Visualization of Cerebral Pressure Autoregulatory Insults in Traumatic Brain Injury.

OBJECTIVES: The first aim was to investigate the combined effect of insult intensity and duration of the pressure reactivity index (PRx) and deviation from the autoregulatory cerebral perfusion pressure target (∆CPPopt = actual CPP - optimal CPP [CPPopt]) on outcome in traumatic brain injury. The second aim was to determine if PRx influenced the association between intracranial pressure (ICP), CPP, and ∆CPPopt with outcome. DESIGN: Observational cohort study. SETTING: Neurocritical care unit, Cambridge, United Kingdom. PATIENTS: Five hundred fifty-three traumatic brain injury patients with ICP and arterial blood pressure monitoring and 6-month outcome data (Glasgow Outcome Scale [GOS]). INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The insult intensity (mm Hg or PRx coefficient) and duration (minutes) of ICP, PRx, CPP, and ∆CPPopt were correlated with GOS and visualized in heatmaps. In these plots, there was a transition from favorable to unfavorable outcome when PRx remained positive for 30 minutes and this was also the case for shorter durations when the intensity was higher. In a similar plot of ∆CPPopt, there was a gradual transition from favorable to unfavorable outcome when ∆CPPopt went below -5 mm Hg for 30-minute episodes of time and for shorter durations for more negative ∆CPPopt. Furthermore, the percentage of monitoring time with certain combinations of PRx with ICP, CPP, and ∆CPPopt were correlated with GOS and visualized in heatmaps. In the combined PRx/ICP heatmap, ICP above 20 mm Hg together with PRx above 0 correlated with unfavorable outcome. In a PRx/CPP heatmap, CPP below 70 mm Hg together with PRx above 0.2-0.4 correlated with unfavorable outcome. In the PRx-/∆CPPopt heatmap, ∆CPPopt below 0 together with PRx above 0.2-0.4 correlated with unfavorable outcome. CONCLUSIONS: Higher intensities for longer durations of positive PRx and negative ∆CPPopt correlated with worse outcome. Elevated ICP, low CPP, and negative ∆CPPopt were particularly associated with worse outcomes when the cerebral pressure autoregulation was concurrently impaired.

Brain tissue oxygen monitoring in traumatic brain injury: part I-To what extent does PbtO2 reflect global cerebral physiology?

BACKGROUND: The primary aim was to explore the association of global cerebral physiological variables including intracranial pressure (ICP), cerebrovascular reactivity (PRx), cerebral perfusion pressure (CPP), and deviation from the PRx-based optimal CPP value (∆CPPopt; actual CPP-CPPopt) in relation to brain tissue oxygenation (pbtO2) in traumatic brain injury (TBI). METHODS: A total of 425 TBI patients with ICP- and pbtO2 monitoring for at least 12 h, who had been treated at the neurocritical care unit, Addenbrooke's Hospital, Cambridge, UK, between 2002 and 2022 were included. Generalized additive models (GAMs) and linear mixed effect models were used to explore the association of ICP, PRx, CPP, and CPPopt in relation to pbtO2. PbtO2 < 20 mmHg, ICP > 20 mmHg, PRx > 0.30, CPP < 60 mmHg, and ∆CPPopt < - 5 mmHg were considered as cerebral insults. RESULTS: PbtO2 < 20 mmHg occurred in median during 17% of the monitoring time and in less than 5% in combination with ICP > 20 mmHg, PRx > 0.30, CPP < 60 mmHg, or ∆CPPopt < - 5 mmHg. In GAM analyses, pbtO2 remained around 25 mmHg over a large range of ICP ([0;50] mmHg) and PRx [- 1;1], but deteriorated below 20 mmHg for extremely low CPP below 30 mmHg and ∆CPPopt below - 30 mmHg. In linear mixed effect models, ICP, CPP, PRx, and ∆CPPopt were significantly associated with pbtO2, but the fixed effects could only explain a very small extent of the pbtO2 variation. CONCLUSIONS: PbtO2 below 20 mmHg was relatively frequent and often occurred in the absence of disturbances in ICP, PRx, CPP, and ∆CPPopt. There were significant, but weak associations between the global cerebral physiological variables and pbtO2, suggesting that hypoxic pbtO2 is often a complex and independent pathophysiological event. Thus, other variables may be more crucial to explain pbtO2 and, likewise, pbtO2 may not be a suitable outcome measure to determine whether global cerebral blood flow optimization such as CPPopt therapy is successful.

Brain tissue oxygen monitoring in traumatic brain injury-part II: isolated and combined insults in relation to outcome.

BACKGROUND: The primary aim was to explore the concept of isolated and combined threshold-insults for brain tissue oxygenation (pbtO2) in relation to outcome in traumatic brain injury (TBI). METHODS: A total of 239 TBI patients with data on clinical outcome (GOS) and intracranial pressure (ICP) and pbtO2 monitoring for at least 12 h, who had been treated at the neurocritical care unit, Addenbrooke's Hospital, Cambridge, UK, between 2002 and 2022 were included. Outcome was dichotomised into favourable/unfavourable (GOS 4-5/1-3) and survival/mortality (GOS 2-5/1). PbtO2 was studied over the entire monitoring period. Thresholds were analysed in relation to outcome based on median and mean values, percentage of time and dose per hour below critical values and visualised as the combined insult intensity and duration. RESULTS: Median pbtO2 was slightly, but not significantly, associated with outcome. A pbtO2 threshold at 25 and 20 mmHg, respectively, yielded the highest x2 when dichotomised for favourable/unfavourable outcome and mortality/survival in chi-square analyses. A higher dose and higher percentage of time spent with pbtO2 below 25 mmHg as well as lower thresholds were associated with unfavourable outcome, but not mortality. In a combined insult intensity and duration analysis, there was a transition from favourable towards unfavourable outcome when pbtO2 went below 25-30 mmHg for 30 min and similar transitions occurred for shorter durations when the intensity was higher. Although these insults were rare, pbtO2 under 15 mmHg was more strongly associated with unfavourable outcome if, concurrently, ICP was above 20 mmHg, cerebral perfusion pressure below 60 mmHg, or pressure reactivity index above 0.30 than if these variables were not deranged. In a multiple logistic regression, a higher percentage of monitoring time with pbtO2 < 15 mmHg was associated with a higher rate of unfavourable outcome. CONCLUSIONS: Low pbtO2, under 25 mmHg and particularly below 15 mmHg, for longer durations and in combination with disturbances in global cerebral physiological variables were associated with poor outcome and may indicate detrimental ischaemic hypoxia. Prospective trials are needed to determine if pbtO2-directed therapy is beneficial, at what individualised pbtO2 threshold therapies are warranted, and how this may depend on the presence/absence of concurrent cerebral physiological disturbances.

Comparison of health-related quality of life in patients with traumatic brain injury, subarachnoid haemorrhage and cervical spine disease.

PURPOSE: The degree of disability that is acceptable to patients following traumatic brain injury (TBI) continues to be debated. While the dichotomization of outcome on the Glasgow Outcome Score (GOSE) into 'favourable' and 'unfavourable' continues to guide clinical decisions, this may not reflect an individual's subjective experience. The aim of this study is to assess how patients' self-reported quality of life (QoL) relates to objective outcome assessments and how it compares to other debilitating neurosurgical pathologies, including subarachnoid haemorrhage (SAH) and cervical myelopathy. METHOD: A retrospective analysis of over 1300 patients seen in Addenbrooke's Hospital, Cambridge, UK with TBI, SAH and patients pre- and post- cervical surgery was performed. QoL was assessed using the SF-36 questionnaire. Kruskal-Wallis test was used to analyse the difference in SF-36 domain scores between the four unpaired patient groups. To determine how the point of dichotomization of GOSE into 'favourable' and 'unfavourable' outcome affected QOL, SF-36 scores were compared between GOSE and mRS. RESULTS: There was a statistically significant difference in the median Physical Component Score (PCS) and Mental Component Score (MCS) of SF-36 between the three neurosurgical pathologies. Patients with TBI and SAH scored higher on most SF-36 domains when compared with cervical myelopathy patients in the severe category. While patients with Upper Severe Disability on GOSE showed significantly higher PC and MC scores compared to GOSE 3, there was a significant degree of variability in individual responses across the groups. CONCLUSION: A significant number of patients following TBI and SAH have better self-reported QOL than cervical spine patients and patients' subjective perception and expectations following injury do not always correspond to objective disability. These results can guide discussion of treatment and outcomes with patients and families.

Systemic inflammation alters the neuroinflammatory response: a prospective clinical trial in traumatic brain injury.

BACKGROUND: Neuroinflammation following traumatic brain injury (TBI) has been shown to be associated with secondary injury development; however, how systemic inflammatory mediators affect this is not fully understood. The aim of this study was to see how systemic inflammation affects markers of neuroinflammation, if this inflammatory response had a temporal correlation between compartments and how different compartments differ in cytokine composition. METHODS: TBI patients recruited to a previous randomised controlled trial studying the effects of the drug anakinra (Kineret®), a human recombinant interleukin-1 receptor antagonist (rhIL1ra), were used (n = 10 treatment arm, n = 10 control arm). Cytokine concentrations were measured in arterial and jugular venous samples twice a day, as well as in microdialysis-extracted brain extracellular fluid (ECF) following pooling every 6 h. C-reactive protein level (CRP), white blood cell count (WBC), temperature and confirmed systemic clinical infection were used as systemic markers of inflammation. Principal component analyses, linear mixed-effect models, cross-correlations and multiple factor analyses were used. RESULTS: Jugular and arterial blood held similar cytokine information content, but brain-ECF was markedly different. No clear arterial to jugular gradient could be seen. No substantial delayed temporal associations between blood and brain compartments were detected. The development of a systemic clinical infection resulted in a significant decrease of IL1-ra, G-CSF, PDGF-ABBB, MIP-1b and RANTES (p < 0.05, respectively) in brain-ECF, even if adjusting for injury severity and demographic factors, while an increase in several cytokines could be seen in arterial blood. CONCLUSIONS: Systemic inflammation, and infection in particular, alters cytokine levels with different patterns seen in brain and in blood. Cerebral inflammatory monitoring provides independent information from arterial and jugular samples, which both demonstrate similar information content. These findings could present potential new treatment options in severe TBI patients, but novel prospective trials are warranted to confirm these associations.

Multimodality neuromonitoring in severe pediatric traumatic brain injury.

Each year, the annual hospitalization rates of traumatic brain injury (TBI) in children in the United States are 57.7 per 100K in the <5 years of age and 23.1 per 100K in the 5-14 years age group. Despite this, little is known about the pathophysiology of TBI in children and how to manage it most effectively. Historically, TBI management has been guided by clinical examination. This has been assisted progressively by clinical imaging, intracranial pressure (ICP) monitoring, and finally a software that can calculate optimal brain physiology. Multimodality monitoring affords clinicians an early indication of secondary insults to the recovering brain including raised ICP and decreased cerebral perfusion pressure. From variables such as ICP and arterial blood pressure, correlations can be drawn to determine parameters of cerebral autoregulation (pressure reactivity index) and "optimal cerebral perfusion pressure" at which the vasculature is most reactive. More recently, significant advances using both direct and near-infrared spectroscopy-derived brain oxygenation plus cerebral microdialysis to drive management have been described. Here in, we provide a perspective on the state-of-the-art techniques recently implemented in clinical practice for pediatric TBI.

Simultaneous navigated cervico-thoracic and thoraco-lumbar fixation.

STUDY DESIGN: Case report. OBJECTIVE: To investigate the feasibility of using two independent image guidance systems to simultaneously fix multiple segment spine fractures. Image guidance is increasingly used to aid spinal fixation. We describe the first use of multiple navigation systems during a single procedure allowing for multi-segment spinal fixations to be performed simultaneously and capitalizing the advantages of navigation. METHOD: Two Medtronic Stealth Station S7™ systems with O-arm image capture were used to guide fixation of C6 and T12, unstable, AO A4, three-column fractures, in a patient with ankylosing spondylitis. RESULTS: Two surgical teams were able to perform cervico-thoracic and thoraco-lumbar fixations simultaneously. Operative time was 2.5 h. Post-operative imaging showed accurate instrumentation placement. The patient recovered without any neurological sequelae. CONCLUSIONS: Optical independence of the Medtronic Stealth Station™ system allowed for simultaneous navigation guided fixation of multiple segment fractures without compromising accuracy. This may result in shortened operative time and morbidity associated with prolonged prone positioning of polytrauma patients, as well as reducing radiation exposure for theatre staff.

Pre-hospital Predictors of Impaired ICP Trends in Continuous Monitoring of Paediatric Traumatic Brain Injury Patients.

OBJECTIVE: Although secondary insults such as raised intracranial pressure (ICP) or cardiovascular compromise strongly contribute to morbidity, a growing interest can be noticed in how the pre-hospital management can affect outcomes after traumatic brain injury (TBI). The objective of this study was to determine whether pre-hospital co-morbidity has influence on patterns of continuously measured waveforms of intracranial physiology after paediatric TBI. MATERIALS AND METHODS: Thirty-nine patients (mean age, 10 years; range, 0.5-15) admitted between 2002 and 2015 were used for the current analysis. Pre-hospital motor score, pupil reactivity, pre-hospital hypoxia (SpO2 < 90%) and hypotension (mean arterial pressure < 70 mmHg) were documented. ICP and arterial blood pressure (ABP) were monitored continuously with an intraparenchymal microtransducer and an indwelling arterial line. Pressure monitors were connected to bedside computers running ICM+ software. Pressure reactivity was determined as the moving correlation between 30 10-s averages of ABP and ICP (PRx). The mean ICP and PRx were calculated for the whole monitoring period for each patient. RESULTS: Those with pre-hospital hypotension were susceptible to higher ICP [20 (IQR 8) vs 13 (IQR 6) mmHg; p = 0.01] and more frequent ICP plateau waves [median = 0 (IQR 1), median = 4 (IQR 9); p = 0.001], despite having similar MAP, CPP and PRx during monitoring. Those with unreactive pupils tended to have higher ICP than those with reactive pupils (18 vs 14 mmHg, p = 0.08). Pre-hospital hypoxia, motor score and pupillary reactivity were not related to subsequent monitored intracranial or systemic physiology. CONCLUSION: In paediatric TBI, pre-hospital hypotension is associated with increased ICP in the intensive care unit.

Computed Tomography Indicators of Deranged Intracranial Physiology in Paediatric Traumatic Brain Injury.

OBJECTIVE: Computed tomography (CT) of the brain can allow rapid assessment of intracranial pathology after traumatic brain injury (TBI). Frequently in paediatric TBI, CT imaging can fail to display the classical features of severe brain injury with raised intracranial pressure. The objective of this study was to determine early CT brain features that influence intracranial or systemic physiological trends following paediatric TBI. MATERIALS AND METHODS: Thirty-three patients (mean age, 10 years; range, 0.5-16) admitted between 2002 and 2015 were used for the current analysis. Presence of petechial haemorrhages, basal cistern compression, subarachnoid blood, midline shift and extra-axial masses on the initial trauma CT head were assessed. ICP and arterial blood pressure (ABP) were then monitored continuously with an intraparenchymal microtransducer and an indwelling arterial line. Pressure monitors were connected to bedside computers running ICM+ software. Pressure reactivity was determined as the moving correlation between 30, 10-s averages of ABP and ICP (PRx). The mean ICP, ABP, cerebral perfusion pressure (CPP; ABP minus ICP) and PRx were calculated for the whole monitoring period for each patient. RESULTS: The presence of subarachnoid blood was related to higher ICP, higher ABP and a trend toward higher PRx. Smaller basal cisterns were related to increased ICP (R = -0.42, p = 0.02), impaired PRx (R = -0.5, p = 0.003). The presence of an extra-axial mass was associated with deranged PRx (-0.02 vs. 0.41, p = 0.003) and a trend toward higher ICP (14 vs. 40, p = 0.07). Interestingly the degree of midline shift was not related to ICP or PRx. CONCLUSIONS: The size of the basal cisterns, the presence of subarachnoid blood or an extra-axial mass are all related to disturbed ICP and pressure reactivity in this paediatric TBI cohort. Patients with these features are ideal candidates for invasive multimodal monitoring.

Predictors of early progression of surgically treated atypical meningiomas.

BACKGROUND: Clinical behaviour of atypical meningiomas is not uniform. While, as a group, they exhibit a high recurrence rate, some pursue a more benign course, whereas others progress early. We aim to investigate the imaging and pathological factors that predict risk of early tumour progression and to determine whether early progression is related to outcome. METHODS: Adult patients with WHO grade II meningioma treated in three regional referral centres between 2007 and 2014 were included. MRI and pathology characteristics were assessed. Gross total resection (GTR) was defined as Simpson 1-3. Recurrence was classified into early and late (≤ 24 vs. > 24 months). RESULTS: Among the 220 cases, 37 (16.8%) patients progressed within 24 months of operation. Independent predictors of early progression were subtotal resection (STR) (p = 0.005), parafalcine/parasagittal location (p = 0.015), peritumoural oedema (p = 0.027) and mitotic index (MI) > 7 (p = 0.007). Adjuvant radiotherapy was negatively associated with early recurrence (p = 0.046). Thirty-two per cent of patients with residual tumour and 26% after GTR received adjuvant radiotherapy. There was a significantly lower proportion of favourable outcomes at last follow-up (mRS 0-1) in patients with early recurrence (p = 0.001). CONCLUSIONS: Atypical meningiomas are a heterogeneous group of tumours with 16.8% patients having recurrence within 24 months of surgery. Residual tumour, parafalcine/parasagittal location, peritumoural oedema and a MI > 7 were all independently associated with early recurrence. As administration of adjuvant radiotherapy was not protocolised in this cohort, any conclusions about benefits of irradiation of WHO grade II meningiomas should be viewed with caution. Patients with early recurrence had worse neurological outcome. While histological and imaging characteristics provide some prognostic value, further molecular characterisation of atypical meningiomas is warranted to aid clinical decision making.

Correlating optic nerve sheath diameter with opening intracranial pressure in pediatric traumatic brain injury.

INTRODUCTION: The use of clinical markers to predict intracranial pressure (ICP) is desirable as a first-line measure to assist in decision making as to whether invasive monitoring is required. Correlations between ICP and optic nerve sheath diameter (ONSD) using CT and MRI have been observed in adult populations. However, data on this modality in children is less well documented. METHODS: ONSD was measured by independent observers and correlated with opening ICP at insertion of invasive monitoring probes in pediatric traumatic brain injury patients admitted to Addenbrookes Hospital between January 2009 and December 2013. RESULTS: Thirty-six patients with a mean age of 8.2 y were admitted to the Pediatric Intensive Care Unit (PICU) with a traumatic head injury and required invasive neurosurgical monitoring. The median ICP was 18 ± 10 mmHg (median ± IQR), the median right ONSD was 5.6 ± 2.5 mm and the left was 5.9 ± 3.2 mm. The Intraclass correlation between observers was 0.91 (P < 0.0001). The correlation of mean ONSD and max ONSD with ICP was 0.712 (P < 0.0001) and 0.713 (P < 0.0001), respectively. Area under ROC curve for both mean and max ONSD is 0.85 (95% CI: 0.73-0.98). CONCLUSION: Where pediatric patients present with an ONSD of over 6.1 mm following a traumatic brain injury (TBI), ICP monitoring should be implemented.

Improved long-term survival with subdural drains following evacuation of chronic subdural haematoma.

BACKGROUND: Chronic subdural haematoma (CSDH) is a common condition that is effectively managed by burrhole drainage but requires repeat surgery in a significant minority of patients. The Cambridge Chronic Subdural Haematoma Trial (CCSHT) was a randomised controlled study that showed placement of subdural drains for 48 h following burrhole evacuation significantly reduces the incidence of reoperation and improves survival at 6 months. The present study examined the long-term survival of the patients in the trial. METHODS: In the original trial patients at a single neurosurgical centre from 2004-2007 were randomly assigned to receive a drain (n = 108) or no drain (n = 107) following burrhole drainage of CSDH. We ascertained whether the trial patients were alive in February 2016-a minimum of 8 years following enrollment-via the UK NHS tracing service. Survival was compared between the trial groups and against expected survival for the UK general population matched for age and sex. RESULTS: At 5 years following surgery the drain group continued to have significantly better survival than the no drain patients (p = 0.027), but this was no longer apparent at 10 years. Survival of patients in the drain group did not differ significantly from that of the general population whereas patients who did not receive a drain had significantly lower survival than expected (p = 0.0006). CONCLUSION: Subdural drains following CSDH evacuation are associated with improved long-term survival, which appears similar to that expected for the general population of the same age and sex. All patients having burrhole CSDH evacuation should receive a drain as standard practice unless specifically contraindicated.

Volumetric growth rates of meningioma and its correlation with histological diagnosis and clinical outcome: a systematic review.

INTRODUCTION: Tumour growth has been used to successfully predict progression-free survival in low-grade glioma. This systematic review sought to establish the evidence base regarding the correlation of volumetric growth rates with histological diagnosis and potential to predict clinical outcome in patients with meningioma. METHODS: This systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Databases were searched for full text English articles analysing volumetric growth rates in patients with a meningioma. RESULTS: Four retrospective cohort studies were accepted, demonstrating limited evidence of significantly different tumour doubling rates and shapes of growth curves between benign and atypical meningiomas. Heterogeneity of patient characteristics and timing of volumetric assessment, both pre- and post-operatively, limited pooled analysis of the data. No studies performed statistical analysis to demonstrate the clinical utility of growth rates in predicting clinical outcome. CONCLUSION: This systematic review provides limited evidence in support of the use of volumetric growth rates in meningioma to predict histological diagnosis and clinical outcome to guide future monitoring and treatment.

Correlation of volumetric growth and histological grade in 50 meningiomas.

INTRODUCTION: Advances in radiological imaging techniques have enabled volumetric measurements of meningiomas to be easily monitored using serial imaging scans. There is limited literature on the relationship between tumour growth rates and the WHO classification of meningiomas despite tumour growth being a major determinant of type and timing of intervention. Volumetric growth has been successfully used to assess growth of low-grade glioma; however, there is limited information on the volumetric growth rate (VGR) of meningiomas. This study aimed to determine the reliability of VGR measurement in patients with meningioma, assess the relationship between VGR and 2016 WHO grading as well as clinical applicability of VGR in monitoring meningioma growth. METHODS: All histologically proven intracranial meningiomas that underwent resection in a single centre between April 2009 and April 2014 were reviewed and classified according to the 2016 edition of the Classification of the Tumours of the CNS. Only patients who had two pre-operative scans that were at least 3 months apart were included in the study. Two authors performed the volumetric measurements using the Slicer 3D software independently and the inter-rater reliability was assessed. Multiple regression analyses of factors affecting the VGR and VDE of meningiomas were performed using the R statistical software with p < 0.05 considered to be statistically significant. RESULTS: Of 548 patients who underwent resection of their meningiomas, 66 met the inclusion criteria. Sixteen cases met the exclusion criteria (NF2, spinal location, previous surgical or radiation treatment, significant intra-osseous component and poor quality imaging). Forty-two grade I and 8 grade II meningiomas were included in the analysis. The VGR was significantly higher for grade II meningiomas. Using receiver-operator characteristic (ROC) curve analysis, the optimal threshold that distinguishes between grade I and II meningiomas is 3 cm3/year. Higher histological grade, high initial tumour volume, MRI T2-signal hyperintensity and presence of oedema were found to be significant predictors of higher VGR. CONCLUSION: Reliable tools now exist to evaluate and monitor volumetric growth of meningiomas. Grade II meningiomas have significantly higher VGR compared with grade I meningiomas and growth of more than 3 cm3/year is strongly suggestive of a higher grade meningioma. A larger, multi-centre prospective study to investigate the applicability of velocity of growth to predict the outcome of patients with meningioma is warranted.

Recovery of oculomotor nerve palsy secondary to posterior communicating artery aneurysms.

BACKGROUND: Recent studies suggest more favourable recovery of oculomotor nerve palsy (ONP) caused by posterior communicating artery (PComA) aneurysms with microsurgical clipping compared to endovascular coiling. We describe a consecutive series of patients with ONP from PComA aneurysms treated by microsurgical clipping or endovascular coiling. METHODS: We retrospectively reviewed medical records of all patients from 2005 to 2009 with complete or partial ONP from PComA aneurysms. RESULTS: Twenty patients were identified, three with unruptured aneurysms. Two patients with ruptured aneurysms were unfit for treatment and therefore excluded. Of the 18 patients included (15 female), 9 underwent microsurgical clipping and 9 received endovascular coiling. Patients treated by surgical clipping were significantly younger compared to those treated by endovascular coiling (mean 52.3 vs. 67.9 years; p = 0.039). Five patients had incomplete ONP (3 clipped, 2 coiled) and thirteen had complete ONP. At 6 months, six of nine patients treated with clipping and five of nine patients treated with coiling had complete resolution of their ONP (p = 1.0); the remainder had partial improvement. There was no significant difference in duration of pre-treatment ONP, age, sex or status of aneurysm (ruptured or unruptured) between patients in the two groups or between those with full or partial recovery. However, all 5 patients with incomplete ONP at presentation recovered fully, compared with 6 of 13 patients who presented with complete ONP. CONCLUSIONS: We found no significant difference between clipping and coiling in the recovery of ONP due to PComA aneurysms. Patient who present with incomplete ONP are more likely to have a full recovery of ONP following either treatment modality than those who present with complete ONP.

Technical considerations and long-term results of endovascular venous stenting to control venous hypertension from meningiomas invading intracranial venous sinuses.

OBJECTIVE: Meningiomas invading the intracranial venous sinuses may cause intracranial venous hypertension, papilledema, and visual compromise. Sinus resection and graft reconstructions, however, add significant complexity to tumor surgery, with the potential for increased morbidity. In this study, the authors explored whether venous sinus stenting might provide an alternative means of controlling venous hypertension that would be sustainable over the long term. METHODS: The authors performed a retrospective review of all 16 patients with intracranial meningiomas who underwent stenting at their institution for venous sinus compromise. At presentation, all had headache and 9 had papilledema. Thirteen patients had 1 meningioma and 3 had 2 or more. Three patients had had previous tumor resection and radiotherapy. One patient had been treated with a lumboperitoneal shunt and radiotherapy. The median length of clinical follow-up was 8 years (range 4 months-18 years). RESULTS: Venous sinus narrowing was often not confined to the site of meningioma, and bilateral transverse sinus narrowing, reminiscent of that seen in idiopathic intracranial hypertension, was present in 7 patients with sagittal sinus meningiomas. Eleven patients had stents placed solely across sinus narrowing caused by meningioma. Five patients had additional stents placed at other sites of venous narrowing at the same time: in one of these patients, a stent was placed across a defect in the sagittal sinus caused by previous surgery, and in the 4 other patients, stents were placed across nontumor narrowings of the transverse sinuses. In 1 patient, the jugular vein was also stented. Nine patients developed symptomatic in-stent restenosis at the meningioma site. Eight had further stenting procedures with variable success in restoring the in-stent lumen. The remaining patient, with a late partial relapse, is being reinvestigated. Papilledema resolved in all patients after stenting. Six patients experienced prolonged and very substantial relief of all symptoms. Five patients had persistent headache despite restoration of the sinus lumen. Five had persistent symptoms associated with resistant in-stent stenosis. There were no significant complications from any of the diagnostic or therapeutic procedures. CONCLUSIONS: In patients who are symptomatic with meningiomas obstructing the venous sinuses, successful stenting of the affected segment can give a good outcome, especially in terms of relieving papilledema. However, further procedures are often necessary to maintain stent patency, other areas of venous compromise frequently coexist, and some patients remain symptomatic despite apparently successful treatment of the index lesion. Long-term surveillance is a requirement.

Reduced temporal muscle thickness predicts shorter survival in patients undergoing chronic subdural haematoma drainage.

BACKGROUND: Chronic subdural haematoma (CSDH) drainage is a common neurosurgical procedure. CSDHs cause excess mortality, which is exacerbated by frailty. Sarcopenia contributes to frailty - its key component, low muscle mass, can be assessed using cross-sectional imaging. We aimed to examine the prognostic role of temporal muscle thickness (TMT) measured from preoperative computed tomography head scans among patients undergoing surgical CSDH drainage. METHODS: We retrospectively identified all patients who underwent CSDH drainage within 1 year of February 2019. We measured their mean TMT from preoperative computed tomography scans, tested the reliability of these measurements, and evaluated their prognostic value for postoperative survival. RESULTS: One hundred and eighty-eight (122, 65% males) patients (median age 78 years, IQR 70-85 years) were included. Thirty-four (18%) patients died within 2 years, and 51 (27%) died at a median follow-up of 39 months (IQR 34-42 months). Intra- and inter-observer reliability of TMT measurements was good-to-excellent (ICC 0.85-0.97, P < 0.05). TMT decreased with age (Pearson's r = -0.38, P < 0.001). Females had lower TMT than males (P < 0.001). The optimal TMT cut-off values for predicting two-year survival were 4.475 mm for males and 3.125 mm for females. TMT below these cut-offs was associated with shorter survival in both univariate (HR 3.24, 95% CI 1.85-5.67) and multivariate (HR 1.86, 95% CI 1.02-3.36) analyses adjusted for age, ASA grade and bleed size. The effect of TMT on mortality was not mediated by age. CONCLUSIONS: In patients with CSDH, TMT measurements from preoperative imaging were reliable and contained prognostic information supplemental to previously known predictors of poor outcomes.

Regional scalp block for postcraniotomy analgesia: a systematic review and meta-analysis.

BACKGROUND: Up to two-thirds of patients report moderate to severe surgical site pain after craniotomy procedures, and there is understandable reluctance to manage these symptoms with systemic opioids that may impair neurological assessment. Furthermore, there is a lack of consensus and evidence concerning alternative analgesia strategies for cranial neurosurgery. Regional scalp block (RSB) is an established technique that involves infiltration of local anesthetic (LA) at well-defined anatomical sites targeting the major sensory innervation of the scalp. However, the efficacy of RSB in reducing postoperative pain remains unclear. In this study, we sought to systematically identify and review randomized controlled trials (RCTs) of RSB and synthesize an overall estimate of efficacy in a quantitative meta-analysis. METHODS: Medline, EMBASE, and the Cochrane Central Register of Controlled Trials databases were searched for all RCTs evaluating the effect of RSB on postoperative pain after craniotomy. Titles, abstracts, and papers were reviewed independently by 2 authors against predefined inclusion criteria. Two authors independently assessed the quality of included studies and extracted data on patient-reported pain scores, other analgesia requirements, and complications of RSB. Pain scores were scaled to a common 0 to 10 interval with higher scores indicating more severe pain. Meta-analysis of the pooled treatment effect was performed with a random-effects inverse-variance weighted model; heterogeneity was quantified with the I(2) statistic. RESULTS: The literature search identified 138 unique citations, from which 7 RCTs with a total recruitment of 320 patients met the inclusion criteria. All studies used standard LA drugs (lidocaine, bupivacaine, or ropivacaine); in 3 studies, LA was combined with epinephrine. In 3 studies, RSB was performed preoperatively; in the other 4 studies, it was administered postoperatively after wound closure. No complications attributable to RSB were reported. Meta-analysis found a pooled reduction in pain score at 1 hour postoperatively (N = 5 studies; mean difference, -1.61; 95% confidence interval, -2.06 to -1.15; P < 0.001; I(2) = 0%). Subgroup analysis of preoperative RSB showed significant reduction in pain scores at 2, 4, and 6 to 8 hours after surgery whereas postoperative RSB was associated with significant reduction in pain scores at 2, 4, 6 to 8 and 12 hours assessments. There was also an overall reduction in the opioid requirements over the first 24 hours postoperatively, although with significant heterogeneity among the studies (N = 6 studies; standardized mean difference, -0.79; 95% confidence interval, -1.55 to -0.03; P = 0.04; I(2) = 86%). CONCLUSION: Published RCTs of RSB are small and of limited methodological quality but meta-analysis shows a consistent finding of reduced postoperative pain. This evidence supports the use of RSB for patients undergoing craniotomy.

Cerebral microdialysis in clinical studies of drugs: pharmacokinetic applications.

The ability to deliver drug molecules effectively across the blood-brain barrier into the brain is important in the development of central nervous system (CNS) therapies. Cerebral microdialysis is the only existing technique for sampling molecules from the brain extracellular fluid (ECF; also termed interstitial fluid), the compartment to which the astrocytes and neurones are directly exposed. Plasma levels of drugs are often poor predictors of CNS activity. While cerebrospinal fluid (CSF) levels of drugs are often used as evidence of delivery of drug to brain, the CSF is a different compartment to the ECF. The continuous nature of microdialysis sampling of the ECF is ideal for pharmacokinetic (PK) studies, and can give valuable PK information of variations with time in drug concentrations of brain ECF versus plasma. The microdialysis technique needs careful calibration for relative recovery (extraction efficiency) of the drug if absolute quantification is required. Besides the drug, other molecules can be analysed in the microdialysates for information on downstream targets and/or energy metabolism in the brain. Cerebral microdialysis is an invasive technique, so is only useable in patients requiring neurocritical care, neurosurgery or brain biopsy. Application of results to wider patient populations, and to those with different pathologies or degrees of pathology, obviously demands caution. Nevertheless, microdialysis data can provide valuable guidelines for designing CNS therapies, and play an important role in small phase II clinical trials. In this review, we focus on the role of cerebral microdialysis in recent clinical studies of antimicrobial agents, drugs for tumour therapy, neuroprotective agents and anticonvulsants.

Traumatic brain injury in adults.

Traumatic brain injury (TBI) remains a major public health problem. This review aims to present the principles upon which modern TBI management should be based. The early management phase aims to achieve haemodynamic stability, limit secondary insults (eg hypotension, hypoxia), obtain accurate neurological assessment and appropriately select patients for further investigation. Since 2003, the mainstay of risk stratification in the UK emergency departments has been a system of triage based on clinical assessment, which then dictates the need for a CT scan of the head. For patients with acute subdural or extradural haematomas, time from clinical deterioration to operation should be kept to a minimum, as it can affect their outcome. In addition, it is increasingly recognised that patients with severe and moderate TBI should be managed in neuroscience centres, regardless of the need for neurosurgical intervention. The monitoring and treatment of raised intracranial pressure is paramount for maintaining cerebral blood supply and oxygen delivery in patients with severe TBI. Decompressive craniectomy and therapeutic hypothermia are the subject of ongoing international multi-centre randomised trials. TBI is associated with a number of complications, some of which require specialist referral. Patients with post-concussion syndrome can be helped by supportive management in the context of a multi-disciplinary neurotrauma clinic and by patient support groups. Specialist neurorehabilitation after TBI is important for improving outcome.