According to a small study of cases and controls published in the December 4th issue of Neurology, patients with heterotopia have dyslexic like symptoms. Specifically, patients with heterotopia have an increase of white matter in the brain that coincides with decreased reading fluency. According to the study, increased white matter is a determinate factor in one’s reading fluency but has nothing to do with intelligence, memory, or attention. Bernard S. Chang, M.D., and colleagues of Beth Israel Deaconess Medical Center, believe that the study may have implications for people with diagnosed dyslexia as well. The study focused on a group of 10 healthy controls, 10 adults with periventricular nodular heterotopia, and ten adults with dyslexia; all underwent a variety of reading skills tests. The following is an excerpt of an article from Medpage Today that reviews the study:
In heterotopia, nodules of gray matter fail to migrate during fetal development and are left lining the lateral ventricles of the brain. However, the “specific and unexpected reading disability” seen with the disorder is not accompanied by problems with intelligence, attention, or working memory, Dr. Chang and colleagues said.
The researchers studied 10 healthy controls with normal reading ability, 10 adults with dyslexia, and 10 adults with periventricular nodular heterotopia diagnosed by MRI after patients had seizures.
The participants underwent a battery of tests for reading skills.
Patients with heterotopia and those with dyslexia had worse phonemic awareness (ability to manipulate the sound segments of words) than controls (P
Both groups also had lower scores than controls at rapid automatized naming with significantly lower scores for both letters and digits (both P
Untimed tests of real and nonreal words showed no difference between groups. However, patients with heterotopia and dyslexia were significantly slower at reading real and nonreal words in timed tests compared with controls (P<0.05).
Nonsignificant trends were seen for poorer accuracy, speed, and fluency in reading a passage of text among participants with heterotopia and dyslexia, although no difference between groups was seen in comprehension.