Faculty Bibliography

BACKGROUND: The treatment of spinal intramedullary arteriovenous malformations (AVMs) presents the risk of spinal cord ischemia because of the vascular nidus and their feeding arteries involving and supplying the spinal cord parenchyma. The multimodal approach includes endovascular embolization and microsurgical excision, both benefiting from intraoperative neurophysiologic monitoring. We present a case study of a patient who underwent several staged embolizations and open surgery for microsurgical excision. PATIENT/METHODS: A 32-year-old man who presented with a recurrent glomus-type intramedullary AVM in the cervical spinal cord, located at the C5-C6 segment, with progressive neurologic deterioration. METHODS: Somatosensory evoked potentials (SEPs) and transcranial motor evoked potentials (MEPs) were performed during three embolizations, a provocative test, and surgery, in addition to D-wave during microsurgical excision. RESULTS: Abolished hand MEP and drop in SEP during a provocative test guided the surgeon to embolize from a safer vessel with no acute neurologic deficit after three embolizations. Before surgery, an angiography showed the left posterior spinal artery supplying the AVM. After resecting the vascular nidus from the spinal parenchyma, left-hand MEP decreased in amplitude and later abolished, and SEP decreased. Interestingly, no D-wave or distal MEPs were affected. Weakness in the left hand immediately and 2 weeks postoperatively advocates for metameric spinal cord ischemia with preservation of long spinal cord pathways. CONCLUSIONS: Intraoperative neurophysiologic monitoring correlates with neurologic outcome after endovascular and surgical treatment of a cervical AVM. Intraoperative monitoring provides continuous functional information of long and metameric spinal cord pathways, which is critical when deciding on the vessel to be embolized and during microsurgical excision where the surgeon is in less control of the AVM hemodynamic flow.

INTRODUCTION/BACKGROUND:Intraoperative neurophysiological monitoring (IONM) is widely used to prevent nervous system injury during surgeries in elderly patients. However, there are no studies that describe the characteristics and changes in neurophysiological tests during the IONM of patients aged 60 years and older. The study aims to describe and compare IONM changes during surgeries in adult patients aged 18 to 59 years with those aged 60 years and older. METHODS:We performed a comparative retrospective study of patients aged 18 to 59 years versus those 60 aged years and older who underwent IONM during 2013 to 2018 in Mexico City. Sociodemographic characteristics were recorded and compared. Intraoperative neurophysiological monitoring techniques, their changes, and surgical procedures for both groups were analyzed and compared using descriptive statistics, Mann-Whitney U, Fisher, and χ tests. The sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS:In total, 195 patients were analyzed: 104 patients, 68.63 ± 6.54 years old (elderly group) and 91 patients, 42.3 ± 10.5 years old (younger group). No differences were found in the rates of signal change during IONM between the group of elderly patients and the younger group. The sensitivity, specificity, and positive and negative predictive values were 80%, 99%, 80%, and 99%, respectively. CONCLUSIONS:Elderly patients have a similar rate of changes in IONM signals compared with younger patients during heterogeneous surgeries guided by IONM.

Traumatic brain injury (TBI) is a risk factor for the later development of neurodegenerative diseases that may have various underlying pathologies. Chronic traumatic encephalopathy (CTE) in particular is associated with repetitive mild TBI (mTBI) and is characterized pathologically by aggregation of hyperphosphorylated tau into neurofibrillary tangles (NFTs). CTE may be suspected when behavior, cognition, and/or memory deteriorate following repetitive mTBI. Exposure to blast overpressure from improvised explosive devices (IEDs) has been implicated as a potential antecedent for CTE amongst Iraq and Afghanistan Warfighters. In this study, we identified biomarker signatures in rats exposed to repetitive low-level blast that develop chronic anxiety-related traits and in human veterans exposed to IED blasts in theater with behavioral, cognitive, and/or memory complaints. Rats exposed to repetitive low-level blasts accumulated abnormal hyperphosphorylated tau in neuronal perikarya and perivascular astroglial processes. Using positron emission tomography (PET) and the [¹⁸F]AV1451 (flortaucipir) tau ligand, we found that five of 10 veterans exhibited excessive retention of [¹⁸F]AV1451 at the white/gray matter junction in frontal, parietal, and temporal brain regions, a typical localization of CTE tauopathy. We also observed elevated levels of neurofilament light (NfL) chain protein in the plasma of veterans displaying excess [¹⁸F]AV1451 retention. These findings suggest an association linking blast injury, tauopathy, and neuronal injury. Further study is required to determine whether clinical, neuroimaging, and/or fluid biomarker signatures can improve the diagnosis of long-term neuropsychiatric sequelae of mTBI.

Low levels of engagement in implementation science (IS) among health researchers is a multifaceted issue. With the aim of guiding efforts to increase engagement in IS research, we sought to identify barriers to engagement in IS within the health research community. We performed an online survey of health researchers in the United States in 2018. Basic science researchers were excluded from the sample. IS engagement was measured by self-reported conduct of or collaboration on an IS study in the past 5 years. Potential barriers tested were (a) knowledge and awareness of IS, (b) attitudes about IS research, (c) career benefits of IS, (d) research community support, and (e) research leadership support. We performed simple logistic regressions and tested multivariable logistic regression models of researcher characteristics and potential barriers as predictors of IS engagement. Of the 1,767 health researchers, 49.7% indicated they engaged in an implementation study. Being able to define IS (aOR 3.42, 95%CI 2.68-4.36, p < .001) and having attended IS training (aOR 3.77, 95%CI 2.96-4.81, p < .001) were associated with engaging in IS research. Among other potential barriers tested, perceptions that engaging in IS would not be good for their career (aOR 0.29, 95%CI 0.2-0.41, p < .001) was strongly associated with decreased engagement in IS research. Efforts to increase researcher familiarity with IS methods and foster support for IS within research communities, along with decreasing barriers to funding and publishing, are likely to be most effective for increasing engagement in IS research.

OBJECTIVE:The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a brief neuropsychological battery that has been validated in the assessment of dementia and other clinical populations. The current study examines the utility of the RBANS in patients with epilepsy. METHODS:Ninety-eight patients with epilepsy completed the RBANS as part of a more comprehensive neuropsychological evaluation. Performance on the RBANS was evaluated for patients with a diagnosis of temporal lobe epilepsy (TLE; n = 51) and other epilepsy patients (non-TLE, n = 47) in comparison to published norms. Multivariate analysis of variance compared group performances on RBANS indices. Rates of impairment were also compared across groups using cutoff scores of ≤1.0 and ≤1.5 standard deviations below the normative mean. Exploratory hierarchical regressions were used to examine the relations between epilepsy severity factors (i.e., age of onset, disease duration, and number of antiepileptic drugs [AEDs]) and RBANS performance. RESULTS:TLE and non-TLE patients performed below the normative sample across all RBANS indices. Those with TLE performed worse than non-TLE patients on the Immediate and Delayed Memory indices and exhibited higher rates of general cognitive impairment. Number of AEDs was the only epilepsy severity factor that significantly predicted RBANS total performance, accounting for 14% of the variance. CONCLUSIONS:These findings suggest that the RBANS has utility in evaluating cognition in patients with epilepsy and can differentiate TLE and non-TLE patients. Additionally, number of AEDs appears to be associated with global cognitive performance in adults with epilepsy.

PURPOSE/OBJECTIVE:To report a case of IgG4-related ophthalmic disease, which presented with papillitis and subretinal deposits. METHODS:Observational case report with multimodal imaging. RESULTS:A 52-year-old man with a history of persistent lymphadenopathy presented with decreased vision in his left eye. Funduscopic examination demonstrated cuticular drusen in both eyes and florid edema of the left optic nerve, along with scattered circumscribed grey-yellow subretinal deposits that were distinct from the cuticular drusen. Swept-source optical coherence tomography demonstrated a hyper-reflective subretinal material corresponding to the grey-yellow subretinal deposits on clinical examination along with diffuse outer retinal disruption. Fundus autofluorescence revealed scattered hypoautofluorescence corresponding to cuticular drusen and also larger patches of hypoautofluorescence corresponding to the grey-yellow subretinal deposits. Fluorescein angiography demonstrated hypofluorescence corresponding to the large subretinal deposits and leakage at the optic nerve. Lymph node biopsy demonstrated IgG4-positive plasma cells and elevated serum IgG4 levels leading to a diagnosis of IgG4-related ophthalmic disease. The patient was treated with oral prednisone with subsequent resolution of the optic nerve edema. CONCLUSION/CONCLUSIONS:We describe multimodal imaging of unique retinal and optic nerve findings associated with IgG4-related ophthalmic disease. Our report broadens the spectrum of ocular involvement associated with IgG4-related disease.

BACKGROUND:The rapid spread of coronavirus disease 2019 (COVID-19) revealed significant constraints in critical care capacity. In anticipation of subsequent waves, reliable prediction of disease severity is essential for critical care capacity management and may enable earlier targeted interventions to improve patient outcomes. The purpose of this study is to develop and externally validate a prognostic model/clinical tool for predicting COVID-19 critical disease at presentation to medical care. METHODS:This is a retrospective study of a prognostic model for the prediction of COVID-19 critical disease where critical disease was defined as ICU admission, ventilation, and/or death. The derivation cohort was used to develop a multivariable logistic regression model. Covariates included patient comorbidities, presenting vital signs, and laboratory values. Model performance was assessed on the validation cohort by concordance statistics. The model was developed with consecutive patients with COVID-19 who presented to University of California Irvine Medical Center in Orange County, California. External validation was performed with a random sample of patients with COVID-19 at Emory Healthcare in Atlanta, Georgia. RESULTS:Of a total 3208 patients tested in the derivation cohort, 9% (299/3028) were positive for COVID-19. Clinical data including past medical history and presenting laboratory values were available for 29% (87/299) of patients (median age, 48 years [range, 21-88 years]; 64% [36/55] male). The most common comorbidities included obesity (37%, 31/87), hypertension (37%, 32/87), and diabetes (24%, 24/87). Critical disease was present in 24% (21/87). After backward stepwise selection, the following factors were associated with greatest increased risk of critical disease: number of comorbidities, body mass index, respiratory rate, white blood cell count, % lymphocytes, serum creatinine, lactate dehydrogenase, high sensitivity troponin I, ferritin, procalcitonin, and C-reactive protein. Of a total of 40 patients in the validation cohort (median age, 60 years [range, 27-88 years]; 55% [22/40] male), critical disease was present in 65% (26/40). Model discrimination in the validation cohort was high (concordance statistic: 0.94, 95% confidence interval 0.87-1.01). A web-based tool was developed to enable clinicians to input patient data and view likelihood of critical disease. CONCLUSIONS AND RELEVANCE:We present a model which accurately predicted COVID-19 critical disease risk using comorbidities and presenting vital signs and laboratory values, on derivation and validation cohorts from two different institutions. If further validated on additional cohorts of patients, this model/clinical tool may provide useful prognostication of critical care needs.

BACKGROUND:Venous thromboembolism (VTE) is a significant source of postoperative morbidity and mortality in patients undergoing common oncologic procedures. We sought to estimate the effect of surgical approach on the risk of developing a VTE. METHODS:IBM Watson Health Marketscan Database was used to conduct this retrospective study. In total, 12 938 patients who underwent either a radical prostatectomy, partial colectomy, or hysterectomy via a minimally invasive or open approach. We used a propensity-weighted logistic regression analysis to assess the independent effect of surgical approach on VTE. The primary outcome of interest was the 90-day rate of VTE after surgery. RESULTS:Patients undergoing minimally invasive surgery across all three surgical procedures were noted to have a lower odds of developing a VTE: (radical prostatectomy, odds ratio [OR]: 0.667, 95% confidence interval [CI]: 0.500-0.891; P = .006 |partial colectomy: OR, 0.620, 95% CI: 0.477-0.805; P < .001| hysterectomy: OR, 0.549 95% CI: 0.353-0.854; P = .008). CONCLUSION/CONCLUSIONS:We found that a minimally invasive approach was associated with significantly lower odds of VTE compared with undergoing the same open procedure. This study highlights how surgical approach may be an independent risk factor for development of VTE and may elucidate potential risk mitigation strategy.

Small vessel cerebrovascular disease, visualized as white matter hyperintensities on T2-weighted magnetic resonance imaging, contributes to the clinical presentation of Alzheimer's disease. However, the extent to which cerebrovascular disease represents an independent pathognomonic feature of Alzheimer's disease or directly promotes Alzheimer's pathology is unclear. The purpose of this study was to examine the association between white matter hyperintensities and plasma levels of tau and to determine if white matter hyperintensities and tau levels interact to predict Alzheimer's disease diagnosis. To confirm that cerebrovascular disease promotes tau pathology, we examined tau fluid biomarker concentrations and pathology in a mouse model of ischaemic injury. Three hundred ninety-one participants from the Alzheimer's Disease Neuroimaging Initiative (74.5 ± 7.1 years of age) were included in this cross-sectional analysis. Participants had measurements of plasma total-tau, cerebrospinal fluid beta-amyloid, and white matter hyperintensities, and were diagnosed clinically as Alzheimer's disease (n = 97), mild cognitive impairment (n = 186) or cognitively normal control (n = 108). We tested the relationship between plasma tau concentration and white matter hyperintensity volume across diagnostic groups. We also examined the extent to which white matter hyperintensity volume, plasma tau, amyloid positivity status and the interaction between white matter hyperintensities and plasma tau correctly classifies diagnostic category. Increased white matter hyperintensity volume was associated with higher plasma tau concentration, particularly among those diagnosed clinically with Alzheimer's disease. Presence of brain amyloid and the interaction between plasma tau and white matter hyperintensity volume distinguished Alzheimer's disease and mild cognitive impairment participants from controls with 77.6% and 63.3% accuracy, respectively. In 63 Alzheimer's Disease Neuroimaging Initiative participants who came to autopsy (82.33 ± 7.18 age at death), we found that higher degrees of arteriosclerosis were associated with higher Braak staging, indicating a positive relationship between cerebrovascular disease and neurofibrillary pathology. In a transient middle cerebral artery occlusion mouse model, aged mice that received transient middle cerebral artery occlusion, but not sham surgery, had increased plasma and cerebrospinal fluid tau concentrations, induced myelin loss, and hyperphosphorylated tau pathology in the ipsilateral hippocampus and cerebral hemisphere. These findings demonstrate a relationship between cerebrovascular disease, operationalized as white matter hyperintensities, and tau levels, indexed in the plasma, suggesting that hypoperfusive injury promotes tau pathology. This potential causal association is supported by the demonstration that transient cerebral artery occlusion induces white matter damage, increases biofluidic markers of tau, and promotes cerebral tau hyperphosphorylation in older-adult mice.

Patients with pre-existing cardiovascular disease and risk factors are more likely to experience adverse outcomes associated with the novel coronavirus disease-2019 (COVID-19). Additionally, consistent reports of cardiac injury and de novo cardiac complications, including possible myocarditis, arrhythmia, and heart failure in patients without prior cardiovascular disease or significant risk factors, are emerging, possibly due to an accentuated host immune response and cytokine release syndrome. As the spread of the virus increases exponentially, many patients will require medical care either for COVID-19 related or traditional cardiovascular issues. While the COVID-19 pandemic is dominating the attention of the healthcare system, there is an unmet need for a standardized approach to deal with COVID-19 associated and other traditional cardiovascular issues during this period. We provide consensus guidance for the management of various cardiovascular conditions during the ongoing COVID-19 pandemic with the goal of providing the best care to all patients and minimizing the risk of exposure to frontline healthcare workers.