Adverse intraoperative events during surgical repair of ruptured cerebral aneurysms: a systematic review.

Compared with endovascular techniques, clipping of ruptured cerebral aneurysms has been shown to associate with increased morbidity in several studies. Despite this, clipping remains the preferred option for many aneurysms. The objective of this study is to describe the reported adverse events of open repair of ruptured cerebral aneurysms and their impact on patient outcome. The PubMed, Embase and Cochrane databases were searched between June 1999 and June 2019 to identify original studies of at least 100 patients undergoing surgical repair of ruptured cerebral aneurysms and in which adverse event rates were reported. Thirty-six studies reporting adverse events in a total of 12,410 operations for repair of ruptured cerebral aneurysms were included. Surgical adverse events were common with 36 event types reported including intraoperative rupture (median rate of 16.6%), arterial injury (median rate of 3.8%) and brain swelling (median rate 5.6%). Only 6 surgical events were statistically shown to associate with poor outcomes by any author and for intraoperative rupture (the most frequently analysed), there was an even split between authors finding a statistical association with poor outcome and those finding no association. Even with modern surgical techniques, the technical demands of surgical aneurysm repair continue to lead to a high rate of intraoperative adverse events. Despite this, it is not known which of these intraoperative events are the most important contributors to the poor outcomes often seen in these patients. More research directed towards identifying the events that most drive operative morbidity has the potential to improve outcomes for these patients.

Craniovertebral junction fixation in children less than 5 years.

PURPOSE: Whilst rigid fixation for craniovertebral instability is the gold standard, in very young, small children conventional management may have to be modified. We present a single-centre experience of craniocervical fixation in children under 5 years. METHODS: A retrospective review of cases that had undergone atlantoaxial (AA) or occipitocervical (OC) fixation aged under 5 years. Fusion was assessed using computerised tomography or flexion extension X-rays. RESULTS: Twenty-six children (median age 2.3, range 0.8-4.9 years, 19 under the age of 3) underwent OC (n = 19) or AA (n = 7) fusion between 1999 and 2016. Pathology comprised 17 congenital, five trauma, two tumour and two post-infection cases. Twenty-one patients underwent sublaminar cable fixation with calvarial, autologous bone graft and halo-body orthosis immobilisation. An occipital plate and rods to sublaminar wire construct were used in four cases. A rigid instrumented fixation with occipital plate and C2 pedicle screws was utilised in one case. Follow-up was for a median of 2.8 years (range 0.03-16.3 years). Initial fusion rate was 91%, reaching 100% following two re-operations. Ninety-two per cent of patients were neurologically stable or improved following surgery. Twenty-one patients had a good overall outcome. Two patients had post-operative neurological deteriorations, and four died due to non-procedure related causes. Pin site morbidity secondary to halo use occurred in five cases. CONCLUSION: High fusion rates with good outcomes are achievable using semi-rigid fixation in the under 5-year-olds. Full thickness, autologous calvarial bone graft secured with wire cables and halo external orthosis offers a safe and effective alternative technique when traditional screw instrumentation is not feasible. These slides can be retrieved under Electronic Supplementary Material.

Disconnection between the default mode network and medial temporal lobes in post-traumatic amnesia.

SEE BIGLER DOI101093/AWW277 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Post-traumatic amnesia is very common immediately after traumatic brain injury. It is characterized by a confused, agitated state and a pronounced inability to encode new memories and sustain attention. Clinically, post-traumatic amnesia is an important predictor of functional outcome. However, despite its prevalence and functional importance, the pathophysiology of post-traumatic amnesia is not understood. Memory processing relies on limbic structures such as the hippocampus, parahippocampus and parts of the cingulate cortex. These structures are connected within an intrinsic connectivity network, the default mode network. Interactions within the default mode network can be assessed using resting state functional magnetic resonance imaging, which can be acquired in confused patients unable to perform tasks in the scanner. Here we used this approach to test the hypothesis that the mnemonic symptoms of post-traumatic amnesia are caused by functional disconnection within the default mode network. We assessed whether the hippocampus and parahippocampus showed evidence of transient disconnection from cortical brain regions involved in memory processing. Nineteen patients with traumatic brain injury were classified into post-traumatic amnesia and traumatic brain injury control groups, based on their performance on a paired associates learning task. Cognitive function was also assessed with a detailed neuropsychological test battery. Functional interactions between brain regions were investigated using resting-state functional magnetic resonance imaging. Together with impairments in associative memory, patients in post-traumatic amnesia demonstrated impairments in information processing speed and spatial working memory. Patients in post-traumatic amnesia showed abnormal functional connectivity between the parahippocampal gyrus and posterior cingulate cortex. The strength of this functional connection correlated with both associative memory and information processing speed and normalized when these functions improved. We have previously shown abnormally high posterior cingulate cortex connectivity in the chronic phase after traumatic brain injury, and this abnormality was also observed in patients with post-traumatic amnesia. Patients with post-traumatic amnesia showed evidence of widespread traumatic axonal injury measured using diffusion magnetic resonance imaging. This change was more marked within the cingulum bundle, the tract connecting the parahippocampal gyrus to the posterior cingulate cortex. These findings provide novel insights into the pathophysiology of post-traumatic amnesia and evidence that memory impairment acutely after traumatic brain injury results from altered parahippocampal functional connectivity, perhaps secondary to the effects of axonal injury on white matter tracts connecting limbic structures involved in memory processing.

Consent: an event or a memory in lumbar spinal surgery? A multi-centre, multi-specialty prospective study of documentation and patient recall of consent content.

STUDY DESIGN: Prospective, multi-centre, multi-specialty medical notes review and patient interview. PURPOSE: The consenting process is an important communication tool which also carries medico-legal implications. While written consent is a pre-requisite before spinal surgery in the UK, the standard and effectiveness of the process have not been assessed previously. This study assesses standard of written consent for elective lumbar decompressive surgery for degenerative disc disease across different regions and specialties in the UK; level of patient recall of the consent content; and identifies factors which affect patient recall. METHODS: Consent forms of 153 in-patients from 4 centres a, b, c, d were reviewed. Written documentation of intended benefits, alternative treatments and operative risks was assessed. Of them, 108 patients were interviewed within 24 h before or after surgeries to assess recall. RESULTS: The written documentation rates of the operative risks showed significant inter-centre variations in haemorrhage and sphincter disturbance (P = 0.000), but not for others. Analysis of pooled data showed variations in written documentation of risks (P < 0.0005), highest in infection (96.1%) and lowest in recurrence (52.3%). For patient recall of these risks, there was no inter-centre variation. Patients' recall of paralysis as a risk was highest (50.9%) and that of recurrence was lowest (6.5%). Patients <65 years old recalled risks better than those ≥65, significantly so for infection (29.9 vs 9.7%, P = 0.027). Patients consented >14 days compared to <2 days before their surgeries had higher recall for paralysis (65.2 vs 43.7%) and recurrence (17.4 vs 2.8%). Patient recall was independent of consenter grade. CONCLUSION: Overall, the standard of written consent for elective lumbar spinal decompressive surgery was sub-optimal, which was partly reflected in the poor patient recall. While consenter seniority did not affect patient recall, younger age and longer consent-to-surgery time improved it.

Obesity and posterior spinal fat content: impact on complications in non-complex lumbar spine surgery.

AIM: Obesity is increasing in prevalence across the world with a potentially very significant impact in spine surgery. This study aimed to characterise this in the setting of neurosurgical spine practise at a single centre in UK. Uniquely, we assess the contribution of posterior spinal fat content to intraoperative complications. MATERIALS AND METHODS: All cases of lumbar spine surgery in 1 year were investigated. Case note review was carried out documenting patient demographics, comorbidities, operative details, complications and length of stay. Ninety-four complete datasets were compiled from 128 cases. The posterior spinal fat content was recorded from T2-weighted MRI. Body mass index (BMI) was correlated with each measure using logistic multiple regression and contingency table analysis. RESULTS: Mean BMI was 28.3 (SD: 5.2) comprising one underweight (BMI <18.5), 26 normal weight (BMI: 18.5-24.9), 32 overweight (BMI ≥25), 33 obese (BMI ≥30) and two morbidly obese patients (BMI ≥40). BMI (coefficient: 0.03, SE: 0.01, p = 0.005) and posterior spinal fat content (coefficient: 0.01, SE: 0.005, p = 0.042) correlated significantly with increasing length of stay. Procedure (p = 0.006) and complication rate (p = 0.010) also correlated with length of stay. Neither BMI nor posterior spinal fat content had a significant effect on the incidence of perioperative complications (p = 0.932, p = 0.742), operating time (p = 0.454, p = 0.748) or blood loss (p = 0.127, p = 0.692). There were three non-operative complications in the obese and overweight groups compared with none in the normal weight group, but this was not significant. Overall complication rate was 15%. CONCLUSION: Obesity and posterior spinal fat content correlate with the length of stay in simple spine surgery. There is a non-significant trend towards increased non-operative complications in overweight and obese patients, which could reach significance with larger numbers and prospective data. Excess posterior spinal fat is not associated with increased operative complications, operating time or blood loss.

The spectrum of traumatic injuries at the craniocervical junction: a review of imaging findings and management.

The craniocervical junction is an area with unique biomechanical properties and injuries conferred often represent high-impact trauma. The vital structures traversing this region are susceptible to injury with frequent, only subtle findings identified on unenhanced CT, with MRI and CT angiography often revealing the full extent of injuries. This article reviews the osseous and ligamentous anatomy of the region and common injury patterns. Endovascular and neurosurgical management will also be discussed.

Occult posterior inferior cerebellar artery dissection requiring endovascular treatment following pediatric head trauma: case report.

This is the eighth case report of a pediatric dissecting posterior inferior cerebellar artery aneurysm. The authors present the case of a 13-year-old boy who presented with posttraumatic posterior fossa subdural, subarachnoid, and intraventricular hemorrhage with hydrocephalus. Initial vascular imaging findings were negative; however, a high level of suspicion is necessary. The aneurysm was identified on day 20, after recurrence of hydrocephalus, and was treated with endovascular vessel sacrifice. The patient made a good recovery. It is important to consider arterial dissection in pediatric traumatic brain injury, especially with suspicious findings on initial CT scan and clinical presentation out of proportion to the mechanism of injury. Delayed vascular imaging is imperative for appropriate management.

Management of cerebral venous thrombosis in a patient with Lane-Hamilton syndrome and coeliac disease, epilepsy and cerebral calcification syndrome.

We describe a case of cerebral venous thrombosis presenting in a patient with Lane-Hamilton syndrome and coeliac disease epilepsy cerebral calcification syndrome. This is a first reported occurrence of this combination. Delayed anticoagulation with early external ventricular drain insertion for life-threatening raised intracranial pressure resulted in a successful outcome.

A 5-year retrospective study assessing the association between seasonal and meteorological change and incidence of aneurysmal subarachnoid haemorrhage.

OBJECTIVE: Seasonal variation in incidence of spontaneous subarachnoid haemorrhage (SAH) is well recognised. This retrospective single-centre study aimed to characterise seasonality of SAH in the temperate climate of London, UK and to determine associations of incidence with meteorological variables. We further investigated whether associations vary according to location of aneurysm. METHODS: Admission data on 647 patients admitted with spontaneous SAH from December 2003 to August 2008 was analysed using our neurosurgical referrals database. Average monthly incidence of SAH was correlated with local temperature, atmospheric pressure and humidity data. In a subset of 467 patients, impact of aneurysm location on seasonal variation was evaluated. RESULTS: A non-significant bi-annual peak incidence was observed in Spring and Autumn with a trough in Summer (chi(2) = 1.5, p = 0.47). This trend was particularly marked with middle cerebral and posterior communicating artery aneurysms. However, anterior communicating artery aneurysmal SAH peaked in Summer only. SAH incidence correlated significantly with average humidity (coefficient 0.213, CI (0.02-0.404), p = 0.035) and peak humidity (coefficient 0.128, CI (0.008-0.248), p = 0.041). Temperature and atmospheric pressure did not correlate with incidence. CONCLUSIONS: This study illustrates a pattern of variation in SAH incidence similar to that seen in other populations and climates. However, our data suggests that this pattern differs according to aneurysm location. Unusually, we also find that humidity, and not temperature or atmospheric pressure, correlates with SAH incidence. Seasonal variability in aneurysm rupture is likely to be multifactorial, but meteorological factors may play an important role.

The utility of brain biopsy in pediatric cryptogenic neurological disease.

OBJECTIVE: The authors' aim was to characterize a single-center experience of brain biopsy in pediatric cryptogenic neurological disease. METHODS: The authors performed a retrospective review of consecutive brain biopsies at a tertiary pediatric neurosciences unit between 1997 and 2017. Children < 18 years undergoing biopsy for neurological pathology were included. Those with presumed neoplasms and biopsy performed in the context of epilepsy surgery were excluded. RESULTS: Forty-nine biopsies in 47 patients (25 females, mean age ± SD 9.0 ± 5.3 years) were performed during the study period. The most common presenting symptoms were focal neurological deficit (28.6%) and focal seizure (26.5%). Histopathological, microbiological, and genetic analyses of biopsy material were contributory to the diagnosis in 34 cases (69.4%). Children presenting with focal seizures or with diffuse (> 3 lesions) brain involvement on MRI were more likely to yield a diagnosis at biopsy (OR 3.07 and 2.4, respectively). Twelve patients were immunocompromised and were more likely to yield a diagnosis at biopsy (OR 6.7). Surgery was accompanied by severe complications in 1 patient. The most common final diagnoses were infective (16/49, 32.7%), followed by chronic inflammatory processes (10/49, 20.4%) and occult neoplastic disease (9/49, 18.4%). In 38 cases (77.6%), biopsy was considered to have altered clinical management. CONCLUSIONS: Brain biopsy for cryptogenic neurological disease in children was contributory to the diagnosis in 69.4% of cases and changed clinical management in 77.6%. Biopsy most commonly revealed underlying infective processes, chronic inflammatory changes, or occult neoplastic disease. Although generally safe, the risk of severe complications may be higher in immunocompromised and myelosuppressed children.

Deep brain stimulation for cluster headache.

Cluster headache is a severely debilitating disorder that can remain unrelieved by current pharmacotherapy. Alongside ablative neurosurgical procedures, neuromodulatory treatments of deep brain stimulation (DBS) and occipital nerve simulation have emerged in the last few years as effective treatments for medically refractory cluster headaches. Pioneers in the field have sought to publish guidelines for neurosurgical treatment; however, only small case series with limited long-term follow-up have been published. Controversy remains over which surgical treatments are best and in which circumstances to intervene. Here we review current data on neurosurgical interventions for chronic cluster headache focusing upon DBS and occipital nerve stimulation, and discuss the indications for and putative mechanisms of DBS including translational insights from functional neuroimaging, diffusion weighted tractography, magnetoencephalography and invasive neurophysiology.

The management and outcome for patients with chronic subdural hematoma: a prospective, multicenter, observational cohort study in the United Kingdom.

OBJECTIVE: Symptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH. METHODS: Data on management and outcomes for patients with CSDH referred to UK and Ireland NSUs were collected prospectively over an 8-month period and audited against criteria predefined from the literature: NSU mortality < 5%, NSU morbidity < 10%, symptomatic recurrence within 60 days requiring repeat surgery < 20%, and unfavorable functional status (modified Rankin Scale score of 4-6) at NSU discharge < 30%. RESULTS: Data from 1205 patients in 26 NSUs were collected. Bur-hole craniostomy was the most common procedure (89%), and symptomatic recurrence requiring repeat surgery within 60 days was observed in 9% of patients. Criteria on mortality (2%), rate of recurrence (9%), and unfavorable functional outcome (22%) were met, but morbidity was greater than expected (14%). Multivariate analysis demonstrated that failure to insert a drain intraoperatively independently predicted recurrence and unfavorable functional outcome (p = 0.011 and p = 0.048, respectively). Increasing patient age (p < 0.00001), postoperative bed rest (p = 0.019), and use of a single bur hole (p = 0.020) independently predicted unfavorable functional outcomes, but prescription of high-flow oxygen or preoperative use of antiplatelet medications did not. CONCLUSIONS: This is the largest prospective CSDH study and helps establish national standards. It has confirmed in a real-world setting the effectiveness of placing a subdural drain. This study identified a number of modifiable prognostic factors but questions the necessity of some common aspects of CSDH management, such as enforced postoperative bed rest. Future studies should seek to establish how practitioners can optimize perioperative care of patients with CSDH to reduce morbidity as well as minimize CSDH recurrence. The BNTRC is unique worldwide, conducting multicenter trainee-led research and audits. This study demonstrates that collaborative research networks are powerful tools to interrogate clinical research questions.

The management and outcome for patients with chronic subdural hematoma: a prospective, multicenter, observational cohort study in the United Kingdom.

OBJECTIVE Symptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH. METHODS Data on management and outcomes for patients with CSDH referred to UK and Ireland NSUs were collected prospectively over an 8-month period and audited against criteria predefined from the literature: NSU mortality < 5%, NSU morbidity < 10%, symptomatic recurrence within 60 days requiring repeat surgery < 20%, and unfavorable functional status (modified Rankin Scale score of 4-6) at NSU discharge < 30%. RESULTS Data from 1205 patients in 26 NSUs were collected. Bur-hole craniostomy was the most common procedure (89%), and symptomatic recurrence requiring repeat surgery within 60 days was observed in 9% of patients. Criteria on mortality (2%), rate of recurrence (9%), and unfavorable functional outcome (22%) were met, but morbidity was greater than expected (14%). Multivariate analysis demonstrated that failure to insert a drain intraoperatively independently predicted recurrence and unfavorable functional outcome (p = 0.011 and p = 0.048, respectively). Increasing patient age (p < 0.00001), postoperative bed rest (p = 0.019), and use of a single bur hole (p = 0.020) independently predicted unfavorable functional outcomes, but prescription of high-flow oxygen or preoperative use of antiplatelet medications did not. CONCLUSIONS This is the largest prospective CSDH study and helps establish national standards. It has confirmed in a real-world setting the effectiveness of placing a subdural drain. This study identified a number of modifiable prognostic factors but questions the necessity of some common aspects of CSDH management, such as enforced postoperative bed rest. Future studies should seek to establish how practitioners can optimize perioperative care of patients with CSDH to reduce morbidity as well as minimize CSDH recurrence. The BNTRC is unique worldwide, conducting multicenter trainee-led research and audits. This study demonstrates that collaborative research networks are powerful tools to interrogate clinical research questions.