Geometry and Symmetry of Willis' Circle and Middle Cerebral Artery Aneurysms Development.

Background: A relationship between the geometry and symmetry of Willis' circle and intracranial aneurysms was reported for anterior communicating and posterior communicating (PCom) aneurysms. A similar association with the middle cerebral artery (MCA) aneurysms instead appeared weaker. Methods: We reviewed 432 patients from six Italian centers with unilateral MCA aneurysms, analyzing the relationship between the caliber and symmetry of Willis' circle and the presence of ruptured and unruptured presentation. CT-angiograms were evaluated to assess Willis' circle geometrical characteristics and the MCA aneurysm side, dimension and rupture status. Results: The hypoplasia of the first segment of the anterior cerebral artery (A1) was in approximately one-quarter of patients and PCom hypoplasia was in almost 40%. About 9% had a fetal PCom ipsilaterally to the aneurysm. By comparing the aneurysmal and healthy sides, only the PCom hypoplasia appeared significantly higher in the affected side. Finally, the caliber of the internal carotid artery (ICA) and the first segment of MCA (M1) caliber were significantly greater in patients with unruptured aneurysms, and PCom hypoplasia appeared related to the incidence of an ipsilateral MCA aneurysm and its risk of rupture. Conclusions: Although according to these findings asymmetries of Willis' circle are shown to be a risk factor for MCA aneurysm formation and rupture, the indifferent association with ipsilateral or contralateral hypoplasia remains a datum of difficult hemodynamic interpretation, thereby raising the concern that this association may be more casual than causal.

Role of 1p/19q Codeletion in Diffuse Low-grade Glioma Tumour Prognosis.

BACKGROUND/AIM: In the latest 2021 WHO classification of central nervous system tumours (CNS), gliomas that present isocitrate dehydrogenase (IDH) mutations are defined as diffuse low-grade gliomas (DLGGs). IDH mutations are commonly observed in this tumour type. The Extent of Resection (EOR) positively influence survival; however, it is still debated whether the predictive value of EOR is independent of the 1p/19q co-deletion. We carried out a retrospective analysis on patients operated on for DLGG at the Sant'Andrea University Hospital Sapienza University of Rome, correlating the outcome with the presence of 1p/19q co-deletion and EOR. PATIENTS AND METHODS: The study examined 66 patients with DLGG who had undergone surgery for tumour resection between 2008 and 2018. Patients with DLGG were divided into two groups; diffuse astrocytoma (DA) in which 1p/19q codeletion is absent and oligodendroglioma (OG) in which 1p/19q codeletion is present. According to EOR, both groups were divided into two subgroups: subtotal resection (STR) and gross total resection (GTR). Three end-point variables were considered: overall survival (OS), progression-free survival (PFS) and time to malignant transformation (TMT). RESULTS: In the DA group, the GTR subgroup had an average OS of 81.6 months, an average PFS of 45.9 months and an average TMT of 63.6 months. After surgery, these patients had an average Karnofsky Performance Score (KPS) of 83.4. The STR subgroup had an average OS of 60.4 months, PFS was 38.7 months, and TMT was 46.4 months, post-operative KPS was 83.4. In contrast, in the OG group, the GTR averagely had 101.7 months of OS, 64.9 months of PFS, 80.3 months of TMT and an average post-operative KPS of 84.2, and the STR subgroup had an average of OS of 73.3 months, PFS of 48.2 months, TMT of 57.3 and an average postoperative KPS of 96.2. CONCLUSION: In patients affected by DLGGs, 1p/19q codeletion is significantly associated with prolonged survival and longer time-to-malignant transformation (TMT) compared to the absence of 1p/19q codeletion. Also, the extent of surgical resection (EOR) in DLGG patients has been confirmed as one of the main prognostic factors. However, its predictive value is substantially influenced by the presence of the 1p/19q codeletion.

An understimated maneuver for oculomotor nerve palsy due to posterior communicating artery aneurysm: the opening of the anterior petroclinoid ligament. A technical note.

Posterior communicating artery aneurysms (PcomAs) present with oculomotor nerve (OMN) palsy in 20-30% of cases, and the sudden onset of OMN palsy has to raise the suspicion of rupture, until proven otherwise. The surgical technique is described in a stepwise fashion. An illustrative case is reported: a 57-year-old female was admitted to our department with the diagnosis of a right sided-PcomA. Three months before the admission, when she harbored with the acute onset of complete ptosis, diplopia, orbital pain, impairment of the medial, upward, and downward gaze, with no pupil dysfunction. The origin of the Pcom and the neck of the aneurysm were easily identified and the aneurysm was clipped. Then, we followed the OMN and cut for less than 4 mm the above-lying anterior petroclinoid ligament (APL) to obtain nerve release. Although few cases are described in the literature, and ours represents a single case, we support that this maneuver should be introduced in the clinical practice of expert neurosurgeons dealing with vascular pathologies, such as the opening of the falciform ligament occurs for the decompression of the optical nerve.

Cortical atrophy in chronic subdural hematoma from ultra-structures to physical properties.

Several theories have tried to elucidate the mechanisms behind the pathophysiology of chronic subdural hematoma (CSDH). However, this process is complex and remains mostly unknown. In this study we performed a retrospective randomised analysis comparing the cortical atrophy of 190 patients with unilateral CSDH, with 190 healthy controls. To evaluate the extent of cortical atrophy, CT scan images were utilised to develop an index that is the ratio of the maximum diameter sum of 3 cisterns divided by the maximum diameter of the skull at the temporal lobe level. Also, we reported, for the first time, the ultrastructural analyses of the CSDH using a combination of immunohistochemistry methods and transmission electron microscopy techniques. Internal validation was performed to confirm the assessment of the different degrees of cortical atrophy. Relative Cortical Atrophy Index (RCA index) refers to the sum of the maximum diameter of three cisterns (insular cistern, longitudinal cerebral fissure and cerebral sulci greatest) with the temporal bones' greatest internal distance. This index, strongly related to age in healthy controls, is positively correlated to the preoperative and post-operative maximum diameter of hematoma and the midline shift in CSDH patients. On the contrary, it negatively correlates to the Karnofsky Performance Status (KPS). The Area Under the Receiver Operating Characteristics (AUROC) showed that RCA index effectively differentiated cases from controls. Immunohistochemistry analysis showed that the newly formed CD-31 positive microvessels are higher in number than the CD34-positive microvessels in the CSDH inner membrane than in the outer membrane. Ultrastructural observations highlight the presence of a chronic inflammatory state mainly in the CSDH inner membrane. Integrating these results, we have obtained an etiopathogenetic model of CSDH. Cortical atrophy appears to be the triggering factor activating the cascade of transendothelial cellular filtration, inflammation, membrane formation and neovascularisation leading to the CSDH formation.

The Surgical Risk Factors of Giant Intracranial Meningiomas: A Multi-Centric Retrospective Analysis of Large Case Serie.

Giant intracranial meningiomas (GIMs) are a subgroup of meningiomas with huge dimensions with a maximum diameter of more than 5 cm. The mechanisms by which a meningioma can grow to be defined as a "giant" are unknown, and the biological, radiological profile and the different outcomes are poorly investigated. We performed a multi-centric retrospective study of a series of surgically treated patients suffering from intracranial meningioma. All the patients were assigned on the grounds of the preoperative imaging to giant and medium/large meningioma groups with a cut-off of 5 cm. We investigated whether the presence of large diameter and peritumoral brain edema (PBE) on radiological diagnosis indicates different mortality rates, grading, characteristics, and outcomes in a multi-variate analysis. We found a higher risk of developing complications for GIMs (29.9% versus 14.8%; p < 0.01). The direct proportional relationship between PBE volume and tumor volume was present only in the medium/large group (Pearson correlation with p < 0.01) and not in the GIM group (p = 0.47). In conclusion, GIMs have a higher risk of developing complications in the postoperative phase than medium/large meningioma without higher risk of mortality and recurrence.

Intracranial Meningioma in Elderly Patients. Retrospective Multicentric Risk and Surgical Factors Study of Morbidity and Mortality.

With the increasing life expectancy, a large number of intracranial meningiomas (IM) have been identified in elderly patients. There is no general consensus regarding the management for IMs nor studies regarding the outcome of older patients undergoing meningioma surgery. We aimed to determine whether preoperative variables and postoperative clinical outcomes differ between age groups after meningioma surgery. We analyzed data from all patients who had undergone IM surgery from our departments. The final cohort consisted of 340 patients affected by IM with ASA class I-II: 188 in the young group (<65) and 152 in the elderly. The two subgroups did not present significant differences concerning biological characteristics of tumor, localization, diameters, lesion and edema volumes and surgical radicality. Despite these comparable data, elderly presented with a significantly lower Karnofsky Performance status value on admission and remained consistently lower during the follow-up. We establish instead that there is no intrinsic correlation to the presence of IM and no significant increased risk of complications or recurrence in elderly patients, but rather only an increased risk of reduced performance status with mortality related to the comorbidity of the patient, primarily cardiovascular disease, and an intrinsic frailty of the aged population.

Microsurgical clipping of Unruptured Intracranial Aneurysms (UIA) by a single surgeon's experience: why we should definitely preserve the neurosurgical skills in our health areas.

BACKGROUND: The long standing comparison between the endovascular and microsurgical treatment is still ongoing. While not any center avails of a neuroendovascular service, and not every aneurysm is suitable for endovascular treatment, the neurovascular technique is slowly disappearing from our territories, whereas in the current Literature, the role of the neurosurgical treatment is being re-appreciated. The objective of this paper is to discuss a single surgeon's clinical and radiological results with the microsurgical management of UIA. METHODS: We retrospectively reviewed the clinical and radiological records of patients treated for UIA, by a single surgeon,in the period ranging between 2015 and 2019. We recorded all the relevant anatomic features of the aneurysm, saliencies of the surgical treatment, such as the need for temporary clipping, intraoperative rupture or postoperative complications. The results of the clinical and radiological follow-up examinations were recorded either. RESULTS: Fifty-eight patient undergoing microsurgical clipping were included, harboring a total of 65 UIAs. CTA with 3D reconstructions was sufficient to reach a reliable preoperative planning in 46 patients (76%). A total of 94% of the cases were unchanged or neurologically unremarkable at follow-up. The presence of postoperative complications was associated to the neck size and predictor of a longer hospitalizations, as well as longer hospitalizations are associated to the patients' age, size of the aneurysms and surgical times. CONCLUSIONS: According to our experience, we believe that microsurgical clipping plays a critical role in the management of UIA, also on the ground of the encouraging results of the relevant Literature.

Impact of early surgery of ruptured cerebral aneurysms on vasospasm and hydrocephalus after SAH: Our preliminary results.

OBJECTIVE: Timing of surgical treatment of ruptured intracranial aneurysms has undergone a drastic change in the last few decades with preference for early surgery Our paper focuses specifically on the prognostic importance of timing of surgery, since early surgery of ruptured aneurysms provides immediately good clinical results. We present a series of cases operated in early and ultra early surgery, evaluating the technical aspects, the efficacy, the safety and the clinical results. PATIENTS AND METHODS: We retrospectively reviewed the clinical records and radiological imaging of patients treated for ruptured intracranial aneurysms who underwent early and ultra early clipping between January 2011 and April 2017 at our Institution. We included patients treated within the first 12 h and subsequently we divided our series in two subgroups based on the timing of surgery comparing the "early surgery" group (within 12 h) with the "ultra early surgery" group (within 6 h). RESULTS: Seventy-six (76) patients undergoing either early or ultra-early surgery for ruptured intracranial aneurysms have been reported Either early or ultra-early surgery showed a statistically favorable impact on reducing the incidence of both postoperative vasospasm and hydrocephalus. Ultra-early surgery group had the best outcome at the statistical analyses. (good postoperative 1Y GOSE.) CONCLUSIONS: We strongly believe that patients affected by ruptured intracranial aneurysms excluding Hunt and Hess grade V patients) should be treated as soon as possible and hence it should be considered as an emergency surgery. This approach prevents immediately a second bleeding of the aneurysm, allows to treat any associated condition of intracranial hypertension including hematomas and hydrocephalus and to use safely aggressive medical therapy such as hypertension.

Trigonal and Peritrigonal Lesions of the Lateral Ventricle: Presurgical Tractographic Planning and Clinic Outcome Evaluation.

BACKGROUND: Surgery of lesions within the atrium of the lateral ventricle remains a challenging procedure because of the deep location and the relationship to vascular structures. The aim of this study was to determine the usefulness of tractography to evaluate the position of white matter tracts located along the course of the surgical access to trigonal and peritrigonal lesions. METHODS: Diffusion tensor imaging (DTI) was acquired in 19 patients. All patients underwent surgical resection of brain tumors. Pre- and postoperative clinical conditions were evaluated by a neurosurgeon, using the Karnofsky Performance Status Scale. The corticospinal tract, optic radiation, and arcuate fasciculum were reconstructed because of their location close to the trigonal region. Two neurosurgeons were asked to assess the surgical approach with and without tractography. RESULTS: According to the tractographic reconstructions, the surgical access was chosen from the middle temporal gyrus in 12 patients (63%) and the posterior parietal gyrus in 7 patients (37%), leading to an a priori change in the surgical approach in 14 patients (73%). Six patients (31%) showed new postsurgical transient symptoms, whereas in 2 patients (10%) the deficits were permanent. After 30 days, the Karnofsky Performance Status Scale evaluation showed an improvement or a substantial stability of symptoms in 90% of cases. In 2 patients, a worsening of 30% of clinical performance was appreciable. CONCLUSIONS: The use of DTI in preoperative planning of trigonal and peritrigonal lesions may help in description of the best surgical approach for patient; this technique allows to reach the tumors, saving the white matter tracts, when it is possible.

Chondromyxoid Fibroma of the Skull Base: Our Experience with an Elusive Disease.

Chondromyxoid fibroma (CMF) is an extremely rare lesion of the skull base. This histologic type typically predilects metaphysis of the long bones. It is locally invasive/infiltrative, and this tendency is more concerning in the skull base, where a radical resection is often technically impossible because of the presence of vital neurovascular structures. We present a case of a 19-year-old woman who presented with a sudden onset of right facial weakness, progressively worsening to a severe disfiguring motor weakness. Gadolinium-enhanced brain magnetic resonance imaging showed an osteolytic lesion located in the right mastoid involving the stylomastoid foramen and the right seventh cranial nerve. A partial mastoidectomy was performed, with an excellent rate of tumor resection and complete local control of the disease at follow-up. The analysis of current literature indicates that a radiologic diagnosis is rarely strictly convincing of CMF. Histologic diagnosis is often difficult due to the lack of a specific immunohistochemical pattern of chondrosarcoma. Surgery is currently recognized as the mainstay to manage this lesion, although a trend toward adjuvant radiation therapy (RT) currently is seen. Although a tendency of local recurrence is well recognized in the literature, the very slow and indolent behavior of this lesion plus the trend to enhance local control of the disease with high-dose RT pushed us to a reappraise the role of radical skull base surgeries burdened by the risks of major complications, cosmetic deformities, and additional neurologic deficits.

Functional Magnetic Resonance Imaging (fMRI), Pre-intraoperative Tractography in Neurosurgery: The Experience of Sant' Andrea Rome University Hospital.

BACKGROUND: The goal of neurosurgery for cerebral intraparenchymal neoplasms of the eloquent areas is maximal resection with the preservation of normal functions, and minimizing operative risk and postoperative morbidity. Currently, modern technological advances in neuroradiological tools, neuronavigation, and intraoperative magnetic resonance imaging (MRI) have produced great improvements in postoperative morbidity after the surgery of cerebral eloquent areas. The integration of preoperative functional MRI (fMRI), intraoperative MRI (volumetric and diffusion tensor imaging [DTI]), and neuronavigation, defined as "functional neuronavigation" has improved the intraoperative detection of the eloquent areas. METHODS: We reviewed 142 patients operated between 2004 and 2010 for intraparenchymal neoplasms involving or close to one or more major white matter tracts (corticospinal tract [CST], arcuate fasciculus [AF], optic radiation). All the patients underwent neurosurgery in a BrainSUITE equipped with a 1.5 T MR scanner and were preoperatively studied with fMRI and DTI for tractography for surgical planning. The patients underwent MRI and DTI during surgery after dural opening, after the gross total resection close to the white matter tracts, and at the end of the procedure. We evaluated the impact of fMRI on surgical planning and on the selection of the entry point on the cortical surface. We also evaluated the impact of preoperative and intraoperative DTI, in order to modify the surgical approach, to define the borders of resection, and to correlate this modality with subcortical neurophysiological monitoring. We evaluated the impact of the preoperative fMRI by intraoperative neurophysiological monitoring, performing "neuronavigational" brain mapping, following its data to localize the previously elicited areas after brain shift correction by intraoperative MRI. RESULTS: The mean age of the 142 patients (89 M/53 F) was 59.1 years and the lesion involved the CST in 66 patients (57 %), the language pathways in 24 (21 %), and the optic radiations in 25 (22 %). The integration of tractographic data into the volumetric dataset for neuronavigation was technically possible in all cases. In all patients intraoperative DTI demonstrated a shift of the bundle position caused by the surgical procedure; its dislocation was both outward and inward in the range of +6 mm and -2 mm. CONCLUSION: We found a high concordance between fMRI/DTI and intraoperative brain mapping; their combination improves the sensitivity of each technique, reducing pitfalls and so defining "functional neuronavigation", increasing the definition of eloquent areas and also reducing the time of surgery.

One-Step Posterior and Anterior Combined Approach for L5 Retroperitoneal Schwannoma Eroding a Lumbar Vertebra.

We report the case of a large lumbar schwannoma eroding the vertebra and originating from spinal canal with invasion of the retroperitoneal space. We also review all the cases in literature reporting lumbar schwannomas eroding the vertebral bodies and invading the retroperitoneal space focusing on the surgical strategies to manage them. Spinal CT-scan revealed a 44 mm × 55 mm inhomogeneous soft-tissue mass arising from the right L5-S1 neural foramen and its most anterior portion had a clear colliquative aspect. Magnetic resonance image showed a neoplastic lesion with homogeneous low signal in T1WI, heterogeneous signal in T2WI, and strong enhancement in postgadolinium examination. It developed as well in the retroperitoneal space, posteriorly to the iliac vein, up to the psoas muscle with wide erosion of the omolateral conjugate foramen. We performed a one-step combined approach together with the vascular surgeon because the lesion was too huge to allow a complete resection via a posterior approach and furthermore its tight relationship with the psoas muscle and the iliac vessels in the retroperitoneal space should be more safely managed via a retroperitoneal approach. We strongly suggest a 1-step surgery first approaching the dumbbell and the intraspinal schwannomas posteriorly achieving the decompression of the spinal canal and the cleavage of the tumor cutting the root of origin and the vascular supply and valuating the stability of the spine for potential artrodesis procedure. The patient must be then operated on via a retroperitoneal approach achieving the complete en bloc resection of the tumor.