Factors Predictive of Treatment Success in CT-Guided Fibrin Occlusion of CSF-Venous Fistulas: A Multicenter Retrospective Cross-Sectional Study.

BACKGROUND AND PURPOSE: CSF-to-venous fistulas contribute to spontaneous intracranial hypotension. CT-guided fibrin occlusion has been described as a minimally invasive treatment strategy; however, its reproducibility across different institutions remains unclear. This multi-institution study evaluated the clinical and radiologic outcomes of CT-guided fibrin occlusion, hypothesizing a correlation among cure rates, fibrin injectate spread, and drainage patterns. MATERIALS AND METHODS: A retrospective evaluation was conducted on CT-guided fibrin glue treatment in patients with CSF-to-venous fistulas from 6 US and UK institutions from 2020 to 2023. Patient information, procedural characteristics, and injectate spread and drainage patterns were examined. Clinical improvement assessed through medical records served as the primary outcome. RESULTS: Of 119 patients at a mean follow-up of 5.0 months, fibrin occlusion resulted in complete clinical improvement in 59.7%, partial improvement in 34.5%, and no improvement in 5.9% of patients. Complications were reported in 4% of cases. Significant associations were observed between clinical improvement and concordant injectate spread with the fistula drainage pattern (P = .0089) and pretreatment symptom duration (P < .001). No associations were found between clinical improvement and cyst puncture, intravascular extension, rebound headache, body mass index, age, or number of treatment attempts. CONCLUSIONS: Fibrin occlusion performed across various institutions shows cure when associated with injectate spread matching the CVF drainage pattern and shorter pretreatment symptom duration, emphasizing the importance of accurate injectate placement and early intervention.

Diagnostic utility of 11 C-methionine PET/CT in primary hyperparathyroidism in a UK cohort: A single-centre experience and literature review.

OBJECTIVE: Primary hyperparathyroidism is a common endocrine disorder, with 80% of all cases usually caused by one single hyperfunctioning parathyroid adenoma. Conventional imaging modalities for the diagnostic work-up of primary hyperparathyroidism (PHPT) include ultrasound of the neck, 99mTc-sestamibi scintigraphy, and four-dimensional computed tomography (4D-CT). However, the role of other imaging modalities, such as 11C-methionine PET/CT, in the care pathway for PHPT is currently unclear. Here, we report our experience of the diagnostic utility of 11C-methionine PET/CT in a single-center patient cohort (n = 45). DESIGN: Retrospective single-center cohort study. PATIENTS AND MEASUREMENTS: The data of eligible patients that underwent 11C-methionine PET/CT between 2014 and 2022 at Addenbrooke's Hospital (Cambridge, UK) were collected and analyzed. The clinical utility of imaging modalities was determined by comparing the imaging result with histopathological and biochemical outcomes following surgery. RESULTS: In patients with persistent primary hyperparathyroidism following previous surgery, 11C-methionine PET/CT identified a candidate lesion in 6 of 10 patients (60.0%), and histologically confirmed in 5 (50.0%). 11C-methionine PET/CT also correctly identified a parathyroid adenoma in 9 out of 12 patients (75.0%) that failed to be localized on other imaging modalities. 11C-methionine PET/CT had a sensitivity of 70.0% (95% CI 55.8 - 84.2%) for the detection of parathyroid adenomas. CONCLUSIONS: This study highlights a diagnostic role for 11C-methionine PET/CT in patients that have undergone unsuccessful prior surgery or have equivocal or negative prior imaging results, aiding localization and a targeted surgical approach.

Multidisciplinary consensus guideline for the diagnosis and management of spontaneous intracranial hypotension.

BACKGROUND: We aimed to create a multidisciplinary consensus clinical guideline for best practice in the diagnosis, investigation and management of spontaneous intracranial hypotension (SIH) due to cerebrospinal fluid leak based on current evidence and consensus from a multidisciplinary specialist interest group (SIG). METHODS: A 29-member SIG was established, with members from neurology, neuroradiology, anaesthetics, neurosurgery and patient representatives. The scope and purpose of the guideline were agreed by the SIG by consensus. The SIG then developed guideline statements for a series of question topics using a modified Delphi process. This process was supported by a systematic literature review, surveys of patients and healthcare professionals and review by several international experts on SIH. RESULTS: SIH and its differential diagnoses should be considered in any patient presenting with orthostatic headache. First-line imaging should be MRI of the brain with contrast and the whole spine. First-line treatment is non-targeted epidural blood patch (EBP), which should be performed as early as possible. We provide criteria for performing myelography depending on the spine MRI result and response to EBP, and we outline principles of treatments. Recommendations for conservative management, symptomatic treatment of headache and management of complications of SIH are also provided. CONCLUSIONS: This multidisciplinary consensus clinical guideline has the potential to increase awareness of SIH among healthcare professionals, produce greater consistency in care, improve diagnostic accuracy, promote effective investigations and treatments and reduce disability attributable to SIH.

Anatomy of the Calvaria and Skull Base.

A thorough understanding of the skull anatomy is of key importance to radiologists as well as specialist physicians and surgeons. We describe the anatomy of the neurocranium comprising calvaria (the skull vault) and the skull base and discuss the most common and clinically relevant anatomic variants.

White Matter Hyperintensities and Cerebral Microbleeds in Ataxia-Telangiectasia.

BACKGROUND AND OBJECTIVES: To systematically assess the occurrence of cerebral microbleeds (CMBs) and white matter hyperintensities (WMHs) in the largest published cohort of adults with ataxia-telangiectasia (AT). METHODS: We assessed 38 adults with AT (age range 18-55 years) including 15 classic and 23 variant AT, evaluated by two independent assessors. WMHs were quantified on T2-fluid attenuated inversion recovery images using the semiquantitative modified Scheltens and Fazekas scales and CMB on susceptibility-weighted imaging and T2*-weighted gradient echo sequences using the Brain Observer MicroBleed Scale. RESULTS: CMBs were more frequently found in classic AT compared with variant AT (66.7% vs 5.9%) predominantly in cortical and subcortical regions. WMHs were seen in 25 (73.5%) probands and CMBs in 9 (31.0%). The burden of WMHs increased with age, and WMHs were focused in periventricular and deep white matter regions. WMHs were more frequently seen in variant than classic AT. DISCUSSION: This cohort study confirms that WMHs and CMBs are a frequent finding in AT. Further longitudinal studies are required to understand how WMHs and CMBs relate to the neurodegeneration that occurs in AT and the predisposition to cerebral hemorrhage.

Imaging of Acquired Skull Base Cerebrospinal Fluid Leaks.

Acquired skull base cerebrospinal fluid (CSF) leaks can result from trauma, tumors, iatrogenic causes, or may be spontaneous. Spontaneous skull base CSF leaks are likely a manifestation of underlying idiopathic intracranial hypertension. The initial assessment of rhinorrhea or otorrhea which is suspected to be due to an acquired skull base CSF leak requires integration of clinical assessment and biochemical confirmation of CSF. Imaging with high-resolution CT is performed to locate osseous defects, while high-resolution T2w MRI may detect CSF traversing the dura and bony skull base. When leaks are multiple or if samples of fluid cannot be obtained for testing, then recourse to invasive cisternography may be necessary.

An Evaluation of the Tolerability and Feasibility of Combining 5-Amino-Levulinic Acid (5-ALA) with BCNU Wafers in the Surgical Management of Primary Glioblastoma.

Background Glioblastoma (GBM) is the commonest primary malignant brain tumour in adults and effective treatment options are limited. Combining local chemotherapy with enhanced surgical resection using 5-aminolevulinic acid (5-ALA) could improve outcomes. Here we assess the safety and feasibility of combining BCNU wafers with 5-ALA-guided surgery. Methods We conducted a multicentre feasibility study of 5-ALA with BCNU wafers followed by standard-of-care chemoradiotherapy (chemoRT) in patients with suspected GBM. Patients judged suitable for radical resection were administered 5-ALA pre-operatively and BCNU wafers at the end resection. Post-operative treatment continued as per routine clinical practice. The primary objective was to establish if combining 5-ALA and BCNU wafers is safe without compromising patients from receiving standard chemoRT. Results Seventy-two patients were recruited, sixty-four (88.9%) received BCNU wafer implants, and fifty-nine (81.9%) patients remained eligible following formal histological diagnosis. Seven (11.9%) eligible patients suffered surgical complications but only two (3.4%) were not able to begin chemoRT, four (6.8%) additional patients did not begin chemoRT within 6 weeks of surgery due to surgical complications. Eleven (18.6%) patients did not begin chemoRT for other reasons (other toxicity (n = 3), death (n = 3), lost to follow-up/withdrew (n = 3), clinical decision (n = 1), poor performance status (n = 1)). Median progression-free survival was 8.7 months (95% CI: 6.4-9.8) and median overall survival was 14.7 months (95% CI: 11.7-16.8). Conclusions Combining BCNU wafers with 5-ALA-guided surgery in newly diagnosed GBM patients is both feasible and tolerable in terms of surgical morbidity and overall toxicity. Any potential therapeutic benefit for the sequential use of 5-ALA and BCNU with chemoRT requires further investigation with improved local delivery technologies.

Cochlear Implantation in NF2 Patients Without Intracochlear Schwannoma Removal.

OBJECTIVE: To determine if cochlear implantation without removal of inner ear schwannomas (IES) is an effective treatment option for Neurofibromatosis 2 (NF2) patients. To determine how the presence of an intracochlear schwannoma might impact cochlear implant (CI) outcomes and programming parameters. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary center for cochlear and auditory brainstem implantation. PATIENTS: Of 10 NF2 patients with IES, 8 are reported with no previous tumor removal on the implanted ear. INTERVENTIONS: Cochlear implant without tumor removal. MAIN OUTCOME MEASURES: Performance outcomes with CI at least 1-year post intervention. Programming parameters, including impedances, for patients with IES. RESULTS: All patients had full insertion of the electrode arrays with round window approaches. Performance outcomes ranged from 0 to 100% for Bamford-Kowal-Bench sentences. Impedance measurements for active electrodes for patients with IES were comparable to those measured in patients without vestibular schwannoma (VS). Only patients who had radiation treatment before receiving their implant had elevated threshold requirements for CI programming compared with CI recipients without VS. CONCLUSION: Cochlear implantation without tumor removal is an effective option for treating NF2 patients with IES. The presence of an intracochlear tumor did not have an impact on CI performance or programming requirements compared with patients without VS; however, previous treatment with radiation may be related to elevated current requirements in the CI settings.

A rare case of paediatric astroblastoma with concomitant MN1-GTSE1 and EWSR1-PATZ1 gene fusions altering management.

In a case of astroblastoma, methylation analysis was uninformative, with no clustering with known CNS-HGNET-MN1 cases. Whole genome sequencing however identified a novel MN1-GTSE1 gene fusion (image), confirming the diagnosis of astroblastoma, as well as an EWSR1-PATZ1 gene fusion. Whole genome sequencing, alongside methylation profiling and conventional neuropathology, will continue to lead to improved diagnostics and prognostication for children with brain tumours.

PET-guided repeat transsphenoidal surgery for previously deemed unresectable lateral disease in acromegaly.

OBJECTIVE: The object of this study was to determine if revision transsphenoidal surgery (TSS), guided by 11C-methionine PET/CT coregistered with volumetric MRI (Met-PET/MRCR), can lead to remission in patients with persistent acromegaly due to a postoperative lateral disease remnant. METHODS: The authors identified 9 patients with persistent acromegaly following primary intervention (TSS ± medical therapy ± radiotherapy) in whom further surgery had initially been discounted because of equivocal MRI findings with suspected lateral sellar and/or parasellar disease (cases with clear Knosp grade 4 disease were excluded). All patients underwent Met-PET/MRCR. Scan findings were used by the pituitary multidisciplinary team to inform decision-making regarding repeat surgery. Revision TSS was performed with wide lateral exploration as guided by the PET findings. Endocrine reassessment was performed at 6-10 weeks after surgery, with longitudinal follow-up thereafter. RESULTS: Met-PET/MRCR revealed focal tracer uptake in the lateral sellar and/or parasellar region(s) in all 9 patients, which correlated with sites of suspected residual tumor on volumetric MRI. At surgery, tumor was identified and resected in 5 patients, although histological analysis confirmed somatotroph tumor in only 4 cases. In the other 4 patients, no definite tumor was seen, but equivocal tissue was removed. Despite the uncertainty at surgery, all patients showed immediate significant improvements in clinical and biochemical parameters. In the 8 patients for whom long-term follow-up data were available, insulin-like growth factor 1 (IGF-1) was ≤ 1.2 times the upper limit of normal (ULN) in all subjects and ≤ 1 times the ULN in 6 subjects, and these findings have been maintained for up to 28 months (median 8 months, mean 13 months) with no requirement for adjunctive medical therapy or radiotherapy. No patient suffered any additional pituitary deficit or other complication of surgery. CONCLUSIONS: This study provides proof of concept that Met-PET/MRCR can be helpful in the evaluation of residual lateral sellar/parasellar disease in persistent acromegaly and facilitate targeted revision TSS in a subgroup of patients.

Skull Base Parachordoma/Myoepithelioma.

Parachordoma is a rare soft tissue mixed tumor, associated with soft tissue myoepithelioma. It is typically growing slowly and considered less aggressive than other similar soft tissue tumors. However, it does recur sporadically, and on rare occasions, it has demonstrated the ability to metastasize. Although imaging is important, definitive diagnosis is achieved by histology, and it is typically treated by a wide local excision. We present the first reported case of a skull base parachordoma in a 15-year-old boy, managed with a wide local excision and with no signs of recurrence or metastases after 24 months of follow-up.

A comparison of radiological descriptions of spinal cord compression with quantitative measures, and their role in non-specialist clinical management.

INTRODUCTION: Magnetic resonance imaging (MRI) is gold-standard for investigating Degenerative Cervical Myelopathy (DCM), a disabling disease triggered by compression of the spinal cord following degenerative changes of adjacent structures. Quantifiable compression correlates poorly with disease and language describing compression in radiological reports is un-standardised. STUDY DESIGN: Retrospective chart review. OBJECTIVES: 1) Identify terminology in radiological reporting of cord compression and elucidate relationships between language and quantitative measures 2) Evaluate language's ability to distinguish myelopathic from asymptomatic compression 3) Explore correlations between quantitative or qualitative features and symptom severity 4) Investigate the influence of quantitative and qualitative measures on surgical referrals. METHODS: From all cervical spine MRIs conducted during one year at a tertiary centre (N = 1123), 166 patients had reported cord compression. For each spinal level deemed compressed by radiologists (N = 218), four quantitative measurements were calculated: 'Maximum Canal Compromise (MCC); 'Maximum Spinal Cord Compression' (MSCC); 'Spinal Canal Occupation Ratio' (SCOR) and 'Compression Ratio' (CR). These were compared to associated radiological reporting terminology. RESULTS: 1) Terminology in radiological reports was varied. Objective measures of compromise correlated poorly with language. "Compressed" was used for more severe cord compromise as measured by MCC (p<0.001), MSCC (p<0.001), and CR (p = 0.002). 2) Greater compromise was seen in cords with a myelopathy diagnosis across MCC (p<0.001); MSCC (p = 0.002) and CR (p<0.001). "Compress" (p<0.001) and "Flatten" (p<0.001) were used more commonly for myelopathy-diagnosis levels. 3) Measurements of cord compromise (MCC: p = 0.304; MSCC: p = 0.217; SCOR: p = 0.503; CR: p = 0.256) and descriptive terms (p = 0.591) did not correlate with i-mJOA score. 4) The only variables affecting spinal surgery referral were increased MSCC (p = 0.001) and use of 'Compressed' (p = 0.045). CONCLUSIONS: Radiological reporting in DCM is variable and language is not fully predictive of the degree of quantitative cord compression. Additionally, terminology may influence surgical referrals.

When Should We Stop Scanning Older Patients with Vestibular Schwannomas?

Objective Observation is a well-accepted management for small- to medium-sized vestibular schwannomas (VSs). Although there are good data on the natural history of this disease within adults, no studies have looked specifically at those aged over 70 years. Thus, there is a need for a surveillance protocol to determine if and when we can stop imaging safely patients aged 70 years and over with a new diagnosis of VSs when managed with observation. Design Over a 13-year period, we retrospectively analyzed all skull base unit patients with a sporadic unilateral VSs managed with an imaging surveillance protocol. All data were collected prospectively with a minimum follow-up of 5 years. Setting Tertiary referral skull base unit Participants Patients aged 70 years and over with sporadic VSs at diagnosis Main Outcome Measures Main outcome measures Results A total of 112 patients met inclusion criteria. The median age at diagnosis was 74 years (range: 70-87 years). The mean follow-up was 82 months (range: 60-144). The size of the VSs at diagnosis was intracanalicular (IC) in 46%, small in 41%, medium in 12%, and large in 2%. Growth was more likely where tumors were extracanalicular (EC) rather than IC at presentation ( p = 0.036) and within the first 18 months after diagnosis ( p < 0.001). Twenty-nine percent of VSs displayed growth (6% continued surveillance, 23% received active treatment). Good hearing at diagnosis did not predict tumor stability for IC or EC tumors ( p = 0.162 and p = 0.536). Conclusions Since no VSs grew after 42 months from diagnosis, our data support an initial magnetic resonance imaging (MRI) at 6 months after diagnosis followed by an annual MRI for 3 years. At this point, consideration could be given to discussing discontinuation or further imaging with patients.

Modern imaging of pituitary adenomas.

Decision-making in pituitary disease is critically dependent on high quality imaging of the sella and parasellar region. Magnetic resonance imaging (MRI) is the investigation of choice and, for the majority of patients, combined T1 and T2 weighted sequences provide the information required to allow surgery, radiotherapy (RT) and/or medical therapy to be planned and long-term outcomes to be monitored. However, in some cases standard clinical MR sequences are indeterminate and additional information is needed to help inform the choice of therapy for a pituitary adenoma (PA). This article reviews current recommendations for imaging of PA, examines the potential added value that alternative MR sequences and/or CT can offer, and considers how the use of functional/molecular imaging might allow definitive treatment to be recommended for a subset of patients who would otherwise be deemed unsuitable for (further) surgery and/or RT.

Genotype, extrapyramidal features, and severity of variant ataxia-telangiectasia.

OBJECTIVE: Variant ataxia-telangiectasia is caused by mutations that allow some retained ataxia telangiectasia-mutated (ATM) kinase activity. Here, we describe the clinical features of the largest established cohort of individuals with variant ataxia-telangiectasia and explore genotype-phenotype correlations. METHODS: Cross-sectional data were collected retrospectively. Patients were classified as variant ataxia-telangiectasia based on retained ATM kinase activity. RESULTS: The study includes 57 individuals. Mean age at assessment was 37.5 years. Most had their first symptoms by age 10 (81%). There was a diagnostic delay of more than 10 years in 68% and more than 20 years in one third of probands. Disease severity was mild in one third of patients, and 43% were still ambulant 20 years after disease onset. Only one third had predominant ataxia, and 18% had a pure extrapyramidal presentation. Individuals with extrapyramidal presentations had milder neurological disease severity. There were no significant respiratory or immunological complications, but 25% of individuals had a history of malignancy. Missense mutations were associated with milder neurological disease severity, but with a higher risk of malignancy, compared to leaky splice site mutations. INTERPRETATION: Individuals with variant ataxia-telangiectasia require malignancy surveillance and tailored management. However, our data suggest the condition may sometimes be mis- or underdiagnosed because of atypical features, including exclusive extrapyramidal symptoms, normal eye movements, and normal alpha-fetoprotein levels in some individuals. Missense mutations are associated with milder neurological presentations, but a particularly high malignancy risk, and it is important for clinicians to be aware of these phenotypes. ANN NEUROL 2019;85:170-180.

Radiological Correlates of Raised Intracranial Pressure in Children: A Review.

Radiological assessment of the head is a routine part of the management of traumatic brain injury. This assessment can help to determine the requirement for invasive intracranial pressure (ICP) monitoring. The radiological correlates of elevated ICP have been widely studied in adults but far fewer specific pediatric studies have been conducted. There is, however, growing evidence that there are important differences in the radiological presentations of elevated ICP between children and adults; a reflection of the anatomical and physiological differences, as well as a difference in the pathophysiology of brain injury in children. Here in, we review the radiological parameters that correspond with increased ICP in children that have been described in the literature. We then describe the future directions of this work and our recommendations in order to develop non-invasive and radiological markers of raised ICP in children.

Analysis of heterogeneity in T2-weighted MR images can differentiate pseudoprogression from progression in glioblastoma.

PURPOSE: To develop an image analysis technique that distinguishes pseudoprogression from true progression by analyzing tumour heterogeneity in T2-weighted images using topological descriptors of image heterogeneity called Minkowski functionals (MFs). METHODS: Using a retrospective patient cohort (n = 50), and blinded to treatment response outcome, unsupervised feature estimation was performed to investigate MFs for the presence of outliers, potential confounders, and sensitivity to treatment response. The progression and pseudoprogression groups were then unblinded and supervised feature selection was performed using MFs, size and signal intensity features. A support vector machine model was obtained and evaluated using a prospective test cohort. RESULTS: The model gave a classification accuracy, using a combination of MFs and size features, of more than 85% in both retrospective and prospective datasets. A different feature selection method (Random Forest) and classifier (Lasso) gave the same results. Although not apparent to the reporting radiologist, the T2-weighted hyperintensity phenotype of those patients with progression was heterogeneous, large and frond-like when compared to those with pseudoprogression. CONCLUSION: Analysis of heterogeneity, in T2-weighted MR images, which are acquired routinely in the clinic, has the potential to detect an earlier treatment response allowing an early change in treatment strategy. Prospective validation of this technique in larger datasets is required.

The use of 11carbon methionine positron emission tomography (PET) imaging to enhance radiotherapy planning in the treatment of a giant, invasive pituitary adenoma.

A 54-year-old male presented with visual loss owing to a giant, infiltrative pituitary adenoma. Following decompressive trans-sphenoidal surgery, the patient was referred for adjuvant radiotherapy. We describe the potential utility of 11carbon methionine positron emission tomography imaging in confirming the true extent of tumour infiltration, which included the cavernous sinuses and the bones of the skull base. The co-registration of positron emission tomography imaging to planning MR and CT imaging provided assurance of complete radiotherapy coverage of the target volume and assisted with the minimisation of collateral radiation dose to adjacent organs at risk.

Isolated oculomotor nerve palsy in patients with mild head injury.

Isolated oculomotor nerve palsy following head injury is uncommon. It can only be diagnosed with confidence if it is known to have developed immediately following trauma and if adequate investigations exclude secondary causes. The recovery is only partial and this has repercussion on patients' quality of life.