Outcome of patients affected by newly diagnosed glioblastoma undergoing surgery assisted by 5-aminolevulinic acid guided resection followed by BCNU wafers implantation: a 3-year follow-up.

The purpose of the study was to evaluate the clinical outcome of the association of BCNU wafers implantation and 5-aminolevulinic acid (5-ALA) fluorescence in the treatment of patients with newly diagnosed glioblastoma (ndGBM). Clinical and surgical data from patients who underwent 5-ALA surgery followed by BCNU wafers implantation were retrospectively evaluated (20 patients, Group I) and compared with data of patients undergoing surgery with BCNU wafers alone (42 patients, Group II) and 5-ALA alone (59 patients, Group III). Patients undergoing 5-ALA assisted resection followed by BCNU wafers implantation (Group I) resulted long survivors (>3 years) in 15 % of cases and showed a median PFS and MS of 11 and 22 months, respectively. Patients treated with BCNU wafers presented a significantly higher survival when tumor was removed with the assistance of 5-ALA (22 months with vs 18 months without 5-ALA, p < 0.0001); these data could be partially explained by the significantly higher CRET achieved in patients operated with 5-ALA assistance (80 % with vs 47 %% without 5-ALA). Moreover, patients of Group I showed a significant increased survival compared with Group III (5-ALA without BCNU) (22 months with vs 21 months without BCNU wafers, p = 0.0025) even with a comparable CRET (80 % vs 76 %, respectively). The occurrence of adverse events related to wafers did not significantly increase with 5-ALA (20 % with and 19 % without 5-ALA) and did not impact in survival outcome. In conclusion, our experience shows that on selected ndGBM patients 5-ALA technology and BCNU wafers implantation show a synergic action on patients' outcome without increasing adverse events occurrence.

Surgery on motor area metastasis.

The role of surgery on central area metastasis remains unclear, and outcome data are still controversial. The aim of our study is to analyze the predictive value of clinical and surgical data on motor and functional outcome of patients, taking into account new emerging data on boundary irregularity of brain metastasis. We retrospectively analyzed 47 consecutive patients who underwent surgery assisted by neurophysiologic monitoring for a solitary metastasis in central area between 2010 and 2013. Inclusion criteria were as follows: good functional status (Karnofsky Performance Status (KPS) ≥70), controlled systemic disease, and absence of extra-cranial dissemination. At 1-month follow up, motor and functional outcomes were compared with preoperative clinical status, response to corticosteroids, extent of tumor resection, boundary irregularity, and size of tumor. Gross total resection was achieved in 93.6% of cases. In preoperative symptomatic patients, motor outcome (according to Medical Research Council grading scale) improved in 55.5% and worsened in 16.7%, while functional outcome (according to KPS score) improved in 50% and worsened in 14.2% of cases. No worsening occurred in preoperative asymptomatic patients. Motor outcome resulted to be not correlated with preoperative deficits, tumor volume, or preoperative response to corticosteroid treatment. Remarkably, motor outcome and extent of surgical resection appeared strongly correlated with tumor boundary irregularity (p < 0.05). Surgery with neurophysiologic monitoring on motor area metastasis can improve functional and motor condition in selected patients. Tumor volume does not represent a limit in surgery. The high correlation between clinical outcome, resection rate, and tumor boundary irregularity strengthens a new belief on the infiltrative growing pattern of brain metastasis. Motor function was evaluated according to Medical Research Council grading scale (Ott et al. 2014) while functional status was assessed according to KPS score.

Remote cerebellar hemorrhage after supratentorial procedures (part 1): a systematic review.

A remote cerebellar hemorrhage (RCH) is a spontaneous bleeding in the posterior fossa, which may rarely occurs as a complication of supratentorial procedures, and it shows a typical bleeding pattern defined "the zebra sign." However, its pathophysiology still remains unknown. We performed a comprehensive review collecting all cases of RCH after supratentorial craniotomies reported in literature in order to identify the most frequently associated procedures and the possible risk factors. We assessed percentages of incidence and 95 % confidence intervals of all demographic, neuroradiological, and clinical features of the patients. Univariate and multivariate analyses were used to evaluate their association with outcome. We included 49 articles reporting 209 patients with a mean age of 49.09 ± 17.07 years and a male/female ratio 130/77. A RCH was more frequently reported as a complication of supratentorial craniotomies for intracranial aneurysms, tumors debulking, and lobectomies. In the majority of cases, RCH occurrence was associated with impairment of consciousness, although some patients remained asymptomatic or showed only slight cerebellar signs. Coagulation disorders, perioperative cerebrospinal fluid drainage, hypertension, and seizures were the most frequently reported risk factors. Zebra sign was the most common bleeding pattern, being observed in about 65 % out of the cases, followed by parenchymal hematoma and mixed hemorrhage in similar percentages. A multivariate analysis showed that symptomatic onset and intake of antiplatelets/anticoagulants within a week from surgery were independent predictors of poor outcome. However, about 75 % out of patients showed a good outcome and a RCH often appeared as a benign and self-limiting condition, which usually did not require surgical treatment, but only prolonged clinical surveillance, unless in the event of the occurrence of complications.

Remote cerebellar hemorrhage after spinal procedures (part 2): a systematic review.

A remote cerebellar hemorrhage (RCH) is a spontaneous bleeding in the posterior fossa, which can be rarely observed as a complication of spine surgery. As well as for RCH reported after supratentorial procedures, it shows a characteristic bleeding pattern defined "zebra sign". Nowadays, RCH pathophysiology still remains unknown. We performed a comprehensive review, collecting all cases of RCH after spine surgery reported in literature in order to identify the procedures most frequently associated with RCH and the possible risk factors. We assessed percentages of incidence and 95 % confidence interval of all demographic, neuroradiological, and clinical features. Univariate and multivariate analyses were used to evaluate their association with outcome. We included 44 articles reporting 57 patients with mean age of 57.6 ± 13.9 years and a male/female ratio of 23/34. A RCH was more frequently reported as a complication of decompressive procedures for spinal canal stenosis, particularly when associated with instrumented fusion, followed by spinal tumor debulking and disc herniation removal. In the majority of cases, RCH occurrence was characterized by progressive impairment of consciousness, whereas some patients complained non-specific symptoms. Coagulation disorders, hypertension, and placement of postoperative subfascial drainages were the most frequently reported risk factors. The occurrence of intraoperative dural lesions was described in about 93 % of patients. Zebra sign was the most common bleeding pattern (about 43 % of cases) followed by parenchymal hematoma (37.5 %) and mixed hemorrhage (about 20 %). Impairment of consciousness at clinical onset and intake of anticoagulants/antiplatelets appeared associated with poor outcome at univariate analysis. However, more than 75 % of patients showed a good outcome and a RCH often appeared as a benign and self-limiting condition, which usually did not require surgical treatment, but only prolonged clinical surveillance, unless of the occurrence of complications.

Deciphering the 8q24.21 association for glioma.

We have previously identified tagSNPs at 8q24.21 influencing glioma risk. We have sought to fine-map the location of the functional basis of this association using data from four genome-wide association studies, comprising a total of 4147 glioma cases and 7435 controls. To improve marker density across the 700 kb region, we imputed genotypes using 1000 Genomes Project data and high-coverage sequencing data generated on 253 individuals. Analysis revealed an imputed low-frequency SNP rs55705857 (P = 2.24 × 10(-38)) which was sufficient to fully capture the 8q24.21 association. Analysis by glioma subtype showed the association with rs55705857 confined to non-glioblastoma multiforme (non-GBM) tumours (P = 1.07 × 10(-67)). Validation of the non-GBM association was shown in three additional datasets (625 non-GBM cases, 2412 controls; P = 1.41 × 10(-28)). In the pooled analysis, the odds ratio for low-grade glioma associated with rs55705857 was 4.3 (P = 2.31 × 10(-94)). rs55705857 maps to a highly evolutionarily conserved sequence within the long non-coding RNA CCDC26 raising the possibility of direct functionality. These data provide additional insights into the aetiological basis of glioma development.

Intraoperative functional mapping of calculation in parietal surgery. New insights and clinical implications.

BACKGROUND: Parietal areas play a crucial role in calculation processing. The purpose of this study is to report our experience in the assessment of calculation processing during awake surgery in parietal areas, focusing on clinical implications and new insights provided by this approach. METHODS: We retrospectively reviewed clinical and surgical data of 13 patients who underwent parietal surgery with calculation mapping. Cortical and sub-cortical areas (in 13 and five patients, respectively) involved in single-digit multiplications and additions were identified using bipolar electro-stimulation. RESULTS: Cortical stimulation data showed that the inferior parietal lobule and the intraparietal sulcus were specifically related to calculation in all cases, regardless of the side (100% of cases, in both sides). Conversely, the superior parietal lobule was inconstantly involved in calculation processing (40% of cases in the left and 75% in the right side), whereas the somatosensory area was never involved. Sub-cortical stimulation was able to detect functional areas for calculation in all patients: in 90% of cases the sub-cortical sites positive for calculation were in close anatomical connection with the cortical sites mapping for the same function. The intraoperative preservation (-or damaging-) of functional sites correlated with the absence (- or occurrence-) of post-operative calculation processing impairment. CONCLUSIONS: Our findings support the specificity of the reported technique in the intraoperative identification of sites functional for calculation. Our data show the bilateral involvement of parietal cortex, especially of the inferior lobule, in calculation processing. Furthermore, our study suggests the existence of a sub-cortical pathway specific for calculation, whose better understanding might be crucial for the clinical outcome of patients.

Intraparenchymal ventricular diverticula in chronic obstructive hydrocephalus: prevalence, imaging features and evolution.

BACKGROUND: Intraparenchymal cavities communicating with the ventricles may appear in patients with chronic obstructive hydrocephalus despite no identifiable surgerical, vascular or traumatic causes. The rate, features, pathogenesis, evolution and clinical impact of intraparenchymal diverticula have not been outlined, yet. METHODS: Brain MRIs of 130 patients (mean age: 11.3 years; age range: 0-67; 60 females) with chronic obstructive hydrocephalus were analyzed. The pathogenesis, neurosurgical treatment, ventricle size, signs of transependymal reabsorption and septum pellucidum integrity of the hydrocephalus were recorded. Subarachnoid outpouching of the ventricles, post-hemorrhagic parenchymal cavities, paths of ventricular shunting and cavities not communicating with the ventricles were excluded. Of patients with intraparenchymal diverticula, all previous available CT and MRI scans were evaluated. RESULTS: Eight patients (6.2 %, mean age: 18.7 years; age range: 2-42) harbored 11 intraparenchymal diverticula sprouting from the temporal (6), occipital (3) or frontal (2) horns of the lateral ventricles. Intraparenchymal diverticula were more frequent in males (p = 0.04) and older patients (18.7 ± 12.7 vs 11.3 ± 9.8 years, p = 0.04). Their presence or evolution (mean neuroradiological follow-up 3.6 years; range: 0-8) showed a trend of association with hydrocephalus severity (bifrontal index) and did not correlate with the surgical treatment. In three patients the diverticula progressed during follow-up. One patient presented with hemiparesis consistent with the intraparenchymal lesion and improved after ventricular shunting. A DTI study revealed that the cortico-spinal tract was partly included in the septum between the ventricle and the intraparenchymal diverticulum. CONCLUSIONS: Clinicians dealing with chronic severe obstructive hydrocephalus should be aware of ventricular intraparenchymal diverticulation. Studies aiming at clarifying their pathogenesis and proper management are warranted.

Lateral ventricle's choroid plexus tumors surgery in children: how I do it.

BACKGROUND: Choroid plexus tumors (CPTs) are intraventricular lesions originating from ventricular neuroepithelium and represent up to 4% of brain neoplasms affecting pediatric population. They are more frequently benign papillomas, but malignant carcinomas can sometimes occur. METHOD: The authors present a description of surgical approach for CPTs, particularly focusing on the complications related to the cerebrospinal fluid (CSF) circulation, which may affect outcome. CONCLUSION: Microsurgical resection represents the first line treatment for CPTs. The goal is the complete removal of the tumor and the restoration of a physiological CSF circulation.

Prognostic impact of the isocitrate dehydrogenase 1 single-nucleotide polymorphism rs11554137 in malignant gliomas.

BACKGROUND: The IDH1 gene, which encodes isocitrate dehydrogenase 1, is frequently mutated in gliomas and acute myeloid leukemia. The single-nucleotide polymorphism (SNP) (reference SNP no. rs11554137:C>T) located on IDH1 codon 105 has been associated with a poor outcome in patients with acute myeloid leukemia but has not been investigated in patients with gliomas. METHODS: The IDH1 codon 105 SNP was genotyped first in a series of 952 patients with grade 2 through 4 gliomas and was correlated with outcomes and tumor genomic profile. Then, it was genotyped in 2 validations sets of 306 patients with glioblastoma (GBM) and 591 patients with glioma. RESULTS: The minor allele codon 105 glycine (GGT) SNP (IDH1(105GGT) ) was identified in 98 of 952 patients (10.3%) and was not associated with the codon 132 (IDH1(132) ) mutation. Patients who had GMB with the IDH1(105GGT) variant had a poorer outcome than patients without the variant (median overall survival [OS], 10.7 months vs 15.5 months; P = .001; median progression-free survival [PFS], 6.4 months vs 8.5 months; P = .003). The prognostic impact was confirmed in an independent validation set of 306 GBMs from the same center (median PFS, 6.8 months vs 9.7 months; P = .006; median OS, 13.9 months vs 18.8 months; P = .0187). In the second validation cohort (591 grade 2-4 gliomas), a significant association was observed between IDH1(105GGT) and an adverse prognosis for the overall series and for patients with World Health Organization grade 3 gliomas, but the difference did not reach significance in patients with GBM. CONCLUSIONS: Taken together, the current data strongly suggested an association between the SNP rs11554137:C>T polymorphism and adverse outcomes in patients with malignant glioma. A single-nucleotide polymorphism (SNP) located on codon 105 of the isocitrate dehydrogenase 1 (IDH1) gene (reference SNP rs11554137) is analyzed in 3 independent series of patients with gliomas. The SNP rs11554137 is independent of the occurrence of somatic mutation on IDH1 codon 132, but, per se, has a prognostic impact in malignant gliomas.

5-aminolevulinic acid (5-ALA) fluorescence guided surgery of high-grade gliomas in eloquent areas assisted by functional mapping. Our experience and review of the literature.

BACKGROUND: Only few data are available on the specific topic of 5-aminolevulinic acid (5-ALA) guided surgery of high-grade gliomas (HGG) located in eloquent areas. Studies focusing specifically on the post-operative clinical outcome of such patients are yet not available, and it has not been so far explored whether such approach could be more suitable for some particular subgroups of patients. METHODS: Patients affected by HGG in eloquent areas who underwent surgery assisted by 5-ALA fluorescence and intra-operative monitoring were prospectively recruited in our Department between June 2011 and August 2012. Resection rate was reported as complete resection of enhancing tumor (CRET), gross total resection (GTR) >98 % and GTR > 90 %. Clinical outcome was evaluated at 7, 30, and 90 days after surgery. RESULTS: Thirty-one patients were enrolled. Resection was complete (CRET) in 74 % of patients. Tumor removal was stopped to avoid neurological impairment in 26 % of cases. GTR > 98 % and GTR > 90 % was achieved in 93 % and 100 % of cases, respectively. First surgery and awake surgery had a CRET rate of 80 % and 83 %, respectively. Even though at the first-week assessment 64 % of patients presented neurological impairment, there was a 3 % rate of severe morbidity at the 90th day assessment. Newly diagnosed patients had a significantly lower morbidity (0 %) and post-operative higher median KPS. Both pre-operative neurological condition and improvement after corticosteroids resulted significantly predictive of post-operative functional outcome. CONCLUSIONS: 5-ALA surgery assisted by functional mapping makes high HGG resection in eloquent areas feasible , through a reasonable rate of late morbidity. This emerges even more remarkably for selected patients.

Multifocal presentation of medulloblastoma in adulthood.

Medulloblastoma in adulthood is uncommon but not rare; annual incidence is 2-20/1,000,000. Some peculiarities characterize medulloblastoma in adult patients compared with the child type: lateral cerebellar location, heterogeneous signal intensity on magnetic resonance imaging, desmoplastic histological variant, and more favourable prognosis. Preoperative diagnosis is crucial for correct management of these patients. However, because of the low incidence of medulloblastoma in the adult population, preoperative diagnosis remains challenging and prognostic factors and best treatment options are still controversial. In this setting, some unusual findings, for example multifocal presentation and extra-axial location, can confound diagnosis and make treatment difficult. We present a short case-illustrated review on these remarkable issues.

Petrous apex's dural arteriovenous fistula (DAVF) mimicking a pineal region tumour: a rare cause of Hakim triad.

A dural arteriovenous fistula (DAVF) is a dural-based shunt between meningeal arteries and meningeal veins, sinuses and/or cortical veins; they have been classified and named according to the location and the flow pattern. Petrous apex DAVFs are located where the petrosal vein penetrates the dura mater into the superior petrosal sinus; there are only few cases reported in the literature, they can show an aggressive behaviour (subarachnoid haemorrhage, severe brainstem oedema) with a high mortality rate. The described case is, to the best of our knowledge, the first case of a DAVF presenting with symptoms mimicking idiopathic normal pressure hydrocephalus. After worsening of gait impairment, memory loss and urinary incontinence an urgent CT of the brain showed hydrocephalus and a hyperdense mass in the pineal region mimicking a pineal tumour; an emergent digital subtraction angiogram showed a left petrous apex Borden type III DAVF. A transvenous embolisation was performed obtaining a complete obliteration.

Postoperative seizure in high grade glioma patients treated with BCNU wafers. A mono-institutional experience.

Anticonvulsant therapy is usually recommended before surgery in all patients affected by high grade glioma who are planned to be treated with Carmustine 1,3-bis [2 chloroetyl]-1-nitrosurea, or BCNU) wafers. In fact, phase III studies have reported a risk of seizures higher than 30% in this group of patients. The aim of the study was the evaluation of rate type time of occurrence of seizures in BCNU-treated patients in the postoperative period as well as the investigation into possible risk factors for seizure occurrence in this population. From April 2007 to September 2010, 55 patients underwent surgical removal of malignant glioma and BCNU wafers implantation at the Department of Neurosurgery of Padova. All patients were given antiepileptic prophylaxis for 3 months after surgery. Clinical data (including preoperative seizure history), radiological data, surgical treatment, antiepileptic treatment were retrospectively reviewed. Nine percent of the patients treated with BCNU wafers presented seizures in the postoperative course. Seizures were partial in 80% of cases; they occurred within 30 days after surgery and in 80% of cases within the first 7 days. Patients with preoperative seizures presented more frequently postoperative epilepsy than patients who were preoperatively seizure-free [P = 0.0006; OR = 48 (2,4;945)]. Postoperative seizures were more common among patients affected by one or more wafers related adverse event than among patients without adverse events [P = 0.006; OR = 21 (2,06;213)]; however, they did not appear associated to the number of implanted wafers. Patients with a sub-therapeutic level of AED at the seventh day after surgery presented a higher seizure occurrence [P = 0.02; OR = 11 (1,5;79,8)]. In our experience, postoperative seizures in BCNU-treated patients were less frequent than expected. Careful patient selection and postoperative monitoring could probably play a role in order to decrease seizure occurrence.

Hemifacial spasm can be the presenting symptom of a fourth ventricle tumour. A short case-illustrated review and pathogenetic considerations.

In this short case-illustrated review we aimed to analyse the possible nuances of hemifacial spasm (HFS) as the presenting symptom of a tumour of the fourth ventricle. The issue is remarkable since HFS can be secondary to a fourth ventricle tumour, even when no other neurological signs are reported. In addition, the possible presentation with only upper facial muscle involvement, as in the presented case, can be deceitful because this is characteristic of the benign and much more frequent "typical" form. Based on our intra-operative data and on the previously reported cases, we think that pathogenesis could be referable to the facial nerve nucleus involvement and that clinical nuances could be related to the specific somatotropy of the nucleus under the fourth ventricle floor that, as in our case, can be infiltrated by tumour. Resolution of the disorder can usually be obtained after the complete resection of the tumour that in the reported case resulted a subependymoma (WHO grade I), so far never described in literature associated with HFS.

What's growing on? The growing teratoma syndrome.

BACKGROUND: The growing teratoma syndrome (GTS) consists of a mature teratoma paradoxically enlarging during or after chemotherapy for malignant nongerminomatous germ cell tumors. METHODS AND RESULTS: We report two cases of GTS occurring in association with NSGCT of the pineal gland. Although an unusual event, clinicians and radiologists should be aware of its natural history. CONCLUSIONS: When normalized tumor markers after chemotherapy are associated with imaging features of a growing mass, the hypothesis of GTS must be taken in consideration. When early diagnosed, GTS can be managed surgically with good results.

The first 3 months after BCNU wafers implantation in high-grade glioma patients: clinical and radiological considerations on a clinical series.

PURPOSE: Carmustine (1,3-bis[2-chloroetyl]-1-nitrosurea (BCNU)) wafers are approved for the local treatment of newly diagnosed and recurrent malignant glioma. Reassuring data on both safety and efficacy of treatment have been previously reported by phase III studies. Although most of related adverse events are reported in the first few months after surgery, there is a lack in the literature of radiological data regarding this period. Few anecdotal experiences have been reported about surgical bed cyst occurrence. The aim of our study is to analyse the radiological course of patients treated with wafers implantation focusing on the relationship between radiological data, and in particular bed cyst occurrence, and safety data. METHODS: Forty-three patients affected by malignant glioma underwent surgical removal and BCNU wafers implantation at the Department of Neurosurgery of Padova from April 2007 to October 2009. Safety data were collected according to previously reported phase III studies. Patients underwent clinical and radiological evaluation (MRI) postoperatively, then before discharge, at 1 month, then every 2 months. In the study were included only patients whose both 1- and 3-month MRIs were available. Finally, 36 out of 43 patients were available for the revision. FINDINGS: Fifty-eight percent of patients treated with BCNU wafers presented a bed cyst of the surgical cave at the 1-month MRI. Forty-eight percent of them were symptomatic. Conversely, among patients who presented one or more adverse event (27%), bed cyst was detected in up to 90% of cases (OR 7.35), being intracranial hypertension more frequently associated (OR 7.35; p value <0.05). In general, cysts presented a benign behaviour in the sense that patients promptly improved with corticosteroid treatment, never required surgery, never reported permanent neurological deficits. CONCLUSIONS: Surgical bed cyst occurrence in BCNU wafer-treated patients resulted more frequent than expected. Familiarity with the event is important to correctly handle a possible evolving phenomenon. However, only further larger experiences and prospective studies could reveal how the understanding of such event might be helpful to improve safety data.

Use of a new absorbable sealing film for preventing postoperative cerebrospinal fluid leaks: remarks on a new approach.

Cerebrospinal fluid (CSF) leak is an adverse event that can affect the postoperative course of neurosurgical patients. Despite the large intra-operative use effective strategies as well as specific devices, CSF leak post-operative occurrence has been recently reported in up to 11% of cases. TissuePatchDural is a new sealant that is now available in neurosurgery in order to repair dural defects and, consequently, to prevent the postoperative formation of CSF fistulas. The device is a synthetic absorbable film that can actively create a firm temporary connection with the external dural surface and thus favour a satisfactory healing of the wound. The authors report a preliminary experience about the use of such device in 12 selected patients.

Microsurgical Clipping of Intracranial Aneurysms Assisted by Neurophysiological Monitoring, Microvascular Flow Probe, and ICG-VA: Outcomes and Intraoperative Data on a Multimodal Strategy.

OBJECTIVE: The aim of this study is to report data on a multimodal monitoring strategy based on the intraoperative use of neurophysiological monitoring, flowmetry by microflow probe, and intraoperative indocyanine green video angiography (ICG-VA) during microsurgical clipping of intracranial aneurysms. METHODS: This retrospective analysis was performed on 85 consecutive patients undergoing clipping of 96 intracranial aneurysms with the present monitoring strategy. Patient outcomes were evaluated by assessing rate of aneurysm exclusion and postoperative occurrence of ischemic injury. Intraoperative data for the strategy in addition to changes in each monitoring technique depending on aneurysm features were reported. RESULTS: Complete aneurysm exclusion was achieved in 98.9% of cases. Postoperative symptomatic ischemic injury was recorded in 2.08% aneurysms. Clip repositioning occurred in 40.6% of cases: because of motor evoked potential (MEP) decrease in 9.3%, flowmetry in 22.91%, and ICG-VA in 8.3% of treated aneurysms (1.05% after ICG injection, 7.4% after the squeezing maneuver). The role of each technique differed according to aneurysm features; flowmetry alterations occurred more frequently in distal than in proximal aneurysms (P = 0.0001) and in atherosclerotic aneurysms (P = 0.0001). MEP impairment occurred more often in proximal aneurysms (P < 0.05). ICG-VA disclosed remnant aneurysms mainly in atherosclerotic aneurysms (P < 0.05); only one false negative remnant neck was recorded with a negative predictive value of 98.8%. CONCLUSIONS: Microsurgical clipping assisted by a multimodal monitoring strategy achieved a high rate of aneurysm exclusion with low morbidity in our series. Our data show that the 3 techniques used in our strategy were complementary and that a monitoring strategy can be tailored to aneurysm features.

Addressing the selective role of distinct prefrontal areas in response suppression: A study with brain tumor patients.

The diverging evidence for functional localization of response inhibition within the prefrontal cortex might be justified by the still unclear involvement of other intrinsically related cognitive processes like response selection and sustained attention. In this study, the main aim was to understand whether inhibitory impairments, previously found in patients with both left and right frontal lesions, could be better accounted for by assessing these potentially related cognitive processes. We tested 37 brain tumor patients with left prefrontal, right prefrontal and non-prefrontal lesions and a healthy control group on Go/No-Go and Foreperiod tasks. In both types of tasks inhibitory impairments are likely to cause false alarms, although additionally the former task requires response selection and the latter target detection abilities. Irrespective of the task context, patients with right prefrontal damage showed frequent Go and target omissions, probably due to sustained attention lapses. Left prefrontal patients, on the other hand, showed both Go and target omissions and high false alarm rates to No-Go and warning stimuli, suggesting a decisional rather than an inhibitory impairment. An exploratory whole-brain voxel-based lesion-symptom mapping analysis confirmed the association of left ventrolateral and dorsolateral prefrontal lesions with target discrimination failure, and right ventrolateral and medial prefrontal lesions with target detection failure. Results from this study show how left and right prefrontal areas, which previous research has linked to response inhibition, underlie broader cognitive control processes, particularly involved in response selection and target detection. Based on these findings, we suggest that successful inhibitory control relies on more than one functionally distinct process which, if assessed appropriately, might help us to better understand inhibitory impairments across different pathologies.