Intraoperative Neurophysiological Monitoring in Neurosurgery.

Intraoperative neurophysiological monitoring (IONM) is a crucial advancement in neurosurgery, enhancing procedural safety and precision. This technique involves continuous real-time assessment of neurophysiological signals, aiding surgeons in timely interventions to protect neural structures. In addition to inherent limitations, IONM necessitates a detailed anesthetic plan for accurate signal recording. Given the growing importance of IONM in neurosurgery, we conducted a narrative review including the most relevant studies about the modalities and their application in different fields of neurosurgery. In particular, this review provides insights for all physicians and healthcare professionals unfamiliar with IONM, elucidating commonly used techniques in neurosurgery. In particular, it discusses the roles of IONM in various neurosurgical settings such as tumoral brain resection, neurovascular surgery, epilepsy surgery, spinal surgery, and peripheral nerve surgery. Furthermore, it offers an overview of the anesthesiologic strategies and limitations of techniques essential for the effective implementation of IONM.

The "state of the art" of intraoperative neurophysiological monitoring: An Italian neurosurgical survey.

Introduction: Intraoperative Neurophysiological Monitoring (IOM) is widely used in neurosurgery but specific guidelines are lacking. Therefore, we can assume differences in IOM application between Neurosurgical centers. Research question: The section of Functional Neurosurgery of the Italian Society of Neurosurgery realized a survey aiming to obtain general data on the current practice of IOM in Italy. Materials and methods: A 22-item questionnaire was designed focusing on: volume procedures, indications, awake surgery, experience, organization and equipe. The questionnaire has been sent to Italian Neurosurgery centers. Results: A total of 54 centers completed the survey. The annual volume of surgeries range from 300 to 2000, and IOM is used in 10-20% of the procedures. In 46% of the cases is a neurologist or a neurophysiologist who performs IOM. For supra-tentorial pathology, almost all perform MEPs (94%) SSEPs (89%), direct cortical stimulation (85%). All centers perform IOM in spinal surgery and 95% in posterior fossa surgery. Among the 50% that perform peripheral nerve surgery, all use IOM. Awake surgery is performed by 70% of centers. The neurosurgeon is the only responsible for IOM in 35% of centers. In 83% of cases IOM implementation is adequate to the request. Discussion and conclusions: The Italian Neurosurgical centers perform IOM with high level of specialization, but differences exist in organization, techniques, and expertise. Our survey provides a snapshot of the state of the art in Italy and it could be a starting point to implement a consensus on the practice of IOM.

Left Vagus Stimulation Modulates Contralateral Subthalamic ß Power Improving the Gait in Parkinson's Disease.

BACKGROUND: Transcutaneous vagus nerve stimulation (VNS) showed early evidence of efficacy for the gait treatment of Parkinson's disease (PD). OBJECTIVES: Providing data on neurophysiological and clinical effects of transauricular VNS (taVNS). METHODS: Ten patients with recording deep brain stimulation (DBS) have been enrolled in a within participant design pilot study, double-blind crossover sham-controlled trial of taVNS. Subthalamic local field potentials (ß band power), Unified Parkinson's Disease Rating Scales (UPDRS), and a digital timed-up-and-go test (TUG) were measured and compared with real versus sham taVNS during medication-off/DBS-OFF condition. RESULTS: The left taVNS induced a reduction of the total ß power in the contralateral (ie, right) subthalamic nucleus and an improvement of TUG time, speed, and variability. The taVNS-induced ß reduction correlated with the improvement of gait speed. No major clinical changes were observed at UPDRS. CONCLUSIONS: taVNS is a promising strategy for the management of PD gait, deserving prospective trials of chronic neuromodulation. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Eagle syndrome: An updated review.

Background: This work aims to review the current literature and our experience on vascular Eagle syndrome (ES) that can present misleading clinical presentations and better understand the possible therapeutic strategies. Methods: We reviewed the existing literature on PubMed from January 1, 2017, to December 31, 2022, including the sequential keywords "vascular AND Eagle syndrome," "vascular AND styloid syndrome," "vascular AND elongated styloid process," "vascular AND stylocarotid syndrome," and "Eagle syndrome AND carotid artery dissection." Results: 38 vascular ES cases, including our experience, were analyzed. The most frequent clinical onset was hemiparesis (n 21, 57%), but other regular clinical presentations were aphasia, loss of consciousness, amaurosis, headache, or a combination of the latter. Massive oral bleeding was reported only once in the literature before our case. Twelve patients were treated with only antiplatelet therapy, either single or double. Nine patients were treated with anticoagulation therapy only. In 14 patients, a carotid artery stent was used, associated with anticoagulation or antiplatelet therapy. In 17 cases, a styloid process (SP) resection was performed. Conclusion: ES has many clinical presentations, and carotid artery dissection resulting in oral bleeding seems rare. Literature results and our experience make us believe that when dealing with vascular ES, the best treatment strategy is endovascular internal carotid artery stenting with antiplatelet therapy, followed by surgical removal of the elongated SP to prevent stent fracture.

Deep Brain Stimulation of the Anterior Nucleus of the Thalamus in Drug-Resistant Epilepsy in the MORE Multicenter Patient Registry.

BACKGROUND AND OBJECTIVES: The efficacy of deep brain stimulation of the anterior nucleus of the thalamus (ANT DBS) in patients with drug-resistant epilepsy (DRE) was demonstrated in the double-blind Stimulation of the Anterior Nucleus of the Thalamus for Epilepsy randomized controlled trial. The Medtronic Registry for Epilepsy (MORE) aims to understand the safety and longer-term effectiveness of ANT DBS therapy in routine clinical practice. METHODS: MORE is an observational registry collecting prospective and retrospective clinical data. Participants were at least 18 years old, with focal DRE recruited across 25 centers from 13 countries. They were followed for at least 2 years in terms of seizure frequency (SF), responder rate (RR), health-related quality of life (Quality of Life in Epilepsy Inventory 31), depression, and safety outcomes. RESULTS: Of the 191 patients recruited, 170 (mean [SD] age of 35.6 [10.7] years, 43% female) were implanted with DBS therapy and met all eligibility criteria. At baseline, 38% of patients reported cognitive impairment. The median monthly SF decreased by 33.1% from 15.8 at baseline to 8.8 at 2 years (p < 0.0001) with 32.3% RR. In the subgroup of 47 patients who completed 5 years of follow-up, the median monthly SF decreased by 55.1% from 16 at baseline to 7.9 at 5 years (p < 0.0001) with 53.2% RR. High-volume centers (>10 implantations) had 42.8% reduction in median monthly SF by 2 years in comparison with 25.8% in low-volume center. In patients with cognitive impairment, the reduction in median monthly SF was 26.0% by 2 years compared with 36.1% in patients without cognitive impairment. The most frequently reported adverse events were changes (e.g., increased frequency/severity) in seizure (16%), memory impairment (patient-reported complaint, 15%), depressive mood (patient-reported complaint, 13%), and epilepsy (12%). One definite sudden unexpected death in epilepsy case was reported. DISCUSSION: The MORE registry supports the effectiveness and safety of ANT DBS therapy in a real-world setting in the 2 years following implantation. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that ANT DBS reduces the frequency of seizures in patients with drug-resistant focal epilepsy. TRIAL REGISTRATION INFORMATION: MORE ClinicalTrials.gov Identifier: NCT01521754, first posted on January 31, 2012.

Deep brain stimulation of the dentato-rubro-thalamic tract in a case of Holmes tremor: a constrained spherical deconvolution (CSD)-guided procedure.

Deep brain stimulation (DBS) is an established treatment for movement disorders, including Holmes tremor (HT). HT is a rest and action tremor that occurs as a late symptom of brainstem lesions such as stroke. Unfortunately, it is frequently refractory to medical treatment, hence DBS surgery may be a good option. Due to variable results, the ideal target for DBS in HT still remains to be established, ranging from the thalamus to the globus pallidus internus, to the subthalamic nucleus. Pre-operative imaging also is very challenging, as the complexity of brain fiber architecture may prevent the correct positioning of the directional lead. Herein, we describe the case of a patient affected by a rubral tremor secondary to a brain hemorrhage, who had advanced pre-operative neuroimaging with constrained spherical deconvolution (CSD)-based tractography obtained from diffusion-weighted imaging (DWI) to identify the dentato-rubro-thalamic tract, involved in the pathophysiology of HT. The patient was then addressed to an awake DBS surgery, and with the help of intraoperative microelectrode recordings, a tailored DRTT-targeted procedure was performed. The stimulation determined an almost complete tremor suppression, with no significant side effects at a follow-up of 6 months, paving the way towards new effective techniques for the planning, i.e., CSD-based tractography and the treatment of refractory tremors.

Modified percutaneous biopsy of the spine: improvement of the technique.

PURPOSE: Biopsy of the spine can be performed by open surgery or percutaneous needle sampling. The first has the highest diagnostic yield while the second is a less invasive procedure with lower rate of complications and shorter hospitalization time. We described a modified technique of percutaneous biopsy using semi-rigid grasping forceps that may offer the advantages of both, open and minimally invasive surgery. METHODS: Thirty consecutive patients with spinal lesions requiring biopsy were admitted to Neurosurgical Unit of Belcolle Hospital (Viterbo, Italy) from January 2017 to September 2021. There was a suspicion of spondylodiscitis in 25 cases and of tumor in 5 cases. Percutanous trans-pedicular spine biopsy has been performed using this new semi-rigid grasping forceps. Combining the opening width, jaw length and full 360° rotation, the device allows a wide and precise sampling. RESULTS: Sampling was sufficient in all cases (100%); tumors was observed in 5 cases (16.7%%) with a percentage of definitive histopathologic diagnosis of 100% (n = 5); among the remaining patients histological examination yielded a diagnosis of spinal infection in 25 cases (100%), and microbiologic culture provided an aetiologic diagnosis in 23 cases (92%). All procedures were well tolerated, and no postoperative complications were observed. Levels involved included: thoracic (T5-T9) in 8 cases, thoracolumbar junction (T10-L2) in 12 cases and lumbar (L3-L5) in 10 cases. CONCLUSIONS: Percutaneous biopsy with the semi-rigid grasping forceps is a safe and effective procedure that can be used for diagnosis of both infectious and tumor lesions of the spine. It allows to obtain a larger specimen volume and to use a multidirectional trajectory for sampling, resulting in a minimally invasive technique with strong ability to yield etiologic diagnosis.

Deep brain stimulation for Parkinson's disease in practice: results of the survey by the Italian Neurosurgery Society.

BACKGROUND: Deep brain stimulation (DBS) is a safe and effective treatment for patients with advanced Parkinson's disease (PD) and many neurosurgical centers in Italy have a DBS program. Considering the prevalence of PD and criteria for DBS implantation, about 3200-10,350 PD patients may benefit from DBS in Italy. The global management of patients underwent DBS is complex and it can be supposed that many differences exist between centers in clinical practice. The Italian Neurosurgery Society (SINch) designed this survey to investigate the state of the art of DBS for PD in Italy. METHODS: A 26-item closed-ended question survey was designed and sanded by email at all Italian Neurosurgery centers. The main topic investigated was DBS teams, anatomical target selection, surgical procedure, neuroimaging, intraoperative target localization, DBS device and patients' follow-up. RESULTS: A total of 23 neurosurgery centers completed the survey. There are mainly low-to medium-volume centers (<20 annual DBS procedures) with dedicated DBS teams. The principal anatomical target used is subthalamic nucleus (STN) and, relative to the surgical technique, it emerges that in Italy DBS are bilaterally implanted in a single-step session with awake anesthesia and with frame-based technique. Final leads positioning is defined by microelectrode recordings (MER) and microstimulation (MS), with limited role of intraoperative neuroimaging (MRI and O-Arm). The stimulation is started at 15 or 30 days from procedure. CONCLUSIONS: Many centers of neurosurgery in Italy have a well-established DBS program for patients with advanced PD and some practical differences in technique between centers exist. Further investigation is needed to investigate specific criteria for selecting one technique over another.

Pituitary Adenoma Apoplexy: Review of Personal Series.

BACKGROUND: Pituitary apoplexy is a life-threatening event with unspecific clinical background and no standardized treatment. MATERIALS AND METHODS: The authors retrospectively analyzed seventeen patients affected by pituitary adenoma apoplexy and treated in a 10-year period. Thirteen patients underwent surgery through transsphenoidal route while four patients have been treated conservatively. RESULTS: The endoscopic surgical procedure showed a better result in term of complete removal of the tumor while in the "conservative" group less frequent evidence of hormones' deficiency has been registered. Once a residual lesions was observed a strict radiological follow-up is mandatory. CONCLUSIONS: According to dedicated literature and pre- and post-operative evidence of personal series, the authors try to provide an algorithm that could help in the standardization of the diagnostic and therapeutic pathways in patients with pituitary adenoma apoplexy.

Delayed Intracerebral Hemorrhage After Pseudoaneurysm of Middle Meningeal Artery Rupture: Case Report, Literature Review, and Forensic Issues.

BACKGROUND: Traumatic pseudoaneurysm of the middle meningeal artery (PMMA) is rare. Its rupture is associated with high mortality, so an early diagnosis is recommended for this risky condition. In the absence of a specific guideline, computed tomography (CT), digital subtraction angiography, and CT angiography (CTA) are proposed for its diagnosis. CTA is the technique of choice even if it is almost never performed, especially in mild head injury. We report a rare case of a delayed rupture of PMMA, analyzed from a forensic point of view. METHODS: Fifteen days after mild blunt head trauma, characterized by temporal fracture and a small hemorrhage near the rim, a wide intraparenchymal hemorrhage (IPH) occurred. The onset of IPH was marked by neurologic deterioration and arm paralysis. Immediate head CT showed IPH, and CTA showed PMMA. Prompt surgery could not help patient survival. The goal of autopsy was to formulate the cause of death and to individuate potential medical negligence. RESULTS: In the literature, 16 cases of 54 are related to PMMA (26%) and are associated with IPH. IPH can be acute or delayed. Eight cases of acute IPH and 8 cases of delayed IPH (including our case), both coexisting with PMMA, are described. The literature review showed that the association of temporal rim fracture and a small hemorrhage nearby is highly predictive of PMMA formation. CONCLUSIONS: Therefore, in the presence of these 2 risk factors after heat trauma, CTA is strongly suggested.

Effects of somatostatin and its analogues on progenitor mesenchymal cells isolated from human pituitary adenomas.

PURPOSE: Progenitor mesenchymal cells (PMCs) have been found also in epithelial tumors and may derive from cancer stem cells (CSCs) by EMT mechanism. In this scenario, the effects of traditionally drugs on PMCs become of primary concern for therapeutic approaches. Previously, we isolated PMCs from acromegalic (GHomas) and not-functioning pituitary adenomas (NFPAs). Here we evaluate: (1) the role of EMT on their origin; (2) the presence of the somatostatin receptors (SSTR1-5); (3) the effects of somatostatin (SST) and its analogues (SSAs) on PMCs proliferation, apoptosis and SSTR1-5 expression. METHODS: PMCs were isolated from GHomas and NFPAs; the expression of E-CADHERIN and TGFßRII (referred to EMT), the expression of the SSTR1-5 as well as the proliferation and apoptosis were tested before and after drugs administration. RESULTS: Results show a decrease of E-CADHERIN and an increase of TGFßRII, confirming an EMT involvement; SSTR1-5 are more expressed by PMCs from GHomas than from NFPAs. SST and SSAs administration does not affect cell proliferation and SSTR1-5 expression on PMCs from NFPAs while in PMCs from GHomas, cell proliferation showed a marked decrease and a corresponding increase in the expression of SSTR1-2. Apoptosis rate and EMT were not affected by drugs administration. CONCLUSIONS: Results indicate as EMT may be related to the presence of PMCs on pituitary tumors; SSAs, currently used in the management of human GHomas, exert anti-proliferative effect also in PMCs that, because of their derivation from CSCs, may be a new meaningful target for drugs treatment.

Extending technology-aided leisure and communication programs to persons with spinal cord injury and post-coma multiple disabilities.

PURPOSE: These two studies extended technology-aided programs to promote leisure and communication opportunities to a man with cervical spinal cord injury and a post-coma man with multiple disabilities. METHOD: The studies involved the use of ABAB designs, in which A and B represented baseline and intervention phases, respectively. The programs focused on enabling the participants to activate songs, videos, requests, text messages, and telephone calls. These options were presented on a computer screen and activated through a small pressure microswitch by the man with spinal cord injury and a special touch screen by the post-coma man. To help the latter participant, who had no verbal skills, with requests and telephone calls, series of words and phrases were made available that he could activate in those situations. RESULTS: Data showed that both participants were successful in managing the programs arranged for them. The man with spinal cord injury activated mean frequencies of above five options per 10-min session. The post-coma man activated mean frequencies of about 12 options per 20-min session. CONCLUSIONS: Technology-aided programs for promoting leisure and communication opportunities might be successfully tailored to persons with spinal cord injury and persons with post-coma multiple disabilities. Implications for Rehabilitation Technology-aided programs may be critical to enable persons with pervasive motor impairment to engage in leisure activities and communication events independently. Persons with spinal cord injury, post-coma extended brain damage, and forms of neurodegenerative disease, such as amyotrophic lateral sclerosis, may benefit from those programs. The programs could be adapted to the participants' characteristics, both in terms of technology and contents, so as to improve their overall impact on the participants' functioning and general mood.

Chronic bilateral subthalamic stimulation after anterior callosotomy in drug-resistant epilepsy: long-term clinical and functional outcome of two cases.

We explored the efficacy and safety of bilateral SubThalamic Nucleus (STN) stimulation in two subjects suffering from drug-resistant epilepsy even after anterior callosotomy. Case 1 had about 65% decrease of partial motor seizures and the complete disappearance of tonic-clonic generalized attacks. Case 2, with sudden drop (atonic) attacks, partial complex seizures, atypical absences and rare tonic-clonic seizures, showed no meaningful reduction of fits and a stimulation associated atypical absence rate increase.

Vagus nerve stimulation: clinical experience in drug-resistant pediatric epileptic patients.

INTRODUCTION: Vagus nerve stimulation (VNS) is an effective alternative treatment for patients with partial refractory epilepsy. Nevertheless, information regarding VNS in children is still limited. MATERIALS AND METHODS: The clinical efficacy, safety and neuropsychological effects of VNS in 34 children (mean age 11.5 years) with drug-resistant epilepsy were studied. Mean follow-up was 30.8 months. Nine patients have been diagnosed with Lennox-Gastaut Syndrome, nine patients were affected by severe partial epilepsy with bisynchronous EEG and drop attacks, and 16 patients suffered from partial epilepsy without bisynchronous EEG and fall seizures. Forms were designed for prospective data collection on each patient's history, seizures, implants, device settings, quality of life (QOL), neuropsychological assessment and adverse events. Surgical technique was performed both by standard two incisions and single neck incision. RESULTS: Mean reduction in total seizures was 39% at 3 months, 38% at 6 months, 49% at 12 months, 61% at 24 months and 71% at 36 months. Significant better results were obtained in partial epilepsy, with and without drop attacks, than in Lennox-Gastaut syndrome--three patients being seizure-free. No operative morbidity was reported. Side-effects were minor and transient--the most common were voice alteration and coughing during stimulation. In two patients, electrode breakage occurred 3 years after surgical procedure; in both cases, a new device was implanted after removing the vagal electrode coils and generator. CONCLUSION: VNS can be considered an appropriate strategy as an add-on treatment in children affected by drug-resistant partial epilepsy and ineligible for resective epilepsy surgery.

Chronic bilateral subthalamic deep brain stimulation in a patient with homozygous deletion in the parkin gene.

Chronic subthalamic nucleus deep brain stimulation (STN-DBS) is an efficacious treatment for idiopathic Parkinson's disease (PD) that cannot be further improved by medical therapy. We present a case of an individual with juvenile parkinsonism caused by homozygous deletion of exon 3 in the parkin gene with disabling long-term side-effects from levodopa who underwent bilateral STN neuromodulation. Parkin-linked parkinsonism may show clinical features different from sporadic PD, yet it shares levodopa responsiveness. Because levodopa responsiveness is a predictor of STN-DBS efficacy, we argued that this kind of surgical approach might be efficacious in hereditary parkin-linked juvenile parkinsonism. We evaluated clinical and functional assessment before and 12 months after surgery. The results showed that the Unified Parkinson Disease Rating Scales Motor score improved by 84% in our patient, the levodopa equivalent daily dose medication (LEDD) was reduced by 66%, and, finally, disabling and severe dyskinesias disappeared.

Gemella morbillorum deep brain abscess successfully treated with combined stereotactic, medical, and imaging approach.

A rare case of brain abscess due to Gemella morbillorum, a normal inhabitant of the oral cavity, is presented. The aim of this report is to draw the attention of radiology literature readers to this little known pathogen, which caused a potentially life-threatening condition in an immunocompetent young man, and to emphasise the usefulness of a combined stereotactic, medical, and imaging approach to deep-located brain abscesses.