Functional approach using intraoperative brain mapping and neurophysiological monitoring for the surgical treatment of brain metastases in the central region

Abstract

OBJECTIVE Brain metastases are the most frequent intracranial malignant tumor in adults. Surgical intervention for metastases in eloquent areas remains controversial and challenging. Even when metastases are not infiltrating intra-parenchymal tumors, eloquent areas can be affected. Therefore, this study aimed to describe the role of a functional guided approach for the resection of brain metastases in the central region. METHODS Thirty-three patients (19 men and 14 women) with perirolandic metastases who were treated at the authors' institution were reviewed. All participants underwent resection using a functional guided approach, which consisted of using intraoperative brain mapping and/or neurophysiological monitoring to aid in the resection, depending on the functionality of the brain parenchyma surrounding each metastasis. Motor and sensory functions were monitored in all patients, and supplementary motor and language area functions were assessed in 5 and 4 patients, respectively. Clinical data were analyzed at presentation, discharge, and the 6-month follow-up. RESULTS The most frequent presenting symptom was seizure, followed by paresis. Gross-total removal of the metastasis was achieved in 31 patients (93.9%). There were 6 deaths during the follow-up period. After the removal of the metastasis, 6 patients (18.2%) presented with transient neurological worsening, of whom 4 had worsening of motor function impairment and 2 had acquired new sensory disturbances. Total recovery was achieved before the 3rd month of follow-up in all cases. Excluding those patients who died due to the progression of systemic illness, 88.9% of patients had a Karnofsky Performance Scale score greater than 80% at the 6-month follow-up. The mean survival time was 24.4 months after surgery. CONCLUSIONS The implementation of intraoperative electrical brain stimulation techniques in the resection of central region metastases may improve surgical planning and resection and may spare eloquent areas. This approach also facilitates maximal resection in these and other critical functional areas, thereby helping to avoid new postoperative neurological deficits. Avoiding permanent neurological deficits is critical for a good quality of life, especially in patients with a life expectancy of over a year.

Intraoperative neuromonitoring as an element of neurophysiological support system high-tech neurosurgical care

“…В функциональной нейрохирургии двига-тельных нарушений (например, при болезни Паркинсона) применяют микроэлектродную регистрацию суммарной активности подкор-ковых структур для последующей установки электродов нейромодулятора. Классическими примерами способов локализации структур-но-функциональных образований, с помощью которых оценивают сохранность определенной функции, стали методики интраоперационно-го картирования моторной коры и речевых зон [2,6,[11][12][13][14].…”

Continuous Dynamic Mapping to Identify the Corticospinal Tract in Motor Eloquent Brain Tumors: An Update

“…[1][2][3]21,37 Several studies showed that decreasing mapping MEP thresholds correlates with the risk of mechanical injury to the CST. 5,6,34,[38][39][40] Applying monopolar subcortical cathodal short train stimulation at low stimulation intensities, we demonstrated that mapping motor thresholds correlate with the risk of CST injury.…”

Is function-based resection using intraoperative awake brain mapping feasible and safe for solitary brain metastases within eloquent areas?

“…The surgical resection of brain metastases located in eloquent areas remains a particular challenge due to the higher risk of postoperative neurological and neurocognitive de cits [5,21]. It is a crucial issue since survival is linked to both the extent of resection and the functional status of the patient [21].…”

“…3) better control of the surgical risks regarding metastases initially deemed inoperable and previously treated with stereotactic radiotherapy for which a histomolecular diagnosis is required. Previous series have reported awake surgery for brain metastases [7,9,10,21]. Two pioneer studies from Dusseldorf reported that awake surgery is feasible for metastases in eloquent areas, minimizing postoperative neurologic de cits and morbidity and permitting supramarginal resection [9,10].…”