Massimiliano Visocchi

The neuraxis—the skull base along with its offshoot, the spine—replicates a bone funnel as a vessel, sustaining the brain, the cerebellum and the spinal cord, along with cranial and radicular nerves

The present Special Issue brings together five contributions that reflect the evolving landscape of modern neurosurgery, where technological innovation, multidisciplinary integration, and individualized patient care increasingly define clinical decision-making

Purpose: To identify positional and intraoperative significant multimodal intraoperative neurophysiological monitoring (mIONM) alert risk factors during anterior cervical surgery in patients with cervical spine myelomalacia. Methods: We analyzed prospectively collected data from the PANDA registry between January 2021 and February 2025. Included were patients undergoing anterior cervical decompression and fusion with MRI-confirmed myelomalacia. A significant alert was defined as a ≥ 50% reduction in MEP and/ SSEP amplitude, a ≥ 10% increase in MEP latency, or a spEMG signal. Patients were categorized into three groups: significant warnings at positioning (Group A), during surgical decompression (Group B), and no significant warnings (Group C). Nineteen anamnestic, clinical, radiological, and surgical factors were evaluated. A standardized anesthesia protocol and alert-response strategy were applied. Results: Seventy-six patients (132 operated levels) were included. Four patients belonged to Group A and 12 to Group B. Group A exhibited only MEP alerts and showed higher prevalence of peripheral vascular disorders, C3-C4 surgeries, and poorer motor scores in the most affected muscle group; the latter independently predicted alerts with 100% sensitivity at an mMRC threshold of 4. Group B was characterized by only MEP and EMG alerts, significantly longer symptom duration, and myelomalacia spanning two to three levels. Both factors independently predicted intraoperative alerts and were protective when symptom duration was less than 37 months and myelomalacia involved less than two levels. No SSEP alerts occurred. Conclusion: These findings support the use of mIONM during positioning and surgical decompression in anterior cervical procedures for patients with cervical myelomalacia, especially in those with segmental motor deficits, prolonged symptoms, and multilevel myelomalacia.

Background: Ventriculoperitoneal shunting (VPS) is the mainstay of treatment for most forms of hydrocephalus; VPS infection (VPSI) is a leading cause of shunt-related morbidity and mortality. A meta-analysis of the existing literature on risk factors for VPSI is currently lacking. Herein, the authors performed a systematic review and meta-analysis to evaluate the role of different clinical factors in the development of VPSI. Methods: A systematic search in the PubMed, Scopus, and Cochrane databases was performed to identify studies comparing patients developing VPSI to controls. The following data were extracted where available: number of patients who developed VPSI vs. number of patients with a regular course, demographics (gender, age at VPS insertion, age > 18 years), average length of hospital stay before shunt implant (days), aetiology of hydrocephalus (tumour-associated hydrocephalus; post-haemorrhagic hydrocephalus; congenital hydrocephalus; spinal dysraphism-associated hydrocephalus; post-infectious hydrocephalus; post-traumatic hydrocephalus; post-craniotomy hydrocephalus), and hydrocephalus type (obstructive hydrocephalus, communicating hydrocephalus, normal-pressure hydrocephalus—NPH). Results: Five studies including 2333 patients (225 with VPS infection) were analysed. Tumour-related hydrocephalus was linked to a lower infection risk (OR 0.418; p < 0.001), while congenital hydrocephalus (OR 2.502; p < 0.001) and spinal dysraphism (OR 2.359; p < 0.001) increased the risk. Conclusions: VPSI represents a serious complication after shunt surgery. Our meta-analysis identifies three key factors influencing the risk of VPSI. VPS-centred, large multicentre prospective studies are needed to possibly confirm the role of the factors we identified and to identify additional ones, enabling earlier detection of VPSI and allowing for better patient care.

Purpose: Cadaveric dissection is a cornerstone of neurosurgical education, providing trainees with a realistic 3D understanding of anatomy and a safe environment to practice surgical approaches. A preservation technique was developed that merges the advantages of fresh-frozen and embalmed cadavers, maintaining tissue realism while enhancing durability. This approach preserves flexibility and natural color, improves anatomical detail, and creates a safe, long-lasting model ideal for neurosurgical training. Methods: Four specimens were thawed, cannulated, and irrigated before implementing a protocol consisting of low concentration formaldehyde with glycerol and ethanol for extended preservation. The specimens were prepared for both neurosurgery training and educational purposes, and their condition was evaluated with a semi-quantitative scale. Each specimen was evaluated independently by two raters, blinded to the time-point, using a semi-quantitative scale anchored to predefined criteria (0–3 per domain). Inter-rater reliability was calculated using the intraclass correlation coefficient (ICC [2,k]) for continuous scores and Cohen’s κ for categorical agreement. Results: Over nine years of intermittent use, the specimens remained in good condition: tissues retained sufficient softness for dissection, injected vessels stayed vivid in color, and no foul odor or microbial growth was observed. The evaluation employed a semi-quantitative scale, with results ranging from 11/14 to 14/14. The mean values demonstrate stable tissue quality over time, with only minor variations in color and perfusion. The inter-rater reliability was high (ICC = 0.91; κ = 0.88). Conclusions: The preservation method leverages the strengths of both fresh-frozen and embalmed models. The results suggest feasibility of long-term reuse, although further quantitative validation is needed.

Study Design.: A systematic literature review and consensus using Delphi method. Objectives.: This review aims to create recommendations on the surgical indications and approaches to treat Chiari malformation (CM) with or without syringomyelia. Summary of Background Data.: Despite the growing body of knowledge on CM, there are diverse and sometimes contradicting perspectives about surgical indications and procedures in both pediatric and adult populations. Methods.: The authors reviewed the literature on CM published from 2011 to 2022. Two consensus conferences were organized by WFNS Spine Committee. The first one was held in Sao Paulo, Brazil on August 2022, and the second one was held in Porto, Portugal on December 2022. Using the Delphi method, a panel of expert spine surgeons and members of the WFNS Spine Committee examined the strength of the literature, elaborated and voted statements about the surgical management of CM. Results.: We present 11 consensus statements on the surgical management of CM. Surgery is recommended for patients who have symptoms or if an MRI shows progression in asymptomatic patients. In pediatrics, osteoligamentous decompression only is indicated, whereas adults can have foramen magnum decompression with duroplasty, which is usually sufficient to control the associated syringomyelia. Syrinx drainage is the last option. Arachnoid opening can be performed in patients who have previously failed surgery or if arachnoid morphological anomalies are identified during the initial procedure. Tonsillar shrinkage provides somewhat better clinical efficacy than decompression alone, but at a larger risk of complications. Only patients with concurrent basilar invagination and atlanto-axial instability are advised to undergo atlanto-axial fixation alone. Conclusions.: The consensus statements created by a collaborative work provide useful information for surgeons treating CM worldwide to achieve better surgical outcomes and avoid complications.

Background: Different lateral and postero-lateral cranial approaches to the petroclival region and to the mid-upper brain stem have been described so far, some of which require extensive osseous demolition and possible damage of neurovascular structures. Neuronavigational systems are now extensively available for preoperative planning and intraoperative navigation to assist the surgeons in choosing the optimally invasive approach for each pathology. Herein, we describe a detailed navigation-augmented morphometric analysis to bring insight into the usefulness of an anterior petrosectomy (AP) to handle lesions in the petroclival region. Methods: Eight cadaveric, silicone injected heads were used. A total of 14 approaches (AP, n = 8; retrosigmoid, RS, n = 6) using a standard microsurgical dissection technique were performed. All specimens had preoperative CT and MRI scans, as well as a post-dissection CT. The neuronavigational system was used for distance measurements, craniotomy sizes and surgical corridor volumes, for each approach. Results: The distance from the skull surface to the petrous apex was significantly shorter in the AP approach when compared with the RS (46.0 ± 1.9 mm versus 71.3 ± 1.8 mm, respectively, p < 0.001). Although the craniotomy size was not different, the volume of the surgical corridor was significantly larger with the AP approach (21.31 ± 1.91 cm³ vs. 13.39 ± 1.8 cm³). The AP approach increased the length of the basilar artery exposure from 6.9 ± 1.5 mm (obtained with a standard subtemporal approach) to 22.1 ± 1.7 mm (p < 0.0001). Conclusions: The surgical corridor to the petroclival region achieved by virtue of an AP was significantly larger and featured shorter working distances, resulting in a higher degree of surgical freedom. Although significant individual anatomical variations of fundamental neurovascular and bony structures were found, these difficulties were overcome by careful pre- and intraoperative use of neuronavigation.

Background: Diffusion tensor imaging (DTI), a variant of Diffusion Weighted Imaging (DWI), enables a neuroanatomical microscopic-like examination of the brain, which can detect brain damage using physical parameters. DTI’s application to traumatic brain injury (TBI) has the potential to reveal radiological features that can assist in predicting the clinical outcomes of these patients. What is the ongoing role of DTI in detecting brain alterations and predicting neurological outcomes in patients with moderate to severe traumatic brain injury and/or diffuse axonal injury? Methods: A scoping review of the PubMed, Scopus, EMBASE, and Cochrane databases was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The aim was to identify all potentially relevant studies concerning the role of DTI in TBI. From an initial pool of 3527 publications, 26 articles were selected based on relevance. These studies included a total of 729 patients with moderate to severe TBI and/or diffuse axonal injury. DTI parameters were analyzed to determine their relationship with neurological outcomes post-TBI, with assessments of several brain functions and regions. Results: The studies included various DTI parameters, identifying significant relationships between DTI variations and neurological outcomes following TBI. Multiple brain functions and regions were evaluated, demonstrating the capability of DTI to detect brain alterations with higher accuracy, sensitivity, and specificity than MRI alone. Conclusions: DTI is a valuable tool for detecting brain alterations in TBI patients, offering enhanced accuracy, sensitivity, and specificity compared to MRI alone. Recent studies confirm its effectiveness in identifying neurological impairments and predicting outcomes in patients following brain trauma, underscoring its utility in clinical settings for managing TBI.

Background: Spontaneous intracranial hypotension (SIH) is a rare and frequently misdiagnosed disorder characterized by a low volume of cerebrospinal fluid (CSF) caused by the leakage of CSF through the spinal dural membrane. Patients with Marfan Syndrome (MS) and other connective tissue disorders are at an increased risk for dural ectasia, which may predispose them to spontaneous CSF leaks due to the structural weakness of their dural membranes. The management of SIH in MS patients is debated. Conservative measures, an epidural blood patch (EBP), and surgical treatments are the options generally provided. Methods: Herein, we report on the case of a 52-year-old female affected by MS, genetically confirmed, with a two-month history of sudden-onset, “thunderclap” headache, worsened in an upright position and horizontal diplopia. A Computed Tomography (CT) scan of the brain showed a bilateral chronic subdural hematoma, slit ventricles, and a caudal descent of the brainstem without overt tonsillar herniation. The Magnetic Resonance Imaging (MRI) scan of the whole spine revealed dural ectasia in the lumbosacral area and presacral perineural cyst without extradural CSF collection. The case was successfully managed with bed rest and high-dose corticosteroid therapy. Then, we discuss the pertinent literature, consisting of 25 papers dealing with the treatment of SIH in patients affected by MS. Results: The literature review yielded 25 papers dealing with SIH management in patients with MS, including 28 patients overall; 21 patients underwent EBP, of whom 7 patients had multiple procedures. Overall, in 23 cases (82%), the symptoms improved. In three cases, the patients were managed conservatively with bed rest. In three of these cases, there was an improvement. In one case, the surgical fenestration of two lumbar intradural spinal meningeal cysts was performed and the patient improved after the procedure. Our patient underwent 15 days of steroid therapy (dexamethasone iv 12 mg/day for 7 days, then reduced to 4 mg/day) and intravenous hydration (Ringer lactate 1500 mL/day). In ten days, the symptoms disappeared. At the 6-month follow-up, the patient was in good clinical condition, and a CT scan showed an almost complete regression of the bilateral subdural hematoma. Conclusions: The management of SIH in MS patients is still challenging. Patients with connective tissue disorders such as MS are at an increased risk for SIH. Few studies have assessed the management of these patients and different strategies. Our case and the available literature provide further data for this type of case.

Classical trigeminal neuralgia (TN) is a chronic pain disorder characterized by severe, unilateral facial pain, often resulting from vasculonervous conflict. A less common cause of TN is vertebrobasilar dolichoectasia (VBD). Microvascular decompression (MVD) is the preferred surgical intervention for TN, but in case of VBD, the surgical procedure is more complex due to the aberrant vascular anatomy. This study aims to review the evidence on MVD for VBD-induced TN, and analyze operative challenges, efficacy, and postoperative outcomes. An illustrative case is also presented. We report on the case of a 62-year-old male with a 7-year history of right-sided TN affecting the maxillary (V2) and mandibular (V3) territories. The patient underwent MVD using the interposition technique, where Teflon sponges were placed between the basilar artery and the nerve. Postoperatively, the patient experienced complete pain relief without neurological deficits. At 12 months follow-up, the patient remained pain-free and off medications. We performed an extensive literature review using PubMed, Scopus, and Web of Sciences, highlighting the most relevant studies and findings on the topic. The literature review showed that, while MVD is effective in providing long-term pain relief in VBD-induced TN, the choice between interposition and transposition techniques remains debated. Interposition is easier to perform but may inadvertently increase nerve compression in some cases, whereas transposition offers more definitive decompression but carries higher technical risks. Our case and the available literature highlight the importance of individualized treatment planning in achieving optimal outcomes for patients with VBD-induced TN. Further research is needed to refine surgical techniques and minimize complications in this subset of TN patients.