Reorganization characteristics of speech cortex during speech restoration following total laryngectomy. A functional magnetic resonance imaging follow-up

During speech restoration following laryngectomy, language-related cortical areas develop connections with new primary motor neurons. The present study followed up 18 patients after total resection of laryngeal carcinoma. According to an evaluation of pronunciation, patients were assigned to three groups: poor, moderate and good pronunciation. Functional magnetic resonance imaging revealed significant increases in the number of activated voxels and the intensity of activation changes in the left middle frontal gyrus, left precentral gyrus, left postcentral gyrus, left supplementary motor area, left anterior cingulate gyrus and right fusiform gyrus between the moderate pronunciation group compared with the poor and good pronunciation groups. We propose that these brain regions play an important role in the progress of speech restoration, and improvements in pronunciation learning for patients following laryngectomy. However, during the later period of speech restoration, the number of activated voxels and intensity changes in these regions decreased to the level of healthy controls, indicating that the learning and instruction effects weakened once patients had mastered pronunciation techniques.