Thalamostriatal disconnection underpins long-term seizure freedom in frontal lobe epilepsy surgery.

Around 50% of patients undergoing frontal lobe surgery for focal drug-resistant epilepsy become seizure free post-operatively; however, only about 30% of patients remain seizure free in the long-term. Early seizure recurrence is likely to be caused by partial resection of the epileptogenic lesion, whilst delayed seizure recurrence can occur even if the epileptogenic lesion has been completely excised. This suggests a coexistent epileptogenic network facilitating ictogenesis in close or distant dormant epileptic foci. As thalamic and striatal dysregulation can support epileptogenesis and disconnection of cortico-thalamostriatal pathways through hemispherotomy or neuromodulation can improve seizure outcome regardless of focality, we hypothesize that projections from the striatum and the thalamus to the cortex may contribute to this common epileptogenic network. To this end, we retrospectively reviewed a series of 47 consecutive individuals who underwent surgery for drug-resistant frontal lobe epilepsy. We performed voxel-based and tractography disconnectome analyses to investigate shared patterns of disconnection associated with long-term seizure freedom. Seizure freedom after 3 and 5 years was independently associated with disconnection of the anterior thalamic radiation and anterior cortico-striatal projections. This was also confirmed in a subgroup of 29 patients with complete resections, suggesting these pathways may play a critical role in supporting the development of novel epileptic networks. Our study indicates that network dysfunction in frontal lobe epilepsy may extend beyond the resection and putative epileptogenic zone. This may be critical in the pathogenesis of delayed seizure recurrence as thalamic and striatal networks may promote epileptogenesis and disconnection may underpin long-term seizure freedom.

Hippocampal resection in temporal lobe epilepsy: Do we need to resect the tail?

INTRODUCTION: Anteromesial temporal lobe resection is the most common surgical technique used to treat drug-resistant mesial temporal lobe epilepsy, particularly when secondary to hippocampal sclerosis. Structural and functional imaging data suggest the importance of sparing the posterior hippocampus for minimising language and memory deficits. Recent work has challenged the view that maximal posterior hippocampal resection improves seizure outcome. This study was designed to assess whether resection of posterior hippocampal atrophy was associated with improved seizure outcome. METHODS: Retrospective analysis of a prospective database of all anteromesial temporal lobe resections performed in individuals with hippocampal sclerosis at our epilepsy surgery centre, 2013-2021. Pre- and post-operative MRI were reviewed by 2 neurosurgical fellows to assess whether the atrophic segment, displayed by automated hippocampal morphometry, was resected, and ILAE seizure outcomes were collected at 1 year and last clinical follow-up. Data analysis used univariate and binary logistic regression. RESULTS: Sixty consecutive eligible patients were identified of whom 70% were seizure free (ILAE Class 1 & 2) at one year. There was no statistically significant difference in seizure freedom outcomes in patients who had complete resection of atrophic posterior hippocampus or not (Fisher's Exact test statistic 0.69, not significant at p < .05) both at one year, and at last clinical follow-up. In the multivariate analysis only a history of status epilepticus (OR=0.2, 95%CI:0.042-0.955, p = .04) at one year, and pre-operative psychiatric disorder (OR=0.145, 95%CI:0.036-0.588, p = .007) at last clinical follow-up, were associated with a reduced chance of seizure freedom. SIGNIFICANCE: Our data suggest that seizure freedom is not associated with whether or not posterior hippocampal atrophy is resected. This challenges the traditional surgical dogma of maximal posterior hippocampal resection in anteromesial temporal lobe resections and is a step further optimising this surgical procedure to maximise seizure freedom and minimise associated language and memory deficits.

COVID-legal study: neurosurgeon experience in Britain during the first phase of the COVID-19 pandemic - medico-legal considerations.

Introduction: The COVID-19 pandemic has resulted in a significant number of changes to elective and emergency neurosurgical practice.Materials and Methods: This paper reports the results of an online survey of Society of British Neurological Surgeons (SBNS) members undertaken between 10th and 24th of June 2020 regarding changes in consent practice in response to COVID-19, as well as the physical challenges experienced while operating under higher levels of personal protective equipment (PPE).Results: Despite the real and substantial risks associated with COVID-19, 23% of surgeons reported they were not made any changes to their usual consent process, and 54% of surgeons indicated that they made reference to COVID-19-associated risks in their written consent documentation. 93% of neurosurgeons reported physical difficulties operating using PPE; 62% reported visors/goggles fogging up, 55% experienced 'overheating', 62% reported fatigue, and 82% of surgeons reported difficulty communicating with the theatre staff.Conclusions: This survey highlights discrepancies in the consent practice between neurosurgeons which needs to be addressed at both local and national levels. The PPE being used in neurosurgical operations is not designed for use with specialist equipment (82% of respondents reported having to remove PPE to use the microscope) and the reported physical difficulties using PPE intraoperatively could significantly impact on both neurosurgeon performance and patient outcomes. This requires urgent attention by NHS procurement and management and should be urgently escalated to trust occupational health authorities as a workplace safety concern.

Surgical consent practice in the UK following the Montgomery ruling: A national cross-sectional questionnaire study.

BACKGROUND: The Supreme Court case of Montgomery vs Lanarkshire Health Board in 2015 was a landmark case for consent practice in the UK which shifted focus from a traditional paternalistic model of consent towards a more patient-centered approach. Widely recognised as the most significant legal judgment on informed consent in the last 30 years, the case was predicted to have a major impact on the everyday practice of surgeons working in the UK National Health Service (NHS). Two years after the legal definition of informed consent was redefined, we carried out an audit of surgical consent practice across the UK to establish the impact of the Montgomery ruling on clinical practice. MATERIALS & METHODS: Data was collected by distribution of an electronic questionnaire to NHS doctors working in surgical specialities with a total of 550 respondents. RESULTS: 81% of surgical doctors were aware of the recent change in consent law, yet only 35% reported a noticeable change in the local consent process. Important barriers to modernisation included limited consent training, a lack of protected time for discussions with patients and minimal uptake of technology to aid decision-making/documentation. CONCLUSIONS: On the basis of these findings, we identify a need to develop strategies to improve the consent process across the NHS and limit the predicted rise in litigation claims.

Successful transfer to sulfonylureas in KCNJ11 neonatal diabetes is determined by the mutation and duration of diabetes.

AIMS/HYPOTHESIS: The finding that patients with diabetes due to potassium channel mutations can transfer from insulin to sulfonylureas has revolutionised the management of patients with permanent neonatal diabetes. The extent to which the in vitro characteristics of the mutation can predict a successful transfer is not known. Our aim was to identify factors associated with successful transfer from insulin to sulfonylureas in patients with permanent neonatal diabetes due to mutations in KCNJ11 (which encodes the inwardly rectifying potassium channel Kir6.2). METHODS: We retrospectively analysed clinical data on 127 patients with neonatal diabetes due to KCNJ11 mutations who attempted to transfer to sulfonylureas. We considered transfer successful when patients completely discontinued insulin whilst on sulfonylureas. All unsuccessful transfers received ≥0.8 mg kg(-1) day(-1) glibenclamide (or the equivalent) for >4 weeks. The in vitro response of mutant Kir6.2/SUR1 channels to tolbutamide was assessed in Xenopus oocytes. For some specific mutations, not all individuals carrying the mutation were able to transfer successfully; we therefore investigated which clinical features could predict a successful transfer. RESULTS: In all, 112 out of 127 (88%) patients successfully transferred to sulfonylureas from insulin with an improvement in HbA1c from 8.2% (66 mmol/mol) on insulin, to 5.9% (41 mmol/mol) on sulphonylureas (p = 0.001). The in vitro response of the mutation to tolbutamide determined the likelihood of transfer: the extent of tolbutamide block was <63% for the p.C166Y, p.I296L, p.L164P or p.T293N mutations, and no patients with these mutations successfully transferred. However, most individuals with mutations for which tolbutamide block was >73% did transfer successfully. The few patients with these mutations who could not transfer had a longer duration of diabetes than those who transferred successfully (18.2 vs 3.4 years, p = 0.032). There was no difference in pre-transfer HbA1c (p = 0.87), weight-for-age z scores (SD score; p = 0.12) or sex (p = 0.17). CONCLUSIONS/INTERPRETATION: Transfer from insulin is successful for most KCNJ11 patients and is best predicted by the in vitro response of the specific mutation and the duration of diabetes. Knowledge of the specific mutation and of diabetes duration can help predict whether successful transfer to sulfonylureas is likely. This result supports the early genetic testing and early treatment of patients with neonatal diabetes aged under 6 months.

Improving weekend handover between junior doctors on medical and surgical wards.

Poor weekend handover has been implicated as one of the causes of observed higher mortality rates at weekends in UK hospitals. In a large teaching hospital we, a group of junior doctors, set about improving the quality and effectiveness of weekend handover. We used the Model for Improvement to implement a weekend handover sticker through an iterative process using multiple Plan/Do/Study/Act (PDSA) cycles. Over the 16 week study period the number of completed weekend tasks increased by 30% and the number of patients with a documented weekend handover increased by nearly 50%. Junior doctors are well positioned to notice the quality and safety shortcomings within hospitals, and by using effective improvement methods they can improve these systems at little or no cost.