Preoperative localization of brain cortex by using magnetic source imaging can increase the veracity of brain neoplasm operation in functional region

Zhiqiang ZHANG; Tao HUANG; Caijun XIE; Tao LIN; Ping ZHANG

ABSTRACT

BACKGROUND:

As a kind of unwounded biomagnetism technique, magnetoencephalography (MEG) relfects immediate information of cerebral function by using magnetic source imaging through recording changes of magnetic field of neurocytes under different functional status.

OBJECTIVE:

To investigate the practicability of magnetoencephalography (MEG) imaging in localizing sensory-motor cortex for brain tumour surgery in 36 patients.

DESIGN:

Observational study.

SETTING:

Department of Neurosurgery, Guangdong Provincial Hospital of Traditional Chinese Medicine.PARTICTPANTS From Janury 2003 to April 2006, 36 patients (17 male and 19 female) with brain tumors selected from Deparment of Neurosurgery, Guangdong 999 Brain Hospital underwent surgery with MEG-guided neuronavigation in the region of the sensory and motor cortex. Ages of the patients ranged from 13 to 70 years. Among the 36 patients, 14 with gliomas (including 5 highly malignant gliomas), 19 with meningomas, 1 with spongy angioma and 2 with adenocarcinoma (due to the metastasis of brain tumor). All patients and relatives provided the confirmed consent and the experiment provided by the local ethics committee.

METHODS:

A 148-channel biomagnetometer (4-D Neuroimaging, USA) was used to determine motor and/or senory cortex with sampling rate 678.17 Hz, high-pass filter 1.0 Hz and bandwith 200 Hz. MRI images were acquired using a Philips Gyroscan Intera 1.5T MR tomography. And then, the functional maps were transfered to the neuronavigation system for the treatment of brain tumor. All patietns followed up by further consultation and telephone call in 2-26 months after operation.MAIN OUTCOME

MEASURES:

Operative outcome and prognosis.

RESULTS:

MEG demonstrated that the tumor lesion changed the sensory-motor cortex in various degrees for the 36 patients. Brain tumors were resected completely in 34 cases. At 2-26 months after surgery, neurological deficits fully recovered in 19 cases, unchanged in 15 cases and deteriorated in 2 cases.

CONCLUSION:

MEG was found to be practical and useful in localizing sensory-motor cortex and brain tumor. It is a valuable non-invasive method for presurgical planning in the treatment of brain tumors.