In-House Intraoperative Monitoring in Neurosurgery in England - Benefits and Challenges.

BACKGROUND: Intraoperative neurophysiological monitoring (IOM) is a valuable adjunct for neurosurgical operative techniques, and has been shown to improve clinical outcomes in cranial and spinal surgery. It is not necessarily provided by NHS hospitals so may be outsourced to private companies, which are expensive and at cost to the NHS trusts. We discuss the benefits and challenges of developing an in-house service. METHODS: We surveyed NHS neurosurgical departments across England regarding their expenditure on IOM over the period January 2018 - December 2022 on cranial neurosurgery and spinal surgery. Out of 24 units, all responded to our Freedom of Information requests and 21 provided data. The standard NHS England salary of NHS staff who would normally be involved in IOM, including physiologists and doctors, was also compiled for comparison. RESULTS: The total spend on outsourced IOM, across the units who responded, was over £8 million in total for the four years. The annual total increased, between 2018 and 2022, from £1.1 to £3.5 million. The highest single unit yearly spend was £568,462. This is in addition to salaries for staff in neurophysiology departments. The mean NHS salaries for staff is also presented. CONCLUSION: IOM is valuable in surgical decision-making, planning, and technique, having been shown to lead to fewer patient complications and shorter length of stay. Current demand for IOM outstrips the internal NHS provision in many trusts across England, leading to outsourcing to private companies. This is at significant cost to the NHS. Although there is a learning curve, there are many benefits to in-house provision, such as stable working relationships, consistent methods, training of the future IOM workforce, and reduced long-term costs, which planned expansion of NHS services may provide.

Traumatic arteriovenous fistula from internal maxillary artery following trigeminal balloon compression.

We describe the development of a direct traumatic arteriovenous fistula arising from the internal maxillary artery after an uneventful percutaneous trigeminal balloon compression for trigeminal neuralgia, and its management through embolization and radiosurgery.

Patient selection and outcome of deep brain stimulation for multiple sclerosis-associated tremor.

INTRODUCTION: Tremor is a disabling symptom of multiple sclerosis (MS), with limited treatment modalities. Thalamic ventral-intermediate-nucleus (VIM) deep brain stimulation (DBS) is a method of neuromodulation. We describe the long-term outcomes of our carefully selected patients who underwent VIM DBS for their MS-associated tremor. METHODS: Patients were referred from the regional neurology units. Pre-operative assessments included suitability for anesthesia, tremor quantification by the Fahn-Tolosa-Marin scores, and quality-of-life (EQ5D) measures. Exclusion criteria included prominent cerebellar symptoms such as ataxia and dysmetria, intracranial pathology such as ventriculomegaly, cerebellar plaques and thalamic abnormality, and comorbid psychiatric symptoms. Seven patients (3M:4F) underwent DBS for MS-associated tremor between September 2013 and February 2019. Mean age was 42 years (±SD 8 years). DBS was performed at a mean of 13 years (±SD 9 years) after diagnosis of MS. RESULTS: There were no postoperative surgical complications. All patients showed improvement in FTM tremor scores, by up to 61% at 6 months postoperatively. There was an improvement of 30-175% in quality-of-life scores at 6 months. Improvement of tremor and quality of life, over baseline, was sustained over a long period of follow-up (mean 26.6 months ± SD 20.7 months), including our longest duration at 72 months. CONCLUSION: With careful selection, DBS is a safe, efficacious intervention for MS-tremor and can positively impact on tremor and quality of life, with effects over a long period. As patients live longer with MS and the advent of new therapies, DBS should be considered for selected patients.

Delayed presentation of bamboo foreign body in brainstem, with novel skull base foramen.

We describe the extremely unusual case of a childhood injury to the skull base presenting after many years, as a foreign body with chronic granulomatous infection of the brainstem, mimicking neoplasm. TB had an inconsequential penetrating injury to the left cheek, from a bamboo spike aged 15. After 4 years, he developed worsening left sided weakness, imaging at this time was normal. After a car accident aged 40, the weakness worsened further and imaging demonstrated a foreign body entering the skull base. At its tip, it had caused a chronic granulomatous reaction within the brainstem. Surgical removal of this bamboo splinter was via an infratemporal, transzygomatic craniotomy and TB made a good recovery postoperatively. This unusual case demonstrates the important of close inspection of imaging, and thorough history taking. It also questions the chronology of the ossification of the skull base.

Percutaneous retrogasserian glycerol rhizotomy for trigeminal neuralgia: an alternative technique.

Background: One of the challenges faced by the modern-day NHS is workplace shortages, and experienced radiographers for intra-operative neurosurgical imaging is one such scenario. We describe our method for Percutaneous Retrogasserian Glycerol Rhizotomy (PRGR) using frameless neuronavigation which can be used effectively in such scenarios.Method: Stealth neuronavigation is used for needle placement within the foramen ovale and injection of glycerol, under sedation.Results: In our experience of ten procedures, it is accurate, safe and effective. Good results were obtained on all occasions. It can be repeated as often as necessary using the same Stealth® CT scan and reduces exposure for staff and patients, where repeated injections are required.Conclusion: This simple modification of PRGR technique is effective and safe provided the surgeon has previous experience in undertaking this procedure.

Early mobilisation does not increase the complication rate from unintended lumbar durotomy.

BACKGROUND: Unintended durotomy is a well-recognised complication of lumbar spine surgery. Reported complications include headaches, intracranial haematomata, pseudomeningocoele and infection. Methods of intraoperative repair vary and although post-operative flat bed rest is advocated by some, there is no consensus on duration. We reviewed a series of unintended durotomies that occurred in our institution and reviewed them to compare management strategies and outcome. METHODS: A retrospective analysis was conducted of adult patients who experienced an unintended durotomy during surgery for lumbar degenerative disease in our neurosurgical unit over a 15-month period. Post-operative complications were followed up for a minimum of 3 months. RESULTS: 1125 patients underwent elective or emergency decompressive lumbar spine surgery. 45 (4%) dural tears were identified; all were repaired intra-operatively with suturing, Tisseal thrombin glue or both. Absence of leakage was confirmed on Valsalva manoeuvre for all cases, before wound closure. 28 patients were mobilised within 24 hrs of surgery, 16 patients between 24-48 hours and 1 patient after 48 hours. Seven patients (16%) with a dural tear experienced a complication. There was no statistically significant relationship between time to post-operative mobilisation and complication rate (p = .76). There was a significantly longer inpatient stay when patients were on bed rest for longer (2 tailed test significant at the 2% level). CONCLUSION: Duration of post-operative bed rest was not related to complication rate but led to delays in discharge. We did not find evidence that early mobilisation lead to increased likelihood of complications.

Anterior cingulotomy improves malignant mesothelioma pain and dyspnoea.

BACKGROUND: Bilateral anterior cingulotomy is a palliative procedure occasionally used for cancer pain, and human studies suggest anterior cingulate cortex is active in dyspnoeic states. OBJECTIVES: A case of debilitating thoracic wall pain due to malignant mesothelioma relieved by bilateral anterior cingulotomy is described and changes in dyspnoea investigated. RESULTS: Improvements in pain, dyspnoea and the extent to which either symptom bothered the patient was seen for 2 months after surgery before disease progression led to death 5 months after surgery. Quality of life improvements were also seen for 2 months after surgery and pain relief was sustained from surgery to death. Arterial blood gas and lung function tests were unchanged by surgery, suggesting a reduction in pain and dyspnoea awareness by cingulotomy. CONCLUSIONS: Bilateral anterior cingulotomy effectively relieved both pain and dyspnoea. The role of the anterior cingulate cortex in pain and autonomic control of respiration is discussed alongside the evidence for this palliative procedure for cancer pain.

Transsphenoidal pituitary surgery in the elderly is safe and effective.

OBJECT: With an increasingly ageing population, the number of elderly people diagnosed with pituitary tumours continues to rise. There is a concern that with increasing age and comorbidities, there is higher anaesthetic risk, as well as peri-operative morbidity and mortality from pituitary surgery. This study aimed to audit the benefits and complications of transsphenoidal surgery performed in a large pituitary centre in elderly patients. METHODS: Data on all elderly patients (age: ≥ 70 years) undergoing transsphenoidal surgery at a large tertiary referral centre between November 2003 and August 2012 were collected retrospectively. RESULTS: A total of 104 operations were performed on 102 patients during 106 months. Median age was 75.2 years (range: 70-94) and 63 (61%) of the patients were male. Median follow-up was 15.2 months (range: 2.3-84.4). The majority presented with either peripheral visual field defects (26.4%) or pituitary hormone deficits (17.9%). A significant number (21.7%) of tumours were incidental radiological findings while investigating other diagnoses like stroke and dementia. 48.1% of operations were undertaken microscopically and the remaining 51.9% were endoscopic. Median hospital stay was 4 days (range: 3-18). Intra-operative complications included hypotension (1.9%) and blood loss requiring transfusion (2.9%). The 30-day complications included transient diabetes insipidus (9.6%), syndrome of inappropriate anti-diuretic hormone secretion (8.7%), delayed cerebrospinal fluid leak requiring lumbar drainage (0.9%) with no patient requiring formal repair. There were no peri-operative deaths. Long-term assessment suggested 79% had improved or stable endocrine function with 7% achieving biochemical cure and 91% showed improved or stable visual fields. CONCLUSIONS: Pituitary surgery in the elderly, whether microscopic or endoscopic, has low morbidity and mortality and is a safe and effective intervention for both symptom control and functional outcomes.

Neurological update: structural and functional imaging in epilepsy surgery.

Structural and functional imaging prior to surgery in drug-resistant focal epilepsy, has an important role to play alongside electroencephalography (EEG) techniques, in planning the surgical approach and predicting post-operative outcome. This paper reviews the role of structural and functional imaging of the brain, namely computed tomography (CT), magnetic resonance imaging (MRI), functional MRI (fMRI), single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging in the preoperative work-up of people with medically refractory epilepsy. In MRI-negative patients, the precise localisation of the epileptogenic zone may be established by demonstrating hypometabolism on PET imaging or hyperperfusion on SPECT imaging in the area surrounding the seizure focus. These imaging modalities are far less invasive than intracranial EEG, which is the gold standard but requires surgical placement of electrodes or recording grids. Even when intracranial EEG is needed, PET or SPECT imaging can assist in the planning of EEG electrode placement, due to its' limited spatial sampling. Multimodal imaging techniques now allow the multidisciplinary epilepsy surgery team to identify and better characterise focal pathology, determine its' relationship to eloquent areas of the brain and the degree of interconnectedness within both physiological and pathological networks, as well as improve planning and surgical outcomes for patients. This paper will update the reader on this whole field and provide them with a practical guide, to aid them in the selection of appropriate investigations, interpretation of the findings and facilitating patient discussions in individuals with drug-resistant focal epilepsy.

Use of an Online Referral Service for Acute Neurosurgical Referrals: An Institutional Experience.

OBJECTIVE: We sought to review the current scope of emergency neurosurgical referrals and examine the long-term use of a web-based referral system. METHODS: This was a single-center retrospective observational study. Referral information was collected retrospectively over a 1-year period after the implementation of a web-based referral system (June 2019-June 2020). Information such as demographics, clinical information, referrer details, and neurosurgical response times and outcomes were collected. Statistical analyses were performed using R Version 6.3.1. RESULTS: Our unit received 5949 referrals with a median age of 63 years old (range: 0-107 years) (male = 50.3%). We observed an average of 16.3 referrals per day (range: 4-32), with Fridays having the highest average and the weekend days receiving statistically fewer referrals (P < 0.001). More than a third (35.9%) of referrals occurred within hours (8:00-17:00 Monday-Friday), with A + E making up approximately 50% of referrals. Common reasons for referral were traumatic brain injury, intracranial tumors, and degenerative spine. The median time from referral to first response was 32 minutes, occurring within an hour in 72.9% of cases. The median time to definite response was 83 minutes, occurring within 2 hours in 58.2% of cases. Factors found to impact the response time were referral emergency and time of day. Our acceptance rate over this period was 18.5%. CONCLUSIONS: With an increasing number of referrals, it is feasible to provide traceable advice in a timely manner through an electronic web-based referral system transferable to any specialty. Insights could be used to direct resources and workforce planning according to emergency referral patterns.

Neurogenic Cough Associated with Hyperintensity in Dorsal Medulla: Case Report and Anatomical Discussion.

BACKGROUND: The nucleus tractus solitarius and paratrigeminal nucleus, which are implicated in the processing of airway-derived sensory information, are found in the dorsal medulla. The mechanism and localization of higher-order processing of urge to cough is poorly understood, and much of the existing anatomical localization is limited to animal studies. CASE DESCRIPTION: A 44-year-old Caucasian lady underwent elective foramen magnum decompression for symptomatic Chiari I malformation; postoperatively she had resolution of Chiari symptoms but developed an intractable neurogenic cough. She has no significant medical history or premorbid respiratory issues. Postoperative magnetic resonance imaging of her head demonstrated signal change in the left dorsal medulla, corresponding with the nucleus tractus solitarius and paratrigeminal nucleus. CONCLUSIONS: We suggest that this lesion explains her isolated new cough and localizes the pathway for "urge to cough" to this region of the medulla.

Neurosurgical Referral Patterns During the Coronavirus Disease 2019 Pandemic: A United Kingdom Experience.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a severe respiratory viral illness that has spread rapidly across the world. However, the United Kingdom has been particularly affected. Evidence has suggested that stroke, cardiac, and spinal presentations decreased during the pandemic as the public avoided seeking care. The effect on neurosurgical presentations and referrals during COVID-19 is unclear. Our aim, therefore, was to describe the referral patterns to a high-volume neurosurgical department in the United Kingdom during the COVID-19 pandemic. METHODS: Electronic referrals were identified from the referrals database from January 1, 2020 to May 31, 2020, inclusive, with January used as the baseline. The demographic data and referral diagnoses were captured on Excel (Microsoft, Redmond, Washington, USA). Statistical analyses were performed using SPSS, version 22 (IBM Corp., Armonk, New York, USA). Differences between referral volumes were evaluated using χ2 goodness-of-fit tests. RESULTS: A total of 2293 electronic referrals had been received during the study period. The median age was 63 years. Overall, the referrals had decreased significantly in volume during the study period [χ2(4) = 60.95; P < 0.001]. We have described the patterns in the daily referrals as the pandemic progressed. The reduction in the volume of referrals for degenerative spine cases and traumatic brain injuries was statistically significant (P < 0.001). CONCLUSIONS: The referrals for degenerative spine and traumatic brain injuries decreased significantly during the pandemic, which can be explained by the lower vehicular traffic and patient avoidance of healthcare services, respectively. The risk of neurological deterioration and increased morbidity and mortality, as a consequence, is of concern, and neurosurgeons worldwide should consider the optimal strategies to mitigate these risks as the pandemic eases.

Idiopathic normal pressure hydrocephalus: an important differential diagnosis.

Idiopathic normal pressure hydrocephalus, an uncommon but important differential diagnosis for ataxia, cognitive impairment and urinary incontinence, is surgically treatable, unlike many of its differential diagnoses. This article discusses its assessment, investigation and therapeutic interventions.