Performance of intraoperative neurocognitive tests during awake surgery for patients with diffuse low-grade glioma.

Despite great advancements and the diffusion of awake surgery for brain tumors, the literature shows that the tests applied during the procedure are heterogeneous and non-standardized. This prospective, observational, descriptive study collected data on intraoperative brain mapping and the performance of multiple neurocognitive tests in 51 awake surgeries for diffuse low-grade glioma. Frequency of use and rate of intraoperative findings of different neurocognitive tests were analyzed. Patients mean age at the time of surgery was 35.1 (20-57) years. We performed 26 (51.0%) surgeries on the left hemisphere (LH) and 25 (49.0%) on the right hemisphere (RH). Significant differences were observed between the total number of functional findings (cortical and subcortical) identified in the LH and RH (p = 0.004). In subcortical findings alone, the differences remained significant (p = 0.0004). The RH subcortical region showed the lowest number of intraoperative findings, and this was correlated with functional outcome: Karnofsky performance scale at five days (p = 0.022), three months (p = 0.002) and one year (p = 0.002) post-surgery. On average, more tests were used to map the RH, with a lower frequency of both cortical and subcortical functional findings. Even though subcortical findings were less frequent than cortical findings, they were crucial to defining the resection margins. Based on the intraoperative findings, frequency of use, and rate of findings per use of the tests analyzed, the most relevant tests for each hemisphere for awake brain mapping were identified.

Awake Craniotomy for Diffuse Low Grade Gliomas in a Resource Limited Setting: Lessons Learned with a Consecutive Series of 51 Surgeries.

OBJECTIVE: Despite benefits of awake craniotomy (AC) many centers do not have access to it. We demonstrated the oncological and functional results of our initial experience in implementing AC in a context of resource limited setting. METHODS: This prospective, observational, and descriptive study collected the first 51 AC for diffuse low-grade glioma, classified according to the 2016 World Health Organization. RESULTS: Mean age was 35.09 ± 9.91 years old. The most common clinical presentation was seizure (89.58%). The average segmented volume was 69.8 cc; with 51% of lesions with more than 6 cm in the largest diameter. Resection of more than 90% of the lesion was achieved in 49% of cases, and greater than 80% in 66.6% of cases. The mean follow-up was 835 days (2.29 years). Satisfactory Karnofsky performance status (KPS) (80 to 100) was observed in 90.1% presurgery, 50.9% at 5 days, 93.7% at 3 months, and 89.7% at 1-year postoperation. At multivariate analysis, tumor volume, new postoperative deficit, and extent of resection were related to KPS at 1 year of follow up. CONCLUSIONS: Functional decline was clearly observed in the immediate postoperative period, but excellent recovery of functional status was observed in the medium and long term. The data presented indicate the benefits of this mapping in both cerebral hemispheres, addressing several cognitive functions in addition to motricity and language. The proposed AC model is a reproducible technique and resource sparing that can be performed safely and with good functional outcomes.

Intraparenchymal Epidermoid Cyst Close to Broca Area-Awake Craniotomy and Gross Total Resection.

BACKGROUND: Epidermoid tumors, or epidermoid cysts (ECs), are benign, slow-growing, congenital, and rare lesions that represent approximately 0.2%-1.8% of all intracranial tumors. Intraparenchymal ECs are very rare lesions that may account for 1.5% of all intracranial epidermoid tumors; frontal lobe involvement is found in 39.2% of intraparenchymal ECs. We present a case using awake craniotomy to achieve maximal safe gross total resection of a rare intraparenchymal EC close to Broca area in a bilingual patient. CASE DESCRIPTION: A 45-year-old man presented with a generalized seizure episode. He was initially treated with levetiracetam, which led to renal failure. Imaging findings demonstrated an intraparenchymal left frontal EC with peripheral coarse calcifications at Broca area. As the patient was bilingual and had a normal neurologic examination, we performed a left frontal awake craniotomy under local anesthesia so as to map both languages, using the motor task and a test for language monitoring, alternating a naming task in Portuguese and English and a semantic task in Portuguese. A gross total resection was achieved with no neurologic deficits. Histopathologic examination confirmed the diagnosis of an epidermoid cyst. After 1 year, the patient is still seizure-free. CONCLUSIONS: Awake surgery proved to be a useful tool for complete resection of the capsule even in a very eloquent language area. In multilingual patients with benign intra-axial lesions, intraoperative mapping should be performed for all the languages in which the patient is fluent to avoid postoperative neurologic deficits.

Awake craniotomy for a cavernous angioma in the Broca's area.

Cavernous angiomas constitute 5%-10% of cerebrovascular malformations and may cause seizure and neurological deficits from bleeding. 4 The authors present a case of a 44-year-old man with a 3.5-year history of epilepsy without complete seizure control despite anticonvulsants. Brain MRI showed a 2.8 cm cavernous angioma at the left pars opercularis, also known as the Broca's area. 3 The patient underwent an awake craniotomy for intraoperative cortical-subcortical language and sensory-motor mapping for a complete resection of the cavernous angioma and the hemosiderin rim. 1-6 The procedure was uneventful, and the patient evolved seizure free and with no deficits. The video can be found here: https://youtu.be/QajbLIsr_vg .