OBJECTIVE In this paper, the authors aimed to illustrate how Holmes tremor (HT) can occur as a delayed complication after brainstem cavernoma resection despite strict adherence to the safe entry zones (SEZs). METHODS After operating on 2 patients with brainstem cavernoma at the Great Metropolitan Hospital Niguarda in Milan and noticing a similar pathological pattern postoperatively, the authors asked 10 different neurosurgery centers around the world to identify similar cases, and a total of 20 were gathered from among 1274 cases of brainstem cavernomas. They evaluated the tremor, cavernoma location, surgical approach, and SEZ for every case. For the 2 cases at their center, they also performed electromyographic and accelerometric recordings of the tremor and evaluated the post-operative tractographic representation of the neuronal pathways involved in the tremorigenesis. After gathering data on all 1274 brainstem cavernomas, they performed a statistical analysis to determine if the location of the cavernoma is a potential predicting factor for the onset of HT. RESULTS From the analysis of all 20 cases with HT, it emerged that this highly debilitating tremor can occur as a delayed complication in patients whose postoperative clinical course has been excellent and in whom surgical access has strictly adhered to the SEZs. Three of the patients were subsequently effectively treated with deep brain stimulation (DBS), which resulted in complete or almost complete tremor regression. From the statistical analysis of all 1274 brainstem cavernomas, it was determined that a cavernoma location in the midbrain was significantly associated with the onset of HT (p < 0.0005). CONCLUSIONS Despite strict adherence to SEZs, the use of intraoperative neurophysiological monitoring, and the immediate success of a resective surgery, HT, a severe neurological disorder, can occur as a delayed complication after resection of brainstem cavernomas. A cavernoma location in the midbrain is a significant predictive factor for the onset of HT. Further anatomical and neurophysiological studies will be necessary to find clues to prevent this complication.

Purpose: To investigate the predictor factors of mortality describing the prognosis of primary surgical resection of Glioblastoma Multiforme (GBM). Materials and Methods: A systemic search was conducted from electronic databases (PubMed/Medline, Cochrane Library, and Google Scholar) from inception to 12th September 2021.  All statistical analysis was conducted in Review Manager 5.4.1. Studies meeting inclusion criteria were selected. A random-effect model was used when heterogeneity was seen to pool the studies, and the result were reported in the Hazards Ratio (HR) and corresponding 95% Confidence interval (CI). Result: Twenty-three cohort studies were selected for meta-analysis. There was statistically significant effect of extent of resection on prognosis of surgery in GBM patients (HR= 0.90 [0.86, 0.95]; p< 0.0001; I2= 96%), male gender (HR= 1.19 [1.06, 1.34]; p= 0.002; I2= 0%) and decrease Karnofsky Performance Status (HR= 0.97 [0.95, 0.99]; p= 0.003; I2= 90%). Age and tumor volume was also analyzed in the study. Conclusion: The results of our meta-analysis suggested that age, gender, pre-operative KPS score and extent of resection have significant effects on the post-surgical mortality rate, therefore, these factors can be used significant predictor of mortality in GBM patients.

Brain low grade lesions of glial origin (LGG) especially those located in or near eloquent areas pose a challenging task for neurosurgeons operating such tumors. Even after the new classification of LGG, age, IDH status and extent of resection (EOR) seem to represent the main points that stratify patients in low or high risk. Often, surgery is the first step in the treatment and may positively impact the overall survival if extensive resection can be achieved with lowest morbidity. Therefore, neurophysiologic monitoring and intra operative MRI can be considered valuable tools in aiding maximal safe resection. Awake surgery has an important role when left side low frontal or posterior temporoparietal gliomas are to be operated on and individualized testing may influence, to our knowledge, on the extent and quality of resection, since anatomic variability may be encountered on different individuals during awake mapping. MATERIALS AND METHODS: a total of 16 LGG (10 astrocytomas, 4 oligoastrocytomas and 2 oligodendroglioma) were submitted to surgery, using awake craniotomy, neurophysiologic monitoring and intra operative MRI. Depending on each patient personal background, when appropriate and with personal consent prior to surgery, individualized testing based on mainly labor activities and hobbies such as playing the guitar and singing, praying, and oral math calculations were conducted and evaluated by a neurophysiologist, in conjunction with brain intra operative cortical and subcortical mapping. 9 patients were male and 7 were female. Median age was 38, maximal age was 54 and the minimal age was 28. All patients had lesions located in or near eloquent speech and/or motor areas. All patients were submitted to immediate post operative CT scan prior to UCI care and all were submitted to control MRI scan to estimate the EOR. 70% patients presented with headache, 62, 5% with seizure, only 1 patient presented as an incidental finding. Post operatively, 10 patients were neurologically intact, 5 had transient worsening of the previous neurological deficit and only one did not totally recover after 3 months post operation. The use of iMRI was helpful to improve EOR in 37,5% cases and positive mapping using individual speech testing that limited resection occurred in 56,25% cases. Gross total resection was achieved in 10 patients. CONCLUSION: brain mapping is an essential tool when performing awake surgery and may be even more specific when combined to individualized intra operative testing. Intra operative MRI, in our cases, combined to neuromonitoring, was a valuable tool when seeking maximal safe LGG resection. BACKGROUND: Brain tumors involving the primary motor cortex are often deemed unresectable due to the potential neurological consequences that result from injury to this region. Nevertheless, we have challenged this dogma for many years, and used asleep, as well as awake, intraoperative stimulation mapping to maximize extent of resection. It remains unclear whether these tumors can be resected with acceptable mor...

Purpose To investigate the predictor factors of mortality describing the prognosis of primary surgical resection of low-grade astrocytoma. Materials and methods A systemic search was conducted from electronic databases (PubMed/Medline, Cochrane Library, and Google Scholar) from inception to November 14, 2021. All statistical analysis was conducted in Review Manager 5.4.1. Studies meeting inclusion criteria were selected. A random-effect model was used when heterogeneity was seen to pool the studies, and the result were reported in the hazards ratio (HR) and corresponding 95% confidence interval. Result Five cohort studies were selected for meta-analysis. There was statistically significant effect of total resection on increase mortality after surgery in low-grade astrocytoma patients (HR = 0.70 [0.52, 0.94]; p = 0.02; I2 = Not applicable). On the other hand, there was statistically nonsignificant effect of patient’s age (HR = 1.27 [0.95, 1.68]; p = 0.11; I2 = 83%), tumor size (HR = 1.13 [0.94, 1.35]; p = 0.19; I2 = 73%), and increasing KPS (HR = 0.59 [0.20, 1.77]; p = 0.35; I2 = 86%) on prognosis of low-grade astrocytoma after surgery. Conclusion The results of meta-analysis showed significant relationship of extent of resection and mortality, while factors such age, KPS score, and tumor size were nonsignificant to determine mortality in patient diagnosed with low-grade astrocytoma. The gross total resection surgery should be preferred over subtotal resection since the incidence of malignant formation is low in gross total resection.

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