Septostomy and Monroplasty in Isolated Lateral Ventricle After Removal of a Third Ventricle Colloid Cyst: 2-Dimensional Operative Video.

Isolated unilateral hydrocephalus (IUH) is a condition caused by unilateral obstruction of the foramen of Monro.1 Etiopathogenic causes include tumors, congenital lesions, infective ventriculitis, intraventricular haemorrhage, and iatrogenic causes such as the presence of contralateral shunts.2,3 Neuroendoscopic management is considered the "gold-standard" treatment in IUH.4 Even if endoscopic septostomy and foraminoplasty in IUH are well-known procedures,5,6 IUH after an interhemispheric transcallosal transchoroidal approach for removal of a III ventricle colloid cyst is a complication barely described in literature. Video 1 describes this rare complication and the neuroendoscopic treatment adopted, including the operative room setup, patient's positioning, instrumentation needed, and a series of intraoperative tips for the performance of septostomy and Monroplasty via a single, precoronal burr hole. The scalp entry point and endoscope trajectory, homolateral to the dilated ventricle, were planned on the neuronavigation system. The avascular septal zone away from the septal veins and body of the fornix was reached, and the ostomy was performed. At the end of the procedure, Monroplasty was performed, too. The procedure was effective in solving the hydrocephalus and patient's clinical picture. No surgical complications occurred. Imaging demonstrated an evident and progressive reduction of enlarged lateral ventricle. In authors' opinion, the single burr-hole approach, ipsilateral to the enlarged ventricle, provides an optimal identification the intraventricular anatomy and allows Monroplasty to be performed, if deemed feasible during surgery. The patient consented to the procedure. The participants and any identifiable individuals consented to publication of their images.

Microsurgical transcranial approaches to the posterior surface of petrosal portion of the temporal bone: quantitative analysis of surgical volumes and exposed areas.

Different microsurgical transcranial approaches (MTAs) have been described to expose the posterior surface of the petrous bone (PPB). A quantitative, anatomical comparison of the most used MTAs, for specific areas of the PPB, is not available. Anatomical dissections were performed on five formalin-fixed, latex-injected cadaver heads (10 sides). Six MTAs were analyzed: Kawase approach (KWA), retrosigmoid approach (RSA), retrosigmoid approach with suprameatal extension (RSAS), retrolabyrinthine approach (RLA), translabyrinthine approach (TLA), and transcochlear approach (TCA). Surgical volumes and exposed areas of each approach were quantified with a dedicated neuronavigation system (ApproachViewer, part of GTx-Eyes II, University Health Network, Toronto, Canada) and adjuvant software (ITK-SNAP and Autodesk Meshmixer 3.5). Areas and volumes were compared using linear mixed models. TCA provided the best exposure of Trautmann's triangle and the retromeatal, suprameatal, meatal, and premeatal regions. RSAs provided the best exposure of the inframeatal region, with RSAS gaining significant exposure of the suprameatal region. KWA had the highest surgical volume, and RLA the lowest. Transpetrosal approaches offer the widest exposure of PPB proportionally to their invasiveness. Retrosigmoid approaches, which get to the studied region through a postero-lateral path, are paramount for the exposure of the inframeatal and suprameatal region and, given the adequate exposure of the remaining PPB, represent an effective approach for the cerebellopontine angle (CPA). These anatomical findings must be considered with approach-related morbidity and the pathological features in order to choose the most appropriate approach in clinical practice.

Posterior Petrous Meningiomas: Surgical Classification and Postoperative Outcomes in a Case Series of 130 Patients Operated via the Retrosigmoid Approach.

OBJECTIVE: A standardized definition and classification of primary posterior petrous meningiomas (PPMs) is lacking, with consequent challenges in comparing different case series. This study aimed to provide an anatomical description and classification of PPMs analyzing a homogeneous series of patients operated via the retrosigmoid approach. METHODS: PPMs originate laterally to the petro-occipital fissure within the venous ring composed of the superior petrosal, sigmoid, inferior petrosal, and cavernous sinuses. We proposed a classification based on tumor site of origin, direction of growth relative to the internal acoustic meatus, and cranial nerves' displacement. Four types of PPMs were defined: retromeatal (type A), meatal (type B), premeatal (type C), and broad-based (type D). We performed a retrospective analysis of 130 consecutive patients with PPMs who underwent surgery as first-line treatment. RESULTS: The PPM classification predicted clinical presentation, postoperative morbidity, and resection rates. Headache, hydrocephalus, and cerebellar deficits were more common in type A (59.0%, 37.7%, 49.2%) and type D (66.7%, 66.7%, 33.3%). Hypoacusia/anacusia was more common in type B (87.5%), while trigeminal hypoesthesia/anesthesia was more common in type C (85.0%). After surgery, patients with type A and D PPMs were at higher risk to develop cerebellar deficits (11.5%-22.2%), whereas patients with type B and C PPMs presented with hypoacusia/anacusia (12.5%) and trigeminal deficits (10.0%), respectively. The near-total resection rate was higher in type A (91.8%), followed by types B (82.5%), C (80.0%), and D (77.8%) PPMs. CONCLUSIONS: The PPM surgical classification has an operative and prognostic relevance. In expert hands, the retrosigmoid approach represents a safe and effective approach to remove PPMs.

De novo cavernous angiomas associated with developmental venous anomaly: a mini-series and literature review.

BACKGROUND: Despite being previously considered as congenital lesions, recent studies agree to classify cerebral cavernous malformations (CCM) as acquired forms with clear correlations with other pathological affections of the central nervous system (CNS). In addition, a special subgroup, notably known as de novo CCMs (dnCCM), are associated in a significant number of cases with developmental venous anomalies (DVAs) and, in other cases, with Radiotherapy treatments. METHODS: A mini-series of 4 patients with clinical history characterized by developing dnCCM is reported. In three patients, the dnCCM was associated with the presence of an isolated DVA. In one case, no DVA was detected, but the patient underwent brain radiotherapy. In three cases, the dnCCM was clinically symptomatic, and the patients were submitted to a surgical procedure for lesion removal. In one case, the dnCCM was detected during MRI follow-up. RESULTS: Adding a review of the literature, we describe 47 patients who presented dnCCMs. The most common presentation is a sporadic CCM with a DVA, and the onset presentation was bleeding in 4 out of 47 cases (8.5%). Bleeding of dnCCM was observed in 9 out of 47 cases (19%), and the choice treatment was surgical in 24 out of 47 cases (51%). CONCLUSIONS: We present our series with a review of the recent literature and discuss the "de novo" cavernous malformation pathogenesis. A throughout review of recent literature is reported to clarify the predisposing factors that may lead to dnCCM development in patients carrying specific genetic and molecular features. Considering the high risk of bleeding, strict follow-up and aggressive treatment should be evaluated in dnCCM management.

Preliminary Validation of FoRCaSco: A New Grading System for Cerebral and Cerebellar Cavernomas.

OBJECTIVE: Surgical indications for cerebral cavernous malformations (CCMs) remain significantly center- and surgeon-dependent; available grading systems are potentially limited, as they do not include epileptologic and radiologic data. Several experienced authors proposed a new grading system for CCM and the first group of patients capable of providing its statistical validation was analyzed. METHODS: A retrospective series of 289 CCMs diagnosed between 2008 and 2021 was collected in a shared anonymous database among 9 centers. The new grading system ranges from -1 to 10. For each patient with cortical and cerebellar cavernous malformations the grading system was applied, and a retrospective outcome analysis was performed. We proposed a score of 4 as a cutoff for surgical indication. RESULTS: Operated patients with a score ≥4 were grouped with non-operated patients with a score <4, as they constituted the group that received correct treatment according to the new grading system. Patients with a score ≥4, who underwent surgery and had an improved outcome, were compared to patients with a score ≥4 who were not operated (P = 0.04), and to patients with a score <4 who underwent surgery (P < 0.001). CONCLUSIONS: This preliminary statistical analysis demonstrated that this new grading would be applicable in surgical reality. The cutoff score of 4 correctly separated the patients who could benefit from surgical intervention from those who would not. The outcome analysis showed that the treated patients in whom the grading system has been correctly applied have a better outcome than those in whom the grading system has not been applied.

Choroid Plexus Cyst of the Fourth Ventricle Associated with Intermittent Obstructive Hydrocephalus.

BACKGROUND: Choroid plexus cysts (CPCs) are a type of neuroepithelial cysts, benign lesions located more frequently in the supratentorial compartment. Symptomatic CPCs in the posterior fossa are extremely rare and can be associated with obstructive hydrocephalus. CASE DESCRIPTION: A previously healthy elderly woman suffered intermittent attacks of headache and vomiting associated with gait instability. Magnetic resonance imaging documented a large cystic lesion occupying all the fourth ventricle. An endoscope-assisted fenestration of the lesion through a telovelar approach determined only temporary improvement, hence a second surgery with gross total resection of the cyst was performed, with successful long-term clinical and radiologic resolution. Histology revealed CPC. CONCLUSIONS: Fourth ventricle symptomatic CPCs are extremely rare lesions, especially in the elderly. Their presence must be carefully evaluated as a possible rare cause of intermittent obstructive hydrocephalus. Even though cyst fenestration with restoration of the cerebrospinal fluid pathway represents the best treatment in the majority of cases, a more aggressive resection is sometimes necessary.

Wall motion at 4D-CT angiography and surgical correlation in unruptured intracranial aneurysms: a pilot study.

BACKGROUND: Unruptured intracranial aneurysms (UIAs) are reported more frequently nowadays but their management is not well established; it depends on different structural features of the aneurysms and on multiple patient's risk factors. With this prospective observational study we report our preliminary experience by using four-dimensional (4D) computed tomographic (CT) angiography with ECG-gated reconstructions in the evaluation of dynamic modifications of the aneurysm wall, as a potential predicting factor of growth or rupture. The novelty of this study consists in the correlation between Angio 4D-CT angiography images and surgical findings; only few scientific papers, in fact, have studied this issue. METHODS: Thirty-one patients (1 male, 30 females; 59.0±12.7 years old) with 43 unruptured aneurysms (medium size: 5.2±3.0 mm) were studied. ECG-triggered 4D-CT angiography was performed with a 320-detector CT system (Aquilion ONE; Toshiba Medical Systems Corporation, Otawara, Japan); ECG-gated reconstruction was performed for visualizing local displacement of the aneurysmal wall over a heart cycle. In the aneurysms surgically treated in our institution we were able to compare the macroscopic features of the aneurysm wall with 4D-CTA findings. We performed long-term follow-up on untreated patients. RESULTS: Pulsation was detected in 13 of 43 unruptured aneurysms. Eighteen aneurysms were treated: thirteen were surgically treated and five underwent embolization with detachable coil placement. In nine aneurysms surgically treated in our institution (5 with pulsation and 4 without) we observed a significant correlation between 4D-CTA findings and macroscopic features of the aneurysms wall, in particular the pulsations detected at 4D-CTA study have shown to correspond to dark-reddish thinner wall at surgery. CONCLUSIONS: Our data confirm the previous reports concerning the reliability of 4D-CT angiography with ECG-gated reconstructions in defining the dynamic and structural features of the aneurysm wall. Moreover, optimal correlation rate between the findings provided by the 4D-CTA and the macroscopic surgical evaluation support a possible role of this technique to identify aneurysms with a higher risk of rupture.

Cervical demyelinating lesion presenting with choreoathetoid movements and dystonia.

Pseudoathetosis and dystonia are rare manifestations of spinal cord disease that have been already reported in lesions involving the posterior columns at the cervical level. We report two patients with a cervical demyelinating lesion at C3-C4 level presenting with hand dystonia and pseudoathetoid movements. The movement disorder disappeared after steroid treatment. The cases we described highlight the importance of identifying secondary causes of movement disorders that can be reversible with appropriate therapy.

Management of growing vestibular schwannomas.

Conservative management of small vestibular schwannomas is frequently proposed as most tumours do not grow. Anyway, tumour growth is reported in 30-40 % of the cases, so that surgery is consequently generally proposed. We primarily observed 161 patients affected by unilateral vestibular schwannomas. All patients were examined by means of gadolinium-enhanced magnetic resonance imaging scans. Tumour growth was recorded in 58 cases (35.8 %) and these subjects set up the group of study. Twenty-two (37.9 %) patients were surgically treated; tumour was always completely removed, all patients had normal facial function after surgery and only one patient suffered from a major complication (cerebellar haematoma). Fourteen patients (24.1 %) were submitted to radiotherapy, while one patient was lost at follow-up and another one died because of other medical reasons. Finally, 20 (34.5 %) subjects continued to be observed for different reasons. The mean follow-up period after identification of growth was 6.1 years. Nine tumours continued to grow, nine tumours stopped growing, one tumour grew and then regressed in size and one tumour decreased. Sixty percent of patients with useful hearing at diagnosis preserved it during the entire observation period. In conclusion, most of VS do not grow; in case of tumour growth, a surgical procedure may be suggested and the outcomes are not negatively influenced by the delay of the procedure. But in some cases, patients can still follow the "wait and scan" policy. In fact, only less than half of the growing tumours continued to grow. Moreover, most of the patients continued to retain a useful hearing.

Seizure outcome of surgical treatment of focal epilepsy associated with low-grade tumors in children.

OBJECT: Low-grade tumor (LGT) is an increasingly recognized cause of focal epilepsies, particularly in children and young adults, and is frequently associated with cortical dysplasia. The optimal surgical treatment of epileptogenic LGTs in pediatric patients has not been fully established. METHODS: In the present study, the authors retrospectively reviewed 30 patients (age range 3-18 years) who underwent surgery for histopathologically confirmed LGTs, in which seizures were the only clinical manifestation. The patients were divided into 2 groups according to the type of surgical treatment: patients in Group A (20 cases) underwent only tumor removal (lesionectomy), whereas patients in Group B (11 cases) underwent removal of the tumor and the adjacent epileptogenic zone (tailored surgery). One of the patients, who underwent 2 operations, is included in both groups. Follow-up ranged from 1 to 17 years. RESULTS: Sixteen (80%) of 20 patients in Group A had an Engel Class I outcome. In this group, 3 of 4 patients who were in Engel Classes II and III had temporomesial lesions. All patients in Group B had temporomesial tumors and were seizure free (Engel Class I). In this series, in temporolateral and extratemporal tumor locations, lesionectomy yielded a good seizure outcome. In addition, a young age at seizure onset (in particular < 4 years) was associated with a poor seizure outcome. CONCLUSIONS: Tailored resection in temporomesial LGTs was associated with excellent seizure outcome, indicating that an adequate presurgical evaluation including extensive neurophysiological evaluation (long-term videoelectroencephalography monitoring) to plan appropriate surgical strategy is advised.

Focal epilepsy associated with dysembryoplastic neuroepithelial tumor in the area of the caudate nucleus.

Dysembryoplastic neuroepithelial tumors (DNTs) are usually located within the supratentorial cortex, often in the temporal lobe and they are frequently associated with intractable complex partial seizures. DNTs in extracortical sites are rare. Thus far, 21 cases of 36 DNT-lesions occurring in these areas have been reported; only 8 out of them had epilepsy. We report a case of a 39-year-old woman who had pharmacoresistant epilepsy associated to a DNT in the caudate nucleus-periventricular area treated by lesionectomy. During a 4-year follow-up period, the patient was seizure free and the tumor did not recur. We discuss the hypothetical epileptogenic mechanism involved and we review the pertinent literature.

Temporo-mesial extraventricular neurocytoma and cortical dysplasia in focal temporal lobe epilepsy.

We describe a 17-year-old boy with a left extraventricular temporo-mesial neurocytoma associated with cortical dysplasia causing focal pharmacoresistant temporal lobe epilepsy. He presented with a long history of medically refractory, temporal complex partial seizures. MRI showed a left temporo-mesial lesion suspect to be a low-grade tumor. Based on the pre-operative non-invasive neurophysiological studies, the patient underwent a left tailored temporal antero-mesial resection. Histopathological examination showed an extraventricular neurocytoma associated with architectural dysplasia (Type 1a) of the temporal pole. The patient was seizure-free at 2 years follow-up. Extraventricular neurocytomas must be considered in the differential diagnosis of the plethora of low-grade tumors associated with focal epilepsy that typically involve the temporal lobe, and are frequently associated with focal cortical dysplasia.

O(6)-methylguanine DNA-methyltransferase methylation status can change between first surgery for newly diagnosed glioblastoma and second surgery for recurrence: clinical implications.

O(6)-methylguanine DNA-methyltransferase (MGMT) promoter methylation status is a prognostic factor in newly diagnosed glioblastoma patients. However, it is not yet clear whether, and if so how, MGMT methylation status may change. Moreover, it is unknown whether the prognostic role of this epigenetic feature is retained during the disease course. A retrospective analysis was made using a database of 614 glioblastoma patients treated prospectively from January 2000 to August 2008. We evaluated only patients who met the following inclusion criteria: age > or = 18 years; performance status 0-2; histological diagnosis of glioblastoma at both first and second surgery for recurrence; postoperative treatment consisting of: (i) radiotherapy (RT) followed by adjuvant temozolomide (TMZ) until 2005 and (ii) TMZ concurrent with and adjuvant to RT after 2005; a time interval > or = 3 months between first and second surgery. MGMT status was evaluated at first and second surgery in all 44 patients (M:F 32:12, median age: 49 years, range: 27-67 years). In 38 patients (86.4%), MGMT promoter status was assessable at both first and second surgery. MGMT methylation status, changed in 14 patients (37%) of second surgery samples and more frequently in methylated than in unmethylated patients (61.5% vs 24%, P = .03). The median survival was significantly influenced only by MGMT methylation status determined at first surgery (P = .04). Significant changes in MGMT methylation status during the course of GBM occur more frequently in MGMT methylated than unmethylated cases. MGMT methylation status determined at first surgery appears to be of prognostic value; however, it is not predictive of outcome following second surgery.

Microvascular decompression for glossopharyngeal neuralgia: a long-term retrospectic review of the Milan-Bologna experience in 31 consecutive cases.

OBJECTIVE: To examine surgical findings and results of microvascular decompression (MVD) for glossopharyngeal neuralgia (GN). METHODS: Between 1990 and 2007, 31 consecutive patients affected by drug-resistant GN underwent MVD through a retromastoid keyhole in the supine position with the head rotated to the opposite side. A retrospective analysis was performed that paid particular attention to the relationship among surgical technique, pain control and side effects. RESULTS: A vascular compression of the glossopharyngeal nerve was found in all cases. Twenty-eight out of 31 patients (90.3%) were found to be pain free without medication at long-term follow-up (1-17 years, mean 7.5 years). Three patients (9.7%) were found to require medication to control pain paroxysms that were less frequent and less severe than those observed preoperatively. Two patients required repeated surgery for a drug-resistant recurrence of pain for a total of 33 MVDs. We observed no mortality and did not find any long-term surgical morbidity. Cranial nerve impairment, when observed, always resolved in the following months. CONCLUSIONS: MVD is a safe and effective treatment for GN in patients of all ages.

Temozolomide concomitant and adjuvant to radiotherapy in elderly patients with glioblastoma: correlation with MGMT promoter methylation status.

BACKGROUND: A recent randomized study conducted on newly diagnosed glioblastoma (GBM) patients demonstrated that concomitant and adjuvant temozolomide added to standard radiotherapy had a survival advantage compared with radiotherapy alone. The overall survival benefit of this aggressive treatment, however, was attenuated in older or poor performance status patients. The aim of the present study was to verify the activity and the toxicity of temozolomide administration concurrent and adjuvant to radiotherapy as first-line treatment for elderly GBM patients, and to explore correlations between clinical outcome and O6 methylguanine-DNA methyltransferase (MGMT) promoter methylation status. METHODS: Newly diagnosed GBM patients>or=65 years were considered eligible. Treatment comprised radiotherapy (60 Gy in 30 fractions over 6 weeks) plus continuous daily temozolomide (75 mg/m2/day), followed by 12 maintenance temozolomide cycles (150 mg/m2 once a day for 5 consecutive days every 28 days) if MRI showed no enhancement suggesting a tumor; otherwise, chemotherapy was delivered until complete response or unequivocal progression. RESULTS: A total of 58 patients (34 males; median age, 68 years; range, 65-82 years) were enrolled. Sixteen patients (43%) presented MGMT promoter methylated and 21 unmethylated (57%) status. The median progression-free survival and median survival time (MST) were 9.5 months (95% confidence interval [CI], 8.6-10.5) and 13.7 months (95% CI, 10-17.3 months), respectively. Mental status deterioration grade 3-4 was detected in 25% of patients. Leukoencephalopathy was diagnosed in 10% of patients. CONCLUSIONS: The overall and progression-free survival of patients given concomitant and adjuvant temozolomide are greater than in those given radiotherapy alone; however, this regimen incurs a greater deterioration in mental status. Further randomized trials should, therefore, be conducted to investigate the efficacy and against the toxicity of this regimen as first-line therapy in patients with GBM.