Preliminary study on the mechanism of reading recovery in a pure alexia by using functional MRI

Objective: To observe the changes of the brain function during reading recovery by using functional MRI (fMRI), and to provide the experimental data in elucidating the mechanism on the recovery of reading and language function. Methods: fMRI was performed in a native Chinese patient with pure alexia on the 45th and 130th day after the onset, respectively. Three kinds of Chinese characters were presented during the scan and the patient was asked to make the judgement weather he could recognize the characters or not. The brain activation maps were acquired after postprocessing, and the activated location and volume were compared between the first and second experiments. Results: In both experiments, Broca area, Wernicke area, and the right extrastriate were significantly activated, while the left extrastriate around the lesion was markedly activated only in the second experiment, and the volume of activation in the right extrastriate in the second experiment was about 3 times as large as that in the first experiment. Conclusion: The left extrastriate cortex is one of the key areas responsible for reading function in the brain. The recovery of reading function can be compensated in contralateral corresponding cortical area, or it can be the result of reorganization in ipsilateral peri-lesion cortex. Both mechanisms may simultaneously play important roles in reading recovery