Neuroradiology Suite Research Articles

Intraoperative use of processed electroencephalogram in a quaternary center: a quality improvement audit.

Although intraoperative electroencephalography (EEG) is not consensual among anesthesiologists, growing evidence supports its use to titrate anesthetic drugs, assess the level of arousal/consciousness, and detect ischemic cerebrovascular events; in addition, intraoperative EEG monitoring may decrease the incidence of postoperative neurocognitive disorders. Based on the known and potential benefits of intraoperative EEG monitoring, an educational program dedicated to staff anesthesiologists, residents of Anesthesiology and anesthesia technicians was started at Cleveland Clinic Abu Dhabi in May 2022 and completed in June 2022, aiming to have all patients undergoing general anesthesia with adequate brain monitoring and following international initiatives promoting perioperative brain health. All the surgical cases performed under General Anesthesia at 24 daily locations were prospectively inspected during 15 consecutive working days in March 2023. The use or absence of a processed EEG monitor was registered. Of 379 surgical cases distributed by 24 locations under General Anesthesia, 233 cases (61%) had processed EEG monitoring. The specialty with the highest use of EEG monitoring was Cardiothoracic Surgery, with 100% of cases, followed by interventional Cardiology (90%) and Vascular Surgery (75%). Otorhinolaryngology (29%), Gastrointestinal Endoscopy (25%), and Interventional Pulmonology (20%) were the areas with the lowest use of EEG monitoring. Of note, in the Neuroradiology suite, no processed EEG monitor was used in cases under General Anesthesia. We identified a reasonable use of EEG monitoring during general anesthesia, unfortunately not reaching our target of 100%. The educational and support program previously implemented within the Anesthesiology Institute needs to be continued and improved, including workshops, online discussions, and journal club sessions, to increase the use of EEG monitoring in underused areas.

Bilateral inferior petrosal sinus sampling in the diagnosis of ACTH-dependent Cushing's syndrome: experience in a tertiary hospital.

Bilateral inferior petrosal sinus sampling (BIPSS) is a useful test for differential diagnosis of central vs. ectopic adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome (CS). We provide a description of the protocol used in our Center and an analysis of its diagnostic accuracy. A retrospective study was conducted of 28 patients who underwent BIPSS combined with corticotropin-releasing hormone (CRH) stimulation. The procedure is performed in an interventional neuroradiology suite, involving a multidisciplinary team of neuroradiologists, endocrinologists and laboratory professionals. The two petrosal sinuses are catheterized and a peripheral blood sample is obtained simultaneously, at baseline and at 3, 6 and 10min following stimulation. ACTH and prolactin are determined by immunochemiluminescence. A total of 19 cases of Cushing's disease (CD) and 1 case of ectopic CS were confirmed. In all cases, BIPSS provided accurate diagnostic guidance, with a sensitivity and specificity of 100%. In 8 patients, remission was not achieved after surgery. In 84% of catheterizations, ACTH ratio peaked at 3-6min following stimulation. Patients with histologically-confirmed CD exhibited higher sinus ACTH ratios and values. Prolactin ratio helped us identify and exclude 28.6% of the samples with inconsistent results. In our series, BIPSS combined with CRH stimulation demonstrated to be a safe, effective procedure. Prolactin emerges as a useful marker of correct catheterization. The participation of a multidisciplinary team is essential.

Anesthesia care in the interventional neuroradiology suite: an update.

The scope of procedures conducted by neurointerventionalists is expanding quickly, with lacking consensus over the best anesthesia modality. Although the procedures involve all age groups, the interventions may be complex and lengthy and may be provided in hospitals currently not yet familiar with the field. Here we review current literature addressing elective outpatient neurointerventional procedures and aim to provide an update on the management of intervention-specific crises, address special patient populations, and provide key learning points for everyday use in the neurointerventional radiology suite. Various studies have compared the use of different anesthesia modalities and preinterventional and postinterventional care. Monitored anesthesia care is generally recommended for elderly patients, whereas children are preferably treated with general anesthesia. Additional local anesthesia is beneficial for procedures, such as percutaneous kyphoplasty and vascular access. Combining different anesthetic modalities is a valuable approach in the neurointerventional radiology suite. More interventional and patient population-specific studies are needed to improve evidence-based perioperative management.

Anesthetic Management of Acute Ischemic Stroke in the Interventional Neuro-Radiology Suite: State of the Art.

This review discusses the general anesthetic approach of endovascular stroke therapy and highlights recent advances and considerations for optimal intraoperative management of acute ischemic stroke. Recent randomized controlled trials have shown no differences in clinical outcomes between monitored anesthesia care with sedation compared with general anesthesia for endovascular stroke therapy. The COVID-19 pandemic has complicated decision-making in the neurointerventional setting. Advances in imaging techniques have extended the window of treatment for endovascular therapy. Optimal time to intervention, hemodynamic stability, novel imaging techniques, and careful consideration of anesthetic plan can impact patient outcomes in reperfusion stroke therapy.

Dexmedetomidine in Modern Neuroanesthesia Practice

The purpose of this review is to discuss the role of dexmedetomidine in various procedures in clinical neurosciences. It also gives an overview of the various neurosurgical procedures where dexmedetomidine has been used perioperatively. Dexmedetomidine possesses many properties that are advantageous for neurosurgical patient including its neuroprotective effect. Its role in the cerebral vasospasm has recently become an area of interest for the researchers. There are number of animal as well as human studies where authors observed an improved neurological outcome following administration of dexmedetomidine. Dexmedetomidine is frequently used in various neurosurgical procedures as adjuvant to anesthetics and also for procedural sedation in neuroradiology suite. Although not approved by the Food and Drug Administration, off label use of dexmedetomidine in children is not uncommon. Dexmedetomidine, as an anesthetic adjuvant and as a sedative in neurosurgical patients is commonly practiced and accepted worldwide. Its potential neuroprotective effects and emerging role in cerebral vasospasm merit further investigation for wider clinical application.

Anesthesia for Endovascular Neurosurgery

This review considers important aspects in the provision of anesthesia for endovascular neurosurgery. Subject literature was reviewed to include important publications which have influenced neuro-interventional practice alongside recent meta-analyses to provide a contemporaneous evidence-based review. The scope of endovascular neurosurgery and interventional neuro-radiology continues to expand. The advancement of catheter and imaging technologies, alongside the development of novel techniques, has allowed a minimally invasive endovascular approach to be applied to pathologies previously only treatable by open surgery, and to patients previously considered unsuitable for invasive surgical approaches. This has led to increasing complexity in both the procedures performed and the patients encountered in the neuro-radiology suite. An understanding of the technical aspects, physiological requirements, and potential problems relating to each procedure is required to facilitate close cooperation between the anesthesiologist and neuro-interventional team, to provide safe and effective care.

COVID-19 and the perioperative neuroscience - A narrative review.

Among the several medical specialties, anesthesiologists are probably the most affected ones from the coronavirus disease (COVID-19) pandemic as they are at the frontline. In the present stage of the pandemic, where we are observing community transmission, more people with elective neurologic and neurosurgical problems are likely to be tested positive for this virulent disease. Neuroanesthesiologists play an important role in the perioperative period and in neuroradiology suite. It is imperative to know the best available ways by which health care providers can manage their patients and also necessary steps to prevent the spread of infection, not only amongst themselves but also between patients. A high index of suspicion in such patients may help avoid delay in diagnosis and catastrophic sequelae. An overall knowledge about the disease will help plan the clinical management of neurologic patients, during the perioperative period.

O-Arm Stereotactic Imaging in Deep Brain Stimulation Surgery Workflow: A Utility and Cost-Effectiveness Analysis

Introduction: Deep brain stimulation (DBS) surgery is an established treatment for movement disorders. Advances in neuroimaging techniques have resulted in improved targeting accuracy that may improve clinical outcomes. This study aimed to evaluate the safety and feasibility of using the Medtronic O-arm device for the acquisition of intraoperative stereotactic imaging, targeting, and localization of DBS electrodes compared with standard stereotactic MRI or computed tomography (CT). Methods: Patients were recruited prospectively into the study. Routine frame-based stereotactic DBS surgery was performed. Intraoperative imaging was used to facilitate and verify the accurate placement of the intracranial electrodes. The acquisition of coordinates and verification of the position of the electrodes using the O-arm were evaluated and compared with conventional stereotactic MRI or CT. Additionally, a systematic review of the literature on the use of intraoperative imaging in DBS surgery was performed. Results: Eighty patients were included. The indications for DBS surgery were dystonia, Parkinson’s disease, essential tremor, and epilepsy. The globus pallidus internus was the most commonly targeted region (43.7%), followed by the subthalamic nucleus (35%). Stereotactic O-arm imaging reduced the overall surgical time by 68 min, reduced the length of time of acquisition of stereotactic images by 77%, reduced patient exposure to ionizing radiation by 24.2%, significantly reduced operating room (OR) costs per procedure by 31%, and increased the OR and neuroradiology suite availability. Conclusions: The use of the O-arm in DBS surgery workflow significantly reduced the duration of image acquisition, the exposure to ionizing radiation, and costs when compared with standard stereotactic MRI or CT, without reducing accuracy.

Management of Acute Ischemic Stroke in the Interventional Neuroradiology Suite During the COVID-19 Pandemic: A Global Survey.

According to early reports, patients affected by coronavirus disease 2019 (COVID-19) are at an increased risk of developing cerebrovascular events, including acute ischemic stroke (AIS). The COVID-19 pandemic may also impose difficulties in managing AIS patients undergoing endovascular thrombectomy (EVT), as well as concerns for the safety of health care providers. This international global survey aims to gather and summarize information from tertiary care stroke centers on periprocedural pathways and endovascular management of AIS patients during the COVID-19 pandemic. A cross-sectional survey-based research questionnaire was sent to 259 tertiary care stroke centers with neurointerventional facilities worldwide. We received 114 responses (response rate: 44%) from 25 different countries across all 5 continents. The number of AIS patients and EVT cases were reported to have decreased during the pandemic. Most participants reported conducting COVID-19 testing before (49%) or after the procedure (31%); 20% of centers did not test at all. Only 16% of participating centers reported using a negative pressure room for the thrombectomy procedure. Strikingly, 50% of participating centers reported no changes in the anesthetic management of AIS patients undergoing EVT during the pandemic. This global survey provides information on the challenges in managing AIS patients undergoing EVT during the COVID-19 pandemic. Its findings can be used to improve patient outcomes and the safety of the health care team worldwide.

Hemodynamic Management of Patients During Endovascular Treatment of Acute Ischemic Stroke Under Conscious Sedation: A Retrospective Cohort Study.

Anesthetic modality and hemodynamic management during mechanical thrombectomy (MT) for acute ischemic stroke (AIS) are potential contributors to the success of revascularization. The aims of our study were to review the hemodynamic management by anesthesiologists and clinical outcomes in patients undergoing MT under conscious sedation. Retrospective cohort study of patients with anterior circulation AIS from January 2012 to March 2016. Primary outcome was hemodynamic intervention, defined as administration of vasoactive drugs to maintain systolic blood pressure (BP) between 140 and 180 mm Hg. The secondary outcome was poor hemodynamic control, defined as BP outside target for >15 minutes despite hemodynamic intervention. We performed regression analysis to determine the predictors of hemodynamic intervention and poor hemodynamic control. A total of 126 patients were included in this study; 92% (116) receiving conscious sedation and 8% (10) no sedation. Upon arrival to the neuroradiology suite, systolic BP was <140 mm Hg in 30.2% of the patients and >180 mm Hg in 14.3%. Hemodynamic intervention was required in 38.9% of patients; 15.1% for hypotension and 19.8% for hypertension. In the multivariate analysis, systolic BP on hospital admission (odds ratio, 1.02; 95% confidence interval, 1.00-1.04; P=0.019) constituted a predictor for hemodynamic intervention. Poor hemodynamic control occurred in 12.7% of patients, with lower baseline systolic BP being associated with higher risk of intraprocedural hypotension (odds ratio, 0.92; 95% confidence interval, 0.89-0.96; P<0.001). In-hospital mortality was 13.6%. Hemodynamic intervention is frequent during MT under conscious sedation. The routine presence of anesthesiologists during MT may be helpful in maintaining hemodynamic stability and allow rapid treatment of emergent complications. An individualized approach with tailored hemodynamic targets is required during management of patients undergoing MT for AIS.

Isolated straight sinus thrombosis

A woman in her 50s with history of breast cancer on Tamoxifen presented with altered mental status. Patient was unresponsive, had preserved pupillary light response with small pupils, and localized to noxious stimuli in upper extremities with triple flexion in the lower extremities. A.Brain tumorB.Venous sinus thrombosisC.Dural arteriovenous fistulaD.Basal ganglia calcification A head CT was performed (Fig. 1A) and a CT venogram showed isolated straight sinus thrombosis. Heparin was initiated and patient was taken to the interventional neuroradiology suite. An attempted thrombectomy was unsuccessful (Fig. 1B). A brain MRI was performed 2 days later (Fig. 1C and D). Patient showed rapid neurological decline and expired 5 days later. Isolated straight sinus thrombosis is a rare condition associated with a very poor prognosis [[1]Valeriano J. Bhagavatula K. Ku A. Snyder P.J. Isolated straight sinus thrombosis: clinical and neuroradiologic correlates.J Neuroimaging. 1998; 8: 106-108PubMed Google Scholar]. Management include heparinization with a few reported cases of endovascular thrombolysis [[2]Gerszten P.C. Welch W.C. Spearman M.P. Jungreis C.A. Redner R.L. Isolated deep cerebral venous thrombosis treated by direct endovascular thrombolysis.Surg Neurol. 1997; 48: 261-266Abstract Full Text PDF PubMed Scopus (52) Google Scholar]. No conflict of interests by any of the authors.

The efficacy of pre-warming on reducing intraprocedural hypothermia in endovascular coiling of cerebral aneurysms.

BackgroundThe anesthetic management of patients undergoing endovascular treatment of cerebral aneurysms in the interventional neuroradiology suite can be challenged by hypothermia because of low ambient temperature for operating and maintaining its equipments. We evaluated the efficacy of skin surface warming prior to induction of anesthesia to prevent the decrease in core temperature and reduce the incidence of hypothermia.MethodsSeventy-two patients were randomized to pre-warmed and control group. The patients in pre-warmed group were warmed 30 minutes before induction with a forced-air warming blanket set at 38°C. Pre-induction tympanic temperature (Tpre) was measured using an infrared tympanic thermometer and core temperature was measured at the esophagus immediately after intubation (T0) and recorded at 20 minutes intervals (T20, T40, T60, T80, T100, and T120). The number of patients who became hypothermic at each time was recorded.ResultsTpre in the control and pre-warmed group were 36.4 ± 0.4°C and 36.6 ± 0.3°C, whereas T0 were 36.5 ± 0.4°C and 36.6 ± 0.2°C. Core temperatures in the pre-warmed group were significantly higher than the control group at T20, T40, T60, T80, T100, and T120 (P < 0.001). Compared to T0, core temperatures at each time were significantly lower in both two groups (P = 0.007 at T20 in pre-warmed group, P < 0.001 at the other times in both groups). The incidence of hypothermia was significantly lower in the pre-warmed group than the control group from T20 to T120 (P = 0.002 at T20, P < 0.001 at the other times).ConclusionPre-warming for 30 minutes at 38°C did not modify the trends of the temperature decrease seen in the INR suite. It just slightly elevated the beginning post intubation base temperature. The rate of decrease was similar from T20 to T120. However, pre-warming considerably reduced the risk of intraprocedural hypothermia.Trial registrationClinical Research Information Service (CRiS) Identifier: KCT0001320. Registered December 19th, 2014.

The use of internal carotid artery stenting in management of bilateral carotid body tumors

Carotid body tumors (CBT) are paragangliomas that arise from chemoreceptors at the carotid bifurcation with surgical removal indicated in the majority of cases[1, 2]. Surgical resection remains complicated by bleeding from the tumor, possible internal carotid artery (ICA) injury, cranial nerve injuries and cerebral ischemic events. In Shamblin type III tumors, the likelihood of vascular injury increases [1]. Therefore facilities for vascular repair, reconstruction, on table balloon occlusion and rapid transfer to the neuroradiology suite should be available for all CBT. ICA stenting is a good option to reduce intraoperative injury and we have utilized this technique for complex tympanojugular paragangliomas without postoperative complications [3–5]. We report a case of large bilateral carotid body tumors where bilateral uncomplicated surgical removal was performed in a staged fashion with the use of uncovered ICA stents.

Unilateral bronchospasm during microcatheter manipulation in an interventional neuroradiology suite

To the Editor: Bronchospasm during general anesthesia has many etiologies, including the patient’s intrinsic disease and mechanical, chemical or neurogenic causes [1, 2]. Reactions to drugs used for embolization and contrast drugs are important causes of bronchospasm in patients undergoing interventional radiological procedures [3, 4]. Unilateral bronchospasm per se is a known but rare entity. We report a case where manipulations of intercostal artery by a microcatheter led to acute unilateral bronchospasm. A 2-year-old girl weighing 12 kg and 65 cm in height was electively scheduled for glue embolization of dorsal (D2) spinal arteriovenous malformation under general anesthesia. Her preoperative respiratory and cardiovascular examinations were normal. The child was premedicated with oral atropine 0.3 mg an hour before the procedure. General anesthesia was induced with propofol 2 mg kg and fentanyl 2 lg kg. A 4-mm ID uncuffed endotracheal tube was placed after complete muscle relaxation, which was achieved with the administration of rocuronium 1 mg kg. The tube was fixed at the 12 cm mark at the angle of the mouth. Anesthesia was maintained with isoflurane in a mixture of nitrous oxide and oxygen (2:1) and intermittent boluses of fentanyl 1 mcg kg and rocuronium 0.1 mg kg. The procedure was performed in the supine position. Forty-five minutes later, the patient had a sudden increase in airway pressure (from 10 to 22 cm H2O) followed by an increase in expired carbon dioxide partial pressure (from 34 to 48 mmHg) and a decrease in peripheral oxygen saturation. On auscultation of the chest, air entry was found to be diminished on the left side along with wheezing and ronchi all over the left lung field. Possible causes of intraoperative bronchospasm such as endobronchial displacement of the tracheal tube, oropharyngeal secretions and inadequate depth of anesthesia and analgesia were ruled out, and after proper oral and tracheal tube suctioning, a combination of theophylline and etophylline was administered along with hydrocortisone. By this time the radiologist had stopped the procedure, as the patient was being managed for bronchospasm. The radiographic image of the chest did not reveal any obvious abnormality and the lung fields appeared normal. On discussing with the radiologist, it was found that he was manipulating the microcatheter through intercostal artery on the side concerned when the problem was noted. Nearly 30–40 min later, following conservative management, the bronchospasm was relieved and the procedure was allowed to continue. The unilateral nature of bronchospasm rules out the possibility of contrast media as the etiology of intraoperative bronchospasm in our patient. The onset and presence of spasm exclusively on the side of catheter manipulation in the intercostal artery is highly suggestive of the possible etiology. It is likely that stimulation of the bronchial artery at its origin from the intercostal artery might have produced vessel spasm and triggered a series of events resulting in bronchospasm. Though it is difficult to speculate about the exact mechanism of bronchospasm, the possibility of some neural or chemical mediators can always be anticipated, as bronchial musculature is always under the influence of parasympathetic tone. Subsequent negotiation of the catheter through the vessel at a later stage did not produce K. Reddy H. Prabhakar (&) N. Yadav G. P. Singh Department of Neuroanaesthesiology, Neurosciences Center, 7th floor, All India Institute of Medical Sciences, New Delhi 110029, India e-mail: prabhakarhemanshu@rediffmail.com

Anaesthesia for interventional neuroradiology

Anaesthesia is required for neuroradiological diagnostic procedures such as angiograms, computerized tomography (CT), and magnetic resonance imaging (MRI) or for therapeutic intervention (Table 1). Interventional neurovascular procedures are part of a trend towards minimally invasive neurosurgery, an important development in which has been the introduction of the Guglielmi detachable coil (GDC) for endovascular aneurysm coiling. Evidence that coiling is associated with a better outcome than craniotomy and clipping is moving more procedures out of theatres into the neuroradiology suite. Prolonged procedures, improved patient safety, and optimal conditions for imaging have resulted in a trend towards a greater use of general anaesthesia (GA), especially in aneurysm and arteriovenous malformation (AVM) treatments, while conscious sedation is preferred for cerebral ischaemic disease (carotid stents, angioplasty, and thrombolysis). Though many of the risks encountered in this newer arena are conceptually similar to traditional neurosurgery, important differences in the working environment and practice exist.

Anesthesia for neuroradiology

The role of anesthesia outside the operating room is rapidly expanding and evolving alongside with the advances in interventional neuroradiology. Increasingly complex diagnostic and therapeutic neuroradiological procedures are being performed on sicker patients. This review provides an overview of the principles of anesthetic management and summarizes recent advances in interventional neuroradiology. There are many new areas of development in interventional neuroradiology, but each also brings with it controversy. Use of newer agents for anesthesia and for anticoagulation may change the intraoperative management of patients. The role of neurophysiological monitoring during endovascular procedures is still to be validated. The optimal mode of treating cerebral aneurysms is still being debated. There has been increasing interest in and evidence of the efficacy of carotid artery stenting in the treatment of carotid artery disease. The utility of intraoperative magnetic resonance imaging in neurosurgery is expanding rapidly. Providing anesthesia in the interventional neuroradiology suite continues to be a challenge to the anesthesiologist. Understanding the anesthetic constraints and complexities and keeping abreast of the current developments in neuroradiology are crucial in ensuring the maximal benefits to and safety of patients.

Pulmonary edema in the neuroradiology suite: a diagnostic dilemma

To present the case of an initially unexplained complication of sudden pulmonary edema in a patient during stenting of the carotid artery in the interventional neurology suite. A 46-yr-old woman (ASA III) having an intracavernous carotid artery angioplasty and stenting procedure under neurolept anesthesia developed sudden pulmonary edema on completion of an otherwise uneventful stenting procedure. The patient responded well to initial management of pulmonary edema although the cause of the edema remained unclear. On retrospective examination of data and with the evolution of clinical signs it became apparent that the patient had suffered a subarachnoid hemorrhage which eventually resulted in her death. Clinical signs of intracerebral events may be slow to evolve. The cause of sudden pulmonary edema in patients undergoing an interventional neuroendovascular procedure is likely to be neurogenic in origin despite the initial lack of neurological signs.

The Interventional Neuroradiology Suite as an Operating Room

The evolution of new neurointerventional techniques, along with improved imaging and catheter developments, has changed the interventional suite into a subspecialized operating room. This article discusses this operating room as a combination of neuroanesthesia, neuromonitoring, nursing, and technician support coordinated by the neruointerventionalist. The coordination of elective and emergent intervention is also discussed, from conception to completion of the plan, including arteriovenous emoblization, endovascular aneurysm obliteration, intra-arterial thrombolysis, extracranial and intracranial carotid angioplasty, and stenting. Specific examples are illustrated, including pharmacologic intervention complementing these techniques.

Capnography facilitates tight control of ventilation during transport

We tested the hypothesis that Paco2 would be more tightly controlled if end-tidal CO2 monitoring was used during hand ventilation for transport of intubated patients. Randomized, prospective analysis of the no-monitor and monitor-blind groups (the monitor was on the bed during transport but only the investigator was aware of the end-tidal CO2 values). Nonrandomized, prospective analysis of the monitor group (ventilation controlled using end-tidal CO2 value from monitor). University hospital operating room and intensive care unit (ICU). Fifty intubated patients who were transported from the operating room to the ICU or from the ICU to the neuroradiology suite were assigned randomly to one of two groups: a) no-monitor group (n = 25); and b) monitor-blind group (n = 25). An additional group (monitor group, n = 10) was subsequently added to the study. Capnography was instituted in all patients in a blocked fashion. Arterial blood gases and end-tidal CO2 values were measured before and after transport. When comparing overall group data, pre- and post-Paco2 values were similar: monitor 39 +/- 2 vs. 41 +/- 2 torr (5.2 +/- 0.3 vs. 5.5 +/- 0.3 no-monitor 39 +/- 1 vs. 37 +/- torr (5.2 +/- 0.1 vs. 5.0 +/- 0.1 kPa). However, when comparing Paco2 values for individual patients, we found that there was significantly greater variability for Paco2 after transport when end-tidal CO2 was not used for control of ventilation during transport. These data do not support routine monitoring of end-tidal CO2 during short transport times in adult patients requiring mechanical ventilation. However, the monitor may prevent morbidity in patients requiring tight control of Paco2.

Transcranial Magnetic Evoked Potentials Used to Monitor the Spinal Cord During Neuroradiologic Angiography of the Spine

A current topic in intraoperative monitoring of the spinal cord is the inability of the somatosensory evoked potentials (SSEP) to adequately document anterior spinal cord function. Transcranial magnetic stimulation (TMS) of the cortex for assessing corticospinal (efferent) pathways is a developing modality. The authors demonstrate a potential application of TMS as a monitoring medium for use in the neuroradiology suite. Limitations of intraoperative applications of cortical magnetic stimulation associated with cortical suppression are caused by anesthetics and neuromuscular blockers. These limitations generally are not an issue in the neuroradiology suite. In this report, motor improvement was correctly predicted by magnetic evoked potential amplitudes, whereas an SSEP remained unchanged during neuroradiologic angiography.