Meth linked to abnormalities in fetuses


POSTED: Saturday, April 18, 2009

University of Hawaii researchers, in the first study of its kind, have found microscopic abnormalities in brains of children with exposure to methamphetamine before birth.

However, Dr. Linda Chang, principal investigator, stresses that the finding does not mean the children are functioning abnormally. “;The brain may be able to normalize because young children's brains are able to adapt,”; she said.

The research by Chang, a professor of medicine in the John A. Burns School of Medicine, and Dr. Christine Cloak, assistant professor of medicine, appeared Wednesday in the online issue of Neurology, journal of the American Academy of Neurology. Cloak was first author of the research paper.

The effects of prenatal meth exposure on a child's developing brain were little known until now despite the increasing problem of meth use among pregnant women, Chang said in an interview and a news release from the academy.

The UH researchers did brain scans on 29 children 3 and 4 years old whose mothers used meth while pregnant and 37 unexposed children the same ages. All the children were volunteered by mothers on Oahu.

The researchers used a $3 million brain-imaging tool at the Queen's Medical Center called the 3 Tesla Magnetic Resonance Imaging system.

The study began about three years ago using diffusion tensor imaging to measure water molecule movements within the brain, Chang said.

“;If the microscopic tissue changes, water molecule movement will be different due to different structure,”; she said. “;It is a way to probe the microscopic environment of the brain.”;

No abnormality was seen in regular MRI scans of the children's brains, she said. But the 3 Tesla MRI, which is twice as powerful and faster than standard MRI machines, allowed microscopic measurements, she said.

The scans showed differences in the white-matter structure and maturation of brains of children with prenatal meth exposure. These children also had up to 4 percent lower diffusion of molecules in the white matter of their brains, Chang said.

She said the suggestion that prenatal meth exposure “;accelerates brain development in an abnormal pattern ... may explain why some children with prenatal meth exposure reach developmental milestones later than others.”;

Chang said she and Cloak are following both groups of children once a year over five years to see how their brains are growing. They are measuring cognitive function to see how they are learning and how they are able to remember things.

Many children already have been back two or three times for the follow-up study, and “;so far they're doing pretty well,”; Chang said.