Health-related quality of life in hereditary hemorrhagic telangiectasia

Sino-Nasal Outcome Test-22: Translation, Cross-cultural Adaptation, and Validation in Hebrew-Speaking Patients

OBJECTIVE

To perform the translation, cross-cultural adaptation, and validation of the Sino-Nasal Outcome Test-22 (SNOT-22) questionnaire to the Hebrew language.

STUDY DESIGN AND SETTING

A single-center prospective cross-sectional study.

SUBJECTS AND METHODS

Seventy-three chronic rhinosinusitis (CRS) patients and 73 patients without sinonasal disease filled the Hebrew version of the SNOT-22 questionnaire. Fifty-one CRS patients underwent endoscopic sinus surgery, out of which 28 filled a postoperative questionnaire. Seventy-three healthy volunteers without sinonasal disease also answered the questionnaire. Internal consistency, test-retest reproducibility, validity, and responsiveness of the questionnaire were evaluated.

RESULTS

Questionnaire reliability was excellent, with a high internal consistency (Cronbach's alpha coefficient, 0.91-0.936) and test-retest reproducibility (Spearman's coefficient, 0.962). Mean scores for the preoperative, postoperative, and control groups were 50.44, 29.64, and 13.15, respectively (P < .0001 for CRS vs controls, P < .001 for preoperative vs postoperative), showing validity and responsiveness of the questionnaire.

CONCLUSION

The Hebrew version of SNOT-22 questionnaire is a valid outcome measure for patients with CRS with or without nasal polyps.

Technique modifications for septodermoplasty: an illustrative case

Background

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease that results in telangiectasia of the sinonasal tract, gastro-intestinal tract as well as possible arteriovenous malformations of the lung, liver and brain. One of the most common disease manifestations of HHT is epistaxis. Severe recurrent epistaxis necessitating iron therapy and blood transfusion is often managed with septodermoplasty. Its initial description was as an open surgical technique requiring nasal packing.

Case presentation

We describe a modified approach to septodermoplasty done completely endoscopically and without nasal packing for a patient with severe epistaxis due to HHT.

Conclusion

The described technique modifications for the presented case allowed for same day discharge following surgery, complete take of the skin graft and resultant epistaxis control that ended thepatient's transfusion dependency. The merits of these modifications should be further evaluated in a clinical trial.

Life experiences of individuals with hereditary hemorrhagic telangiectasia and disclosing outside the family: a qualitative analysis

Hereditary hemorrhagic telangiectasia (HHT; OMIM 187300) is a disorder that affects 1:5000-1:10,000 people worldwide, with an estimated 60,000 affected individuals in the USA. Approximately 50 % of patients with HHT experience potentially life-threatening health complications such as stroke, brain abscess, or heart failure. However, the most common symptom is spontaneous and frequent nosebleeding. HHT is a hereditary condition with significant health consequences, but little is known about how individuals cope with HHT on a daily basis and how individuals share information about the disorder with social groups outside of the family. The objectives of this study were to improve understanding of the daily experiences of patients with diagnosed HHT and to investigate how they disclose their diagnosis to various social groups (friends, dating partners, employers, and coworkers) outside of their biological family. Adult patients seen at a university HHT clinic and who had been diagnosed with HHT for at least 6 months were recruited by mail. Participants completed semi-structured telephone interviews (n = 19). A qualitative content analysis of interview transcripts identified four major categories: (1) the emotional impact of HHT, (2) the social impact of HHT, (3) concerns for current and future health related to HHT, and (4) social context drives disclosure of HHT. Participants reported that although HHT was a manageable hereditary disorder, the symptoms negatively affected their daily life. It is important for health care providers to understand how individuals with rare genetic disorders are managing.

How to manage patients with hereditary haemorrhagic telangiectasia

Hereditary haemorrhagic telangiectasia is a rare systemic autosomal dominantly inherited disorder of the fibrovascular tissue with a wide variety of clinical manifestations. Diagnosis is based on the clinical Curaçao criteria or molecular genetic testing. Dilated vessels can develop into telangiectases or larger vascular malformations in various organs, calling for an interdisciplinary approach. Epistaxis and gastrointestinal bleeding can result from these vascular defects. Various conservative and interventional treatments have been described for these conditions. However, no optimal therapy exists. Treatment can become especially difficult due to progressive anaemia or when anticoagulant or anti-thrombotic therapy becomes necessary. Screening for pulmonary arteriovenous malformations (PAVM) should be performed in all confirmed and suspected patients. Treatment by percutaneous transcatheter embolotherapy and antibiotic prophylaxis is normally effective for PAVM. Cerebral or hepatic vascular malformations and rare manifestations need to be evaluated on a case-by-case basis to determine the best course of action for treatment.

Combination treatment with an erythropoiesis-stimulating agent and intravenous iron alleviates anaemia in patients with hereditary haemorrhagic telangiectasia

BACKGROUND

Patients with hereditary haemorrhagic telangiectasia (HHT) suffer from recurrent epistaxis and bleeding from gastrointestinal telangiectasias that occur despite otherwise normal haemostasis and result in iron deficiency anaemia with increasing severity. In advanced disease, anaemia may be severe, be irresponsive to iron supplementation, and may lead to red blood cell transfusion dependency.

METHODS

We conducted a retrospective study at our Centre for Osler's Disease to evaluate the effectiveness of adding an erythropoiesis-stimulating agent (ESA) to intravenous iron supplementation in the management of anaemic HHT patients. Blood values and treatment parameters were collected for nine months before combination therapy (iron supplementation only) and 12 months during combination therapy (iron supplementation plus ESA).

RESULTS

Four patients received intravenous iron and an ESA with mean weekly doses of 126 mg and 17,300 units (U), respectively. Mean haemoglobin improved significantly during combination therapy, from 106 g/L to 119 g/L (p < 0.001).

CONCLUSION

Anaemia can be alleviated in patients with HHT who are irresponsive to intravenous iron supplementation, by addition of an ESA. The proposed mechanism behind the iron irresponsiveness is that the anaemia is caused by a combination of recurrent haemorrhage and anaemia of chronic disease.

Optimal management of hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT), also known by the eponym Osler-Weber-Rendu syndrome, is a group of related disorders inherited in an autosomal dominant fashion and characterized by the development of arteriovenous malformations (AVM) in the skin, mucous membranes, and/or internal organs such as brain, lungs, and liver. Its prevalence is currently estimated at one in 5,000 to 8,000. Most cases are due to mutations in the endoglin (HHT1) or ACVRLK1 (HHT2) genes. Telangiectasias in nasal and gastrointestinal mucosa generally present with recurrent/chronic bleeding and iron deficiency anemia. Larger AVMs occur in lungs (~40%-60% of affected individuals), liver (~40%-70%), brain (~10%), and spine (~1%). Due to the devastating and potentially fatal complications of some of these lesions (for example, strokes and brain abscesses with pulmonary AVMs), presymptomatic screening and treatment are of utmost importance. However, due to the rarity of this condition, many providers lack an appreciation for the whole gamut of its manifestations and complications, age-dependent penetrance, and marked intrafamilial variation. As a result, HHT remains frequently underdiagnosed and many families do not receive the appropriate screening and treatments. This article provides an overview of the clinical features of HHT, discusses the clinical and genetic diagnostic strategies, and presents an up-to-date review of literature and detailed considerations regarding screening for visceral AVMs, preventive modalities, and treatment options.

The effects of epistaxis on health-related quality of life in patients with hereditary hemorrhagic telangiectasia

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease mainly characterized by epistaxis in more than 96% of patients. Recently, a validated questionnaire known as the HHT Epistaxis Severity Score (ESS) was developed. However, little is known about the relationship between epistaxis and quality of life. We hypothesize that epistaxis severity is a major factor predicting health-related quality of life (HR-QoL) in HHT patients.

METHODS

This is a cross-sectional study. The ESS questionnaire and Medical Outcomes Study 36-item short form (SF-36) were administered to subjects through an Internet survey. All participants had a definitive diagnosis of HHT through Curaçao criteria or genetic testing. Demographic information, genetics, and extensive histories were also collected. Descriptive analyses were performed with calculations of means and standard deviations (SDs) for continuous variables and proportions for categorical variables. Linear regressions were then performed to assess the association between HR-QoL and ESS.

RESULTS

A total of 604 subjects participated between April and August 2008. All patients reported epistaxis, 285 (47.2%) had telangiectasias, and 545 (90.2%) had a family history of HHT; 167 (27.6%) patients had mild epistaxis (ESS <4), 285 (47.2%) reported moderate epistaxis (≥4 ESS <7), and 152 (25.2%) reported severe epistaxis (ESS ≥7). Patients with severe epistaxis had lower scores for both the Physical Component Summary (PCS) and the Mental Component Summary (MCS) of HR-QoL when compared to those with mild epistaxis (p < 0.001, p < 0.001).

CONCLUSION

The ESS is a major determinant of HR-QoL and should be considered as a measurement of treatment efficacy in HHT-related epistaxis.

Targeting under-diagnosis in hereditary hemorrhagic telangiectasia: a model approach for rare diseases?

Background

Hereditary hemorrhagic telangiectasia (HHT), a rare autosomal dominant disease, is considered under-diagnosed. Our primary objective was to provide evidence of under-diagnosis of HHT in a North American population. We hypothesized that variation would exist in the diagnosed prevalence (D-prevalence) across regions in the province of Ontario, Canada and across age groups, due to under-diagnosis in certain groups. Our secondary objective was to collect data regarding contact and local access to consult specialists by HHT patients to help guide potential future diagnostic programs.

Methods

Primary objective- 556 adult patients with a definite HHT diagnosis seen at the Toronto HHT Centre were identified and geocoded with postal codes. Prevalence rates were calculated using Canadian census data. Secondary objective- A driving network model was developed in ArcGIS. Service area buffers around ear, nose and throat (ENT) clinics in Ontario were generated to evaluate the proportion of the Ontario population with access to these clinics. A survey was also sent to the email contact list of HHT Foundation International, targeting people with diagnosed HHT, regarding consultation with ENT physicians for epistaxis and timing of HHT diagnosis.

Results

Primary objective- D-prevalence rates varied among regions, from no cases to 1.1 cases per 5000 in large Ontario cities. There were no significant differences between urban and rural prevalence rates. Variation in prevalence was seen across age groups, with greater prevalence in older adults (≥50 years-old) compared with adults 20–49 years-old (0.36 versus 0.26 per 5000, p < 0.0005). Secondary objective- Most Ontarians had access to ENT clinics within a 30, 60 and 90 minute modeled drive time (92.7%, 97.8% and 98.6%, respectively). Nearly 40% of surveyed patients consulted an ENT physician for their epistaxis, on average 13.9 ± 12.2 years prior to being diagnosed with HHT.

Conclusions

The prevalence of HHT in Ontario is highly variable across regions and age-groups, suggesting under-diagnosis. Given that patients with HHT frequently consult ENT physicians for epistaxis prior to HHT diagnosis, and that there is almost universal access to ENTs in Ontario, we propose targeting ENT clinics as a province-wide approach to detect undiagnosed HHT patients and families.

Impact of pulmonary arteriovenous malformations on respiratory-related quality of life in patients with hereditary haemorrhagic telangiectasia

Fifteen to fifty percent of patients with hereditary haemorrhagic telangiectasia have pulmonary arteriovenous malformations. The objective of this study was to measure the effect of the presence of pulmonary arteriovenous malformations and of their embolisation on respiratory-related quality of life (QoL). We prospectively recruited patients with a diagnosis of hereditary haemorrhagic telangiectasia based on the Curaçao criteria and/or the identification of a pathogenic mutation. Respiratory-related quality of life was measured using the Saint George's Respiratory Questionnaire (SGRQ). Patients who underwent embolisation of pulmonary arteriovenous malformations completed the questionnaire before and 6-12 mo after the procedure. The 56 participants were divided into three groups: no pulmonary arteriovenous malformation (group A, n = 10), small pulmonary arteriovenous malformations not accessible to embolotherapy (group B, n = 19), and large pulmonary arteriovenous malformations accessible to embolotherapy (group C, n = 27). The SGRQ score was significantly higher in group C compared to the other groups, indicating a worse respiratory-specific QoL. There was no significant difference between groups A and B. Among the 17 patients who underwent an embolisation, the SGRQ score decreased significantly after the procedure, to a value similar to that in patients without pulmonary arteriovenous malformation. Our results indicate that the presence of large but not small pulmonary arteriovenous malformations negatively affects the respiratory-related quality of life and that embolisation of pulmonary arteriovenous malformations normalizes the respiratory-related quality of life.

Hereditary hemorrhagic telangiectasia patients can tolerate anticoagulation

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by arteriovenous malformations (AVMs) and hemorrhage. HHT patients can also suffer from unrelated medical conditions requiring anticoagulant or antiplatelet treatment (collectively "AT"), though clinicians generally consider HHT a contraindication to AT. We hypothesized that HHT patients can tolerate AT with minimal hemorrhage. Through a chart review of 469 definite HHT patients (1997-2009), we found that 64 (14 %) had received AT. Forty-three out of 64 (67 %) underwent a telephone survey to retrospectively inquire about prescription, early cessation, and HHT-related bleeding. At the time of the study, nine patients were deceased, nine declined, and three were unreachable. During AT treatment, ten (23 %) reported severe complications (blood transfusion, emergency room visit, or hospital admission), while 25 (58 %) reported minor complications (increase or development of epistaxis, gastrointestinal bleeding, and anemia). No patients reported pulmonary/cerebral hemorrhage. The 43 patients received a total of 69 courses of AT. Fourteen out of 69 (20 %) AT courses in 13 patients required early cessation, mostly due to epistaxis. Two out of nine (22 %) deceased patients required early cessation. We conclude that HHT patients can be treated with AT but should be monitored closely given their risk for worsening chronic bleeding and should be screened/treated for pulmonary or cerebral AVMs prior to AT treatment.

Living with hereditary haemorrhagic telangiectasia: coping and psychological distress - a cross-sectional study

PURPOSE

The purpose of this study was to examine the relationship between coping strategies measured by Coping Orientation to Problems Experienced Scale (COPE) and psychological distress measured by Hospital Anxiety and Depression Scale (HADS) and Becks Hopelessness Scale (BHS) in individuals living with Hereditary hemorrhagic telangiectasia (HHT) and to examine if coping strategies might have a mediating role between experienced illness and psychological distress. HHT is mainly caused by mutations in the ENG- or ALK1-genes and associated with a shorter life span. 90% of patients have recurrent nosebleeds.

METHOD

66 individuals affected of HHT participated in this cross-sectional study, completing questions due to demographic variables, Experience of illness, COPE, BHS and HADS. X(2) test, bivariate correlations with Pearson r and hierarchical multiple regression were used using PASW 18.

RESULTS

Experience of illness made the highest variance in anxiety, depression and hopelessness and the coping strategy "behavioral disengagement" seems to have a mediating role between nose bleedings, being afraid of complications, satisfied with life and psychological distress.

CONCLUSIONS

Experience of illness is of big importance in psychological distress in individuals affected of HHT, and behavioral disengagement explained the actual relationship between experience of illness and psychological distress.

Bevacizumab in hereditary hemorrhagic telangiectasia-associated epistaxis: effectiveness of an injection protocol based on the vascular anatomy of the nose

OBJECTIVE/HYPOTHESIS

To evaluate the effectiveness of a standardized intranasal bevacizumab injection in treating hereditary hemorrhagic telangiectasia (HHT)-associated epistaxis.

STUDY DESIGN

Prospective pilot study.

METHODS

A total dose of 100 mg bevacizumab (25 mg/mL Avastin) was injected submucosally, 50 mg on each side. A total of 0.5 mL was injected in the sphenopalatine area, upper part of bony septum, upper part of the later nasal wall, and the anterior part of nasal floor. No cauterizations or laser therapy were done during or after the procedure. The hemoglobin level and grades of epistaxis were recorded before and monthly after the procedure. The IFT grading system (intensity [I], frequency [F] of epistaxis, and the amount of blood transfusion [T]) and epistaxis severity score (ESS) for hereditary hemorrhagic telangiectasia system were used. Quality of life (QoL) was evaluated before and 4 weeks after the procedure using the Short Form-36 Health Survey questionnaire, Cantril's Self-Anchoring Ladder questionnaire, and Slotosch disease-specific QoL questionnaire.

RESULTS

A significant improvement was found in IFT grading (P = .007), ESS grading (P = .001), and hemoglobin level (P = .01). The QoL differences were statistically not significant.

CONCLUSIONS

The four-injection site technique of intranasal administration of bevacizumab is an effective treatment option in HHT-associated epistaxis, at least on the short-term effect. Long-term and comparative studies are needed to further evaluate the significance of this treatment modality.

Quality of life in patients with hereditary hemorrhagic telangiectasia in Norway: a population based study

Hereditary hemorrhagic telangiectasia (HHT) is a rare, autosomal dominant disease characterized by the presence of recurrent epistaxis and small characteristic malformations of the peripheral blood vessels near the surface of the skin or mucosal linings. Arteriovenous malformations (AVM) of the lung, liver, and CNS are also known clinical findings. The purpose of this study was to examine quality of life (QoL) in patients with HHT in Norway. Sixty-six affected patients (39 women and 27 men) were included. QoL on overall-, health-related (HR-QoL), and disease-specific levels were measured with Cantril's Ladder (CL), Short Form 36 (SF-36), and a Symptom-specific QoL question in HHT patients (SFB-HHT-Q), respectively. Comparisons were made between patients and an age and gender adjusted normative sample from the Norwegian population (N = 990). Overall, the results reflected that several HHT disease-related variables were associated with reduced QoL on all three levels; overall QoL (CL), HR-QoL (SF36) as well as disease-specific QoL (SFB-HHT-Q), while demographic variables impacted HR-QoL in HHT patients. Compared to the normative sample, all subscales of SF36, but bodily pain, were significantly poorer in the HHT patients. HHT disease variables had the strongest association with QoL compared to demographic variables. The results substantiate that disease severity is associated with poorer QoL in this patients. Pain contributed independently to all levels of QoL.

Quality of life in rare genetic conditions: a systematic review of the literature

Quality of life (QoL) refers to an individual's sense of overall well-being encompassing physical, psychological, emotional, social, and spiritual dimensions. Although genetics healthcare providers strive to promote patient well-being, and the term QoL is often invoked to refer to this outcome, there is lack of clarity as to what actually constitutes QoL from the patient's perspective. This systematic literature review aims to summarize and integrate research findings to help elucidate how healthcare providers can more effectively enhance the QoL of patients affected with rare genetic conditions. Eligible studies were those that measured QoL as a primary outcome variable using a validated, multi-dimensional scale. Detailed criteria were used to rate quality of design, methodology, and analytic rigor. Fifty-eight studies were selected for inclusion in the review, and a narrative synthesis of the data was performed. A central theme emerging from the literature is that, although genetic conditions have the potential to have significant negative consequences for individuals' lives, having a genetic condition does not necessarily entail poor QoL. Evidence demonstrates that factors beyond the physical manifestations of the disease, such as psychological well-being, coping, and illness perceptions, influence QoL and may serve as potent targets for intervention. The field of research on QoL in rare genetic conditions will be advanced by uniting around a clear conceptualization of QoL and using more rigorous methodology with comprehensive measures of global QoL.

Real-time imaging of de novo arteriovenous malformation in a mouse model of hereditary hemorrhagic telangiectasia

Arteriovenous malformations (AVMs) are vascular anomalies where arteries and veins are directly connected through a complex, tangled web of abnormal arteries and veins instead of a normal capillary network. AVMs in the brain, lung, and visceral organs, including the liver and gastrointestinal tract, result in considerable morbidity and mortality. AVMs are the underlying cause of three major clinical symptoms of a genetic vascular dysplasia termed hereditary hemorrhagic telangiectasia (HHT), which is characterized by recurrent nosebleeds, mucocutaneous telangiectases, and visceral AVMs and caused by mutations in one of several genes, including activin receptor-like kinase 1 (ALK1). It remains unknown why and how selective blood vessels form AVMs, and there have been technical limitations to observing the initial stages of AVM formation. Here we present in vivo evidence that physiological or environmental factors such as wounds in addition to the genetic ablation are required for Alk1-deficient vessels to develop to AVMs in adult mice. Using the dorsal skinfold window chamber system, we have demonstrated for what we believe to be the first time the entire course of AVM formation in subdermal blood vessels by using intravital bright-field images, hyperspectral imaging, fluorescence recordings of direct arterial flow through the AV shunts, and vascular casting techniques. We believe our data provide novel insights into the pathogenetic mechanisms of HHT and potential therapeutic approaches.

Impact of genotype and mutation type on health-related quality of life in patients with hereditary hemorrhagic telangiectasia

CONCLUSIONS

Patients with hereditary hemorrhagic telangiectasia genotype ALK-1 (HHT2-ALK-1) with nonsense mutation demonstrated tendentially higher health-related quality of life (HR-QOL) scores than patients with HHT with genotype ENG (HHT1-ENG) with missense mutation.

OBJECTIVE

HHT, also known as Osler-Weber-Rendu syndrome, comprises different expressions depending on genetic type and mutation type. The influence of HHT type on HR-QOL has not been established and is addressed in this paper.

PATIENTS AND METHODS

A total of 94 patients with confirmed diagnoses of HHT (Curaçao criteria) participated in this study. EDTA (ethylene diamine tetraacetic acid) blood samples of 24 patients were sequenced genetically into genotype HHT1 (ENG) vs HHT2 (ALK-1) and mutation type missense vs nonsense. HR-QOL was assessed with the German Short Form 36 Health Survey (SF-36).

RESULTS

HHT2 patients (genotype ALK-1) demonstrated significantly higher physical component scores than HHT1 patients (effect size d=0.62). Patients with genotype ENG (HHT1) with nonsense mutations showed significantly higher mental component scores than patients with missense mutations (effect size=0.79).

Correlation of severity of epistaxis with nasal telangiectasias in hereditary hemorrhagic telangiectasia (HHT) patients

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, is an autosomal dominant disease that leads to multiregional angiodysplasia. The presence of telangiectasias in nasal mucosa leads to recurrent epistaxis that affects up to 96% of patients but with unpredictable severity. Some authors have previously explained that endonasal morphology and distribution of telangiectasias can be variable too. The purpose of this study was to evaluate any possible relationship between the severity of epistaxis and the different morphology and distribution of nasal telangiectasias in HHT patients.

METHODS

A review was performed of nasal endoscopy records of 76 consecutive HHT patients treated for epistaxis between 2003 and 2007 at our institution. An evaluation was performed of severity of epistaxis in the same patient group using a questionnaire and considering frequency, intensity, duration of nosebleeds, and need for blood transfusions. Comparison of data collected on morphology and distribution of nasal telangiectasias with data collected on severity of epistaxis was performed.

RESULTS

Morphology and distribution of nasal telangiectasias showed a statistically significant correlation with frequency and intensity of epistaxis. Presence of telangiectasias endoscopically appearing as large and prominent correlates with higher frequency of epistaxis. An increase in number of nasal subsites involved correlates with higher intensity of nosebleeds.

CONCLUSION

Our data suggest that to reduce frequency and intensity of epistaxis in HHT patients, treatments should be directed also at lesions located in the posterior part of nasal fossae and especially on telangiectasias endoscopically appearing as large and prominent.

An Association of Migraine with Hereditary Haemorrhagic Telangiectasia Independently of Pulmonary Right-to-Left Shunts

Hereditary haemorrhagic telangiectasia (HHT) is a genetic disorder characterized by epistaxis, telangiectasia and visceral vascular manifestations. It is associated with migraine with aura due to pulmonary arteriovenous malformations (pAVMs). The aim of the study was to evaluate headache prevalence in 106 consecutive HHT patients (67 female, 39 male, age 53.5 ± 14.5 years) and age- and gender-matched controls. An extensive clinical work-up was performed and headache prevalence was determined. Lifetime prevalence of migraine was higher in HHT patients (39.6%) than in controls (19.8%) [ P < 0.001, χ2 = 12.17, odds ratio (OR) 3.0; 95% confidence interval 1.6 < OR < 5.7]. A positive association was confirmed between HHT patients with pAVMs and migraine with aura (38.5% vs. 10%). Furthermore, HHT patients without pAVMs had a higher prevalence of migraine without aura (11.5% vs. 26.3%; χ2 = 11.85; d.f. = 2; P = 0.003). We speculate that pathophysiological mechanisms, including dysfunction of the transforming growth factor-beta pathways and resulting vascular changes, contribute to the higher prevalence of migraine without aura in HHT patients without pAVMs.