Deep brain stimulation of the subthalamic nucleus under general anesthesia versus local anesthesia in the treatment of Parkinson's disease: a meta-analysis of randomized clinical trials.

Deep brain stimulation (DBS) stands as the preferred treatment for Parkinson's disease (PD) patients manifesting refractory motor symptoms or when medication side effects outweigh the benefits. Though traditionally administered under local anesthesia coupled with sedation (LA + S), recent evidence hints at comparable outcomes under general anesthesia (GA). This systematic review and meta-analysis aimed to scrutinize post-surgical outcomes in randomized PD patients undergoing DBS surgery while GA versus LA + S. We searched PubMed, Cochrane, and Embase databases following PRISMA guidelines. We included randomized studies directly comparing DBS surgery under GA versus LA + S, delineating clinical outcomes. Safety outcomes assessed disparities in infection and hemorrhage risk. Mean differences (MD) and Risk Differences (RD) with 95% Confidence Intervals (CI) were utilized to evaluate outcomes, under a random-effects model. Heterogeneity was evaluated through I² statistics, and in studies exhibiting high heterogeneity, exclusion analysis was performed. Evaluated outcomes encompassed motor improvement, complications, behavioral and mood effects gauged by the Unified Parkinson's Disease Rating Scale (UPDRS), Parkinson's Disease Questionnaire 39 (PDQ39), and daily levodopa equivalent dose (LEDD). A total of 3 studies, encompassing 203 patients, were reviewed. At a 6-month follow-up, in patients undergoing GA during surgery, there was no statistically significant difference compared to the LA + S group in terms of UPDRS III ON (MD 0.19; 95% CI -2.21 to 2.59; p = 0.88; I²=0%), UPDRS III OFF (MD 0.58; 95% CI -4.30 to 5.45; p = 0.21; I²=0%), UPDRS IV ON ( (MD 0.98; 95% CI -0.95 to 2.92; p = 0.32; I²=23%), PDQ39 (MD -1.27; 95% CI -6.31 to 3.77; p = 0.62; I²=0%), and LEDD (MD -1.99; 95% CI -77.88 to 73.90; p = 0.96; I²=32%). There was no statistically significant difference between groups in terms of infection (RD 0.02; 95% CI -0.02 to 0.05; p = 0.377; I²=0%) or hemorrhage (RD 0.04; 95% CI -0.03 to 0.11; p = 0.215; I²=0%). Our findings suggest, based on short-term follow-up, that GA is not inferior to LA + S in terms of benefits for the selected outcomes. However, further studies are needed to determine whether there are significant long-term clinical differences between these groups.

Large acute epidural hematoma from head pin fixation fracture.

Regarding head immobilization practices in neurosurgery, secondary fixation fractures are rare, underscoring the importance of precise pin positioning and an adequate force in the three-point clamp to achieve adequate fixation. Attention should be given to factors such as changes in bone metabolism.

Predicting short-term outcomes in brain-injured patients: a comprehensive approach with transcranial Doppler and intracranial compliance assessment.

Neurocritical patients frequently exhibit abnormalities in cerebral hemodynamics (CH) and/or intracranial compliance (ICC), all of which significantly impact their clinical outcomes. Transcranial Doppler (TCD) and the cranial micro-deformation sensor (B4C) are valuable techniques for assessing CH and ICC, respectively. However, there is a scarcity of data regarding the predictive value of these techniques in determining patient outcomes. We prospectively included neurocritical patients undergoing intracranial pressure (ICP) monitoring within the first 5 days of hospital admission for TCD and B4C assessments. Comprehensive clinical data were collected alongside parameters obtained from TCD (including the estimated ICP [eICP] and estimated cerebral perfusion pressure [eCPP]) and B4C (measured as the P2/P1 ratio). These parameters were evaluated individually as well as in combination. The short-term outcomes (STO) of interest were the therapy intensity levels (TIL) for ICP management recommended by the Seattle International Brain Injury Consensus Conference, as TIL 0 (STO 1), TIL 1-3 (STO 2) and death (STO 3), at the seventh day after last data collection. The dataset was randomly separated in test and training samples, area under the curve (AUC) was used to represent the noninvasive techniques ability on the STO prediction and association with ICP. A total of 98 patients were included, with 67% having experienced severe traumatic brain injury and 15% subarachnoid hemorrhage, whilst the remaining patients had ischemic or hemorrhagic stroke. ICP, P2/P1, and eCPP demonstrated the highest ability to predict early mortality (p = 0.02, p = 0.02, and p = 0.006, respectively). P2/P1 was the only parameter significant for the prediction of STO 1 (p = 0.03). Combining B4C and TCD parameters, the highest AUC was 0.85 to predict death (STO 3), using P2/P1 + eCPP, whereas AUC was 0.72 to identify ICP > 20 mmHg using P2/P1 + eICP. The combined noninvasive neuromonitoring approach using eCPP and P2/P1 ratio demonstrated improved performance in predicting outcomes during the early phase after acute brain injury. The correlation with intracranial hypertension was moderate, by means of eICP and P2/P1 ratio. These results support the need for interpretation of this information in the ICU and warrant further investigations for the definition of therapy strategies using ancillary tests.

Predicting Outcomes in Patients with Diffuse Axonal Injury: External Validation of the Widely Used Prognostic Instruments.

AIM: Accurate prognosis of diffuse axonal injury (DAI) is important in directing clinical care, allocating resources appropriately, and communicating with families and surrogate decision-makers. METHODS: A study was conducted on patients with clinical DAI due to closed-head traumatic brain injury treated at a trauma center in Brazil from July 2013 to September 2015.  The objective efficacy of the Glasgow Coma Scale (GCS), Trauma and Injury Severity Scoring system (TRISS), New Trauma and Injury Severity Scoring system (NTRISS), Abbreviated Injury Scale (AIS)/head, Corticosteroid Randomization After Significant Head Injury (CRASH), and International Mission on Prognosis and Analysis of Clinical Trials (IMPACT) models in the prediction of mortality at 14 days and 6-months and unfavorable outcomes at 6 months was tested. RESULTS: Our cohort comprised 95 prospectively recruited adults (85 males, 10 females, mean age 30.3 ± 10.9 years) admitted with DAI. Model efficacy was assessed through discrimination (area under the curve [AUC]), and Cox calibration. The AIS/head, TRISS, NTRISS, CRASH, and IMPACT models were able to discriminate both mortality and unfavorable outcomes (AUC 0.78-0.87). IMPACT models resulted in a statistically perfect calibration for both 6-month outcome variables; mortality and 6-month unfavorable outcome. Calibration also revealed that TRISS, NTRISS, and CRASH systematically overpredicted both outcomes, except for 6-month unfavorable outcome with TRISS. CONCLUSIONS: The results of this study suggest that TRISS, NTRISS, CRASH, and IMPACT models satisfactorily discriminate between mortality and unfavorable outcomes. However, only the TRISS and IMPACT models showed accurate calibration when predicting 6-month unfavorable outcome.

Spin in traumatic brain injury literature: prevalence and associated factors. A systematic review.

OBJECTIVE: Spin is characterized as a misinterpretation of results that, whether deliberate or unintentional, culminates in misleading conclusions and steers readers toward an excessively optimistic perspective of the data. The primary objective of this systematic review was to estimate the prevalence and nature of spin within the traumatic brain injury (TBI) literature. Additionally, the identification of associated factors is intended to provide guidance for future research practices. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations were followed. A search of the MEDLINE/PubMed database was conducted to identify English-language articles published between January 1960 and July 2020. Inclusion criteria encompassed randomized controlled trials (RCTs) that exclusively enrolled TBI patients, investigating various interventions, whether surgical or nonsurgical, and that were published in high-impact journals. Spin was defined as 1) a focus on statistically significant results not based on the primary outcome; 2) interpreting statistically nonsignificant results for a superiority analysis of the primary outcome; 3) claiming or emphasizing the beneficial effect of the treatment despite statistically nonsignificant results; 4) conclusion focused in the per-protocol or as-treated analysis instead of the intention-to-treat (ITT) results; 5) incorrect statistical analysis; or 6) republication of a significant secondary analysis without proper acknowledgment of the primary outcome analysis result. Primary outcomes were those explicitly reported as such in the published article. Studies without a clear primary outcome were excluded. The study characteristics were described using traditional descriptive statistics and an exploratory inferential analysis was performed to identify those associated with spin. The studies' risk of bias was evaluated by the Cochrane Risk of Bias Tool. RESULTS: A total of 150 RCTs were included and 22% (n = 33) had spin, most commonly spin types 1 and 3. The overall risk of bias (p < 0.001), a neurosurgery department member as the first author (p = 0.009), absence of a statistician among authors (p = 0.042), and smaller sample sizes (p = 0.033) were associated with spin. CONCLUSIONS: The prevalence of spin in the TBI literature is high, even at leading medical journals. Studies with higher risks of bias are more frequently associated with spin. Critical interpretation of results and authors' conclusions is advisable regardless of the study design and published journal.

A Comprehensive Perspective on Intracranial Pressure Monitoring and Individualized Management in Neurocritical Care: Results of a Survey with Global Experts.

BACKGROUND: Numerous trials have addressed intracranial pressure (ICP) management in neurocritical care. However, identifying its harmful thresholds and controlling ICP remain challenging in terms of improving outcomes. Evidence suggests that an individualized approach is necessary for establishing tolerance limits for ICP, incorporating factors such as ICP waveform (ICPW) or pulse morphology along with additional data provided by other invasive (e.g., brain oximetry) and noninvasive monitoring (NIM) methods (e.g., transcranial Doppler, optic nerve sheath diameter ultrasound, and pupillometry). This study aims to assess current ICP monitoring practices among experienced clinicians and explore whether guidelines should incorporate ancillary parameters from NIM and ICPW in future updates. METHODS: We conducted a survey among experienced professionals involved in researching and managing patients with severe injury across low-middle-income countries (LMICs) and high-income countries (HICs). We sought their insights on ICP monitoring, particularly focusing on the impact of NIM and ICPW in various clinical scenarios. RESULTS: From October to December 2023, 109 professionals from the Americas and Europe participated in the survey, evenly distributed between LMIC and HIC. When ICP ranged from 22 to 25 mm Hg, 62.3% of respondents were open to considering additional information, such as ICPW and other monitoring techniques, before adjusting therapy intensity levels. Moreover, 77% of respondents were inclined to reassess patients with ICP in the 18-22 mm Hg range, potentially escalating therapy intensity levels with the support of ICPW and NIM. Differences emerged between LMIC and HIC participants, with more LMIC respondents preferring arterial blood pressure transducer leveling at the heart and endorsing the use of NIM techniques and ICPW as ancillary information. CONCLUSIONS: Experienced clinicians tend to personalize ICP management, emphasizing the importance of considering various monitoring techniques. ICPW and noninvasive techniques, particularly in LMIC settings, warrant further exploration and could potentially enhance individualized patient care. The study suggests updating guidelines to include these additional components for a more personalized approach to ICP management.

Retrosigmoid versus middle fossa approach for hearing and facial nerve preservation in vestibular schwannoma surgery: A systematic review and comparative meta-analysis.

BACKGROUND: Vestibular schwannomas (VS) are benign tumors arising from vestibular nerve's Schwann cells. Surgical resection via retrosigmoid (RS) or middle fossa (MF) is standard, but the optimal approach remains debated. This meta-analysis evaluated RS and MF approaches for VS management, emphasizing hearing preservation and Cranial nerve seven (CN VII) outcomes stratified by tumor size. METHODS: Systematic searches across PubMed, Cochrane, Web of Science, and Embase identified relevant studies. Hearing and CN VII outcomes were gauged using the American Academy of Otolaryngology-Head and Neck Surgery, Gardner Robertson, and House-Brackmann scores. RESULTS: Among 7228 patients, 56 % underwent RS and 44 % MF. For intracanalicular tumors, MF recorded 38 % hearing loss, compared to RS's 54 %. In small tumors (<1.5 cm), MF showed 41 % hearing loss, contrasting RS's lower 15 %. Medium-sized tumors (1.5 cm-2.9 cm) revealed 68 % hearing loss in MF and 55 % in RS. Large tumors (>3cm) were only reported in RS with a hearing loss rate of 62 %. CONCLUSION: Conclusively, while MF may be preferable for intracanalicular tumors, RS demonstrated superior hearing preservation for small to medium-sized tumors. This research underlines the significance of stratified outcomes by tumor size, guiding surgical decisions and enhancing patient outcomes.

Moderate Traumatic Brain Injury in Adult Population: The Latin American Brain Injury Consortium Consensus for Definition and Categorization.

Moderate traumatic brain injury (TBI) is a diagnosis that describes diverse patients with heterogeneity of primary injuries. Defined by a Glasgow Coma Scale between 9 and 12, this category includes patients who may neurologically worsen and require increasing intensive care resources and/or emergency neurosurgery. Despite the unique characteristics of these patients, there have not been specific guidelines published before this effort to support decision-making in these patients. A Delphi consensus group from the Latin American Brain Injury Consortium was established to generate recommendations related to the definition and categorization of moderate TBI. Before an in-person meeting, a systematic review of the literature was performed identifying evidence relevant to planned topics. Blinded voting assessed support for each recommendation. A priori the threshold for consensus was set at 80% agreement. Nine PICOT questions were generated by the panel, including definition, categorization, grouping, and diagnosis of moderate TBI. Here, we report the results of our work including relevant consensus statements and discussion for each question. Moderate TBI is an entity for which there is little published evidence available supporting definition, diagnosis, and management. Recommendations based on experts' opinion were informed by available evidence and aim to refine the definition and categorization of moderate TBI. Further studies evaluating the impact of these recommendations will be required.

Management of shunt dysfunction using noninvasive intracranial pressure waveform monitoring: illustrative case.

BACKGROUND: Normal pressure hydrocephalus (NPH) treatment consists of using valves for drainage, as it is for hydrocephalus in general. Despite this, complications can occur, putting the patient at risk, and neurological monitoring is crucial. OBSERVATIONS: A 61-year-old male, who had been diagnosed with NPH 3 years prior and was being treated with a ventriculoperitoneal shunt with a programmable valve, presented to the emergency department because of a traumatic brain injury due to a fall from standing height. No previous complications were reported. He had an altered intracranial pressure (ICP) waveform in the emergency room when monitored with the brain4care device, with a P2/P1 ratio of 1.6. Imaging helped to confirm shunt dysfunction. Revision surgery normalized the ratio to 1.0, and the patient was discharged. Upon return after 14 days, an outpatient analysis revealed a ratio of 0.6, indicating improvement. LESSONS: In selected cases of NPH, noninvasive ICP waveform morphology analysis can be effective as a diagnostic aid, as well as in the pre- and postsurgical follow-up, given the possibility of comparing the values of ICP preoperatively and immediately postoperatively and the outpatient P2/P1 ratio, helping to manage these patients.

Fractionated stereotactic radiotherapy in craniopharyngiomas: A systematic review and single arm meta-analysis.

INTRODUCTION: Numerous studies have demonstrated Fractionated Stereotactic Radiotherapy's (FSRT) effectiveness in tumor control post-resection for craniopharyngiomas. Nevertheless, past literature has presented conflicting findings particularly regarding endocrine and visual function outcomes. This study aims to elucidate FSRT's efficacy and safety for this population. METHODS: Adhering to PRISMA, a systematic review and meta-analyses was conducted. Included studies had to report the effects of FSRT for treating craniopharyngiomas in a sample greater than four patients, addressing at least one of the outcomes of interest: improvement in visual acuity or field, new-onset hypopituitarism, effectiveness, and tumor progression. Relative risk with 95% confidence intervals were used to assess the outcomes. RESULTS: After retrieving a total of 1292 studies, 10 articles met the predefined criteria and thus were finally selected, amounting to a total of 256 patients. The improvement in visual acuity was estimated at 45% (95% CI: 6-83%), while the improvement in the visual field was 22% (95% CI: 0-51%). Regarding endocrine function, the new-onset hypopituitarism rate was found to be 5% (95% CI: 0-11%). Relative to FSRT effectiveness, the pooled estimate of the complete tumor response rate was 17% (95% CI: 4-30%), and the tumor progression rate was 7% (95% CI: 1-13%). Also, a 3-year progression-free survival rate of 98% (95% CI: 95-100%) was obtained. CONCLUSION: Despite limitations and risks, FSRT shows promise as a viable therapeutic option for craniopharyngiomas, offering notable benefits for visual functions and tumor control. Further research is required to better understand the associated risks, benefits, and clinical utility.

Ultrasound-Guided Resection of High-Grade Gliomas: A Single-Arm Meta-Analysis.

BACKGROUND: High-grade gliomas (HGGs) present a challenge in neuro-oncology, often necessitating surgical resection for optimal management. Ultrasound holds promise in achieving better gross total resection (GTR) and improving outcomes. This meta-analysis systematically evaluates literature providing robust evidence on the use of intraoperative ultrasonography (iUSG) in HGG resection. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines a comprehensive search was made across PubMed, Embase, Cochrane, and Web of Science utilized terms related to iUSG for HGG resection. The meta-analysis examined randomized trials and observational cohort studies on iUSG-guided HGG resection. GTR, subtotal resection, and postresection complications were assessed. Statistical analysis, employing R software for a single proportion analysis with confidence intervals of 95%, I2 statistics for heterogeneity, and the instrumental variables method with restricted maximum likelihood for a random effects model. RESULTS: A total of 178 patients were included in our study. The GTR overall rate in patients with iUSG-guided resection was found to be 64% (95% confidence interval: 46%-81%). Two-dimensional ultrasound remains dominant at 80% against other options of ultrasound. Complications were reported at a 15% rate (95% confidence interval: 7%-23%). CONCLUSIONS: Our study provided robust data on the utilization of iUSG-guided resection regarding the attainment of GTR and the complications related to resection. However, challenges such as outcome heterogeneity and limited complication reporting highlight the need for further research to optimize iUSG in HGG treatment. Long-term follow-up studies on patient survival and postsurgery quality of life will complement existing literature, guiding clinical practices in managing HGG.

Assessing short-term and long-term security and efficacy of anterior nucleus of the thalamus deep brain stimulation for treating drug-resistant epilepsy: A systematic review and single-arm meta-analysis.

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is a widespread invasive procedure for treating drug-resistant epilepsy. Nonetheless, there is a persistent debate regarding the short-term and long-term efficacy and safety of ANT-DBS. Thus we conducted a systematic review and meta-analysis. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we searched PubMed, Cochrane, Embase, and Web of Science for studies treating refractory epilepsy with ANT-DBS. Short-term analysis was considered for studies with a mean follow-up of 3 years or less. The following outcomes were assessed for data extraction: procedure responders and nonresponders, increased seizure frequency, complications, and procedure-related mortality. Of 650 studies, 25 fit our inclusion criteria, involving 427 patients. Previous surgical treatments have been reported in 214 patients (50.1%) and a median average baseline seizure frequency of 64.9 monthly seizures. In the short-term analysis, we observed a proportion of 67% (95% confidence interval [CI] 54%-79%) of responders and 33% (95% CI 21%-46%) of nonresponders. In addition, 4% (95% CI 0%-9%) of the patients presented increased seizure frequency. In the long-term analysis, we observed 72% (95% CI 66%-78%) responders and 27% (95% CI 21%-34%) nonresponders. Moreover, there was a 2% (95% CI 0%-5%) increase in seizure frequency. No procedure-related mortality was reported at any follow-up. ANT-DBS effectively treats refractory epilepsy, with lasting short-term and long-term benefits. It remains safe and efficient despite complications, showing no procedure-linked fatalities, high patient responsiveness, and minimal increased seizures. Consistent results over time and low morbidity/mortality rates emphasize its worth. Further research is necessary to diminish the discrepancy among results.

Natural history and neuro-oncological approach in spinal gangliogliomas: a systematic review.

To describe the natural history of spinal gangliogliomas (GG) in order to determine the most appropriate neuro-oncological management. A Medline search for relevant publications up to July 2023 using the key phrase "ganglioglioma spinal" and "ganglioglioma posterior fossa" led to the retrieval of 178 studies. This corpus provided the basis for the present review. As an initial selection step, the following inclusion criteria were adopted: (i) series and case reports on spinal GG; (ii) clinical outcomes were reported specifically for GG; (iii) GG was the only pathological diagnosis for the evaluation of the tumor; (iv) papers written only in English was evaluated; and (v) papers describing each case in the series were included. The World Health Organization (WHO) 2021 grading criteria for gangliogliomas were applied. A total of 107 tumors were evaluated (63 from male patients and 44 from female patients; 1.43 male/1.0 female ratio, mean age 18.34 ± 15.84 years). The most common site was the cervical spine, accounting for 43 cases (40.18%); GTR was performed in 35 cases (32.71%) and STR in 71 cases (66.35%), while this information was not reported in 1 case (0.94%). 8 deaths were reported (7.47%) involving 2 males (25%) and 6 females (75%) aged 4-78 years (mean 34.27 ± 18.22) years. GGs located on the spine displayed the same gender ratio as these tumors in general. The most frequent symptom was pain and motor impairment, while the most prevalent location was the cervical spinal cord. GTR of the tumor posed a challenge for neurosurgeons, due to the difficulty of resecting the lesion without damaging the spinal eloquent area, explaining the lower rate of cure for this tumor type.

Unruptured Brain Arteriovenous Malformations: A Systematic Review and Meta-Analysis of Mortality and Morbidity in Aruba-Eligible Studies.

BACKGROUND: Treating unruptured brain arteriovenous malformations (bAVMs) represent significant challenges, with numerous uncertainties still in debate. The ARUBA trial induced further investigation into optimal management strategies for these lesions. Here, we present a systematic-review and meta-analysis focusing on ARUBA-eligible studies, aiming to correlate patient data with outcomes and discuss key aspects of these studies. METHODS: Following PRISMA guidelines, we conducted a systematic-review. Variables analyzed included bAVM Spetzler-Martin (SM) grade, treatment modalities, and outcomes such as mortality and neurological deficits. We compared studies with a minimum of 50% cases classified as SM 1-2 lesions and those with less than 50% in this category. Similarly, a comparison between studies with at least 50% microsurgery-cases and those with less than 50% was performed. We examined correlations between mortality incidence, SM distribution, and treatment modalities. RESULTS: Our analysis included 16 studies with 2.417 patients. The frequency of bAVMs SM-grade 1-2 ranged from 44% to 76%, SM-grade 3 from 19% to 48%, and SM 4-5 from 5 to 23%. Notably, studies with more than 50% cases presenting lesions SM-grade 1-2 presented significantly lower mortality rates than those with less than 50% cases of SM 1-2 lesions (P < 0.001). No significant difference in mortality rates or neurological deficits was identified between studies with more than 50% of microsurgery-cases and those with less than 50%. CONCLUSIONS: The analysis revealed that studies with a higher proportion of bAVMs presenting SM 1-2 lesions were associated with lower mortality rates. Mortality did not show a significant association with treatment modalities.

ICP wave morphology as a screening test to exclude intracranial hypertension in brain-injured patients: a non-invasive perspective.

Intracranial hypertension (IH) is a life-threating condition especially for the brain injured patient. In such cases, an external ventricular drain (EVD) or an intraparenchymal bolt are the conventional gold standard for intracranial pressure (ICPi) monitoring. However, these techniques have several limitations. Therefore, identifying an ideal screening method for IH is important to avoid the unnecessary placement of ICPi and expedite its introduction in patients who require it. A potential screening tool is the ICP wave morphology (ICPW) which changes according to the intracranial volume-pressure curve. Specifically, the P2/P1 ratio of the ICPW has shown promise as a triage test to indicate normal ICP. In this study, we propose evaluating the noninvasive ICPW (nICPW-B4C sensor) as a screening method for ICPi monitoring in patients with moderate to high probability of IH. This is a retrospective analysis of a prospective, multicenter study that recruited adult patients requiring ICPi monitoring from both Federal University of São Paulo and University of São Paulo Medical School Hospitals. ICPi values and the nICPW parameters were obtained from both the invasive and the noninvasive methods simultaneously 5 min after the closure of the EVD drainage. ICP assessment was performed using a catheter inserted into the ventricle and connected to a pressure transducer and a drainage system. The B4C sensor was positioned on the patient's scalp without the need for trichotomy, surgical incision or trepanation, and the morphology of the ICP waves acquired through a strain sensor that can detect and monitor skull bone deformations caused by changes in ICP. All patients were monitored using this noninvasive system for at least 10 min per session. The area under the curve (AUC) was used to describe discriminatory power of the P2/P1 ratio for IH, with emphasis in the Negative Predictive value (NPV), based on the Youden index, and the negative likelihood ratio [LR-]. Recruitment occurred from August 2017 to March 2020. A total of 69 patients fulfilled inclusion and exclusion criteria in the two centers and a total of 111 monitorizations were performed. The mean P2/P1 ratio value in the sample was 1.12. The mean P2/P1 value in the no IH population was 1.01 meanwhile in the IH population was 1.32 (p < 0.01). The best Youden index for the mean P2/P1 ratio was with a cut-off value of 1.13 showing a sensitivity of 93%, specificity of 60%, and a NPV of 97%, as well as an AUC of 0.83 to predict IH. With the 1.13 cut-off value for P2/P1 ratio, the LR- for IH was 0.11, corresponding to a strong performance in ruling out the condition (IH), with an approximate 45% reduction in condition probability after a negative test (ICPW). To conclude, the P2/P1 ratio of the noninvasive ICP waveform showed in this study a high Negative Predictive Value and Likelihood Ratio in different acute neurological conditions to rule out IH. As a result, this parameter may be beneficial in situations where invasive methods are not feasible or unavailable and to screen high-risk patients for potential invasive ICP monitoring.Trial registration: At clinicaltrials.gov under numbers NCT05121155 (Registered 16 November 2021-retrospectively registered) and NCT03144219 (Registered 30 September 2022-retrospectively registered).

New perspectives on assessment and understanding of the patient with cranial bone defect: a morphometric and cerebral radiodensity assessment.

Background: Skull defects after decompressive craniectomy (DC) cause physiological changes in brain function and patients can have neurologic symptoms after the surgery. The objective of this study is to evaluate whether there are morphometric changes in the cortical surface and radiodensity of brain tissue in patients undergoing cranioplasty and whether those variables are correlated with neurological prognosis. Methods: This is a prospective cohort with 30 patients who were submitted to cranioplasty and followed for 6 months. Patients underwent simple head CT before and after cranioplasty for morphometric and cerebral radiodensity assessment. A complete neurological exam with Mini-Mental State Examination (MMSE), modified Rankin Scale, and the Barthel Index was performed to assess neurological prognosis. Results: There was an improvement in all symptoms of the syndrome of the trephined, specifically for headache (p = 0.004) and intolerance changing head position (p = 0.016). Muscle strength contralateral to bone defect side also improved (p = 0.02). Midline shift of intracranial structures decreased after surgery (p = 0.004). The Anterior Distance Difference (ADif) and Posterior Distance Difference (PDif) were used to assess morphometric changes and varied significantly after surgery. PDif was weakly correlated with MMSE (p = 0.03; r = -0.4) and Barthel index (p = 0.035; r = -0.39). The ratio between the radiodensities of gray matter and white matter (GWR) was used to assess cerebral radiodensity and was also correlated with MMSE (p = 0.041; r = -0.37). Conclusion: Morphological anatomy and radiodensity of the cerebral cortex can be used as a tool to assess neurological prognosis after DC.

Perfusion tomography in early follow-up of acute traumatic subdural hematoma: a case series.

Perfusion Computed Tomography (PCT) is an alternative tool to assess cerebral hemodynamics during trauma. As acute traumatic subdural hematomas (ASH) is a severe primary injury associated with poor outcomes, the aim of this study was to evaluate the cerebral hemodynamics in this context. Five adult patients with moderate and severe traumatic brain injury (TBI) and ASH were included. All individuals were indicated for surgical evacuation. Before and after surgery, PCT was performed and cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were evaluated. These parameters were associated with the outcome at 6 months post-trauma with the extended Glasgow Outcome Scale (GOSE). Mean age of population was 46 years (SD: 8.1). Mean post-resuscitation Glasgow coma scale (GCS) was 10 (SD: 3.4). Mean preoperative midline brain shift was 10.1 mm (SD: 1.8). Preoperative CBF and MTT were 23.9 ml/100 g/min (SD: 6.1) and 7.3 s (1.3) respectively. After surgery, CBF increase to 30.7 ml/100 g/min (SD: 5.1), and MTT decrease to 5.8s (SD:1.0), however, both changes don't achieve statistically significance (p = 0.06). Additionally, CBV increase after surgery, from 2.34 (SD: 0.67) to 2.63 ml/100 g (SD: 1.10), (p = 0.31). Spearman correlation test of postoperative and preoperative CBF ratio with outcome at 6 months was 0.94 (p = 0.054). One patient died with the highest preoperative MTT (9.97 s) and CBV (4.51 ml/100 g). CBF seems to increase after surgery, especially when evaluated together with the MTT values. It is suggested that the improvement in postoperative brain hemodynamics correlates to favorable outcome.