Dyslexia commonly develops after stroke

Many therapy sessions are spent helping stroke patients regain their ability to speak. But not much time is spent helping previously literate patients learn to read. According to Margaret Greenwald, PhD, assistant professor of audiology and speech-language pathology, stroke patients are commonly diagnosed with acquired dyslexia as a result of brain injury, but they rarely receive treatment for their reading deficits.

With a three-year grant from the National Institutes of Health, Dr. Greenwald is developing a program for diagnosis and treatment of reading deficits for stroke patients. As co-director of the Brain, Language and Communication Laboratory, she is working with clinicians and researchers in the departments of neurology and psychiatry and behavioral neurosciences, and she has joined forces with Dr. Steven Levine and the Comprehensive Stroke Program.

In the diagnostic component of the grant, Dr. Greenwald is studying how normal reading systems are organized in the brain, and how those systems break down after neurological impairment. In most cases, stroke patients retain at least partial function of cognitive components of reading. The overall deficit may reflect difficulty in translating between diverse processing systems involved in visual word recognition, semantic memory and phonological word retrieval.

For example, in a recent issue of the journal, Cognitive Neuropsychology, Dr. Greenwald describes a patient with a selective deficit in encoding abstract letter position information from print. This has inspired Dr. Greenwald to study the critical role of an Ordinal Graphemic Code in normal reading, in translating between visual-spatial codes and temporal-serial phonological codes.

Through the treatment component of the grant, Dr. Greenwald is offering individualized reading therapy for stroke patients. “We are developing new treatment approaches for the various forms of dyslexia, particularly deficits in visual recognition,” she said.

The treatment program will offer approximately 35 stroke patients up to 40 reading therapy sessions each. Treatment tests will be presented on a laptop computer and can be practiced at home.

“The exciting thing about this work is that many critical areas are now working together,” said Dr. Greenwald. “Specialists in neurology, cognitive psychology, psychiatry, and speech-language pathology are working to put all these elements together for patients.”