Background: Neurological immune related adverse events (N-irAEs) following immune checkpoint inhibitor (ICI) therapy are associated with significant morbidity and mortality. The early involvement of neurological services is therefore recommended to assist diagnosis and guide management. However, the practical experience of specialist neurology involvement is poorly understood. Methods: A multi-centre, retrospective case note review was performed in a unified healthcare setting in the United Kingdom via predetermined proforma to investigate the involvement and impact of neurology services in this setting. Results: One hundred and nine patients with N-irAE were identified with a median time from ICI treatment to symptom onset of 52 days. Neurology service models, reasons for referral and referral rates varied by centre. Overall, eighty-seven (79.8%) patients (range 52.9–100% by centre) had neurology involvement. Neurology input was associated with younger age (median 67.2 vs. 72.8 years), anatomical location (Central > Peripheral) and severity of neurotoxicity (p < 0.001, q < 0.004). Patients with neurology involvement were more likely to undergo specialist investigations: MR imaging (p = 0.041, q = 0.043), lumbar puncture (p < 0.001, q < 0.004), and neurophysiology (p = 0.005, q = 0.007) resulting in a broader range of specific N-irAE diagnoses. Steroids were appropriately prescribed, with second line treatment (Intravenous immunoglobulins/Plasma exchange) associated with neurology involvement. At lower grades (CTCAE ≤ 2), resolution rates were similar in those with or without neurology involvement. At grades 3–4, one-third of patients with neurology involvement had resolution. In a centre with a model of early neurology involvement for all possible N-irAEs the aetiology of the neurological presentation was changed in 63.7%. Conclusions: This study highlights the potential to improve diagnosis and treatment algorithms and therefore patient outcomes through development of uniform N-irAE models of care to support this area of growing clinical need.

Background Cenobamate is a newly licensed anti-seizure medication (ASM) for refractory epilepsy. We describe Cardiff’s experience. Methods All patients prescribed cenobamate in Cardiff and Vale UHB had their records parsed. Descrip- tive analysis conducted in R (v.4.2.2) Results 69 patients were included (median age: 41 (IQR: 29 – 52), epilepsy onset age: median 15.5 (IQR: 7.25 – 24.5)). 68 had focal seizures and 66 had generalised tonic clonic seizures. Vagal nerve stimulators were present in 15.9% with previous epilepsy surgery in 11.6%. Pre-cenobamate there were a median 15 (IQR: 4 – 30) seizures per month and after 13.5 (IQR: 10.25 – 16). For those with follow up, 77.8% had improved control and 75% are still taking cenobamate. Median 3 (IQR: 2 – 3) other antiseizure medications, most commonly clobazam (40%) and lamotrigine (30%). 17 (20%) took levetiracetam. For those with follow up, 6 (46%) patients were still taking cenobamate despite side effects. Side effects included: fatigue (54%), dysequilibrium (31%), and mood and personality changes (23%) among others. Discussion Cenobamate appears to improve seizure control in our cohort. Further longitudinal data is required to offset censoring bias and assess tolerability, drug-drug interactions, and optimal ASM combinations.

Cerebral amyloid angiopathy (CAA) is usually an agerelated degenerative condition caused by deposition of betaamyloid in the walls of cerebral small vessels.It is associated with micro-haemorrhages, lobar haemorrhages, focal superficial siderosis and changes in cerebral white matter.In addition to a range of persistent and fixed deficits, it can also be associated with transient symptoms commonly referred to as "amyloid spells".As a result, urgent review in Transient Ischaemic Attack (TIA) clinics is common.However, the approach required for the diagnosis and management of these patients can differ substantially from the more traditional assessment offered to patients with common causes of suspected cerebral ischaemia.The gold standard for diagnosis remains histopathological examination, although the Edinburgh and Boston criteria provide clinicians with a probabilistic approach for diagnosis largely based on imaging characteristics.In this month's Journal Club, we review the latest version of the Boston criteria based on Magnetic Resonance Imaging (MRI), the Simplified Edinburgh criteria based on computed tomography (CT) and the use of complement as a potential biomarker in this disease.

BACKGROUND: CRANIAL (CSF Rhinorrhoea After Endo nasal Intervention to the Skull Base) is a prospective multicenter observational study seeking to determine 1) the scope of skull base repair methods used and 2) corresponding rates of postoperative cerebrospinal fluid (CSF) rhinorrhea in the endonasal transsphenoidal approach (TSA) and the expanded endonasal approach (EEA) for skull base tumors. We sought to pilot the project, assessing the feasibility and acceptability by gathering preliminary data. METHODS: A prospective observational cohort study was piloted at 12 tertiary neurosurgical units in the United Kingdom. Feedback regarding project positives and challenges were qualitatively analyzed. RESULTS: A total of 187 cases were included: 159 TSA (85%) and 28 EEA (15%). The most common diseases included pituitary adenomas (n = 142/187), craniopharyngiomas (n = 13/187). and skull base meningiomas (n = 4/187). The most common skull base repair techniques used were tissue glues (n = 132/187, most commonly Tisseel), grafts (n = 94/187, most commonly fat autograft or Spongostan) and vascularized flaps (n = 51/187, most commonly nasoseptal). These repairs were most frequently supported by nasal packs (n = 125/187) and lumbar drains (n = 20/187). Biochemically confirmed CSF rhinorrhea occurred in 6/159 patients undergoing TSA (3.8%) and 2/28 patients undergoing EEA (7.1%). Four patients undergoing TSA (2.5%) and 2 patients undergoing EEA (7.1%) required operative management for CSF rhinorrhea (CSF diversion or direct repair). Qualitative feedback was largely positive (themes included user-friendly and efficient data collection and strong support from senior team members), demonstrating acceptability. CONCLUSIONS: Our pilot experience highlights the acceptability and feasibility of CRANIAL. There is a precedent for multicenter dissemination of this project, to establish a benchmark of contemporary practice in skull base neurosurgery, particularly with respect to patients u ndergoing EEA.

-BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, concerns have been raised regarding the increased risk of perioperative mortality for patients with COVID-19, and the transmission risk to healthcare workers, especially during endonasal neurosurgical operations. The Pituitary Society has produced recom-mendations to guide management during this era. We sought to assess contemporary neurosurgical practice and the effects of COVID-19. -METHODS: A multicenter prospective observational cohort study was conducted at 12 tertiary neurosurgical -nits (United Kingdom and Ireland). Data were collected from March 23 to July 31, 2020, inclusive. The data points collected included patient demographics, preoperative COVID-19 test results, operative modifications, and 30-day COVID-19 infection rates. -RESULTS: A total of 124 patients were included. Of the 124 patients, 116 (94%) had undergone COVID-19 testing preoperatively (transsphenoidal approach, 97 of 105 [92%]; expanded endoscopic endonasal approach, 19 of 19 [100%]). One patient (1 of 116 [0.9%]) had tested positive for COVID-19 preoperatively, requiring a delay in surgery until the infection had been confirmed as resolved. Other than transient diabetes insipidus, no other complications were reported for this patient. All operating room staff had worn at least level 2 personal protective equipment. Adapta-tions to surgical techniques included minimizing drilling, draping modifications, and the use of a nasal iodine wash. At 30 days postoperatively, no evidence of COVID-19 infection (symptoms or positive formal testing results) were found in our cohort and no mortality had occurred. -CONCLUSIONS: Preoperative screening protocols and operative modifications have facilitated endonasal neuro-surgery during the COVID-19 pandemic, with the Pituitary Society guidelines followed for most of these operations. We found no evidence of COVID-19 infection in our cohort and no mortality, supporting the use of risk mitigation strategies to continue endonasal neurosurgery in subse-quent pandemic waves.

Background The endonasal transsphenoidal approach (TSA) has emerged as the preferred approach in order to treat pituitary adenoma and related sellar pathologies. The recently adopted expanded endonasal approach (EEA) has improved access to the ventral skull base whilst retaining the principles of minimally invasive surgery. Despite the advantages these approaches offer, cerebrospinal fluid (CSF) rhinorrhoea remains a common complication. There is currently a lack of comparative evidence to guide the best choice of skull base reconstruction, resulting in considerable heterogeneity of current practice. This study aims to determine: (1) the scope of the methods of skull base repair; and (2) the corresponding rates of postoperative CSF rhinorrhoea in contemporary neurosurgical practice in the UK and Ireland. Methods We will adopt a multicentre, prospective, observational cohort design. All neurosurgical units in the UK and Ireland performing the relevant surgeries (TSA and EEA) will be eligible to participate. Eligible cases will be prospectively recruited over 6 months with 6 months of postoperative follow-up. Data points collected will include: demographics, tumour characteristics, operative data), and postoperative outcomes. Primary outcomes include skull base repair technique and CSF rhinorrhoea (biochemically confirmed and/or requiring intervention) rates. Pooled data will be analysed using descriptive statistics. All skull base repair methods used and CSF leak rates for TSA and EEA will be compared against rates listed in the literature. Ethics and dissemination Formal institutional ethical board review was not required owing to the nature of the study - this was confirmed with the Health Research Authority, UK. Conclusions The need for this multicentre, prospective, observational study is highlighted by the relative paucity of literature and the resultant lack of consensus on the topic. It is hoped that the results will give insight into contemporary practice in the UK and Ireland and will inform future studies.