BACKGROUND: The neurosurgical resection of mass lesions in the vicinity of the corticospinal tract (CST) may induce a postoperative impairment of motor function. The etiology and localisation of lesions causing postoperative motor deterioration were analysed by preoperative and postoperative magnetic resonance imaging (MRI). PATIENTS AND METHODS: In 32 patients with mass lesions near the CST and intraoperative deterioration of the motor-evoked potentials, preoperative and postoperative MRI was performed and evaluated for new lesions along the CST. These lesions were classified into edema, infarction and haemorrhage. All patients were examined for perioperative central motor function. RESULTS: New lesions along the CST were found in 19 of the 32 patients. Postoperatively new or deteriorated motor function was found in 13 of these 19 patients (edemas: 4 out of 6, haemorrhages: 4 out of 7; infarctions: 5 out of 6). Of the 13 patients without new MRI lesion along the CST one had a new motor deficit. CONCLUSION: The postoperative MRI in patients with mass lesions near the CST and postoperative central motor deterioration sensitively showed the etiology and localisation of the lesion. Apart from being due to infarctions and haemorrhages, a larger number of postoperative motor impairments may be caused by edema.
BACKGROUND: The neurosurgical resection of mass lesions in the vicinity of the corticospinal tract (CST) may induce a postoperative impairment of motor function. The etiology and localisation of lesions causing postoperative motor deterioration were analysed by preoperative and postoperative magnetic resonance imaging (MRI). PATIENTS AND METHODS: In 32 patients with mass lesions near the CST and intraoperative deterioration of the motor-evoked potentials, preoperative and postoperative MRI was performed and evaluated for new lesions along the CST. These lesions were classified into edema, infarction and haemorrhage. All patients were examined for perioperative central motor function. RESULTS: New lesions along the CST were found in 19 of the 32 patients. Postoperatively new or deteriorated motor function was found in 13 of these 19 patients (edemas: 4 out of 6, haemorrhages: 4 out of 7; infarctions: 5 out of 6). Of the 13 patients without new MRI lesion along the CST one had a new motor deficit. CONCLUSION: The postoperative MRI in patients with mass lesions near the CST and postoperative central motor deterioration sensitively showed the etiology and localisation of the lesion. Apart from being due to infarctions and haemorrhages, a larger number of postoperative motor impairments may be caused by edema.
Authors: Justin S Smith; Soonmee Cha; Mary Catherine Mayo; Michael W McDermott; Andrew T Parsa; Susan M Chang; William P Dillon; Mitchel S Berger Journal: J Neurosurg Date: 2005-09 Impact factor: 5.115