NF2-related schwannomatosis and other schwannomatosis: an updated genetic and epidemiological study.

OBJECTIVES: New diagnostic criteria for NF2-related schwannomatosis (NF2) were published in 2022. An updated UK prevalence was generated in accordance with these, with an emphasis on the rate of de novo NF2 (a 50% frequency is widely quoted in genetic counselling). The distribution of variant types among de novo and familial NF2 cases was also assessed. METHODS: The UK National NF2 database identifies patients meeting updated NF2 criteria from a highly ascertained population cared for by England's specialised service. Diagnostic prevalence was assessed on 1 February 2023. Molecular analysis of blood and, where possible, tumour specimens for NF2, LZTR1 and SMARCB1 was performed. RESULTS: 1084 living NF2 patients were identified on prevalence day (equivalent to 1 in 61 332). The proportion with NF2 inherited from an affected parent was only 23% in England. If people without a confirmed molecular diagnosis or bilateral vestibular schwannoma are excluded, the frequency of de novo NF2 remains high (72%). Of the identified de novo cases, almost half were mosaic. The most common variant type was nonsense variants, accounting for 173/697 (24.8%) of people with an established variant, but only 18/235 (7.7%) with an inherited NF2 pathogenic variant (p<0.0001). Missense variants had the highest proportion of familial association (56%). The prevalence of LZTR1-related schwannomatosis and SMARCB1-related schwannomatosis was 1 in 527 000 and 1 in 1.1M, respectively, 8.4-18.4 times lower than NF2. CONCLUSIONS: This work confirms a much higher rate of de novo NF2 than previously reported and highlights the benefits of maintaining patient databases for accurate counselling.

The burden of migraine on acute and emergency services in a London teaching hospital.

OBJECTIVE: There is a lack of data on the burden of primary headache disorders such as migraine on emergency services. Existing data relies on a coding of "headache", which encompasses both primary and secondary headache of all causes; for example, subarachnoid haemorrhage. Guy's and St Thomas' NHS Trust in London is one of the UK's busiest emergency departments with 150,000 attendances per year. Our aim was to assess the healthcare resource utilisation of primary headaches, in particular migraine, in acute medical services. METHODS: We conducted an audit of all adult presentations to the emergency department of Guy's and St Thomas' Hospitals which were coded as "headache" over the first 6 months of 2018. We reviewed the initial diagnosis at presentation and also at discharge, investigations and outcome. RESULTS: Of 78,273 attendances to the emergency department, there were 976 presentations to the emergency department with "headache" as their primary complaint. "Migraine" was the most frequent of all diagnoses, accounting for 30% of all headache presentations and 25% of headache admissions. We calculated the cost of admitting and investigating migraine as £131,250 over the 6-month period. CONCLUSION: Emergency admissions for migraine represent an avoidable cost and burden for both the hospital and the migraineur. This data informs us about the need to develop better care pathways for migraine in the community and to improve headache education for physicians and patients.

Incidence of mosaicism in 1055 de novo NF2 cases: much higher than previous estimates with high utility of next-generation sequencing.

PURPOSE: To evaluate the incidence of mosaicism in de novo neurofibromatosis 2 (NF2). METHODS: Patients fulfilling NF2 criteria, but with no known affected family member from a previous generation (n = 1055), were tested for NF2 variants in lymphocyte DNA and where available tumor DNA. The proportion of individuals with a proven or presumed mosaic NF2 variant was assessed and allele frequencies of identified variants evaluated using next-generation sequencing. RESULTS: The rate of proven/presumed mosaicism was 232/1055 (22.0%). However, nonmosaic heterozygous pathogenic variants were only identified in 387/1055 (36.7%). When variant detection rates in second generation nonmosaics were applied to de novo cases, we assessed the overall probable mosaicism rate to be 59.7%. This rate differed by age from 21.7% in those presenting with bilateral vestibular schwannoma <20 years to 80.7% in those aged ≥60 years. A mosaic variant was detected in all parents of affected children with a single-nucleotide pathogenic NF2 variant. CONCLUSION: This study has identified a very high probable mosaicism rate in de novo NF2, probably making NF2 the condition with the highest expressed rate of mosaicism in de novo dominant disease that is nonlethal in heterozygote form. Risks to offspring are small and probably correlate with variant allele frequency detected in blood.

Migraine: navigating the hormonal minefield.

Migraine affects 959 million people worldwide,1 with the highest prevalence being in women of childbearing age. The interplay between female hormones and migraine can be a challenging area to navigate since issues relating to pregnancy, contraception and the menopause are often out of the neurology comfort zone. This review aims to help the neurologist to manage women with migraine, from menarche to menopause.

Identifying the deficiencies of current diagnostic criteria for neurofibromatosis 2 using databases of 2777 individuals with molecular testing.

PURPOSE: We have evaluated deficiencies in existing diagnostic criteria for neurofibromatosis 2 (NF2). METHODS: Two large databases of individuals fulfilling NF2 criteria (n = 1361) and those tested for NF2 variants with criteria short of diagnosis (n = 1416) were interrogated. We assessed the proportions meeting each diagnostic criterion with constitutional or mosaic NF2 variants and the positive predictive value (PPV) with regard to definite diagnosis. RESULTS: There was no evidence for usefulness of old criteria "glioma" or "neurofibroma." "Ependymoma" had 100% PPV and high levels of confirmed NF2 diagnosis (67.7%). Those with bilateral vestibular schwannoma (VS) alone aged ≥60 years had the lowest confirmation rate (6.6%) and reduced PPV (80%). Siblings as a first-degree relative, without an affected parent, had 0% PPV. All three individuals with unilateral VS and an affected sibling were proven not to have NF2. The biggest overlap was with LZTR1-associated schwannomatosis. In this category, seven individuals with unilateral VS plus ≥2 nondermal schwannomas reduced PPV to 67%. CONCLUSIONS: The present study confirms important deficiencies in NF2 diagnostic criteria. The term "glioma" should be dropped and replaced by "ependymoma." Similarly "neurofibroma" should be removed. Dropping "sibling" from first-degree relatives should be considered and testing of LZTR1 should be recommended for unilateral VS.

Cerebral vasculopathy in childhood neurofibromatosis type 2: cause for concern?

Unlike adult neurofibromatosis type 2 (NF2), which presents with symptoms related to bilateral vestibular schwannomas, children with NF2 most frequently present with ocular, dermatological, and neurological symptoms. Arteriopathy, a well-established feature in neurofibromatosis type 1, is not a widely recognized feature of NF2. Here we report three children with NF2 with cerebral arteriopathy and/or arterial ischaemic stroke. Bevacizumab, a vascular endothethial growth factor inhibitor, is an established treatment for rapidly growing vestibular schwannomas; however, it carries a risk of both ischaemic and haemorrhagic stroke. Thus, the role of screening and risk to benefit ratio of bevacizumab in NF2 merit further consideration. WHAT THIS PAPER ADDS: Children with neurofibromatosis type 2 (NF2) may be at increased risk of cerebral vasculopathy and arterial ischaemic stroke. Targeted magnetic resonance angiography should be performed in children with NF2 who are being considered for bevacizumab therapy.

Aneurysms in neurofibromatosis type 2: Evidence for vasculopathy?

There have been anecdotal reports of vasculopathy associated with Neurofibromatosis Type 2 (NF2). Given the increasing use of bevacizumab, a vascular endothelial growth factor inhibitor which results in an increased risk of bleeding, it is important to ascertain if there is a predisposition to vascular abnormalities in NF2. In our unit NF2 patients undergo annual MRI brain and internal auditory meatus imaging. We noted incidental intracranial aneurysms in some patients and sought to determine the prevalence of intracranial aneurysms in our cohort of NF2 patients. We conducted a retrospective audit of the MRI images of 104 NF2 patients from 2014 to 2016. Axial T2 brain MRI images were assessed for vascular abnormalities by two neuroradiologists blinded to patient's clinical details. Intracranial aneurysms were detected in four patients and an aneurysm clip related to previous surgery was noted in one additional patient. Using standard MRI imaging sequences alone we provide evidence of intracranial aneurysms in 4.4% of our cohort. This compares with an estimated overall prevalence of 3% in the general population. We discuss these findings as well as other evidence for a vasculopathy associated with NF2.

Toxicity profile of bevacizumab in the UK Neurofibromatosis type 2 cohort.

Bevacizumab is considered an established part of the treatment strategies available for schwannomas in patients with Neurofibromatosis type 2 (NF2). In the UK, it is available through NHS National Specialized Commissioning to NF2 patients with a rapidly growing target schwannoma. Regrowth of the tumour on suspension of treatment is often observed resulting in prolonged periods of exposure to bevacizumab to control the disease. Hypertension and proteinuria are common events with bevacizumab use and there are concerns with regards to the long-term risks of prolonged treatment. Dosing, demographic and adverse event (CTCAE 4.03) data from the UK NF2 bevacizumab cohort are reviewed with particular consideration of renal and cardiovascular complications. Eighty patients (48 male:32 female), median age 24.5 years (range 11-66 years), were followed for a median of 32.7 months (range 12.0-60.2 months). The most common adverse events were fatigue, hypertension and infection. A total of 19/80 patients (24 %) had either a grade 2 or grade 3 hypertension event and 14/80 patients (17.5 %) had proteinuria. Of 36 patients followed for 36 months, 78 % were free from hypertension and 86 % were free of proteinuria. Logistic regression modeling identified age and induction dosing regime to be independent predictors of development of hypertension with dose of 7.5 mg/kg 3 weekly and age >30years having higher rates of hypertension. Proteinuria persisted in one of three patients after cessation of bevacizumab. One patient developed congestive heart failure and the details of this case are described. Further work is needed to determine optimal dosing regimes to limit toxicity without impacting on efficacy.

Evaluation of quality of life in adults with neurofibromatosis 1 (NF1) using the Impact of NF1 on Quality Of Life (INF1-QOL) questionnaire.

BACKGROUND: Neurofibromatosis 1 (NF1) is an inherited, multi-system, tumour suppressor disorder with variable complications that cause psychological distress and social isolation. The study aim was to develop and validate a disease-specific questionnaire to measure quality of life (QOL) in NF1 that is suitable both as an assessment tool in clinical practice and in clinical trials of novel therapy. METHODS: The Impact of NF1 on Quality of Life (INF1-QOL) questionnaire was developed by a literature search for common terms, focus group (n = 6), semi-structured interviews (n = 21), initial drafts (n =50) and final 14 item questionnaire (n = 50). Bivariate correlations between items, exploratory factor analysis, correlations with severity and EuroQol were employed. RESULTS: INF1-QOL showed good internal reliability (Cronbach's alpha 0.87), mean total INF1-QOL score was 8.64 (SD 6.3), median 7.00, range 0-30 (possible range 0-42); no significant correlations with age or gender. The mean total EuroQol score was 7.38 (SD 2.87), median 6.5, mean global EuroQol score was 76.34 (SD 16.56), median 80. Total INF1-QOL score correlated with total EuroQol r = 0.82, p < 0.0001. The highest impact on QOL was moderate or severe problems with anxiety and depression (32%) and negative effects of NF1 on role and outlook on life (42%). The mean inter-relater reliability for grading of clinical severity scores was 0.71 (range 0.65-0.79), and intra-class correlation was 0.92. The mean clinical severity score was 1.95 (SD 0.65) correlating r = 0.34 with total INF1-QOL score p < 0.05 and correlated 0.37 with total EuroQol score p < 0.01. The clinical severity score was mild in 17 (34%), moderate in 16 (32%) and 17 (34%) individuals had severe disease. CONCLUSIONS: INF1-QOL is a validated, reliable disease specific questionnaire that is easy and quick to complete. Role and outlook on life and anxiety and depression have the highest impact on QOL indicating the variability, severity and unpredictability of NF1. INFI-QOL correlates moderately with clinical severity. The moderate relationship between INF1-QOL and physician rated severity emphasizes the difference between clinical and patient perception. INFI-QOL will be useful in individual patient assessment and as an outcome measure for clinical trials.

Clinical and molecular predictors of mortality in neurofibromatosis 2: a UK national analysis of 1192 patients.

BACKGROUND: Neurofibromatosis 2 (NF2) is an autosomal-dominant tumour predisposition syndrome characterised by bilateral vestibular schwannomas, considerable morbidity and reduced life expectancy. Although genotype-phenotype correlations are well established in NF2, little is known about effects of mutation type or location within the gene on mortality. Improvements in NF2 diagnosis and management have occurred, but their effect on patient survival is unknown. METHODS: We evaluated clinical and molecular predictors of mortality in 1192 patients (771 with known causal mutations) identified through the UK National NF2 Registry. Kaplan-Meier survival and Cox regression analyses were used to evaluate predictors of mortality, with jackknife adjustment of parameter SEs to account for the strong intrafamilial phenotypic correlations that occur in NF2. RESULTS: The study included 241 deaths during 10 995 patient-years of follow-up since diagnosis. Early age at diagnosis and the presence of intracranial meningiomas were associated with increased mortality, and having a mosaic, rather than non-mosaic, NF2 mutation was associated with reduced mortality. Patients with splice-site or missense mutations had lower mortality than patients with truncating mutations (OR 0.459, 95% CI 0.213 to 0.990, and OR 0.196, 95% CI 0.213 to 0.990, respectively). Patients with splice-site mutations in exons 6-15 had lower mortality than patients with splice-site mutations in exons 1-5 (OR 0.333, 95% CI 0.129 to 0.858). The mortality of patients with NF2 diagnosed in more recent decades was lower than that of patients diagnosed earlier. CONCLUSIONS: Continuing advances in molecular diagnosis, imaging and treatment of NF2-associated tumours offer hope for even better survival in the future.

Cilioretinal Artery Territory Infarction Associated With Papilledema in a Patient With Neurofibromatosis Type 2.

Cilioretinal artery territory infarction can occur in isolation or in association with other vascular compromise of the retinal circulation. Our patient, an 18-year-old woman with neurofibromatosis type 2, developed a cilioretinal artery territory infarction in the setting of papilledema. Our case, together with one previous report, suggests that cilioretinal artery territory infarction in the context of papilledema, although rare, is a real entity.

Prevalence and clinical presentation of headache in a National Neurofibromatosis 1 Service and impact on quality of life.

In our clinical practice, we noticed a high frequency of headaches amongst NF1 patients. We sought to characterize the phenotype and prevalence of headache in our cohort of NF1 patients attending the London NF clinic and to determine the impact on quality of life. Participants over the age of 16 fulfilling diagnostic criteria for NF1 from the general NF1 outpatient clinics at Guy's and St. Thomas' NHS Foundation Trust and the nationally commissioned Complex NF1 service were asked to fill in a questionnaire during the clinic consultation. Data were recorded regarding the headache frequency, intensity, duration, and phenotype, and a validated quality of life questionnaire, HIT-6 was also completed by the participant. IHS (International Headache Society) criteria were used to diagnose migraine. One hundred fifteen patients (48 males, 67 females) completed the questionnaire. The age range of participants was 16-67 with a mean age of 36 years. Twenty-five reported no headaches. Seventy-five (65%) fulfilled IHS diagnostic criteria for migraine (15 with aura). The mean HIT-6 score was 56 (out of a maximum 78) implying a significant effect on quality of life. Migraine is common in our NF1 population and has a significant impact on quality of life. Patients may not volunteer information regarding headache and this should be actively sought during consultations and the headache phenotype should be carefully characterized.

Special considerations in migraine during pregnancy and lactation.

Migraine is estimated to affect 959 million people worldwide and has a female preponderance of 3:1. This is thought to be due to the influence of female hormones as before puberty both sexes are affected equally. The prevalence is highest in women of childbearing age at 24%. It is, therefore, important to have a good understanding of how pregnancy influences migraine and how to advise and manage women with migraine during pregnancy and lactation.

Radiation treatment of benign tumors in NF2-related-schwannomatosis: A national study of 266 irradiated patients showing a significant increase in malignancy/malignant progression.

Background: Radiation treatment of benign tumors in tumor predisposition syndromes is controversial, but short-term studies from treatment centers suggest safety despite apparent radiation-associated malignancy being reported. We determined whether radiation treatment in NF2-related schwannomatosis patients is associated with increased rates of subsequent malignancy (M)/malignant progression (MP). Methods: All UK patients with NF2 were eligible if they had a clinical/molecular diagnosis. Cases were NF2 patients treated with radiation for benign tumors. Controls were matched for treatment location with surgical/medical treatments based on age and year of treatment. Prospective data collection began in 1990 with addition of retrospective cases in 1969. Kaplan-Meier analysis was performed for malignancy incidence and survival. Outcomes were central nervous system (CNS) M/MP (2cm annualized diameter growth) and survival from index tumor treatment. Results: In total, 1345 NF2 patients, 266 (133-Male) underwent radiation treatments between 1969 and 2021 with median first radiotherapy age of 32.9 (IQR = 22.4-46.0). Nine subsequent CNS malignancies/MPs were identified in cases with only 4 in 1079 untreated (P < .001). Lifetime and 20-year CNS M/MP was ~6% in all irradiated patients-(4.9% for vestibular schwannomas [VS] radiotherapy) versus <1% in the non-irradiated population (P < .001/.01). Controls were well matched for age at NF2 diagnosis and treatment (Males = 133%-50%) and had no M/MP in the CNS post-index tumor treatment (P = .0016). Thirty-year survival from index tumor treatment was 45.62% (95% CI = 34.0-56.5) for cases and 66.4% (57.3-74.0) for controls (P = .02), but was nonsignificantly worse for VS radiotherapy. Conclusion: NF2 patients should not be offered radiotherapy as first-line treatment of benign tumors and should be given a frank discussion of the potential 5% excess absolute risk of M/MP.

Reliability of functional outcome measures in adults with neurofibromatosis 2.

Objective: To determine inter- and intra-rater reliability of functional performance outcome measures in people with neurofibromatosis 2. To ascertain how closely objective and subjective measures align. Methods: Twenty-nine people with neurofibromatosis 2 were recorded performing the modified clinical test of sensory integration and balance, four square step test and modified nine-hole peg tests. Three raters scored each measure to determine inter-rater reliability. One rater scored the measures a second time to determine intra-rater reliability. Participants also completed a disease-specific quality of life questionnaire and dynamic visual acuity testing. Results: Inter-rater and intra-rater reliability scores (intra-class correlation coefficient) were excellent for all tests (intra-class correlation coefficient r ⩾ 0.9). The four square step test correlated with perceived walking challenges and modified clinical test of sensory integration and balance correlated with perceived balance challenges in a neurofibromatosis 2 quality of life patient report outcome measure. Conclusion: The modified clinical test of sensory integration and balance, four square step test and modified nine-hole peg tests are potentially useful measures for monitoring neurofibromatosis 2.

Case report of a man with multiple paragangliomas and pathogenic germline variants in both NF1 and SDHD.

We report a novel case of multiple paragangliomas in a patient who was identified with pathogenic variants in both NF1 and SDHD genes. The proband is a man with known familial NF1 disease, diagnosed clinically in childhood. Multiple head and neck paragangliomas (HNPGL) were found during investigations for acute left sided neurological symptoms, in the region of his known plexiform neurofibroma. He was referred for genetic counselling. He underwent surgery to remove a left carotid body tumor (CBT). A pheochromocytoma and paraganglioma gene panel was tested. Blood and HNPGL tumor DNA were analyzed by whole exome sequencing. In addition to the NF1 truncating variant c.5107delA, p.(Ser1703AlafsTer7), the SDHD truncating pathogenic variant c.3G > A, p.(Met1?) was found. Tumor sequencing showed no LOH of SDHD or NF1, but monoallelic loss of 11p15 and 11q12.2-q12.3 was observed. Co-occurrence of pathogenic variants in multiple cancer susceptibility genes is rare but possible, identified by the increased use of panel testing. This is the first description of a patient presenting with NF1 and SDHD dual pathology, with HNPGL development due to SDHD. This case illustrates the central role of genetic sequencing in PPGLs and the strong genotype-phenotype correlations of different genes.

Relevant factors for neurologists to define effectiveness of migraine preventive drugs and take decisions on treatment. My-LIFE European Delphi survey.

BACKGROUND: Clinical guidelines agree that preventive treatment should be considered in patients with uncontrolled migraine despite acute medications or patients with ≥4 migraine days per month. However, the criteria to define the effectiveness of treatment and the factors that inform the decision to (dis)continue it are not clearly defined in clinical practice. METHODS: Overall, 148 healthcare practitioners from five European countries completed a two-wave questionnaire. The Steering Committee defined a simulated set of 108 migraine patient profiles based on the combination of five factors (frequency of the attacks, intensity of the attacks, use of acute migraine medications, patient perception and presence/absence of tolerable side effects). These profiles were used in a Delphi survey among European neurologists to identify the criteria that should be used to decide treatment response and continuation using a conjoint analysis approach. RESULTS: Consensus was reached for 82/108 (76%) of profiles regarding treatment response, and for 86/108 (80%) regarding treatment continuation. Multivariable logistic regression analysis showed that a ≥50% reduction in the use of acute migraine medications and positive patient's perception of treatment were the most important factors that lead to the decision of continuing (combined factors, OR = 18.3, 95% CI 13.4-25.05). CONCLUSIONS: This survey identifies two relevant outcome measures: one objective (use of acute migraine treatment medications) and one subjective (positive patient perception) that guide the clinician decision to continue preventive treatment in migraine patients. SIGNIFICANCE: In clinical practice, criteria to define the effectiveness of migraine preventive treatment and factors that guide treatment stop or continuation are not clearly defined. In this simulated clinical setting study, a reduction in the use of acute migraine medications was the factor associated with preventive treatment effectiveness definition. This study also revealed that factors strongly associated with the decision of treatment continuation in real life are the acute migraine medications use and a positive patient's perception of treatment effectiveness.

Management of chronic headache with referral from primary care to direct access to MRI compared with Neurology services: an observational prospective study in London.

OBJECTIVES: To evaluate the cost, accessibility and patient satisfaction implications of two clinical pathways used in the management of chronic headache. INTERVENTION: Management of chronic headache following referral from Primary Care that differed in the first appointment, either a Neurology appointment or an MRI brain scan. DESIGN AND SETTING: A pragmatic, non-randomised, prospective, single-centre study at a Central Hospital in London. PARTICIPANTS: Adult patients with chronic headache referred from primary to secondary care. PRIMARY AND SECONDARY OUTCOME MEASURES: Participants' use of healthcare services and costs were estimated using primary and secondary care databases and questionnaires quarterly up to 12 months postrecruitment. Cost analyses were compared using generalised linear models. Secondary outcomes assessed: access to care, patient satisfaction, headache burden and self-perceived quality of life using headache-specific (Migraine Disability Assessment Scale and Headache Impact Test) and a generic questionnaire (5-level EQ-5D). RESULTS: Mean (SD) cost up to 6 months postrecruitment per participant was £578 (£420) for the Neurology group (n=128) and £245 (£172) for the MRI group (n=95), leading to an estimated mean cost difference of £333 (95% CI £253 to £413, p<0.001). The mean cost difference at 12 months increased to £518 (95% CI £401 to £637, p<0.001). When adjusted for baseline and follow-up imbalances between groups, this remained statistically significant. The utilisation of brain MRI improved access to care compared with the Neurology group (p<0.001). Participants in the Neurology group reported higher levels of satisfaction associated with the pathway and led to greater change in care management. CONCLUSION: Direct referral to brain MRI from Primary Care led to cost-savings and quicker access to care but lower satisfaction levels when compared with referral to Neurology services. Further research into the use of brain MRI for a subset of patient population more likely to be reassured by a negative brain scan should be considered. TRIAL REGISTRATION NUMBER: NCT02753933.

Current concepts in migraine and their relevance to pregnancy.

The prevalence of migraine in women of childbearing age is high, estimated at 24%. Migraine management during pregnancy and lactation can be challenging. Our understanding of the way in which medications affect the unborn fetus is still incomplete and the evidence is constantly changing with more recent emphasis on longitudinal studies and childhood development. The aim of this article is to describe the relationship between migraine and pregnancy and review the current evidence on treatment options in pregnancy and lactation.