, Physical and Occupational Therapy, Feldenkrais Therapy, Gait Analysis, Neuropsychology and Vision Assessment, Hematology.
Referrals - To physician specialists in areas including pediatric genetics, neurosurgery, neuromuscular and movement disorders specialists; physical medicine rehabilitation; audiology; otolaryngology; speech, physical and occupational therapy, gait analysis and neuropsychology.
Education - Educational consultants experienced in evaluating the educational needs of children with neurological problems.
Treatment - When treatment is necessary, our clinic offers pharmacological and non-pharmacological treatments and referrals.
Non-pharmacological treatments which might include referrals to speech, physical and/or occupational therapy, rehab and/or assistive technology, educational recommendations, botulinum toxin injections, baclofen pumps, cochlear implants, or deep brain stimulators.