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.

"Flow void sign": flow artefact on T2-weighted MRI can be an indicator of dural defect location in ventral type 1 spinal CSF leaks.

Patients with spontaneous intracranial hypotension caused by type 1 dural defects typically have an epidural fluid collection on MRI, but the location of the defect is not usually readily identifiable on standard MRI sequences and can be at any point along the length of the collection. The most common location for type 1 leaks is ventral and as such are most commonly associated with ventral predominant epidural fluid. Dynamic myelography (either digital subtraction myelography or dynamic CT myelography) is currently the standard of care to localise the defect. We describe an imaging sign on T2-weighted images caused by CSF-flow egress at the site of the defect that may permit accurate prediction of the site of the CSF leak non-invasively. Importantly, this sign was only observed on 2D T2-weighted and STIR images and not on 3D acquisitions, which notably suppress artefact. This has implications for optimal MRI spine protocol construction. This sign can be used to limit myelographic range, reduce radiation dose and may increase diagnostic confidence to dural defect location.ABBREVIATIONS: dCTM = Dynamic CT Myelography; DSM = Digital Subtraction Myelography; SIH = Spontaneous Intracranial Hypotension.

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.

Perfusion MRI in the evaluation of brain metastases: current practice review and rationale for study of baseline MR perfusion imaging prior to stereotactic radiosurgery (STARBEAM-X).

Stereotactic radiosurgery is an established focal treatment for brain metastases with high local control rates. An important side-effect of stereotactic radiosurgery is the development of radionecrosis. On conventional MR imaging, radionecrosis and tumour progression often have similar appearances, but have contrasting management approaches. Perfusion MR imaging is often used in the post-treatment setting in order to help distinguish between the two, but image interpretation can be fraught with challenges.Perfusion MR plays an established role in the baseline and post-treatment evaluation of primary brain tumours and a number of studies have concentrated on the value of perfusion imaging in brain metastases. Of the parameters generated, relative cerebral blood volume is the most widely used variable in terms of its clinical value in differentiating between radionecrosis and tumour progression. Although it has been suggested that the relative cerebral blood volume tends to be elevated in active metastatic disease following treatment with radiosurgery, but not with treatment-related changes, the literature available on interpretation of the ratios provided in the context of defining tumour progression is not consistent.This article aims to provide an overview of the role perfusion MRI plays in the assessment of brain metastases and introduces the rationale for the STARBEAM-X study (Study of assessment of radionecrosis in brain metastases using MR perfusion extra imaging), which will prospectively evaluate baseline perfusion imaging in brain metastases. We hope this will allow insight into the vascular appearance of metastases from different primary sites, and aid in the interpretation of post-treatment perfusion imaging.

Mosaicism in Hartsfield syndrome.

Hartsfield syndrome is a rare condition characterised by the co-occurrence of ectrodactyly and holoprosencephaly spectrum disorders; cleft lip and palate is a common associated feature. This is due to either monoallelic, or less commonly, biallelic variants in FGFR1 with a loss of function or dominant negative effect. To date 37 individuals have been reported, including two instances of germline mosaicism. We report a further family with Hartsfield syndrome due to a novel variant in FGFR1, with two affected fetuses, and somatic and germline mosaicism in the father detected on Sanger sequencing. The father had not come to medical attention prior to this finding. In light of our findings and those in the published literature, we suggest that mosaicism, either germline or germline and somatic, may be a relatively frequent finding, affecting 3 of 35 (9%) reported families, which has important implications for genetic counselling.

Treatment of spontaneous intracranial hypotension: experiences in a UK regional neurosciences Centre.

A robust treatment paradigm for spontaneous intracranial hypotension has yet to be agreed upon. We present retrospective data from the patient cohort at our UK regional neurosciences centre from 2010-2020 and describe our locally developed treatment pathway.Seventy-three patients were identified: 31 men and 42 women; mean age was 42 years. The majority presented with a headache of variable duration, and most had positive imaging. Very few patients (7%) responded to conservative treatment. Sixty-six underwent epidural blood patching, with 39 (59%) having a good response. Twenty-three patients underwent myelography and targeted treatment (injection of fibrin sealant at the leak site), with 13 (57%) showing a good response. One patient had successful surgery. The relapse rate after response to epidural blood patching was 10%, and after response to targeted treatment was 23%. Most patients who relapsed responded to repeated treatments.The outcome data for our diverse patient cohort shows the success of a staged approach to treatment. Relapse rates are low, and surgery is only rarely required. We use these data to inform our discussions with patients, and present them here to enable other centres to develop robust investigation and treatment paradigms of their own.

Testicular sonography: Is an echogenic ring a sign of a benign lesion?

The differentiation of benign from malignant testicular lesions is important to avoid unnecessary surgical intervention but is often difficult, particularly in the case of focal hypoechoic lesions. We present the description of 3 cases of an echogenic ring that appeared around a hypoechoic testicular mass on sonograms. The ring proved to be a fibrous capsule around a benign lesion. If these observations are confirmed in larger series, the sonographic pattern described here may help reduce the number of orchiectomies performed for benign lesions.