Alterations in the functional anatomy of reading induced by rehabilitationof an alexic patient

Objective: The goal of the study was to measure regional cerebral blood flo w (CBF) in a stroke patient with acquired phonologic alexia before and afte r therapy using the Auditory Discrimination in Depth (ADD) program. Backgro und: After rehabilitation of acquired language disorders, functional imagin g can detect activity in brain structures that do not mediate language duri ng normal conditions. However, the anatomic correlates of recovery or rehab ilitation from acquired reading disorders are largely undescribed. Methods: Cerebral SPECT scans were obtained before and after the intervention with Auditory Discrimination in Depth. The first and last activation tasks neces sitated that the patient read nonwords during radionuclide uptake. Another (control) scan was acquired during performance of a nonlinguistic task shor tly before the end of the ADD program. Results: Before therapy, the right h emisphere was inactive during nonword reading relative to the nonlinguistic task. After treatment, nonword reading increased cerebral blood flow in th e posterior right perisylvian cortices homologous to the dominant hemispher e areas engaged by reading. Brain activity also increased in Broca's area o f both hemispheres. Conclusions: Dyslexia rehabilitation may facilitate rig ht-hemisphere cortical networks in the reading process and increase engagem ent of phonologic articulatory motor representations in Broca's area.