Kimberly Seifert

Regarding "Neurovascular Manifestations of Hereditary Hemorrhagic Telangiectasia: A Consecutive Series of 376 Patients during 15 Years".

BACKGROUND AND PURPOSE: Hereditary hemorrhagic telangiectasia is associated with a wide range of neurovascular abnormalities. The aim of this study was to characterize the spectrum of cerebrovascular lesions, including brain arteriovenous malformations, in patients with hereditary hemorrhagic telangiectasia and to study associations between brain arteriovenous malformations and demographic variables, genetic mutations, and the presence of AVMs in other organs. MATERIALS AND METHODS: Consecutive patients with definite hereditary hemorrhagic telangiectasia who underwent brain MR imaging/MRA, CTA, or DSA at our institution from 2001 to 2015 were included. All studies were re-evaluated by 2 senior neuroradiologists for the presence, characteristics, location, and number of brain arteriovenous malformations, intracranial aneurysms, and nonshunting lesions. Brain arteriovenous malformations were categorized as high-flow pial fistulas, nidus-type brain AVMs, and capillary vascular malformations and were assigned a Spetzler-Martin score. We examined the association between baseline clinical and genetic mutational status and the presence/multiplicity of brain arteriovenous malformations. RESULTS: Three hundred seventy-six patients with definite hereditary hemorrhagic telangiectasia were included. One hundred ten brain arteriovenous malformations were noted in 48 patients (12.8%), with multiple brain arteriovenous malformations in 26 patients. These included 51 nidal brain arteriovenous malformations (46.4%), 58 capillary vascular malformations (52.7%), and 1 pial arteriovenous fistula (0.9%). Five patients (10.4%) with single nidal brain arteriovenous malformation presented with hemorrhage. Of brain arteriovenous malformations, 88.9% (88/99) had a Spetzler-Martin score of ≤2. Patients with brain arteriovenous malformations were more likely to be female (75.0% versus 57.6%, P = .01) and have a family history of hereditary hemorrhagic telangiectasia (95.8% versus 84.8%, P = .04). The prevalence of brain arteriovenous malformation was 19.7% in endoglin (ENG) mutations and 12.5% in activin receptor-like kinase (1ACVRL1) mutations. CONCLUSIONS: Our study of 376 patients with hereditary hemorrhagic telangiectasia demonstrated a high prevalence of brain arteriovenous malformations. Nidal brain arteriovenous malformations and capillary vascular malformations occurred in roughly equal numbers.

Letter to the Editor Regarding “Preoperative Digital Subtraction Angiography in Incidental Unruptured Intracranial Aneurysms”

We would like to commend the authors Herzberg et al. for their study assessing the role of preoperative digital subtraction angiography (DSA) in unruptured intracranial aneurysms (UIAs) [1]; however we have some questions and comments about the study. The authors conclude that four-vessel angiography can be indicated in patients with multiple aneurysms because 4 out of 5 UIA missed on magnetic resonance imaging (MRI) in this study were in patients with multiple aneurysms; however, as the authors state, between 20% and 27% of all patients may have multiple UIAs. That would still be a significant proportion of patients with UIAs. All the UIAs missed on MRA were very small ( 3mm). We would like the authors to comment if these could be seen on the MRA in retrospect. The authors mention positive bias towards MRA in the limitations; however, the same bias applies to DSA, as the person performing DSA was aware of the MRA findings: the assumption here is that DSA is perfect. The implication of these additional findings on DSA is not clear. This is partly because the natural history of these small UIAs is not well understood [2]. Out of five aneurysms missed on MRA in this study four were not treated but received surveillance imaging. The guidelines do not specify the frequency and duration of imaging followup [3]. There is also significant heterogeneity in practice re-

Longitudinal Analysis of Superficial Midfacial Fat Volumes Over a 10-Year Period

BackgroundVolumetric changes to facial fat that occur with aging remain poorly understood. The aim of this study was to evaluate for longitudinal changes to midfacial fat volumes in a group of individuals.MethodsWe conducted a retrospective longitudinal study of adult subjects who underwent multiple facial computed tomographic (CT) scans timed at least 8xa0years apart. Subjects who underwent facial surgery or suffered facial trauma were excluded. Facial CT scans were analyzed, and superficial cheek fat volumes were measured and compared to track changes that occurred with aging.ResultsFourteen subjects were included in our analysis of facial aging (5 male, 9 female; mean initial age 50.9xa0years; mean final age 60.4xa0years). In the right superficial cheek there was an increase in mean (SD) superficial fat volume from 10.33 (2.01) to 10.50 (1.80)xa0cc, which was not statistically significant (Pu2009=u20090.75). Similar results were observed in the left cheek. There were no statistically significant longitudinal changes to caudal, middle, or cephalad subdivisions of bilateral superficial cheek fat. A simple linear regression was performed to predict superficial cheek fat pad volume based on age which did not reach statistical significance (Pu2009=u20090.31), with an R2 of 0.039.ConclusionsThis study is the first to quantitatively assess for longitudinal changes to midfacial fat in a group of individuals. Superficial cheek fat remained stable as subjects aged from approximately 50 to 60xa0years old, with no change in total volume or redistribution within a radiographically defined compartment.Level of Evidence IVThis journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Blunt Cerebrovascular Artery Injury and Stroke in Severely Injured Patients: An International Multicenter Analysis

Dear Editor, We would like to commend the authors Weber et al. [1] for their study assessing BCVI and stroke in such a large series of patients. However, we have a few questions and concerns about the study. Computed tomographic angiography (CTA) was applied for primary blunt cerebrovascular injury (BCVI) screening, but the authors do not specify whether all 76,480 individuals received a CTA study. If not, what criteria were used to screen patients with CTA? The conclusions drawn about the utility of screening criteria in predicting BCVI would be valid if all patients were screened. Retrospective analysis of risk factors may not be an accurate method if all patients were not consistently screened. The literature is very heterogeneous about the sensitivity and specificity of CTA, and different studies advocate conventional angiography in CTA-negative and CTApositive patients, respectively [2, 3]. We would request the authors to comment on the use of conventional angiography in their dataset. The reported incidence of BCVI in the literature is reflective of not only the screening criteria used, but also the sensitivity of the imaging used to screen patients. It would also be helpful to know from the authors the use of medical prophylaxis in both screened and unscreened patients. 30/58 strokes in this study happened despite prophylaxis, and 10/58 happened before start of therapy. The utility of screening criteria and CTAs has to be seen in the context of use of subsequent treatment and thereby prevention of stroke. Greater awareness of BCVI, the grading of injury and imaging pitfalls would help improve noninvasive imaging diagnosis [4]. Optimized, selective CTA in high-risk populations may be the most cost-effective strategy for BCVI detection [5].

Letter to the Editor Regarding “Growth of Untreated Unruptured Small-sized Aneurysms (<7 mm): Incidence and Related Factors”

We would like to commend the authors Choi et al. for their study assessing the growth of untreated unruptured small (<7mm) aneurysms [1]. The natural history of small unruptured intracranial aneurysms (UIA) is not well understood, and small UIAs have low growth and rupture rates reported in literature [2]. The high selection bias in the literature is also seen in the current study, with 994 UIAs being treated in the study period while 173 were followed up. Small (<7mm) UIAs may not be a homogeneous group. In a previous meta-analysis, we found the growth and rupture rates to be extremely low in <3mm and 3–5mm aneurysms relative to 5–7mm aneurysms [2]. This is also reflected in clinical practice as the authors confess that 4–7mm aneurysms may have been preferentially treated (only 13 out of 173 aneurysms in the study were >5mm). It is important therefore that the authors discuss the breakdown of the study group (173 UIAs) as to how many were <3mm and 3–5mm. Interestingly, only 1 out

Blunt Cerebrovascular Injuries: Advances in Screening, Imaging, and Management Trends

We would like to commend Nagpal et al[1][1] for their study assessing the advances in screening, imaging, and management trends for blunt cerebrovascular injury (BCVI). However, we would like to point out a few persisting controversies regarding the management of patients with BCVI.nnA major

Patterns of Superficial Midfacial Fat Volume Distribution Differ by Age and Body Mass Index

BackgroundThe changes that occur to midfacial fat with increasing age and BMI are poorly understood. The aim of this study was to determine how superficial cheek fat volume and distribution are differentially predicted by changes in BMI versus age.MethodsWe conducted a retrospective observational study of patients with facial computed tomography scans. Superficial cheek fat volumes were measured, and multiple linear regression analysis was performed to model the relationships between cheek fat and corresponding sex, age, and BMI data.ResultsA total of 109 patients were included in our analysis (51 male, 58 female). The subjects’ ages ranged from 21.7 to 91.1xa0years with a mean (SD) age of 59.7 (15.0) years. The mean (SD) superficial cheek volume of the subjects was 10.46 (2.57) cc. Female subjects had a significantly greater mean total superficial cheek fat volume compared to male subjects (11.18xa0cc vs. 9.64xa0cc; Pu2009<u20090.001). The results of multiple linear regression analysis indicated that together, age, sex, and BMI explained 50.8% of the variance in cheek fat volumes (R2u2009=u20090.51, Pu2009<u20090.001). BMI significantly predicted total cheek fat volume (βu2009=u20090.239, Pu2009<u20090.001), in addition to age (βu2009=u20090.029, Pu2009<u20090.017) and sex (βu2009=u2009−u20091.183, Pu2009=u20090.001; femaleu2009=u20090, maleu2009=u20091). Age predicted the greatest gain of fat in the caudal subdivision of cheek (βu2009=u20090.015, Pu2009<u20090.001), whereas BMI predicted the greatest gain in the cephalad subdivision (βu2009=u20090.106, Pu2009<u20090.001).ConclusionsAge, sex, and BMI are important predictors of midfacial fat volume. This study shows that increases in age and BMI differentially predict the distribution of superficial cheek fat.Level of Evidence IVThis journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.