The role of functional magnetic resonance imaging in evaluating the hand motor area in patients with perirolandic lesion

Objective: This study aims to investigate the role of functional magnetic resonance imaging (fMRI) in localization of the hand motor area compared to conventional magnetic resonance imaging (cMRI) in patients with peri-rolandic lesions and to analyze the correlation of lesion to activation distance (LAD) with presurgical motor deficit.Methods: A single-center, retrospective case series of 37 patients with perirolandic lesions who underwent both cMRI and fMRI prior to neurosurgical intervention was performed. The anatomical landmarks associated with the hand motor area in both hemispheres were interpreted using cMRI. The distance between the hand motor areas localized on fMRI and cMRI was measured. LAD on fMRI was determined and based on that, the patients were categorized into three groups: LAD less than 1 cm, 1-2 cm, and greater than 2 cm. The percentages of preoperative motor deficit among these patient groups were subsequently compared.Results: The rates of detecting anatomical landmarks related to the hand motor area on lesion-affected hemi-spheres were significantly lower than those on unaffected hemispheres. The average distance between the hand motor areas as determined by fMRI and cMRI was 11.81 & PLUSMN; 5.83 mm, and in 22.58% of cases, this distance exceeded 20 mm. The frequency of preoperative motor deficit increased from 7.69% in patients with LAD exceeding 2 cm to 53.33% in patients with LAD between 1 and 2 cm, and further to 77.78% in patients with LAD of less than 1 cm. This study revealed a significant correlation between LAD and the degree of motor deficit before surgery (p = 0.002).Conclusion: fMRI was found to be significantly better than cMRI at localizing the hand motor area in patients with perirolandic lesions and might be considered as a valuable tool for neurosurgical planning.