S. Josephson

Utility of MRI in spinal arteriovenous fistula

Objective and background: Spinal arteriovenous fistula (SAVF) is a rare but treatable cause of myelopathy. The diagnostic accuracy of MRI for detecting SAVF is unknown. Our objective was to determine the sensitivity and specificity of MRI in the diagnosis SAVF and characterize its radiographic features. Methods: We conducted a retrospective case-control study of all SAVF treated at our institution from 1995 to 2010, including patients who presented with myelopathy, had MRIs available for review, and underwent either spinal angiogram or had another diagnosis confirming test. Two blinded board-certified radiologists reviewed a series of MRIs and listed the most likely diagnoses, radiologic findings, and recommended follow-up. Sensitivities and specificities of MRI compared to spinal angiogram were calculated. We additionally conducted a literature review of cases describing MRI findings in spinal dural and perimedullary arteriovenous fistula. Results: We identified 36 cases of SAVF (median age 56, 67% male) and 32 controls (median age 54, 44% male). MRI was sensitive in identifying SAVF as the primary diagnosis in 94% (radiologist A, 95% confidence interval [CI] 0.87–1.02) and 89% (radiologist B, 95% CI 0.79–0.99) of cases. The sensitivity of spinal cord T2 hyperintensity or flow voids was 100% and the specificity of T2 hyperintensity and flow voids was 97%. Conclusions: Among patients with myelopathy, spinal angiography is mandatory in the presence of both T2 hyperintensity and flow voids but may be unnecessary if both of these findings are absent. Neurology® 2012;79:25–30

A Prospective Comparison of Informant-based and Performance-based Dementia Screening Tools to Predict In-Hospital Delirium.

Dementia is an important risk factor for delirium, but the optimal strategy for incorporating cognitive impairment into delirium risk assessment at the time of hospital admission is unknown. We compared 2 informant-based screening tools for dementia and mild cognitive impairment [AD8 and D=(MC)2] to the Mini Mental State Examination (MMSE) and Mini-cog in predicting hospital-acquired delirium. This prospective cohort study at an academic medical center consisted of 162 medical inpatients over age 50 years without delirium upon admission. Each participant was evaluated using the MMSE, Mini-cog, AD8, and D=(MC)2 upon admission and was assessed daily for delirium. An MMSE⩽24 carried a 5.5 [95% confidence intervals (CI), 2.7-11.1] relative risk for delirium, whereas cognitive impairment detected by the Mini-cog, D=(MC)2, or AD8 carried a 2-fold risk. Adding the D=(MC)2 to the MMSE increased the sensitivity for predicting delirium from 52% (range, 32% to 73%) for the MMSE alone to 65% (range, 46% to 85%) if either test was positive. If both were positive, specificity was maximized at 97% (range, 94% to 100%), but sensitivity was 17% (range, 2% to 33%). The MMSE and Mini-cog identify a large proportion of patients at risk for hospital-acquired delirium, but the combination of performance-based and an informant-based screens may maximize specificity and sensitivity.

Dementia=(MC)2: a 4-item screening test for mild cognitive impairment and dementia.

To develop a practical informant-based screening tool that reliably identifies patients with mild cognitive impairment (MCI) and dementia, we analyzed data from a sample of patients and normal controls seen in a memory clinic. All patients were evaluated with the Clinical Dementia Rating scale. Individual Clinical Dementia Rating responses were dichotomized and entered into a forward stepwise multivariable logistic regression model. Four independent predictors of MCI and dementia thus identified were combined into a prediction rule that was validated in a separate cohort drawn from the same clinic. Using a cut point of 2 or more positive responses to the 4 questions, the final prediction rule had sensitivity of 95% (95% confidence interval (CI): 92-97%) for MCI or dementia, and a specificity of 91% (95% CI: 86-95%). When applied to the validation cohort, the sensitivity for MCI or dementia was 96% (95% CI: 94-98%), and the specificity was 96% (95% CI: 92-98%). Using both cohorts, the positive likelihood ratio for MCI or dementia was 15.6 (95% CI: 14.0-17.3) and the negative likelihood ratio was 0.05 (95% CI: 0.04-0.07). This tool has the potential to identify patients who warrant further cognitive evaluation in busy outpatient or emergency department settings.

Neurohospitalist: A newly popular career choice

The rapid expansion of neurohospitalist programs nationally has been fueled by recent graduates as well as by practicing neurologists increasingly choosing this career direction. An inpatient-focused job is compelling from an intellectual perspective as it allows the opportunity to treat acute disorders where new treatments are constantly emerging. Challenges entail arranging coverage, defining financial models of reimbursement, expanding into rural and international settings, and assuring proper training for those entering this emerging field. A diverse set of opportunities in both practice and academics are viable career options. Those choosing to embark on the neurohospitalist path have the opportunity to lead the field through a time of tremendous growth and change for years to come.

Whole-Genome mRNA Gene Expression Differs Between Patients With and Without Delirium

Objective: To identify differences in gene expression between patients with in-hospital delirium from a known etiology (urinary tract infection [UTI]) and patients with delirium from an unknown etiology, as well as from nondelirious patients. Methods: Thirty patients with delirium (8 with UTI) and 21 nondelirious patients (11 with UTI) were included in this prospective case–control study. Transcriptomic profiles from messenger RNA sequencing of peripheral blood were analyzed for gene expression and disease-specific pathway enrichment patterns, correcting for systemic inflammatory response syndrome. Genes and pathways with significant differential activity based on Fisher exact test (P < .05, |Z score| >2) are reported. Results: Patients with delirium with UTI, compared to patients with delirium without UTI, exhibited significant activation of interferon signaling, upstream cytokines, and transcription regulators, as well as significant inhibition of actin cytoskeleton, integrin, paxillin, glioma invasiveness signaling, and upstream growth factors. All patients with delirium, compared to nondelirious patients, had significant complement system activation. Among patients with delirium without UTI, compared to nondelirious patients without UTI, there was significant activation of elF4 and p7056 K signaling. Conclusions: Differences exist in gene expression between delirious patients due to UTI presence, as well as due to the presence of delirium alone. Transcriptional profiling may help develop etiology-specific biomarkers for patients with delirium.