Degenerative L4-L5 spondylolisthesis and stenosis surgery: does over-level flavectomy technique influence clinical outcomes and rates of cranial adjacent segment disease?

BACKGROUND: One of the most dreaded long-term complications related to L4-L5 lumbar arthrodesis is the onset of adjacent segment disease, which most frequently occurs at the cranial level. Few studies have compared the rates of cranial adjacent segment disease (CASD) in patients undergoing lumbar fusion associated with total laminectomy at the same level with those undergoing partial laminectomy. No study has examined the role of selective over-level flavectomy (OLF; i.e., L3-L4). METHODS: A total of 299 patients undergoing posterolateral arthrodesis (PLA) for L4-L5 degenerative spondylolisthesis were retrospectively analyzed with a 5-year follow-up. 148 patients underwent PLA + L4-L5 flavectomy + L4 partial laminectomy (control group), while 151 underwent PLA + L4-L5 flavectomy + total L4 laminectomy + L3-L4 flavectomy (OLF group). Rates of reoperations due to CASD were examined utilizing Cox proportional hazard models, while clinical improvement at follow-up (measured in ODI) was analyzed using generalized linear models (GLMs). Adjustments for potential confounders were made (grade of lumbar lordosis, age, sex, BMI, intervertebral disc degeneration, and presurgical cranial spinal stenosis). RESULTS: At 5 years from the operation, 16 patients (10.8%) in the control group had undergone revision surgery for CASD compared to 5 patients (3.3%) in the OLF group (p = 0.013). Survival analysis and GLM demonstrated that the OLF group had a significantly lower incidence of CASD and presented more favorable clinical outcome. There were no differences in the rate of discal degeneration or the onset of Meyerding's grade I degenerative spondylolisthesis at the adjacent segment. BMI was the only other significant predictor of ODI improvement and of the incidence of CASD. CONCLUSIONS: In patients with L4-L5 degenerative spondylolisthesis and stenosis, the OLF technique may lower rates of CASD and improve clinical outcomes by preventing cranial spinal stenosis without increasing iatrogenic instability or accelerating intervertebral disc degenerative changes.

Diagnostic approach, therapeutic strategies, and surgical indications in intradural thoracic disc herniation associated with CSF leak, intracranial hypotension, and CNS superficial siderosis.

BACKGROUND AND PURPOSE: Intradural disc herniation (IDH) can manifest with radicular or medullary syndrome. In about 15% of cases, IDH may be responsible, through a dural laceration, for a CSF leak, determining spontaneous intracranial hypotension (SIH) and CNS superficial siderosis (CNSss). This paper attempts to present an overview on IDH as the cause for both CSF leak, and subsequent SIH, and CNSss, and to describe a peculiar clinical and neuroradiological scenario related to this condition. METHODS: A search on the PUBMED database was performed. Although the investigation did not rigorously follow the criteria for a systematic review (we consider only articles about thoracic IDH), nonetheless, the best quality evidence was pursued. Furthermore, an illustrative case was presented. RESULTS: A 69-year-old woman was referred to our hospital for slowly progressive gait disturbances and hearing impairment. Brain imaging revealed diffuse bilateral supratentorial and infratentorial superficial siderosis, mostly of the cerebellum, the eighth cranial nerves, and the brainstem. Spinal imaging disclosed a posterior disc herniation determining a dural tear at D6-D7. Lumbar puncture revealed low opening pressure and hemorrhagic CSF with siderophages. A posterior transdural herniectomy and dural sealing determined a stabilization of hearing and a significant improvement in both gait and balance. CONCLUSIONS: The diagnostic workup of CNSss with suspected CNS leak demands whole neuraxis imaging, especially in cases presenting SIH or myelopathic symptoms. This may avoid delays in detection of IDH and spinal dural leaks. The different forms of treatment available depend on the type and severity of the clinical picture.

Occipital Intradiploic Pseudomeningocele - A Rare Complication of Pediatric Posterior Cranial Fossa Surgery: Case Report and Review of the Literature.

INTRODUCTION: Intradiploic pseudomeningoceles, also called intradiploic cerebrospinal fluid (CSF) fistulas, are abnormal CSF collections between the two bony tables of the calvaria resulting from postsurgical CSF leakage. To date, only six cases of intradiploic pseudomeningocele have been reported, all occurring in the occipital area. In this paper, we report the seventh case of late-onset occipital intradiploic pseudomeningocele (OIP) occurring in a young female patient who underwent surgery for the removal of a cerebellar pilocytic astrocytoma. In this regard, we also review the literature on the few recognized cases of OIP. CASE PRESENTATION: The case of an 18-year-old female patient known to our institute for an operation 12 years earlier to remove a pilocytic astrocytoma is illustrated. At admission, the patient complained only of occasional orthostatic headache. Brain imaging demonstrated a pseudomeningocele extended intradiploically from the occipital squama to the condylar and clivus regions, thinning both occipital bone tables and dilating the CSF-filled diploe. Watertight duroplasty and cranioplasty were effectively performed. CONCLUSION: Pediatric patients undergoing posterior cranial fossa craniotomy/craniectomy may postoperatively develop OIP. In this setting, treatment of any dural CSF fistula should be considered because of the risk of progressive extension and bone erosion.

Deep brain stimulation in Huntington's disease: a literature review.

BACKGROUND: Huntington's disease (HD) is a neurodegenerative disorder characterized by involuntary movements, cognitive decline, and behavioral changes. The complex constellation of clinical symptoms still makes the therapeutic management challenging. In the new era of functional neurosurgery, deep brain stimulation (DBS) may represent a promising therapeutic approach in selected HD patients. METHODS: Articles describing the effect of DBS in patients affected by HD were selected from Medline and PubMed by the association of text words with MeSH terms as follows: "Deep brain stimulation," "DBS," and "HD," "Huntington's disease," and "Huntington." Details on repeat expansion, age at operation, target of operation, duration of follow-up, stimulation parameters, adverse events, and outcome measures were collected. RESULTS: Twenty eligible studies, assessing 42 patients with HD, were identified. The effect of globus pallidus internus (GPi) DBS on Unified Huntington's Disease Rating Scale (UHDRS) total score revealed in 10 studies an improvement of total score from 5.4 to 34.5%, and in 4 studies, an increase of motor score from 3.8 to 97.8%. Bilateral GPi-DBS was reported to be effective in reducing Chorea subscore in all studies, with a mean percentage reduction from 21.4 to 73.6%. CONCLUSIONS: HD patients with predominant choreic symptoms may be the best candidates for surgery, but the role of other clinical features and of disease progression should be elucidated. For this reason, there is a need for more reliable criteria that may guide the selection of HD patients suitable for DBS. Accordingly, further studies including functional outcomes as primary endpoints are needed.

The suprasellar volume of nonfunctioning pituitary adenomas: a useful tool for predicting visual field deficits.

PURPOSE: The aim of the present study is to assess the predictive value of the suprasellar volume (SSV) of nonfunctioning pituitary adenomas (NFPAs) for visual field (VF) impairment in order to guide clinical decision-making and improve neurosurgical management. METHODS: Two independent samples of patients with NFPAs (exploratory population N = 50, testing population N = 98) were included in the present study. In the first phase, we determined the optimal cut-off value of the SSV correlating with VF deficits in the exploratory population. In the second phase, we then studied the accuracy of identified cut-off in predicting a VF deficit in the testing population. RESULTS: In the exploratory population, the optimal cut-off value of the SSV to determine the presence of a VF deficit was 1.5 mL. Sensitivity and specificity of the cut-off were 81.3 and 100%, respectively. The positive predictive value (PPV) and the negative predictive value (NPV) were 100 and 75%, respectively. When we checked the identified cut-off score on the testing population, we found a sensitivity of 71% and a specificity of 100%. The PPV and NPV were 100 and 59.2%, respectively. In six cases with VF defects and SSV inferior to 1.5 mL, the displacement of optic chiasm was in superior position. CONCLUSION: The SSV may represent an accurate method in routinely clinical practice for predicting VF deficit in patients affected by NFPA.

Exoscopic-assisted posterior approach for the removal of thoracic dumbbell schwannoma: Three-dimensional operative video.

"Dumbbell" tumors are described as benign neoplasms presenting both intraspinal and extraspinal extensions, connected through the intervertebral foramen (McCormick, 1996) [1]. About 90 % of such tumors are histologically classified as schwannomas that most frequently arise in the thoracic region (Takamura and et al., 1997) [2]. Diagnosis is usually achieved as soon as the dimensional increase of the intracanal portion results in nerve or spinal cord compression (Ishikawa and et al., 2002) [3]. How to obtain a complete surgical resection of tumors with large or ventrally located extraforaminal components with a minimally invasive approach is still debated (Payer and et al., 2006) [4]. The single-stage posterior removal of the tumor is the most performed approach for lesions presenting with a small extra-foraminal component (Payer and et al., 2006) [4]. However, due to the reduced visual surgical field and poor control of the surrounding structures that could be obtained with an operative microscopic (OM) view, the application of this approach still appears to be limited to lesions with a large extraspinal component. An alternative surgical approach is the lateral transthoracic transpleural approach, which, however, carries greater risks of complications and often requires assistance from a thoracic surgeon. During the last decade, the exoscope was developed as a hybrid optical instrument, standing between the OM and the endoscope, merging the pros and cons of both visualization technologies, providing a wide viewing angle, high-resolution images, and non-monoaxial view. In this work we present a case of a 60-years old male patient with a 6-month history of dorsal pain and mild left limb paresthesia resistant to conservative treatment in which for the first time a single stage exoscopic-assisted (Olympus ORBEYE 4K-3D exoscope) posterior approach was used to remove entirely a thoracic dumbbell schwannoma with large extraspinal involvement.

Articular arthrodesis with the facet wedge technique for the treatment of unstable lumbar degenerative disease and associated conditions: A retrospective study of 96 patients.

Background: Lumbar articular fusion with the facet wedge (FW) technique is gaining increasing interest among surgeons for the treatment of vertebral instability due to its limited invasiveness and ease of use. Studies on cadavers have reported biomechanical properties similar to pedicle screws. Yet, the evidence supporting their use is still limited and moreover focused only on spinal degenerative disease. Methods: 96 cases of lumbar articular fusion with the FW techniques performed at 3 different centers between 2014 and 2022 were retrospectively analyzed based on the specific surgical indications: 1) degenerative spondylolisthesis/unstable lumbar stenosis; 2) synovial cysts; 3) adjacent segment disease (ASD). Medical records were reviewed to identify rates of complications and measures of functional outcome (ODI, low back pain VAS and modified Macnab scale) were collected both at baseline and at the follow-up visits. Wilcoxon signed-rank test was adopted to test for significant functional improvements. Results: Significative clinical improvements were observed from baseline to follow-up regarding ODI and VAS scores. Overall rate of moderate and severe complications (according to Landriel-Ibañez scale) was 7.9%. Only 3.4% of patients with degenerative disease developed ASD requiring reoperations. Only one case of radicular deficit and one of device mobilization were reported. 2/4 cases of synovial cysts treated with unilateral fusions developed contralateral complications. 9 out of 16 (56.25%) patients who underwent long-term postoperative CT scans presented adequate degree of articular fusion. Conclusion: FW technique is easy, safe, and effective. Its low rate of complications justifies its use for cases of mild lumbar instability.

Proposal of a new score system (Cervical Surgical Score) for management of degenerative cervical myelopathy.

BACKGROUND: To date, no shared algorithms with the aim of guiding surgical strategy in complex cases of degenerative cervical myelopathy (DCM) exist. Our purpose is to present the Cervical Surgical Score (CSS) which could help in identifying complex DCM cases, suggesting a surgical strategy. METHODS: We created the CSS based on multidisciplinary and literature-focused discussions, based on eight parameters including number of levels of cervical pathology and myelopathy, type and predominance of compression and grade of clinical myelopathy. We prospectively enrolled surgical DCM patients in a 15-months period, collecting clinical and radiological data. During outpatient clinic a specific surgical indication was offered to DCM patients. To validate the score, each outpatient clinic surgical indication was compared a posteriori to the one that resulted from multidisciplinary CSS scoring, focusing on patients for which both an anterior and posterior approach were considered suitable. RESULTS: A total of 100 patients operated on for DCM at our Institution between December 2021 and February 2023 were prospectively enrolled. In 53% of patients the pathology was present at more than two levels. According to CSS calculation, 14% of patients resulted in the "grey zone", where both an anterior and posterior approach were deemed feasible. Among them, in 42.8% of cases the CSS allowed a modification of the originally planned surgery. Looking at outcome, an improvement of m-JOA score in 62% of patients was disclosed. CONCLUSIONS: This preliminary study showed the reliability and usefulness of CSS in detecting complex DCM cases, requiring further analysis by expert spine surgeons, suggesting a surgical strategy.

Integrative approaches in spinal cord stimulation: Neuropathic pain management and motor recovery in spinal cord injury. A narrative review.

Introduction: Spinal cord stimulation is a widespread treatment of chronic neuropathic pain from different conditions. Several novel and improving technologies have been recently developed to increase the effect of neuromodulation in patients refractory to pharmacological therapy. Research question: To explore spinal cord stimulation's mechanisms of action, indications, and management. Material and methods: The paper initially explores the mechanism of action of this procedure based on the generation of an electric field between electrodes placed on the posterior dural surface of the spinal cord probably interfering with the transmission of pain stimuli to the brain. Subsequently, the most consolidated criteria for selecting patients for surgery, which constitute a major issue of debate, were defined. Thereafter, the fundamental patterns of stimulation were summarized by exploring the advantages and side effects. Lastly, the most common side effects and the related management were discussed. Results: Proper selection of the patient is of paramount importance to achieve the best results from this specific neuromodulation treatment. Regarding the different types of stimulation patterns, no definite evidence-based guidelines exist on the most appropriate approach in relation to the specific type of neuropathic pain. Both burst stimulation and high-frequency stimulation are innovative techniques that reduce the risk of paresthesias compared with conventional stimulation. Discussion and conclusion: Novel protocols of stimulation (burst stimulation and high frequency stimulation) may improve the trade-off between therapeutic benefits and potential side effects. Likewise, decreasing the rates of hardware-related complications will be also useful to increase the application of neuromodulation in clinical settings.

A Benefit/Risk Assessment of Intrathecal Ziconotide in Chronic Pain: A Narrative Review.

BACKGROUND: Ziconotide is an intrathecal drug administered for the treatment of chronic pain. The current literature lacks an exhaustive benefit/risk assessment on this drug. We herein focus on Ziconotide's pharmacology and clinical applications. METHODS: Literature research was conducted to identify studies on Ziconotide administration for the treatment of chronic pain, published between January 1990 and March 2023 and located via PubMed, Embase, Medline, Cinahl, and Web of Science, using the following keywords: Ziconotide, Omega conotoxin, Prialt, SNX-111, intrathecal therapy, and neuropathic pain. Only publications written in English were selected. RESULTS: Among the 86 selected studies, we found 4 Randomized Controlled Trials (RCTs) and 3 prospective long-term studies concerning the intrathecal use of Ziconotide as a monotherapy in chronic pain. Other studies described the intrathecal infusion of Ziconotide combined with other drugs. Overall, Ziconotide has been proved to have strong efficacy for relieving chronic pain, although patients with co-morbid psychiatric disorders require a careful monitoring when treated with Ziconotide. CONCLUSIONS: Overall, the use of Ziconotide, as a monotherapy or in conjunction with other therapies for the treatment of chronic pain, was reported to be efficacious. Overall, its use in patients with chronic pain refractory to other pharmacologic agents outweighs the possible adverse consequences, thus resulting in a favorable benefit/risk assessment.

Anesthesia-induced Takotsubo cardiomyopathy in trigeminal neuralgia: illustrative case.

BACKGROUND: Takotsubo syndrome (TS) represents a form of nonischemic cardiomyopathy characterized by sudden and temporary weakening of the myocardium. Many data suggest a primary role for sympathetic overstimulation in its pathogenesis. Nevertheless, these correlates are less easily identified during anesthesia. OBSERVATIONS: A 50-year-old female patient with a 4-year history of drug-resistant left trigeminal neuralgia. She was scheduled for surgical microvascular decompression. In the operating room, after induction of general anesthesia and oral intubation, the electrocardiogram revealed a significant ST segment elevation along with a sudden decrease in systolic blood pressure and heart rate. Administration of atropine caused a conversion into ventricular tachycardia. The advanced cardiac life support protocols were applied with prompt defibrillation and rapid recovery at sinus rhythm. A transthoracic echocardiogram revealed apical akinesia with ballooning of the left ventricle with a reduction of systolic function. An emergency coronary arteriography was performed, showing normal epicardial coronary vessels. After 4 days, echocardiography revealed normalization of the left ventricular function with improvement of the ejection fraction. LESSONS: In patients affected by trigeminal neuralgia, chronic pain can lead to a state of adrenergic hyperactivation, which can promote TS during the induction of general anesthesia, probably through the trigeminocardiac reflex.

Intraoperative Neurophysiologic and Angiographic Techniques to Identify the Posterior Median Sulcus for Midline Myelotomy.

Accurate midline myelotomy through the posterior median sulcus (PMS) is the key step to minimize surgical morbidity during intramedullary tumor removal.1,2 When an intramedullary mass is present, the cord is usually rotated and it may be difficult to distinguish its sulci.2-4 Inadvertent dissection through the dorsal columns exposes the patient to disabling postoperative deficits.5 In recent years, together with the well-established neurophysiologic phase-reversal method, newer intraoperative angiographic techniques have been developed to identify the PMS.1-4 In order to illustrate the combination of the 2, we present the case of a 31-year-old man with a right claw hand syndrome who underwent surgical excision of a C6-D1 ependymoma (Video 1).6,7 After localizing the tumor with ultrasound, somatosensory evoked potentials (obtained by stimulating the dorsal columns with the use of a bipolar handheld neurostimulator) were employed to identify the PMS by means of the phase reversal technique, which uncovered the silent central line corresponding to the PMS. Use of indocyanine green fluorescence (ICG) later confirmed with certainty the location of the spinal cord's midline by enabling identification of the dorsal medullary veins exiting the PMS. As expected, the midline was significantly laterally displaced by the tumor. After penetrating the PMS, gentle dissection between the 2 posterior chordae enabled the surgeon to reach and enucleate the tumor in a minimally traumatic fashion. No postoperative deficits were reported. This method represents a direct and effective way to reduce morbidity resulting from this type of surgery.

MER and increased operative time are not risk factors for the formation of pneumocephalus during DBS.

Although only recently directional leads have proven their potential to compensate for sub-optimally placed electrodes, optimal lead positioning remains the most critical factor in determining Deep Brain Stimulation (DBS) outcome. Pneumocephalus is a recognized source of error, but the factors that contribute to its formation are still a matter of debate. Among these, operative time is one of the most controversial. Because cases of DBS performed with Microelectrode Recordings (MER) are affected by an increase in surgical length, it is useful to analyze whether MER places patients at risk for increased intracranial air entry. Data of 94 patients from two different institutes who underwent DBS for different neurologic and psychiatric conditions were analyzed for the presence of postoperative pneumocephalus. Operative time and use of MER, as well as other potential risk factors for pneumocephalus (age, awake vs. asleep surgery, number of MER passages, burr hole size, target and unilateral vs. bilateral implants) were examined. Mann-Whitney U and Kruskal-Wallis tests were utilized to compare intracranial air distributions across groups of categorical variables. Partial correlations were used to assess the association between time and volume. A generalized linear model was created to predict the effects of time and MER on the volume of intracranial air, controlling for other potential risk factors identified: age, number of MER passages, awake vs. asleep surgery, burr hole size, target, unilateral vs. bilateral surgery. Significantly different distributions of air volume were noted between different targets, unilateral vs. bilateral implants, and number of MER trajectories. Patients undergoing DBS with MER did not present a significant increase in pneumocephalus compared to patients operated without (p = 0.067). No significant correlation was found between pneumocephalus and time. Using multivariate analysis, unilateral implants exhibited lower volumes of pneumocephalus (p = 0.002). Two specific targets exhibited significantly different volumes of pneumocephalus: the bed nucleus of the stria terminalis with lower volumes (p < 0.001) and the posterior hypothalamus with higher volumes (p = 0.011). MER, time, and other parameters analyzed failed to reach statistical significance. Operative time and use of intraoperative MER are not significant predictors of pneumocephalus during DBS. Air entry is greater for bilateral surgeries and may be also influenced by the specific stimulated target.

A new study protocol for in-vivo assessment of tumor diagnosis and microscopic tumor infiltration at the resection cavity in central nervous system tumors by a new miniature confocal endomicroscope (CONVIVO system).

BACKGROUND: Confocal laser technology has been recently suggested as a promising method to obtain near real-time intraoperative histological data. We recently demonstrated the accuracy of a newly designed confocal endomiscroscope (CONVIVO) in offering an intraoperative diagnosis during high-grade gliomas (HGGs) removal in an ex vivo study. With this work we aim to perform a standardized, prospective and blinded-to-histological section study for evaluating the potentiality of CONVIVO in offering in-vivo data regarding histological diagnosis and presence of tumor at margins during resection of central nervous system (CNS) tumors. METHODS: This prospective, observational, standardized, blinded-to-histological section, clinical trial was approved by the institutional review board in Carlo Besta Neurologic Institute IRCCS Foundation in Milan and is expected to last 24 months. 75 patients will be included, with at least 53 of them being HGGs based on the statistical sample size calculation. Main objectives will be the assessing of the concordance of tumor diagnoses between CONVIVO images and frozen section at the center of all tumor subtypes and the evaluation of the accuracy of CONVIVO in the identification of tumor tissue at the margins, compared to standard histology. For this purpose, "virtual biopsies" and physical biopsies will be performed directly on patient tumor tissue and surrounding brain parenchima during tumor resection, comparing the results of CONVIVO analysis and frozen and histological sections. RESULTS: Despite promising preliminary data on ex vivo usefulness of CLE machines are emerging in literature, still few studies are available when looking at in vivo potentiality of CONVIVO. At this regard, this study will be the first work where a standardized, prospective, and blinded-to-histological section CONVIVO analysis will be performed in an in-vivo setting in neuro-oncological surgery. CONCLUSIONS: We hypothesize that this new technique may have a role in offering data regarding presence of tumor tissue, eventually giving an intraoperative diagnosis in neuro-oncological surgery, rendering more fluid the decision-making process in the operating room. Furthermore, the result of this study will provide a solid base for further expanding the clinical applications of confocal machines in neurosurgery.

Sporadic spinal psammomatous malignant melanotic nerve sheath tumor: A case report and literature review.

Background: Sporadic Spinal Psammomatous Malignant Melanotic Nerve Sheath Tumor (SSP-MMNST) is a rare subgroup of peripheral nerve sheath tumors arising along the spine. Only a few reports of SSP-MMNST have been described. In this paper, we review the literature on SSP-MMNST focusing on clinical, and diagnostic features, as well as investigating possible pathogenetic mechanisms to better implement therapeutic strategies. We also report an illustrative case of a young female presenting with cervicobrachial pain due to two SSP-MMNSTs arising from C5-6 right spinal roots. Case description: We report a case of a 28-year-old woman presenting with right arm weakness and dysesthesia. Clinical examination and neuroimaging were performed, and, following surgical removal of both lesions, a histological diagnosis of SSP-MMNST was obtained. Results: The literature review identified 21 eligible studies assessing 23 patients with SSP-MMNST, with a mean onset age of 41 years and a slight male gender preference. The lumbar district was the most involved spinal segment. Gross-total resection (GTR) was the treatment of choice in all amenable cases, followed in selected cases with residual tumor by adjuvant radiotherapy or chemotherapy. The metastatic and recurrence rates were 31.58% and 36.8%, respectively. Conclusion: Differently from common schwannomas, MMNST represents a rare disease with known recurrence and metastatization propensity. As reported in our review, SSP-MMNST has a greater recurrence rate when compared to other forms of spinal MMNST, raising questions about the greater aggressiveness of the former. We also found that residual disease is related to a higher risk of systemic disease spreading. This metastatic potential, usually associated with primary lumbar localization, is characterized by a slight male prevalence. Indeed, whenever GTR is unachievable, considering the higher recurrence rate, adjuvant radiation therapy should be taken into consideration.

Small spheno-ethmoidal meningoencephalocele versus ethmoidal mucocele in spontaneous intracranial hypotension.

Background: Meningoencephalocele is defined as an abnormal sac of brain tissue and meninges extending beyond natural skull margins, often leading to cerebrospinal fluid (CSF) leakage. When this condition arises in the spheno-ethmoidal region, the diagnosis becomes more challenging as it can be mistaken for other nasal pathologies, such as mucocele. Research question: We show in this case report a non-congenital sphenoethmoidal meningoencephalocele causing rhinoliquoral fistula and spontaneous intracranial hypotension. Results: this 65-year-old woman presented with sporadic rhinoliquorrhoea associated with orthostatic headache, nausea and dizziness. Brain MRI revealed a small lesion of an ethmoidal sinus, which was successfully treated with endoscopic endonasal surgery. Histology confirmed the presence of meningoencephalic tissue positive for S100 protein on immunohistochemistry. Conclusions: When dealing with lesions of the paranasal sinuses in contact with the anterior skull base, rhinoliquorrhoea presence suggests meningoencephalocele. In dubious cases, a proper workup, including a thorough clinical history and neurological examination, specific imaging, and a direct search of CSF-like markers, is essential to support the differential diagnosis. In such cases, a transnasal endoscopic surgical approach is recommended to obtain a final histological diagnosis and to perform eventual dural plastic surgery.

Are Thalamic Intrinsic Lesions Operable? No-Man's Land Revisited by the Analysis of a Large Retrospective, Mono-Institutional, Cohort.

Thalamic gliomas represent a heterogeneous subset of deep-seated lesions for which surgical removal is advocated, although clear prognostic factors linked to advantages in performance status or overall survival are still lacking. We reviewed our Institutional Cancer Registry, identifying patients who underwent surgery for thalamic gliomas between 2006 and 2020. Associations between possible prognostic factors such as tumor volume, grade, the extent of resection and performance status (PS), and overall survival (OS) were evaluated using univariate and multivariate survival analyses. We found 56 patients: 31 underwent surgery, and 25 underwent biopsy. Compared to biopsy, surgery resulted positively associated with an increase in the OS (hazard ratio, HR, at multivariate analysis 0.30, 95% confidence interval, CI, 0.12-0.75). Considering the extent of resection (EOR), obtaining GTR/STR appeared to offer an OS advantage in high-grade gliomas (HGG) patients submitted to surgical resection if compared to biopsy, although we did not find statistical significance at multivariate analysis (HR 0.53, 95% CI 0.17-1.59). Patients with a stable 3-month KPS after surgery demonstrated to have a better prognosis in terms of OS if compared to biopsy (multivariate HR 0.17, 95% CI, 0.05-0.59). Age and histological grades were found to be prognostic factors for this condition (p = 0.04 and p = 0.004, respectively, chi-square test). Considering the entire cohort, p53 positivity (univariate HR 2.21, 95% CI 1.01-4.82) and ATRX positivity (univariate HR 2.69, 95% CI 0.92-7.83) resulted associated with a worse prognosis in terms of OS. In this work, we demonstrated that surgery aimed at tumor resection might offer a stronger survival advantage when a stable 3-month KPS after surgery is achieved.

Role of deep brain stimulation in management of psychiatric disorders.

Nowadays, most of patients affected by psychiatric disorders are successfully treated with conservative therapies. Still, a variable percentage of them demonstrate resistance to conventional treatments, and alternative methods can then be considered. During the last 20 years, there is a progressive interest in use of deep brain stimulation (DBS) in mental illnesses. It has become clear nowadays, that this modality may be effectively applied under specific indications in some patients with major depressive disorder, obsessive-compulsive disorder, anorexia nervosa and other eating disorders, Tourette syndrome, schizophrenia, substance use disorder, and even pathologically aggressive behavior. Despite the fact that the efficacy of neuromodulation with DBS, as well as of various lesional interventions, in cases of mental illnesses is still not fully established, there are several premises for wider applications of such "unclassical" psychiatric treatments in the future. Novel technologies of DBS, developments in non-invasive lesioning using stereotactic radiosurgery and transcranial magnetic resonance-guided focused ultrasound, and advances of neurophysiological and neuroimaging modalities may bolster further clinical applications of psychiatric neurosurgery, improve its results, and allow for individually selected treatment strategies tailored to specific needs of the patient.

Microvascular Decompression Through Cyanoacrylate Glue-Coated Teflon Sling Transposition Technique.

Vertebral artery dolichoectasia may produce a variety of clinical scenarios depending on the level of compression of several nervous structures along its course. Despite the fact that the pathophysiology is not fully clarified, it would seem that this pathologic elongation and dilation of the artery are acquired and determined by a thinning of the internal elastic lamina exposed to chronic arterial hypertension or as a result of degeneration and atherosclerosis of the arterial wall with age. When treatment is indicated, several techniques to relieve compression have been proposed, but they are usually challenging and nonstandardized. We present a case of a 78-year-old female with a 4-year history of left trigeminal neuralgia resistant to adequate dosage of multiple anticonvulsant medications and allergic to carbamazepine. She presented with a surgical history of a percutaneous microcompression of the Gasserian ganglion and 2 consecutive percutaneous radiofrequency thermorizotomies of the trigeminal nerve with transient benefit. The symptomatology was present for most of the day and impaired her quality of life, leading to severe mood decline. The patient underwent a left suboccipital retrosigmoid craniotomy (Video 1). A Teflon sling was wrapped around the vertebral artery. The 2 ends of the sling were anchored to the lateral dura by cyanoacrylate glue (Glubran 2, GEM Italy, Viareggio, Italy), pulling the vertebral artery away from the trigeminal nerve and brainstem. The patient reported complete suppression of facial pain. The case presentation, surgical anatomy, operative nuances, and postoperative course and outcome are reviewed. The patient gave written consent for participating in the procedure, surgical video, and publication of her images. Unfortunately, we did not take the picture of patient positioning for this specific case. For this reason, in order to better illustrate this surgical phase, we used the picture of another patient, who expressed her consent for publication and was operated on for a microvascular decompression with the same position as the one used for the patient described in this paper.

Neuronavigation Applied to Piezosurgery: Toward Robotic Image-Aided Craniotomy? A Technical Note.

BACKGROUND: Although simple in its concept, craniotomy can still cause serious consequences to the patient. A recent alternative to standard techniques (i.e., perforator and craniotome) is represented by piezosurgery (PS), which exploits a microvibration-emitting blade that cuts the bone directly from the outer surface of the skull. Although PS has been demonstrated to decrease complications, dural lacerations and neurovascular injuries are still possible from inadvertent penetration of the inner tabula. Modern neuronavigation systems can provide the surgeon with the possibility to track the instrument while carving the skull, thus potentially lowering the complication rates. METHODS: Two cases of miniretromastoid craniotomy for trigeminal neuralgia were performed using neuronavigated PS. Before surgery, the patients underwent volumetric brain magnetic resonance imaging and computed tomography. The piezosurgical cutter was registered on the S8 StealthStation neuronavigation system (Medtronic, Dublin, Ireland) using the step-by-step cranial standard instrument calibration protocol. RESULTS: The craniotomy was performed with the surgeon using the neuronavigation monitor to visualize both the position and the trajectory of the instrument's blade while penetrating the bone. No dural lacerations or neurovascular injuries were reported. At the end of the procedure, the bone flaps were perfectly repositioned within their craniotomy margins without the use of cranial fixation devices. CONCLUSIONS: Neuronavigated PS has the potential to decrease craniotomy-related complication rates. By allowing for real-time visualization of the blade's level of penetration, it provides the surgeon with the ability to halt progression when needed, avoiding dural lacerations and neurovascular injuries. The principles behind this technique could anticipate the advent of robotic-image aided craniotomy.