Citations

Abstract We present a case of a traumatic skull base internal carotid artery (ICA) pseudoaneurysm treated with endovascular flow diversion stenting. The patient was a 27-year-old male who was involved in a motorcycle accident suffering multiple traumatic injuries including a large skull base fracture that extended through the carotid canal. Computed tomography angiography revealed a 2-cm right ICA pseudoaneurysm. Once the patient was stable, a digital subtraction angiography demonstrated enlargement of the pseudoaneurysm. After his other injuries were addressed by trauma and orthopedic surgery, at day 9 after his initial injury, the patient was loaded with aspirin and clopidrogel in preparation for stent reconstruction of his ICA injury. Under conscious sedation and systemic heparinization, the patient underwent endovascular reconstruction of the large pseudoaneurysm using telescoping flow diversion stents. Immediate intra-aneurysm flow stasis was observed. No procedure-related complications occurred. The patient did well and at last follow-up remained neurologically intact.

Progressive multifocal leukoencephalopathy rarely occurs in patients with multiple myeloma. Intracranial central nervous system invasion is also an uncommon event in multiple myeloma, occurring in less than 1% of cases. We describe herein an exceptional case of coexisting progressive multifocal leukoencephalopathy and intraparenchymal central nervous system myeloma infiltration. A 73-year-old woman with relapsed multiple myeloma was treated with 15 cycles of lenalidomide and dexamethasone, but therapy had to be stopped because of a hip fracture after a fall. During hospitalization, the patient developed progressive multifocal leukoencephalopathy caused by John Cunningham virus, and a prominent intra-parenchymal CD138-positive infiltrate was detected. VDJ rearrangements of the immunoglobulin heavy chain gene and the mutational profile of plasma cells in bone marrow at the time of diagnosis and in brain biopsy after progression were analyzed by next generation sequencing, showing genetic differences between medullary and extramedullary myeloma cells. The role of long-term treatment with lenalidomide and dexamethasone in the development progressive multifocal leukoencephalopathy or intraparenchymal central nervous system myeloma infiltration remains unknown. However, our results suggest that both events may have arisen as a consequence of treatment-related immunosuppression. Thus, an appropriate clinical approach compatible with the simultaneous treatment of progressive multifocal leukoencephalopathy and multiple myeloma should be developed.

OBJECTIVEThe long-term effects of surgical fusion on the growing subaxial cervical spine are largely unknown. Recent cross-sectional studies have demonstrated that there is continued growth of the cervical spine through the teenage years. The purpose of this multicenter study was to determine the effects of rigid instrumentation and fusion on the growing subaxial cervical spine by investigating vertical growth, cervical alignment, cervical curvature, and adjacent-segment instability over time.METHODSA total of 15 centers participated in this multi-institutional retrospective study. Cases involving children less than 16 years of age who underwent rigid instrumentation and fusion of the subaxial cervical spine (C-2 and T-1 inclusive) with at least 1 year of clinical and radiographic follow-up were investigated. Charts were reviewed for clinical data. Postoperative and most recent radiographs, CT, and MR images were used to measure vertical growth and assess alignment and stability.RESULTSEighty-one patients were included in the study, with a mean follow-up of 33 months. Ninety-five percent of patients had complete clinical resolution or significant improvement in symptoms. Postoperative cervical kyphosis was seen in only 4 patients (5%), and none developed a swan-neck deformity, unintended adjacent-level fusion, or instability. Of patients with at least 2 years of follow-up, 62% demonstrated growth across the fusion construct. On average, vertical growth was 79% (4-level constructs), 83% (3-level constructs), or 100% (2-level constructs) of expected growth. When comparing the group with continued vertical growth to the one without growth, there were no statistically significant differences in terms of age, sex, underlying etiology, surgical approach, or number of levels fused.CONCLUSIONSContinued vertical growth of the subaxial spine occurs in nearly two-thirds of children after rigid instrumentation and fusion of the subaxial spine. Failure of continued vertical growth is not associated with the patient’s age, sex, underlying etiology, number of levels fused, or surgical approach. Further studies are needed to understand this dichotomy and determine the long-term biomechanical effects of surgery on the growing pediatric cervical spine.

Background Evidence exists for racial/ethnic differences in left ventricular mass index (LVMI). How this translates to future cardiovascular disease (CVD) events is unknown. Hypothesis The impact of racial/ethnic differences in LVMI on incident cardiovascular outcomes could have potential implications for the optimization of risk stratification strategies. Methods Using the prospectively collected database of the Multi‐Ethnic Study of Atherosclerosis (MESA) involving 4 racial/ethnic groups (non‐Hispanic Whites, Chinese, Blacks, and Hispanics) free of CVD at baseline, we assessed for racial/ethnic differences in the relationship between LVMI and incident CVD using a Cox model. Results 5004 participants (mean age, 62 ± 10 years; 48% male) were included in this study. After an average follow‐up of 10.2 years, 369 (7.4%) CVD events occurred. Significant racial/ethnic differences existed in the relationship between LVMI and incident CVD ( P for interaction = 0.04). Notably, the relationship was strongest for Chinese (HR per 10‐unit increase in LVMI: 1.7, 95% CI: 1.1–2.8) and Hispanics (HR per 10‐unit increase in LVMI: 1.9, 95% CI: 1.5–2.2). Non‐Hispanic Whites demonstrated the lowest relationship (HR: 1.3, 95% CI: 1.1–1.5). LVMI values of 36.9 g/m 2.7 , 31.8 g/m 2.7 , 39.9 g/m 2.7 , and 41.7 g/m 2.7 were identified as optimal cutpoints for defining left ventricular hypertrophy (LVH) for non‐Hispanic Whites, Chinese, Blacks, and Hispanics, respectively. In secondary analysis of LVH (vs no LVH) using these optimal cutpoints, we found a similar pattern of association as above ( P for interaction = 0.04). For example, compared with those without LVH, Chinese with LVH had HR: 5.3, 95% CI: 1.6–17, whereas non‐Hispanic Whites with LVH had HR: 1.6, 95% CI: 1.2–2.1 for CVD events. Conclusions Among 4 races/ethnicities studied, LVMI has more prognostic utility predicting future CVD events for Chinese and Hispanics and is least significant for non‐Hispanic Whites.

Abstract In 2011, the National Institute on Aging and Alzheimer's Association created separate diagnostic recommendations for the preclinical, mild cognitive impairment, and dementia stages of Alzheimer's disease. Scientific progress in the interim led to an initiative by the National Institute on Aging and Alzheimer's Association to update and unify the 2011 guidelines. This unifying update is labeled a “research framework” because its intended use is for observational and interventional research, not routine clinical care. In the National Institute on Aging and Alzheimer's Association Research Framework, Alzheimer's disease (AD) is defined by its underlying pathologic processes that can be documented by postmortem examination or in vivo by biomarkers. The diagnosis is not based on the clinical consequences of the disease (i.e., symptoms/signs) in this research framework, which shifts the definition of AD in living people from a syndromal to a biological construct. The research framework focuses on the diagnosis of AD with biomarkers in living persons. Biomarkers are grouped into those of β amyloid deposition, pathologic tau, and neurodegeneration [AT(N)]. This ATN classification system groups different biomarkers (imaging and biofluids) by the pathologic process each measures. The AT(N) system is flexible in that new biomarkers can be added to the three existing AT(N) groups, and new biomarker groups beyond AT(N) can be added when they become available. We focus on AD as a continuum, and cognitive staging may be accomplished using continuous measures. However, we also outline two different categorical cognitive schemes for staging the severity of cognitive impairment: a scheme using three traditional syndromal categories and a six‐stage numeric scheme. It is important to stress that this framework seeks to create a common language with which investigators can generate and test hypotheses about the interactions among different pathologic processes (denoted by biomarkers) and cognitive symptoms. We appreciate the concern that this biomarker‐based research framework has the potential to be misused. Therefore, we emphasize, first, it is premature and inappropriate to use this research framework in general medical practice. Second, this research framework should not be used to restrict alternative approaches to hypothesis testing that do not use biomarkers. There will be situations where biomarkers are not available or requiring them would be counterproductive to the specific research goals (discussed in more detail later in the document). Thus, biomarker‐based research should not be considered a template for all research into age‐related cognitive impairment and dementia; rather, it should be applied when it is fit for the purpose of the specific research goals of a study. Importantly, this framework should be examined in diverse populations. Although it is possible that β‐amyloid plaques and neurofibrillary tau deposits are not causal in AD pathogenesis, it is these abnormal protein deposits that define AD as a unique neurodegenerative disease among different disorders that can lead to dementia. We envision that defining AD as a biological construct will enable a more accurate characterization and understanding of the sequence of events that lead to cognitive impairment that is associated with AD, as well as the multifactorial etiology of dementia. This approach also will enable a more precise approach to interventional trials where specific pathways can be targeted in the disease process and in the appropriate people.

PurposeThe purpose of this study was to demonstrate an objective quality control framework for the image review process.Methods and materialsA total of 927 cone‐beam computed tomography (CBCT) registrations were retrospectively analyzed for 33 bilateral head and neck cancer patients who received definitive radiotherapy. Two registration tracking volumes (RTVs) — cervical spine (C‐spine) and mandible — were defined, within which a similarity metric was calculated and used as a registration quality tracking metric over the course of treatment. First, sensitivity to large misregistrations was analyzed for normalized cross‐correlation (NCC) and mutual information (MI) in the context of statistical analysis. The distribution of metrics was obtained for displacements that varied according to a normal distribution with standard deviation of σ = 2 mm, and the detectability of displacements greater than 5 mm was investigated. Then, similarity metric control charts were created using a statistical process control (SPC) framework to objectively monitor the image registration and review process. Patient‐specific control charts were created using NCC values from the first five fractions to set a patient‐specific process capability limit. Population control charts were created using the average of the first five NCC values for all patients in the study. For each patient, the similarity metrics were calculated as a function of unidirectional translation, referred to as the effective displacement. Patient‐specific action limits corresponding to 5 mm effective displacements were defined. Furthermore, effective displacements of the ten registrations with the lowest similarity metrics were compared with a three dimensional (3DoF) couch displacement required to align the anatomical landmarks.ResultsNormalized cross‐correlation identified suboptimal registrations more effectively than MI within the framework of SPC. Deviations greater than 5 mm were detected at 2.8σ and 2.1σ from the mean for NCC and MI, respectively. Patient‐specific control charts using NCC evaluated daily variation and identified statistically significant deviations. This study also showed that subjective evaluations of the images were not always consistent. Population control charts identified a patient whose tracking metrics were significantly lower than those of other patients. The patient‐specific action limits identified registrations that warranted immediate evaluation by an expert. When effective displacements in the anterior–posterior direction were compared to 3DoF couch displacements, the agreement was ±1 mm for seven of 10 patients for both C‐spine and mandible RTVs.ConclusionsQualitative review alone of IGRT images can result in inconsistent feedback to the IGRT process. Registration tracking using NCC objectively identifies statistically significant deviations. When used in conjunction with the current image review process, this tool can assist in improving the safety and consistency of the IGRT process.