Study on Chinese character writing related cortical areas mapped by navigated transcranial magnetic stimulation / 中国神经精神疾病杂志

ABSTRACT

Objective To identify Chinese character writing related cortex (WRC) and its relationship with hand motor cortical areas. Methods Ten native Chinese-speaking, right-hand volunteers were recruited in the study. NTMS mapping was conducted during picture naming task. The WRC were mapped based on nTMS-induced impairment of Chinese character writing. The extent and area of WRC was calculated. The right-hand motor representations were mapped while motor-evoked potentials were produced under nTMS stimulation. EMG data and coordinates of positive stimulus were recorded. The relationship between WRC and hand motor cortex (HMC) was analyzed on the basis of area comparison and distance calculation. Results The cortical areas related to Chinese character writing were mapped successfully in all subjects by nTMS. WRC was primarily centered in left posterior middle frontal gyrus (pMFG) (86%,55/64). The mean WRC area (161.03 mm2 ±62.58mm2) was significantly smaller than the mean HMC area (589.50 mm2±227.34mm2) (P<0.001). The WRC and HMC were not conjoined or overlapped in the dominant hemisphere. The distance between those two was 12.58mm±2.71mm. Conclusions NTMS can provide reliable assistance in mapping WRC areas. The WRC is relatively fixed and centralized in pMFG but is not overlapped with the HMC.