Interventional Neuroradiology Procedures Research Articles

Monitoring Radiation Doses during Diagnostic and Therapeutic Neurointerventional Procedures: Multicenter Study for Establishment of Reference Levels.

PurposeTo assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL).Materials and MethodsConsecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution.ResultsAnalysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group.ConclusionVarious RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.

Common ground, different path: Ulnar artery access for interventional neurovascular procedures.

Recently, radial artery access has gained popularity for interventional neurovascular procedures due to patient comfort and fewer complications. However, there are instances where the radial artery approach is not feasible. In such cases, trans-ulnar artery access (TUA) can offer an alternate route. There is limited data regarding neuro-interventional procedures performed via this approach. This study aims to evaluate the feasibility and safety of trans-ulnar approach for a wide range of interventional neurovascular procedures. The data for all patients who underwent ulnar artery access for diagnostic or interventional neuroradiology procedures was retrospectively collected between September 2020 and March 2021. Patient demographics, procedural details, procedure success, and complications were recorded. During the study period, 23 patients underwent 24 trans-ulnar approach procedures. The mean age of patients was 50.1 ± 14.2 years. Fourteen diagnostic cerebral angiograms and ten interventional procedures were performed. All procedures were successfully completed via trans-ulnar approach without a switch to alternate access. No major access site complication was observed. Ulnar artery access is a safe and feasible option for neurovascular procedures. It can be effectively utilized for diagnostic cerebral angiography and a wide range of interventional procedures.

Exploring the path less traveled: Distal radial access for diagnostic and interventional neuroradiology procedures

BackgroundRecently there is a trend for radial first which advocates radial artery access as the first choice to perform diagnostic and interventional neurovascular procedures. Although safer than the conventional common femoral artery access, it is associated with a high rate of radial artery occlusion. Distal radial artery access is recently proposed to avoid this complication. This study aims to assess the feasibility and safety of distal radial artery access across a wide range of interventional neurovascular procedures. Materials and methodsAll Interventional neurovascular cases attempted via distal radial artery access from September 2019 till March 2021 were included in the study. Data regarding patient demographics, distal radial artery diameter, access site cannulation, size of the sheath, procedural details including success rate and complications were collected. ResultsDuring the study period, 102 patients underwent 114 procedures via the distal radial artery approach. The mean age of patients was 41.9 ± 15.2 years. Overall procedure success rate via DRA was 94.7% (108/114). 72 diagnostic cerebral angiograms and 36 interventional procedures were successfully completed while six procedures required switching to alternate access. ConclusionDistal radial artery access is a safe and feasible option for diagnostic cerebral angiography and a wide range of neurovascular procedures.

Postoperative complications in cranial and spine neurosurgery: a prospective observational study.

Postoperative complications do occur in all neurosurgical departments, but the way they are defined, and their true incidence vary a lot. The aim of the present study was to objectively assess the morbidity and mortality related to all neurosurgical procedures performed in our department and provide insight on their main causes and identify key factors to reduce their incidence. Data were retrieved from a prospectively maintained database regarding all patients undergoing a cranial or spinal neurosurgical procedure between November 2016 and April 2016 in the neurosurgical department in Timone University Hospital (APHM- Marseille). Patients undergoing a functional, pediatric, or interventional neuroradiological procedures were not included. The medical records of a total number of 963 patients were analyzed. A postoperative complication occurred in 208 patients (21.6%) including 115 (26.6%) in the cranial surgery group and 93 (17.5%) in the spinal surgery group. A complication occurred 1.5 more frequently in the cranial than in the spinal surgery group. Cranial surgery is 1.5 times more at risk of complications than spinal surgery (P=0.007). Preoperative comorbidities (ASA Score >3 to 4) were significantly associated with the occurrence of complications (P<0.001). In the cranial group, procedures performed in an emergency setting were 1.8 times more at risk of complications than scheduled surgeries (P<0.001). Conversely, in the spine group, scheduled surgeries were 1.4 times less at risk than emergency procedures (P=0.04). The main complication in both groups was found to be postoperative infection, with an incidence of 9.3% and 11.1% for cranial and spinal surgery respectively. Postoperative mortality reached 4.9% and 1.7% and the average length of stay was 12 and 11 days respectively. The incidence of complication in our series was found to be relatively high with predominantly infection as the main cause of postoperative complications. Reinforcing good practice measures at every step should help to significantly decrease our complication rate.

Radioprotection of eye lens using protective material in neuro cone-beam computed tomography: Estimation of dose reduction rate and image quality.

In cerebral angiography, for diagnosis and interventional neuroradiology, cone-beam computed tomography (CBCT) scan is frequently performed for evaluating brain parenchyma, cerebral hemorrhage, and cerebral infarction. However, the patient's eye lens is more frequently exposed to excessive doses in these scans than in the previous angiography and interventional neuroradiology (INR) procedures. Hence, radioprotection for the lenses is needed. This study selects the most suitable eye lens protection material for CBCT from among nine materials by evaluating the dose reduction rate and image quality. To determine the dose reduction rate, the lens doses were measured using an anthropomorphic head phantom and a real-time dosimeter. For image quality assessment, the artifact index was calculated based on the pixel value and image noise within various regions of interest in a water phantom. The protective materials exhibited dose reduction; however, streak artifacts were observed near the materials. The dose reduction rate and the degree of the artifact varied significantly depending on the protective material. The dose reduction rates were 14.6%, 14.2%, and 26.0% when bismuth shield: normal (bismuth shield in the shape of an eye mask), bismuth shield: separate (two separate bismuth shields), and lead goggles were used, respectively. The "separate" bismuth shield was found to be effective in dose reduction without lowering the image quality. We found that bismuth shields and lead goggles are suitable protective devices for the optimal reduction of lens doses.

Choosing Neuroanaesthesia as a career: Marching towards new horizons.

Anaesthesiology is an ever-changing science and amongst its sub-specialities, the field of neuroanaesthesia is making rapid strides. The fragility of the brain and spinal cord and the multitude of complexities involved in neurosurgery and interventional neuroradiological procedures demand dedicated training in neuroanaesthesia. With rapid advancement in other neuroscience specialties, neuroanaesthesia too has made outstanding progress, owing to establishment of structured training, publication of high-quality scientific research, and invention of novel medications and monitoring modalities. The opportunities for training in India and abroad and resources to broaden knowledge in neuroanaesthesia have increased over the last two decades. A career in neuroanaesthesia offers a great future for budding anaesthesiologists.

Typical values related to the complexity of interventional treatment of acute ischemic stroke.

Interventional Neuroradiology (INR) procedures are often complex, requiring prolonged high-dose exposures. This leads to increased radiation exposure to both patient and operating staff. The purpose of this study is to identify parameters related to the complexity of acute ischemic stroke (AIS) procedures that increase patient exposure and derive DRLs according to ICRP 135. Data from 145 patients treated for AIS between 2017 and 2019 in a Hub Stroke center were retrospectively analyzed. Dosimetric parameters, demographic and clinical data were collected for each patient. The INR operator and the fluoroscopy system used were included. A multivariable analysis was performed to identify which parameters significantly influence the dosimetric data. Thrombus location and the use of stent retriever were noted as the most likely parameters of complex INR procedures. Male sex is an indicator of complex procedure only with regards to the Kerma area product and the air kerma. Patient age significantly affects the exposure time alone. Senior or more experienced operator's data demonstrated reduced patient's exposure time and therefore the KAP and Kar values. The type of X-ray equipment influenced the outcome of the procedure in terms of number of images acquired. Typical values obtained are 168 Gycm2, 0.68Gy, 19min and 181 images. Typical values derived in this study promote patient dose optimization, when considering the complexity of INR procedures. The clinical variables related to the complexity of procedure that mainly affect the dosimetric data in our experience are thrombus location and use of stent retrievers.

A Questionnaire Survey of Management of Patients with Aneurysmal Subarachnoid Haemorrhage in Poland.

Background: Aneurysmal subarachnoid haemorrhage (aSAH) remains a potentially devastating threat to the brain with a serious impact on mortality and morbidity. We attempted to investigate correspondence between the current guidelines for aSAH management and real clinical practice in Poland. Methods: A web-based questionnaire was performed between 03.2019 and 06.2019. Centres performing neuro-interventional radiology procedures and neuro-critical care were included (n = 29). One response from each hospital was recorded. Results: In three (10.4%) centres, there was no clear protocol for an interventional treatment plan. Endovascular embolisation was predominantly used in 11 (37.9%) hospitals, and microsurgical clipping, in 10 (34.5%). A written protocol for standard anaesthetic management was established only in six (20.7%) centres for coiling and in five (17.2%) for microsurgical clipping. The diagnosis of cerebral vasospasm was based on transcranial Doppler as the first-choice method in seven (24.1%) units. “3-H therapy” was applied by 15 (51.8%) respondents, and “2-H therapy”, by four (13.8%) respondents. In only eight (27.6%) centres were all patients with aSAH being admitted to the ICU. Conclusion: Many discrepancies exist between the available guidelines and clinical practice in aSAH treatment in Poland. Peri-procedural management is poorly standardised. Means must be undertaken to improve patient-oriented treatment and care.

Transradial access for diagnostic angiography and interventional neuroradiology procedures: A four-year single-center experience.

The objective of this study was to assess the efficacy and safety of transradial access for diagnostic angiography and interventional neuroradiology procedures. This was a retrospective analysis of a single-center experience based on 225 patients attended between August 2015 and October 2019, in which transradial access was used for diagnostic angiography and endovascular interventions. Ultrasound-guided access was done at the level of the forearm or anatomical or snuffbox (distal transradial access). Conventional forearm transradial access was done in 179 procedures (right, left and bilateral in 169, 5 and 5, respectively), while distal transradial access was done in 46 cases (41 right and 5 left). Primary outcome measures included successful catheterization, need to change access, or technical complications. In the group of 131 diagnostic angiographies, the technique success rate was 100% to target the right vertebral artery, 97% for the right internal carotid, 93.5% for the left internal carotid, 82% for the left vertebral artery, and 100% for both common and external carotid arteries. All patients were discharged within 2-4 h after the procedure. A total of 94 interventional procedures were performed, including aneurysms in 39 cases, stroke in 34, and other procedures (carotid stents, arteriovenous malformations, carotid-cavernous fistula) in the remaining 21. The overall technical success in both diagnostic angiographies and interventional procedures was 97.7%. In four cases of diagnostic angiography and in 1 intervention, it was necessary to switch from transradial access to transfemoral access. Three cases of hematoma related to the access site were recorded. In our experience, transradial access is an alternative approach for diagnostic angiography and neuro-interventions.

Assessment of Eye Lens Dose Reduction When Using Lateral Lead Shields on the Patient's Head during Neurointerventional Fluoroscopic Procedures and Cone-beam Computed Tomography (CBCT) Scans.

The purpose of this study was to evaluate the effect of placing small lead shields on the temple region of the skull to reduce radiation dose to the lens of the eye during interventional fluoroscopically-guided procedures and cone-beam computed tomography (CBCT) scans of the head. EGSnrc Monte-Carlo code was used to determine the eye lens dose reduction when using lateral lead shields for single x-ray projections, CBCT scans with different protocols, and interventional neuroradiology procedures with the Zubal computational head phantom. A clinical C-Arm system was used to take radiographic projections and CBCT scans of anthropomorphic head phantoms without and with lead patches, and the images were compared to assess the effect of the shields. For single lateral projections, a 0.1 (0.3)-mm-thick lead patch reduced the dose to the left-eye lens by 40% to 60% (55% to 80%) from 45° to 90° RAO and to the right-eye lens by around 30% (55%) from 70° to 90° RAO. For different CBCT protocols, the reduction of lens dose with a 0.3-mm-thick lead patch ranged from 20% to 53% at 110 kVp. For CBCT scans of the anthropomorphic phantom, the lead patch introduced streak artifacts that were mainly in the orbital regions but were insignificant in the brain region where most neurointerventional activity occurs. The dose to the patient's eye lens can be reduced considerably by placing small lead shields over the temple region of the head without substantially compromising image quality in neuro-imaging procedures.

Abstract WP435: Post Procedural Monitoring Tool Improves the Joint Commission Comprehensive Stroke Center Standard Compliance

Background: The Joint Commission (TJC) Comprehensive Stroke Center standard requires monitoring of patients after IV tPA administration, diagnostic angiography, aneurysm coiling, carotid angioplasty and stenting, mechanical endovascular reperfusion (MER) and carotid endarterectomy. Meeting 100% compliance of the standard is challenging. In 2018, monitoring and documentation were among the TJC’s top ten cited survey findings. Purpose: To determine if an electronic tool can improve documentation compliance and reduce delays in monitoring of vital signs, and neurologic, pedal pulse and skin site assessments. Methods: The initiative was implemented in 2018 with the objective for all patients to have 100% of their post procedural monitoring completed. A documentation tool was created and introduced to nursing units via annual stroke education updates. The tool was added to an online nursing resource SharePoint website and application, which was accessible to all nurses within the hospital. The procedure end time was entered in the tool, which automatically calculated the documentation times. Data was compared 12 months pre and post intervention. Analysis and reporting of data were conducted monthly via the program’s quality oversight committee. Data was analyzed using T-Test. Results: In post-IV tPA patients, more patients had 100% complete documentation (79% post vs. 29% pre-implementation; p=0.006). For all post neuro-interventional radiology procedures, more patients had 100% complete documentation (68% post vs. 17% pre-implementation; p&lt;0.001). For post carotid endarterectomy revascularization, there was a trend toward more patients with 100% complete documentation (83% vs 38%; p=0.07). Conclusion: Utilization of an electronic monitoring tool for post procedural documentation adherence can improve the percentage of patients who have 100% completed assessments and help meet the TJC standard.

In Memoriam Grant Hieshima, MD: 1942–2019: Pioneer, Mentor, Visionary, Friend

Grant Hieshima, MD died unexpectedly on August 9, 2019, at the age of 77, while enjoying one of his lifelong passions, deep-sea fishing, with his son Michael at his side....

DNA damage and gene expression changes in patients exposed to low-dose X-radiation during neuro-interventional radiology procedures

Interventional radiology-based imaging is the preferred choice for diagnosis and therapy of many complex diseases, despite possible adverse effects of the radiation exposures. We have measured induced DNA damage and changes in gene expression in relation to entrance surface dose (ESD) in peripheral blood samples of patients (n = 51) who underwent neuro-interventional radiological procedures. The ESD values, measured by thermoluminescence dosimetry, were 4.9–273 mGy (forehead), 14–398 mGy (eyes), 8–433.3 mGy (shoulders), and 4.7–242.5 mGy (thyroid). The in-built recorded Dose Area Product (DAP) values were 74.61–558.55 and 13.17–2825.12 Gy*cm2 for diagnostic and therapeutic procedures, respectively. The mean fluorescence intensity (MFI) on the phosphorylation of γ-H2AX and p53ser−15 was higher in samples obtained post-exposure vs. pre-exposure. However, the increase was statistically significant only for p53ser−15 (P < 0.01). Consistent with γ-H2AX, CDKN1A, FDXR, BAX, DDB2, SESN1, BCL2, MDM2, TNFSF10B, and PCNA showed (non-significant) decreased expression while GADD45A, ATM, and TNFSF9 showed (non-significant) increased expression. Our results suggest that most of the patients had increased DNA damage and altered gene expression after receiving relatively low doses of ionising radiation. This implies that these procedures should be carried out at the lowest possible doses of radiation that do not compromise image quality.

Laryngeal mask airway for general anesthesia in interventional neuroradiology procedures

Objectives:To evaluate whether using laryngeal mask airway (LMA) made a difference in terms of airway security, hemodynamic changes, complications, and recovery times compared to tracheal intubation during the procedure in patients undergoing general anesthesia for endovascular treatments of unruptured cerebrovascular aneurysms.Methods:The electronic medical records database, patient files, and anesthesia charts were examined between May 2008 and September 2016 to identify patients with the following inclusion criteria: 1) aged 18-70 years; 2) American Society of Anesthesiologists (ASA) classification I-III; 3) diagnosis of unruptured CVA; 4) Glasgow coma scale of 15 without neurological deficit; and 5) underwent elective EVT under general anesthesia.Results:Tracheal tube (TT) was used in 46 patients (group TT, n=46) and LMA in 42 patients (group LMA, n=42). Mean arterial pressure (MAP) levels were increased to >20% of baseline in 14 patients (30.4%) after intubation and in 6 (13%) after extubation in group TT. All LMA patients remained within normal MAP limits (p<0.05). Six patients (13%) displayed coughing or straining at extubation in group TT whereas none in group LMA (p<0.05). Recovery and discharge times were similar (p>0.05).Conclusion:Laryngeal mask airway and TT provided comparable airway security during procedure. Laryngeal mask airway attenuated stress response in hemodynamic parameters at intubation and extubation and smoother emergence compared to TT without delay in recovery.

Comparison of Two Methods of Anesthesia Using Patient State Index: Propofol Versus Sevoflurane During Interventional Neuroradiology Procedure.

BackgroundOver the past few decades, interventional neuroradiology (INR) has been a rapidly growing and evolving area of neurosurgery. Sevoflurane and propofol are both suitable anesthetics for INR procedures. While the depth of anesthesia is widely monitored, few studies have examined the patient state index (PSI) during clinical neuroanesthesia.ObjectivesThis study aimed to investigate the differences in PSI values and in hemodynamic variables between sevoflurane anesthetic and propofol anesthetic during INR procedures.MethodsWe reviewed the medical charts of the patients who underwent embolization of a non-ruptured intracranial aneurysm by a single operator at a single university hospital from May 2013 to December 2014. Sixty-five patients were included and divided into two groups: S group (sevoflurane anesthesia, n = 33) vs. P group (propofol anesthesia, n = 32). The PSI values, hemodynamic variables, and use of hemodynamic drugs between two groups were analyzed.ResultsThere were significant differences between the PSI values obtained through different perioperative stages in the two groups (P < 0.0001). During the procedure, the PSI values were significantly lower in the P group than in the S group (P = 0.000). The P group patients had a more prolonged extubation time (P = 0.005) and more phenylephrine requirement than the S group patients (P = 0.007). More anti-hypertensive drugs were administered to the patients in the S group during extubation (P = 0.0197).ConclusionsThe PSI can be used to detect changes in anesthetics concentration and in the depth of anesthesia during INR procedures. Although the extubation was faster under sevoflurane anesthetic, propofol anesthetic showed rather smoother recovery.

Radiation exposure during neurointerventional procedures in modern angiographic systems: A single center experience

Background/Aim. Interventional neuroradiology procedures expose patients to ionizing radiation. The aim of this study was to assess doses received by patients during interventional neuroradiology procedures and to establish dose range with an estimate of risk from adverse consequences of irradiation. Methods. Our study describes series of patients submitted to diagnostic and/or therapeutic procedures at the Department of Interventional Neuroradiology, Clinical Center Kragujevac, Serbia, from December 1, 2014 to December 1, 2016. The following variables were considered for this study: kerma-area product, air kerma and fluoroscopy exposure time; peak skin dose and effective dose calculated from the kerma-area product. Results. Median kerma-area product was 87.802 Gy?cm2, 78.567 Gy?cm2, 117.626 Gy?cm2; effective dose was 12.731 mSv, 11.392 mSv, 17.056 mSv; peak skin dose was 0.456 Gy, 0.409 Gy, 0.612 Gy, and estimated brain dose was 254.62 mGy, 227.84 mGy, 341.12 mGy, for diagnostic, therapeutic and combined procedures, respectively. Conclusion. Interventional neuroradiology procedures show significant variability in radiation dose, due to patient constitution, radiologist expertise and equipment factors. Knowing the doses can have a great benefit for patients and medical and paramedical stff in terms of prevention of possible deterministic and stochastic effects of the radiation.

Patient Radiation Dose in Neurointerventional Radiologic Procedure: A Tertiary Care Experience.

PurposeNeurointerventional radiology procedures often require a long time to perform. Patient radiation dose is an important issue due to the hazards of ionizing radiation. The objective of this study was to measure the peak skin dose (PSD) and effective dose to estimate the deterministic and stochastic effects of a therapeutic interventional neuroradiologic procedure.Materials and MethodsThe cumulative dose (CD) and dose area product (DAP) were automatically recorded by a fluoroscopic machine and collected prospectively between April and November 2015. The study included 54 patients who underwent therapeutic neurointerventional radiology procedures. The CD of each patient was used to estimate the peak skin dose and the DAP was also calculated to estimate the effective dose.ResultsThe average estimated peak skin dose was 1,009.68 mGy. Two patients received radiation doses of more than 2 Gy, which is the threshold that may cause skin complications and radiation-induced cataract. The average effective dose was 35.32 mSv. The majority of patients in this study (85.2%) who underwent therapeutic neurointerventional radiologic procedures received effective doses greater than 20 mSv.ConclusionNot all therapeutic neurointerventional radiology procedures are safe from deterministic complications. A small number of patients received doses above the threshold for skin complications and radiation induced cataract. In terms of stochastic complications, most neurointerventional radiology procedures in this study were quite safe in terms of radiation-induced cancer.

Monitoring and Follow-Up of High Radiation Dose Cases in Interventional Radiology

To assess the implementation of radiation dose monitoring software, create a process for clinical follow-up and documentation of high-dose cases, and quantify the number of patient reported radiation-induced tissue reactions in fluoroscopically guided interventional radiology (IR) and neuro-interventional radiology (NIR) procedures. Web-based radiation dose monitoring software was installed at our institution and a process to flag all procedures with reference point air kerma (Ka,r) > 5000 mGy was implemented. The entrance skin dose was estimated and formal reports generated, allowing for physician-initiated clinical follow-up. To evaluate our process, we reviewed all IR and NIR procedures performed at our hospital over a 1-year period. For all procedures with Ka,r > 5000 mGy, retrospective medical chart review was performed to evaluate for patient reported tissue reactions. Three thousand five hundred eighty-two procedures were performed over the 1-year period. The software successfully transferred dose data on 3363 (93.9%) procedures. One thousand three hundred ninety-three (368 IR and 1025 NIR) procedures were further analyzed after excluding 2189 IR procedures with Ka,r < 2000 mGy. Ten of 368 (2.7%) IR and 52 of 1025 (5.1%) NIR procedures exceeded estimated skin doses of 5000 mGy. All 10 IR cases were abdominal/pelvic trauma angiograms with/without embolization; there were no reported tissue reactions. Of 52 NIR cases, 49 were interventions and 3 were diagnostic angiograms. Five of 49 (10.2%) NIR patients reported skin/hair injuries, all of which were temporary. Software monitoring and documentation of radiation dose in interventional procedures can be successfully implemented. Radiation-induced tissue reactions are relatively uncommon.

F173. Seizure risk from intraoperative motor evoked potential stimulation

Introduction Intraoperative Neurophysiologic Monitoring (IONM) tests the function of the brain and spine to help prevent new neurological deficits during surgery. IONM modalities can include electroencephalography (EEG) and motor evoked potentials (MEPs). MEPs involve high-intensity electrical stimulation to the scalp (transcranial) or brain (direct cortical) to test responses through the motor pathways. Transcranial stimulation can provoke a seizure, and previous studies have estimated that risk to be 0.8%. Methods 1175 adult IONM cases, in 605 females and 570 males, between July 1, 2015 and June 30, 2016 were retrospectively examined. There were 394 craniotomies, 178 interventional neuroradiology procedures, 509 spinal, 5 trans-nasal, 71 vascular, 1 neck, and 18 peripheral nerve cases with patients 18 to 95 years old. Seizures were identified through EEG, clinical observation of movement, and electronic medical chart review. Results Only two (0.170%) intraoperative seizures occurred. Electrographic seizure and clinical movement were observed in both. One was during an awake craniotomy with direct cortical stimulation for the resection of a left temporal metastasis. The other was a craniotomy for brainstem tumor resection under general anesthesia with transcranial MEPs. Although 98 cases (8.340%) involved a patient with one or more pre-operative seizures, usually from a new brain lesion, 0% of these patients experienced intraoperative seizures. Out of 14 awake craniotomy cases, only one (7.143%) had an intraoperative seizure. Conclusion The rate of intraoperative seizures in cases involving IONM is very low; and in this review, lower than previously published data. Having a seizure prior to surgery does not seem to confer added risk when using MEPs.

Initial assessment and management of stroke

This second article, in a two-part series on stroke, will review and outline the importance of the initial assessment and management of patients with stroke in hospital. Stroke affects over 111 000 individuals per year, with almost 1 million individuals managing daily with its after-effects in England. The management of patients with stroke has rapidly developed in recent years, with widespread access to intravenous thrombolytic therapy for the preponderance (85%) of acute ischaemic stroke, while the remaining haemorrhagic strokes (15%) can potentially be managed with a decompressive hemicraniectomy procedure. Further developments include mechanical thrombectomy that treats large-vessel occlusive stroke using an interventional neuroradiology procedure called mechanical thrombectomy. Ensuring delivery of appropriate stroke treatments relies on the accurate assessment of the patient, with particular attention to their past medical history, cardiovascular risk factors and access to hyperacute stroke care. The key risks factors for stroke will also be discussed, as many of these may only present at stroke diagnosis. A range of stroke assessment tools, including their effectiveness, will be discussed in addition to differential stroke diagnosis and stroke mimics.