Faculty Bibliography

BACKGROUND:Economic and social marginalization among American Indians and Alaska Natives (AI/ANs) results in higher chronic disease prevalence. Potential causal associations between toxic environmental exposures and adverse health outcomes within AI/AN communities are not well understood. OBJECTIVES/OBJECTIVE:This review examines epidemiological literature on exposure to toxicants and associated adverse health outcomes among AI/AN populations. METHODS:PubMed, Embase, Cochrane, Environment Complete, Web of Science Plus, DART, and ToxLine were searched for English-language articles. The following data were extracted: lead author's last name, publication year, cohort name, study location, AI/AN tribe, study initiation and conclusion, sample size, primary characteristic, environmental exposure, health outcomes, risk estimates, and covariates. RESULTS:About 31 articles on three types of environmental exposures met inclusion criteria: persistent organic pollutants (POPs), heavy metals, and open dumpsites. Of these, 17 addressed exposure to POPs, 10 heavy metal exposure, 2 exposure to both POPs and heavy metals, and 2 exposure to open dumpsites. Studies on the Mohawk Nation at Akwesasne; Yupik on St. Lawrence Island, Alaska; Navajo Nation; Gila River Indian Community; Cheyenne River Sioux; 197 Alaska Native villages; and 13 tribes in Arizona, Oklahoma, North Dakota, and South Dakota that participated in the Strong Heart Study support associations between toxicant exposure and various chronic conditions including cardiovascular conditions, reproductive abnormalities, cancer, autoimmune disorders, neurological deficits, and diabetes. DISCUSSION/CONCLUSIONS:The complex interplay of environmental and social factors in disease etiology among AI/ANs is a product of externally imposed environmental exposures, systemic discrimination, and modifiable risk behaviors. The connection between environmental health disparities and adverse health outcomes indicates a need for further study.

Our perspective on anatomy frequently depends on how this anatomy is utilized in clinical practice, and by which methods knowledge is acquired. The thrombectomy revolution, of which the middle cerebral artery (MCA) is the most common target, is an example of a clinical paradigm shift with a unique perspective on cerebrovascular anatomy. This article reviews important features of MCA anatomy in the context of thrombectomy. Recognizing that variation, frequently explained by evolutionary concepts, is the rule when it comes to branching pattern, vessel morphology, territory, or collateral potential is key to successful thrombectomy strategy.

BACKGROUND AND PURPOSE/OBJECTIVE:Patients with the Coronavirus Disease of 2019 (COVID-19) are at increased risk for thrombotic events and mortality. Various anticoagulation regimens are now being considered for these patients. Anticoagulation is known to increase the risk for adverse bleeding events, of which intracranial hemorrhage (ICH) is one of the most feared. We present a retrospective study of 33 patients positive for COVID-19 with neuroimaging-documented ICH and examine anticoagulation use in this population. METHODS:Patients over the age of 18 with confirmed COVID-19 and radiographic evidence of ICH were included in this study. Evidence of hemorrhage was confirmed and categorized by a fellowship trained neuroradiologist. Electronic health records were analyzed for patient information including demographic data, medical history, hospital course, laboratory values, and medications. RESULTS:We identified 33 COVID-19 positive patients with ICH, mean age 61.6 years (range 37-83 years), 21.2% of whom were female. Parenchymal hemorrhages with mass effect and herniation occurred in 5 (15.2%) patients, with a 100% mortality rate. Of the remaining 28 patients with ICH, 7 (25%) had punctate hemorrhages, 17 (60.7%) had small- moderate size hemorrhages, and 4 (14.3%) had a large single site of hemorrhage without evidence of herniation. Almost all patients received either therapeutic dose anticoagulation (in 22 [66.7%] patients) or prophylactic dose (in 3 [9.1] patients) prior to ICH discovery. CONCLUSIONS:Anticoagulation therapy may be considered in patients with COVID-19 though the risk of ICH should be taken into account when developing a treatment regimen.

KEY POINTS/CONCLUSIONS:Individuals with Hereditary Sensory & Autonomic Neuropathy type III (HSAN III), also known as Riley-Day syndrome or Familial Dysautonomia, do not have functional muscle spindle afferents but do have essentially normal cutaneous mechanoreceptors Lack of muscle spindle feedback from the legs may account for the poor proprioception at the knee and the ataxic gait typical of HSAN III Given that functional muscle spindle afferents are also absent in the upper limb, we assessed whether proprioception at the elbow was likewise compromised Passive joint angle matching showed that proprioception was normal at the elbow, suggesting that individuals with HSAN III rely more on cutaneous afferents around the elbow ABSTRACT: Hereditary Sensory & Autonomic Neuropathy type III (HSAN III) is a rare neurological condition that features a marked ataxic gait that progressively worsens over time. We have shown that functional muscle spindle afferents are absent in the upper and lower limbs in HSAN III, and we have argued that this may account for the ataxia. We recently used passive joint angle matching to demonstrate that proprioception of the knee joint is very poor in HSAN III but can be improved towards normal by application of elastic kinesiology tape across the knee joints, which we attribute to the presence of intact cutaneous mechanoreceptors. Here we assessed whether proprioception was equally compromised at the elbow joint, and whether it could be improved through taping. Proprioception at the elbow joint was assessed using passive joint angle matching in 12 HSAN III patients and 12 age-matched controls. There was no difference in absolute error, gradient or correlation coefficient of the relationship between joint angles of the reference and indicator arms. Unlike at the knee, taping did not improve elbow proprioception in either group. Clearly, the lack of muscle spindles compromised proprioception at the knee but not at the elbow, and we suggest that the HSAN III patients rely more on proprioceptive signals from the skin around the elbow. This article is protected by copyright. All rights reserved.

Purpose/UNASSIGNED:The aim of this study was to test the discomfort experienced during intravitreal injections with eyelid retraction between an eyelid speculum, cotton-tipped applicator (CTA), and unimanual eyelid retraction techniques. Methods/UNASSIGNED:In total, 99 patients receiving intravitreal bevacizumab were enrolled into this prospective study. Participants were randomized to one of the three methods, given subconjunctival 2% lidocaine and then injected in the superior temporal quadrant. Immediately after the procedure, each patient was given a visual analog scale (VAS) to rate their discomfort. Results/UNASSIGNED:The mean pain scores for eyelid retraction with unimanual, CTA, and speculum groups were 0.788 (standard deviation [SD] 0.70, 95% confidence interval [CI] 0.448-1.128), 0.945 (SD 1.28, 95% CI 0.600-1.291), and 1.561 (SD 1.28, 95% CI 1.210-1.912), respectively. A one-way analysis of variance (ANOVA) test revealed a significant difference between the groups (P = 0.006). Post hoc analysis also revealed a difference in mean pain scores between the speculum and both the CTA and the unimanual methods. Conclusion/UNASSIGNED:Our study shows that the unimanual and CTA methods for eyelid retraction are significantly less painful for patients compared to the speculum method. Patient comfort is of the utmost importance as intravitreal injections are performed millions of times a year with most patients requiring multiple injections.

BACKGROUND AND PURPOSE/OBJECTIVE:Tentorial sinus venous channels within the tentorium cerebelli connecting various cerebellar and supratentorial veins, as well as the basal vein, to adjacent venous sinuses are a well-recognized entity. Also well-known are "dural lakes" at the vertex. However, the presence of similar channels in the supratentorial dura, serving as recipients of the Labbe, superficial temporal, and lateral and medial parieto-occipital veins, among others, appears to be underappreciated. Also under-recognized is the possible role of these channels in the angioarchitecture of certain high-grade dural fistulas. MATERIALS AND METHODS/METHODS:A retrospective review of 100 consecutive angiographic studies was performed following identification of index cases to gather data on the angiographic and cross-sectional appearance, location, length, and other features. A review of 100 consecutive dural fistulas was also performed to identify those not directly involving a venous sinus. RESULTS:Supratentorial dural venous channels were found in 26% of angiograms. They have the same appearance as those in the tentorium cerebelli, a flattened, ovalized morphology owing to their course between 2 layers of the dura, in contradistinction to a rounded cross-section of cortical and bridging veins. They are best appreciated on angiography and volumetric postcontrast T1-weighted images. Ten dural fistulas not directly involving a venous sinus were identified, 6 tentorium cerebelli and 4 supratentorial. CONCLUSIONS:Supratentorial dural venous channels are an under-recognized entity. They may play a role in the angioarchitecture of dural arteriovenous fistulas that appear to drain directly into a cortical vein. We propose "dural venous channel" as a unifying name for these structures.