. [60] have used both anaesthesia techniques. GA, general anaesthesia. doi:10.1371/journal.pone.0156448.gPLOS ONE | DOI:10.1371/journal.pone.0156448 May 26,31 /Anaesthesia Management for Awake Craniotomyintraoperative seizures and their consequences [10,17?9,31?9,42?4,47,49?5,57?0,62]. The total number of performed AC procedures in these studies was 4942 and 351 (7.1 ) intraoperative seizures were reported (Table 4). Only twenty-three (0.5 ) intraoperative seizures led to a failure of AC, but they were resolved get RG7666 without any serious problems and the surgery was continued in GA [33,34,42,43,55,57]. Interestingly, the AAA technique showed a high proportion of eight seizures in fifty AC procedures, but only one led to AC failure due to required intubation [33]. Intraoperative seizures were more common in younger patients and those with a history of seizures [31,42]. A meta-analysis was performed for thirty-four studies, [10,17?6,28,29,32,34?39,43,47,49?5,57?0,62], which used the MAC and SAS technique, excluding the MS-275 site duplicate studies from Tel Aviv [31,42] and Glostrup [27,44]. Meta-analysis showed an estimated proportion of seizures of 8 [95 CI: 6?1] with substantial heterogeneity between studies (I2 = 75 ) (Fig 4). In the meta-regression analysis, the techniques used did not explain the differences in the studies (QM < 0.001, df = 1, p = 0.983). The OR comparing SAS to MAC technique was 1.01 [CI95 : 0.52?.88]. Postoperative neurological dysfunction (new/ late). Description of particular postoperative neurological dysfunctions differed significantly in the included studies. Therefore we have subsumed all kinds of new neurological dysfunctions under these superordinate two outcome variables. Of note, we did not include data of patients with deterioration of a pre-existing neurological dysfunction. Twenty-nine studies [10,18,19,23,24,28,29,31,33?5,37,38,40?43,48,49,51?5,57?9,61,62] reported new postoperative neurological dysfunctions after 565 (14.0 ) of totally 4029 AC procedures. A later follow up result (six months) was provided for 279 of these patients with new neurological dysfunction. It showed a persistent neurological dysfunction in 64 patients. Of note, late neurological outcome after six months was reported in only seventeen studies comprising 2085 AC procedures in total. Considering twenty-six studies [10,18,19,23,24,28,29,34,35,37,38,40,41,43,48,49,51?5,57?9,61,62], which were reasonable included in our meta-analysis, the proportion of new neurological dysfunction was estimated to be 17 [95 CI: 12?3], with a high heterogeneity (I2 = 90 ) (Fig 5). Meta-regression analysis did not reveal a difference depending on the anaesthesia technique (MAC/ SAS) (QM = 1.52, df = 1, p = 0.217), with an OR of 1.66 [95 CI: 1.35?.70]. Furthermore, there is a large proportion of residual heterogeneity (QE = 187.55, df = 24, p < .0001), which cannot be explained by the applied anaesthesia technique. However, it has to be noted that there are only six studies available in the SAS group. Other adverse events/outcomes. The other extracted adverse events and outcome data are shown in Tables 4 and 5. Mortality was very low with 10 patients (0.2 ) of all forty-four studies comprising 5381 patients, which reported the outcome variable mortality (Table 5). Of note, two deaths include probably duplicate patients [42,43] to the study of Grossman et al. [31]. Furthermore, we have only included deaths within 30 days after surgery in this analysis. Interestingly.. [60] have used both anaesthesia techniques. GA, general anaesthesia. doi:10.1371/journal.pone.0156448.gPLOS ONE | DOI:10.1371/journal.pone.0156448 May 26,31 /Anaesthesia Management for Awake Craniotomyintraoperative seizures and their consequences [10,17?9,31?9,42?4,47,49?5,57?0,62]. The total number of performed AC procedures in these studies was 4942 and 351 (7.1 ) intraoperative seizures were reported (Table 4). Only twenty-three (0.5 ) intraoperative seizures led to a failure of AC, but they were resolved without any serious problems and the surgery was continued in GA [33,34,42,43,55,57]. Interestingly, the AAA technique showed a high proportion of eight seizures in fifty AC procedures, but only one led to AC failure due to required intubation [33]. Intraoperative seizures were more common in younger patients and those with a history of seizures [31,42]. A meta-analysis was performed for thirty-four studies, [10,17?6,28,29,32,34?39,43,47,49?5,57?0,62], which used the MAC and SAS technique, excluding the duplicate studies from Tel Aviv [31,42] and Glostrup [27,44]. Meta-analysis showed an estimated proportion of seizures of 8 [95 CI: 6?1] with substantial heterogeneity between studies (I2 = 75 ) (Fig 4). In the meta-regression analysis, the techniques used did not explain the differences in the studies (QM < 0.001, df = 1, p = 0.983). The OR comparing SAS to MAC technique was 1.01 [CI95 : 0.52?.88]. Postoperative neurological dysfunction (new/ late). Description of particular postoperative neurological dysfunctions differed significantly in the included studies. Therefore we have subsumed all kinds of new neurological dysfunctions under these superordinate two outcome variables. Of note, we did not include data of patients with deterioration of a pre-existing neurological dysfunction. Twenty-nine studies [10,18,19,23,24,28,29,31,33?5,37,38,40?43,48,49,51?5,57?9,61,62] reported new postoperative neurological dysfunctions after 565 (14.0 ) of totally 4029 AC procedures. A later follow up result (six months) was provided for 279 of these patients with new neurological dysfunction. It showed a persistent neurological dysfunction in 64 patients. Of note, late neurological outcome after six months was reported in only seventeen studies comprising 2085 AC procedures in total. Considering twenty-six studies [10,18,19,23,24,28,29,34,35,37,38,40,41,43,48,49,51?5,57?9,61,62], which were reasonable included in our meta-analysis, the proportion of new neurological dysfunction was estimated to be 17 [95 CI: 12?3], with a high heterogeneity (I2 = 90 ) (Fig 5). Meta-regression analysis did not reveal a difference depending on the anaesthesia technique (MAC/ SAS) (QM = 1.52, df = 1, p = 0.217), with an OR of 1.66 [95 CI: 1.35?.70]. Furthermore, there is a large proportion of residual heterogeneity (QE = 187.55, df = 24, p < .0001), which cannot be explained by the applied anaesthesia technique. However, it has to be noted that there are only six studies available in the SAS group. Other adverse events/outcomes. The other extracted adverse events and outcome data are shown in Tables 4 and 5. Mortality was very low with 10 patients (0.2 ) of all forty-four studies comprising 5381 patients, which reported the outcome variable mortality (Table 5). Of note, two deaths include probably duplicate patients [42,43] to the study of Grossman et al. [31]. Furthermore, we have only included deaths within 30 days after surgery in this analysis. Interestingly.