Profiling Dizziness in Older Primary Care Patients: An Empirical Study

The diagnostic approach to dizzy, older patients is not straightforward as many organ systems can be involved and evidence for diagnostic strategies is lacking. A first differentiation in diagnostic subtypes or profiles may guide the diagnostic process of dizziness and can serve as a classification system in future research. In the literature this has been done, but based on pathophysiological reasoning only

Development of a diagnostic protocol for dizziness in elderly patients in general practice: a Delphi procedure

<p>Abstract</p> <p>Background</p> <p>Dizziness in general practice is very common, especially in elderly patients. The empirical evidence for diagnostic tests in the evaluation of dizziness is scarce. Aim of our study was to determine which set of diagnostic tests should be part of a diagnostic protocol for evaluating dizziness in elderly patients in general practice.</p> <p>Methods</p> <p>We conducted a Delphi procedure with a panel of 16 national and international experts of all relevant medical specialities in the field of dizziness. A selection of 36 diagnostic tests, based on a systematic review and practice guidelines, was presented to the panel. Each test was described extensively, and data on test characteristics and methodological quality (assessed with the Quality Assessment of Diagnostic Accuracy Studies, QUADAS) were presented. The threshold for in- or exclusion of a diagnostic test was set at an agreement of 70%.</p> <p>Results</p> <p>During three rounds 21 diagnostic tests were selected, concerning patient history (4 items), physical examination (11 items), and additional tests (6 items). Five tests were excluded, although they are recommended by existing practice guidelines on dizziness. Two tests were included, although several practice guidelines question their diagnostic value. Two more tests were included that have never been recommended by practice guidelines on dizziness.</p> <p>Conclusion</p> <p>In this study we successfully combined empirical evidence with expert opinion for the development of a set of diagnostic tests for evaluating dizziness in elderly patients. This comprehensive set of tests will be evaluated in a cross-sectional diagnostic study.</p

Cognitive Control Predicts Use of Model-based Reinforcement Learning

■ Accounts of decision-making and its neural substrates have long posited the operation of separate, competing valuation systems in the control of choice behavior. Recent theoretical and experimental work suggest that this classic distinction be-tween behaviorally and neurally dissociable systems for habitual and goal-directed (or more generally, automatic and controlled) choice may arise from two computational strategies for reinforce-ment learning (RL), called model-free and model-based RL, but the cognitive or computational processes by which one system may dominate over the other in the control of behavior is a matter of ongoing investigation. To elucidate this question, we leverage the theoretical framework of cognitive control, demonstrating that individual differences in utilization of goal-related contextual information—in the service of overcoming habitual, stimulus-driven responses—in established cognitive control paradigms predict model-based behavior in a separate, sequential choice task. The behavioral correspondence between cognitive control and model-based RL compellingly suggests that a common set of processes may underpin the two behaviors. In particular, computational mechanisms originally proposed to underlie con-trolled behavior may be applicable to understanding the inter-actions betweenmodel-based andmodel-free choice behavior.

Rate and Predictors of Serious Neurologic Causes of Dizziness in the Emergency Department

OBJECTIVE: To describe the rate and predictors of central nervous system (CNS) disease in emergency department (ED) patients with dizziness in the modern era of neuroimaging. PATIENTS AND METHODS: We retrospectively reviewed the medical records of all adults presenting between January 1, 2007, and December 31, 2009, to an academic ED for a primary triage complaint of dizziness, vertigo, or imbalance. The final diagnosis for the cause of dizziness was independently assigned by 2 neurologists, with a third neurologist resolving any disagreements. The primary outcome was a composite of ischemic stroke, intracranial hemorrhage, transient ischemic attack, seizure, brain tumor, demyelinating disease, and CNS infection. Univariate and multivariate logistic regression were used to assess the association between clinical variables and serious CNS causes of dizziness. RESULTS: Of 907 patients experiencing dizziness (mean age, 59 years; 58% women [n=529]), 49 (5%) had a serious neurologic diagnosis, including 37 cerebrovascular events. Dizziness was often caused by benign conditions, such as peripheral vertigo (294 patients [32%]) or orthostatic hypotension (121 patients [13%]). Age 60 years or older (odds ratio [OR], 5.7; 95% confidence interval [CI], 2.5-11.2), a chief complaint of imbalance (OR, 5.9; 95% CI, 2.3-15.2), and any focal examination abnormality (OR, 5.9; 95% CI, 3.1-11.2) were independently associated with serious neurologic diagnoses, whereas isolated dizziness symptoms were inversely associated (OR, 0.2; 95% CI, 0.0-0.7). CONCLUSION: Dizziness in the ED is generally benign, although a substantial fraction of patients harbor serious neurologic disease. Clinical suspicion should be heightened for patients with advanced age, imbalance, or focal deficits