Oumar Sacko

Awake craniotomy vs surgery under general anesthesia for resection of supratentorial lesions.

BACKGROUND:The use of an awake craniotomy in the treatment of supratentorial lesions is a challenge for both patients and staff in the operation theater. OBJECT:To assess the safety and effectiveness of an awake craniotomy with brain mapping in comparison with a craniotomy performed under general anesthesia. METHODS:We prospectively compared 2 groups of patients who underwent surgery for supratentorial lesions: those in whom an awake craniotomy with intraoperative brain mapping was used (AC group, n = 214) and those in whom surgery was performed under general anesthesia (GA group, n = 361, including 72 patients with lesions in eloquent areas). The AC group included lesions in close proximity to the eloquent cortex that were surgically treated on an elective basis. RESULTS:Globally, the 2 groups were comparable in terms of sex, age, American Society of Anesthesiologists score, pathology, size of lesions, quality of resection, duration of surgery, and neurological outcome, and different in tumor location and preoperative neurological deficits (higher in the AC group). However, specific data analysis of patients with lesions in eloquent areas revealed a significantly better neurological outcome and quality of resection (P < .001) in the AC group than the subgroup of GA patients with lesions in eloquent areas. Surgery was uneventful in AC patients and they were discharged home sooner. CONCLUSION:AC with brain mapping is safe and allows maximal removal of lesions close to functional areas with low neurological complication rates. It provides an excellent alternative to craniotomy under GA.

Intracranial meningioma surgery in the ninth decade of life.

OBJECTIVEThe aims of this study are to assess the surgical outcome of elderly patients aged 80 years or more, to analyze the factors influencing postoperative course, and to propose a grading system to standardize the surgical indication of intracranial meningioma in the elderly. METHODSBetween 1990 and 2005, we surgically treated 74 consecutive patients aged 80 years or more for intracranial meningiomas (47 women, 27 men; mean age, 82 yr; age range, 80–90 yr). The median follow-up period was 94 months (range, 15–147 mo). We retrospectively analyzed the factors influencing surgical outcome and retained the significant factors to form the Sex, Karnofsky Performance Scale, American Society of Anesthesiology Class, Location of Tumor, and Peritumoral Edema (SKALE) grading system. RESULTSThere was no perioperative mortality, and the 1-year mortality rate was 9.4%. Postoperative mortality was lower in women with a Karnofsky Performance Scale score of 60 or greater, an American Society of Anesthesiology Class of 1 or 2, a noncritical tumor location, and a moderate or absent peritumoral edema. Patients with a SKALE score of more than 8 had an excellent outcome, whereas those with a SKALE score of less than 8 had a poor outcome. The rate of postoperative complications was 9.4%. Large tumors, critical locations, severe peritumoral edema, and total surgical excision were associated with a higher risk of postoperative complications. CONCLUSIONSurgery of intracranial meningioma in elderly patients is feasible when the SKALE score is 8 or greater. Prospective studies are required to validate this grading system.

Cortical calculation localization using electrostimulation

OBJECT A naming task has been used to spare cortical areas involved in language. In the present study, a calculation task was combined with electrostimulation mapping (awake surgery) to spare cortical areas involved in calculation in patients undergoing surgery for brain lesions. The organization of language and calculation areas was analyzed in relation to these surgical data. METHODS Twenty patients with brain lesions close to areas possibly involved in calculation (dominant parietal lobe and F2) were prospectively studied over a 4-year period. Four patients had preoperative symptoms of acalculia and therefore were not included in the brain mapping procedure. RESULTS In 16 patients, direct electrostimulation caused calculation interferences in localized small cortical areas (< 2 cm(2)). Of the 53 calculation interferences found, 23 were independent of language areas, especially those in the inferior left parietal lobule. Various patterns of interference were observed (11 complete acalculia, 5 acalculia with wrong answers, 2 hesitations, and 5 mixed responses), although error patterns were fairly similar across angular, parietal, and frontal stimulation sites. Calculation areas in 4 patients could not be spared for oncological reasons; postoperatively, 3 of these patients showed significant acalculia symptoms. In contrast, none of the patients whose calculation areas were spared had arithmetic difficulties 1 month after surgery. Improvements in acalculia symptoms after surgery were also found in 3 of the 4 patients with preoperative calculation difficulties. CONCLUSIONS To limit the risk of personal and professional disturbances caused by acquired anarithmetia in patients undergoing surgery for brain tumors or epilepsy, the authors think it is necessary to use a calculation task during brain mapping, especially when operating in the dominant parietal lobe.

Spinal meningioma surgery in elderly patients with paraplegia or severe paraparesis: a multicenter study.

OBJECTIVEIn a multicenter study, 102 patients aged 70 years or older with paraplegia or severe paraparesis, and who underwent operation for spinal meningiomas, are presented to correlate surgery and outcome and to determine the most influential factors that affected this outcome. METHODSFive French neurosurgical centers participated in this retrospective study between 1990 and 2007. Pre- and postoperative neurological status were assessed using a grading system. All patients underwent operation, and neurological evaluations were conducted 3 months and 1 year after surgery. The median follow-up period was 49.5 months (range, 12–169 months). Data were analyzed using a multiple logistic regression model. RESULTSTwenty-six patients were paraplegic (Grade 4). Complete tumor removal was obtained in 93 patients. There was no surgical mortality, and morbidity was 9%. Three months after surgery, 7 of the patients were unchanged, 87 patients had improved, and 8 were not evaluated. One year after surgery, 7 of the 100 surviving patients were clinically unchanged and 93 had improved. Of those who had improved, 49 patients experienced complete recovery. CONCLUSIONAdvanced age did not seem to contraindicate surgery, even in patients with severe preoperative neurological deficits and/or an American Society of Anesthesiologists class of III. Quality of life can be improved in most cases.

Responses of heart rate variability to acute pain after minor spinal surgery: optimal thresholds and correlation with the numeric rating scale.

Background: The autonomic nervous system is influenced by many stimuli including pain. Heart rate variability (HRV) is an indirect marker of the autonomic nervous system. Because of paucity of data, this study sought to determine the optimal thresholds of HRV above which the patients are in pain after minor spinal surgery (MSS). Secondly, we evaluated the correlation between HRV and the numeric rating scale (NRS). Methods: Following institutional review board approval, patients who underwent MSS were assessed in the postanesthesia care unit after extubation. A laptop containing the HRV software was connected to the ECG monitor. The low-frequency band (LF: 0.04 to 0.5 Hz) denoted both sympathetic and parasympathetic activities, whereas the high-frequency band (HF: 0.15 to 0.4 Hz) represented parasympathetic activity. LF/HF was the sympathovagal balance. Pain was quantified by the NRS ranging from 0 (no pain) to 10 (worst imaginable pain). Simultaneously, HRV parameters were noted. Optimal thresholds were calculated using receiver operating characteristic curves with NRS>3 as cutoff. The correlation between HRV and NRS was assessed using the Spearman rank test. Results: We included 120 patients (64 men and 56 women), mean age 51±14 years. The optimal pain threshold values were 298 ms2 for LF and 3.12 for LF/HF, with no significant change in HF. NRS was correlated with LF (r=0.29, P<0.005) and LF/HF (r=0.31, P<0.001) but not with HF (r=0.09, NS). Conclusions: This study suggests that, after MSS, values of LF>298 m2 and LF/HF>3.1 denote acute pain (NRS>3). These HRV parameters are significantly correlated with NRS.

Hemangioblastoma of the corpus callosum: A case report and review of the literature on its origin

A third case of corpus callosum hemangioblastoma (HB) is presented. With no preoperative embolization, surgery was uneventful and the postoperative course was excellent. Based on the literature, we attempted to clarify the histogenesis of HB and to explain why they are exceptional in the supratentorial region in contrast to the posterior cranial fossa. The VHL gene is expressed particularly in Purkinje cells of the cerebellum, but this expression is also possible in supratentorial structures. Its mutation leads to developmental arrest of angioblasts that become potentially neoplastic cells. These CD133-positive pluripotent neoplastic angioblasts, similar to stem cells, may be immature HB in the brain. They also express VEGF, coexpress Epo/EpoR, and are capable of differentiation into primitive vascular structures. This coexpression may not only mediate developmental stagnation, but may also induce HB proliferation. Therefore, HB tumorigenesis may be initiated during embryogenesis and may originate from angiomesenchyma because of the expression of three cell types (stromal cells, pericytes, and endothelial cells) in vimentin. Their capacity for proliferation and differentiation in HB depends on the microenvironment.