Dr. Michael Church tested infants born with Fetal Alcohol Syndrome (FAS) and found that all of them suffered from one or more types of hearing disorders. Comparing that to the general population, in which less than 10 percent of children have hearing problems, Dr. Church saw a need for early detection and intervention in FAS cases.
In a series of projects funded by the National Institutes of Health, Michael Church, PhD, associate professor of ob/gyn, has determined that prenatal alcohol or cocaine exposure can result in four types of hearing disorders--all of which may adversely affect a child’s speech skills, language acquisition, cognitive abilities, intellectual maturity, and behavior. The four types of hearing disorders are: delayed hearing maturation, sensorineural hearing loss, conductive hearing loss secondary to recurrent serous otitis media, and central hearing deficits.
The National Institute on Alcohol Abuse and Alcoholism (NIAAA) has provided a million dollars to fund Dr. Church’s project, "BAEP Screening of Neonates Prenatally Exposed to Alcohol and/or Cocaine." BAEP, which stands for brainstem auditory evoked potentials, is a special type of brainwave that is generated by auditory structures in the inner ear and brainstem. These brainwaves can be monitored in response to sounds that are administered to the baby through special headphones. The BAEP can help detect infant hearing problems caused by prenatal drug exposure or other causes.
"Usually, we don’t know about a child’s hearing deficits until they get to school," says Dr. Church. "By that time, there are major problems. If the hearing problem isn’t treated in the first three years of life, the child will have permanent deficits because they’ve missed the critical window of language and speech development." By testing the hearing of newborn infants before they leave the hospital, Dr. Church and his colleagues hope to provide early clinical interventions and better patient outcomes.
After the initial newborn testing, the progress of each FAS infant is followed until at least 12 months of age, when more hearing and developmental tests are performed. Those infants with hearing, speech, language, cognitive or craniofacial problems receive appropriate intervention with the expertise of physicians, scientists and specialists at Wayne State University, The Detroit Medical Center, and Children’s Hospital.
Co-investigators on this infant hearing project include Drs. Susan Martier, Dale Robinson, Enrique Ostrea, Frances Eldis, Sandra Jacobson, Melissa Kaplan-Estrin, Joel Ager and Robert Sokol. Dr. Church is the principal investigator.
SIDEBAR:
Lab models provide preliminary clues about effects of prenatal exposures
Dr. Church started his career as a basic scientist doing animal research. Recently however, he established the BAEP screening program, or infant hearing study, in which his laboratory findings are being transferred directly to patients. Continuing on a translational pathway, Dr. Church is making discoveries which have potential for clinical application.
Dr. Church’s animal models have shown, for example, that prenatal exposures to cocaine, alcohol or retinoic (vitamin A) acid can produce hearing, visual, and other birth defects. This research has provided important information about the relative toxicity of these exposures and the types of damage they can cause to the fetus.
Regarding hearing impairments, for example, prenatal alcohol seems more destructive than prenatal cocaine. Retinoids, such as vitamin A and Accutane, are the most toxic of all exposures. Infants and laboratory animals prenatally exposed to retinoids have been born with severe birth defects including reduced limbs, vascular diseases, facial deformities, neurological disorders, blindness, deafness and deformities of internal organs.
"This is a particularly startling effect that has direct translational warnings for pregnant women," said Dr. Church. "Expectant mothers have been advised not to take retinoic acids such as Accutane, a common acne medication. They can have severe effects which are as bad or even worse than those of Fetal Alcohol Syndrome." Dr. Church explains that adults can tolerate very high doses of vitamin A, but for some reason, the embryonic child is very susceptible to its toxic damage.
Scientific findings such as these are often secondary to the original research questions, but they raise clinical concerns. In a similar situation, Dr. Church is collaborating with scientists from various departments at WSU to study an unusual finding. Some mice that had prenatal drug exposures are now having difficulty walking on their hind legs and they’re exhibiting other morbidities in old age. Investigators are collaborating to determine if prenatal drug exposure contributes to new types of age-related degeneration.