Cerebrospinal fluid production rate in various pathological conditions: a preliminary study.

INTRODUCTION: The cerebrospinal fluid (CSF) production rate in humans is not clearly defined but is estimated to be 18-24 ml/h (Trevisi et al Croat Med J 55(4):377-387 (24); Casey and Vries Childs Nerv Syst 5(5):332-334 (8)). A frequent clinical observation is that patients often drain higher volumes of CSF than can be explained by the assumed 'normal' CSF production rate (PRcsf). In the National Hospital for Neurology and Neurosurgery PRcsf was recorded in a variety of common neurosurgical pathologies using LiquoGuard7, an automated peristaltic pump that accurately controls CSF drainage and maintains a pre-set CSF pressure. METHODS: A prospective observational study was performed from September 2021 onwards, on all patients in the National Hospital for Neurology and Neurosurgery who required CSF drainage as part of their ongoing treatment. The external drain was connected to a LiquoGuard7 pump (Möller Medical GmbH, Fulda, Germany), and the internal software of LiquoGuard7 was used to measure PRcsf. Statistical analysis used SPSS (version 25.0, IBM) by paired t test, comparing measured rates to hypothetical 'normal' CSF production rates calculated and published by Ekstedt (16-34ml/h) (Ekstedt J Neurol Neurosurg Psychiatry 41(4):345-353 (14)), assuming a similar distribution. RESULTS: PRcsf was calculated in 164 patients. Suspected normal pressure hydrocephalus (n=41): PRcsf of 79ml/h±20SD (p<0.0001). Post-surgical CSF leak (n=26): PRcsf of 90ml/h±20SD (p<0.0001). Subarachnoid haemorrhage (n=34): PRcsf of 143ml/h±9SD (p<0.0001). Intracerebral haemorrhage (n=22): PRcsf of 137ml/h±20SD (p<0.0001). Spinal lesions (n=7): PRcsf of 130ml/h±20SD (p<0.0032). Pituitary adenomas (n=10): PRcsf of 29 ml/h±9SD (p<0.049). Idiopathic intracranial hypertension (n=15): PRcsf of 86ml/h±10SD (p<0.0001). Decompensated long-standing overt ventriculomegaly (n=4): PRcsf of 65ml/h±10SD (p<0.0001). Cerebral infection (n=5): PRcsf of 90ml/h±20SD (p<0.0001). CONCLUSION: Net CSF production rate may be higher than expected in many conditions, as measured with new device LiquoGuard7 through the study of net flow rate, which may have implications for clinical decisions on CSF diversion. The conventional understanding of CSF production and circulation does not explain the findings of this study. More extensive studies are needed to validate this technique.

Syringosubarachnoid shunt: insertion technique.

BACKGROUND: Syringomyelia is a rare disorder but its impact on patients' quality of life can be devastating. The exact pathophysiology remains unknown; the syrinx can either be idiopathic or associated with conditions such as Chiari malformation, scoliosis, malignancy, infection and trauma. Several techniques have been described to decompress syringomyelia with distal drainage to the subarachnoid space, pleura or peritoneum. METHOD: We present a modification of the syringosubarachnoid shunt insertion technique with minimal myelotomy and the use of a T shaped shunt which does not require suturing to the pia matter to prevent shunt migration. CONCLUSION: This technique for syringosubarachnoid shunt insertion is likely to prevent shunt migration and scarring whilst minimizing suturing and optimising syrinx decompression.

Protocol for the development of a multidisciplinary clinical practice guideline for the care of patients with chronic subdural haematoma.

Introduction: A common neurosurgical condition, chronic subdural haematoma (cSDH) typically affects older people with other underlying health conditions. The care of this potentially vulnerable cohort is often, however, fragmented and suboptimal. In other complex conditions, multidisciplinary guidelines have transformed patient experience and outcomes, but no such framework exists for cSDH. This paper outlines a protocol to develop the first comprehensive multidisciplinary guideline from diagnosis to long-term recovery with cSDH. Methods: The project will be guided by a steering group of key stakeholders and professional organisations and will feature patient and public involvement. Multidisciplinary thematic working groups will examine key aspects of care to formulate appropriate, patient-centered research questions, targeted with evidence review using the GRADE framework. The working groups will then formulate draft clinical recommendations to be used in a modified Delphi process to build consensus on guideline contents. Conclusions: We present a protocol for the development of a multidisciplinary guideline to inform the care of patients with a cSDH, developed by cross-disciplinary working groups and arrived at through a consensus-building process, including a modified online Delphi.

Retrospective review of the epidemiology, microbiology, management and outcomes of intra-cranial abscesses at a neurosurgical tertiary referral centre, 2018-2020.

BACKGROUND: Intracranial abscesses are rare but serious, and are associated with significant morbidity and mortality. Due to both the rarity and severity of these infections, well-controlled trials have not been reported in the literature, and optimal management is a matter for expert opinion. Advances in surgical management have improved outcomes and increased rates of microbiological diagnosis. However, the approach to antimicrobial chemotherapy varies considerably, including the choice of antibiotic, the duration of treatment, and the timing of oral switch. METHODS: We conducted a retrospective review of 43 cases of intracranial abscesses from a large, tertiary neurosurgical centre in London, UK, between 2018 and 2020, including 29 primary intra-parenchymal abscesses, 11 subdural abscesses and 3 extradural abscesses. RESULTS: The majority of cases had surgical intervention; 6/43 (14%) required repeat intervention (all intra-parenchymal abscesses). A microbiological diagnosis was made in 83% of cases. Intravenous antibiotics were given for a median of 33 days (IQR 23-44 days), with a variable duration of oral follow-on antibiotics. Total duration of antibiotic treatment ranged from 0 to 467 days. Only three patients from our cohort are known to have died. CONCLUSION: Shorter courses of intravenous antibiotics for brain abscesses were not associated with increased mortality. In the absence of well-controlled trials, a national registry of intracranial abscesses would provide invaluable data to inform optimal treatment.

Safety of Endoscopic Transsphenoidal Pituitary Surgery during the COVID-19 Pandemic and Comparison to the Pre-Pandemic Era.

Objective The COVID-19 pandemic has caused significant disruption to the surgical care of patients with pituitary tumors. Guidance issued early during the pandemic suggested avoiding transnasal approaches to minimize risks of transmitting COVID-19 to health care professionals involved in these procedures. Methods This observational, single-center study compares results of endoscopic transsphenoidal approach (TSA) for pituitary tumors since the start of the pandemic to a pre-pandemic period. Anesthetic time, surgical time, and complication rates were compared. Newly acquired COVID-19 infections and transmission rates to patients and staff were reviewed. Data were analyzed by using the independent t -test, Mann-Whitney U test, and Pearson Chi-square test, significance set at p <0.05. Results Over a 12-month period, a total of 50 and 69 patients underwent endoscopic TSA for pituitary tumor during and before the pandemic, respectively. All patients tested negative for COVID-19 preoperatively. Median duration of anesthesia was 35 minutes (interquartile range [IQR]: 22) during the pandemic and 25 minutes (IQR: 8, p = 0.0002) pre-pandemic. Median duration of surgery was 70 minutes (IQR: 28) during the pandemic and 79 minutes (IQR: 33.75, p = 0.126) pre-pandemic. There were no statistically significant differences between intraoperative CSF leaks and complication rates. No staff members tested positive for COVID-19. Three patients tested positive for COVID-19 postdischarge, but the infections were community acquired. Conclusion In contrast to published guidelines, adequate preoperative testing, a multidisciplinary approach and the implementation of standardized protocols and vaccination against COVID-19 allow for endoscopic transsphenoidal surgery to be performed safely in patients with pituitary pathology during the pandemic.

Ultrasound guided brain abscess aspiration.

A brain abscess is a neurosurgical emergency and frequently requires drainage to relieve intracranial pressure and identify the offending organism. Surgical adjuncts including neuronavigation and intra-operative CT and MRI facilitate surgery, but have limitations, including cost and not offering real time intracranial views. Intra-operative ultrasound is a fast and relatively cheap tool which offers live, real time imaging and visualisation of an abscess being aspirated, but is less frequently used. We describe our technique of ultrasound guidance as an adjunct with neuronavigation for brain abscess aspiration, review the literature on surgical adjuncts and remind the neurosurgical community of its value in this and other cranial procedures. We summarise our recent experience in its use in six patients with a brain abscess. There is a learning curve to using intra-operative ultrasound, but we recommend its routine use in abscess drainage surgery.

Women in neurosurgery: where does the United Kingdom stand?

Despite over half of medical students in the United Kingdom (UK) being female, women represent only a small proportion of the workforce in the traditional "male" specialties, including neurosurgery. There is increasing global attention to and awareness of gender discrimination in the workplace across several industries, including health care. The authors set out to explore the opinions and attitudes of UK neurosurgeons and neurosurgery trainees on gender issues via a large-scale national survey. The results highlight key perceptions and gaps in mentorship and leadership and provide ideas for change. This should be used as a foundation to delve deeper and to address specific questions in order to achieve a fairer, more meritocratic environment in which neurosurgeons can thrive.

Giant thoracic discs: treatment, outcome, and follow-up of 33 patients in a single centre.

PURPOSE: To help guide treatment strategies and create insight into functional outcomes in patients with Giant herniated thoracic discs (GHTD), which are defined as occupying more than 40% of spinal canal. METHODS: Authors did a retrospective analysis of prospective cohort of 33 cases of GHTD, using clinical letters, notes, and telephonic questionnaires to determine their pre and postoperative functional status, surgical details, and complication rates. 16 males and 17 females operated between 2006 and 2014 were included in the study. A total of 23 patients underwent thoracotomy, 9 costotransversectomy, and 2 transpedicular approaches for excision of thoracic discs. Neuromonitoring was used in seven patients. RESULTS: Frankel grade improved by 1 in 13 patients and by 2 in 1 patient. One patient of T11/12 GHTD with neurogenic claudication recovered completely, taking the overall improvement rate to 45.5%. It remained static in 15 patients (45.5%) and deteriorated by 1 in 3 patients (9%). By mJOA scoring too, the outcome was favorable in majority (84.4%) of patients. There were three intraoperative complications (9%), which included two incidental durotomies and one massive blood loss. Late postoperative complications were seen in 12(39%) patients. They included intercostal neuralgia, mechanical pain around costotransversectomy, progressive thoracic paraplegia due to spinal cord herniation and residual disc fragments, reactive pleural effusion, CSF fistula induced pleural effusion, and infective discitis. CONCLUSIONS: Surgery for giant herniated thoracic disc has favorable outcome in majority (91%) of patients. However, significant approach-related complications are to be anticipated in patients undergoing thoracotomies, most of them being manageable. Author recommends costotransversectomy, only in paracentral discs with smaller percentage canal stenosis.

Referrers' point of view on the referral process to neurosurgery and opinions on neurosurgeons: a large-scale regional survey in the UK.

OBJECTIVES: There is an increased reliance on online referral systems (ORS) within neurosurgical departments across the UK. Opinions of neurosurgeons on ORS are extensively reported but those of referrers have hardly been sought. Our study aims at ascertaining our referring colleagues' views on our ORS and its impact on patient care, their opinions on neurosurgeons and how to improve our referral process. SETTING: 14 district general hospitals and one teaching hospital. PARTICIPANTS: 641 healthcare professionals across a range of medical and surgical specialties including doctors of all grades, nurses and physiotherapists. Survey responses were obtained by medical students using a smartphone application. RESULTS: Although 92% of respondents were aware of the ORS, 74% would routinely phone the on-call registrar either before or after making referrals online. The majority (44%) believed their call to relate to a life-threatening emergency. 62% of referrers considered the ORS helpful in informing patients' care and 48% had a positive opinion of their interaction with neurosurgical registrars. On ways to improve the ORS, 50% selected email/text confirmation of response sent to referrers and 16% to referring consultants. CONCLUSION: Our results confirm that referrers feel that using our ORS positively impacts patient care but that it remains in need of improvement in order to better suit our colleagues' needs when it comes to managing neurosurgical patients. We feel that the promotion of neurosurgical education and mitigation of the effects of adverse workplace human factors are likely to achieve the common goal of neurosurgeons and referrers alike: a high standard in patient care.

Spinal epidural haematoma following thrombolysis for acute ischaemic stroke in patient within 48h of emergency lumbar microdiscectomy.

The ideal regimen and the optimal starting point for thromboembolic prophylaxis in spinal procedures remain unclear. We report a case of postoperative spinal epidural haematoma following thrombolysis for stroke in patient within 48 h of emergency lumbar microdiscectomy. Thrombolysis should be considered in patients with spinal surgery who developed arterial cerebral thrombosis.

Intracranial stimulation for children with epilepsy.

OBJECTIVES: To evaluate the efficacy of intracranial stimulation to treat refractory epilepsy in children. METHODS: This is a retrospective analysis of a pilot study on all 8 children who had intracranial electrical stimulation for the investigation and treatment of refractory epilepsy at King's College Hospital between 2014 and 2015. Five children (one with temporal lobe epilepsy and four with frontal lobe epilepsy) had subacute cortical stimulation (SCS) for a period of 20-161 h during intracranial video-telemetry. Efficacy of stimulation was evaluated by counting interictal discharges and seizures. Two children had thalamic deep brain stimulation (DBS) of the centromedian nucleus (one with idiopathic generalized epilepsy, one with presumed symptomatic generalized epilepsy), and one child on the anterior nucleus (right fronto-temporal epilepsy). The incidence of interictal discharges was evaluated visually and quantified automatically. RESULTS: Among the three children with DBS, two had >60% improvement in seizure frequency and severity and one had no improvement. Among the five children with SCS, four showed improvement in seizure frequency (>50%) and one chid did not show improvement. Procedures were well tolerated by children. CONCLUSION: Cortical and thalamic stimulation appear to be effective and well tolerated in children with refractory epilepsy. SCS can be used to identify the focus and predict the effects of resective surgery or chronic cortical stimulation. Further larger studies are necessary.