In this randomized trial comparing 2 methods of neurologic examination by trainees, a hypothesis-driven approach resulted in greater sensitivity and a trend toward shorter examination times at the cost of lower specificity than with the traditional screening approach.
Our findings suggest that a hypothesis-driven approach may be superior when the history is concerning for an acute focal neurologic process. On the one hand, the higher specificity of the screening examination may result in fewer false findings and therefore less unnecessary testing and consultation, favoring its use in low-risk settings. Furthermore, our hypothesis-driven approach relies on linking specific symptoms to worst-case anatomical locations (for example, acute bilateral leg weakness is assumed to be from a spinal cord lesion until proven otherwise), whereas a screening examination may be more helpful in patients with an unclear history or multifocal complaints, because it can help generate hypotheses and ensure that alternative diagnoses are not missed. Conversely, a hypothesis-driven approach may be superior in acute situations with a high likelihood of serious disease, because higher sensitivity ensures that patients with focal lesions are reliably identified and referred for appropriate testing and treatment. Therefore, our study supports supplementing traditional methods of teaching the neurologic examination with a hypothesis-driven approach.
This study involved both pedagogical and utilitarian aspects, because we examined the performance of students who both learned (more specifically, reviewed) and performed the neurologic examination using 2 different strategies. Further studies will be required to more clearly delineate these 2 aspects when the hypothesis-driven approach is compared with the traditional screening approach. In particular, larger studies will be required to measure the impact of screening vs hypothesis-driven examination strategies on providers' usage of tests and imaging, the rates of correct diagnoses, and ultimately patients' clinical outcomes. In parallel, it will be important to measure the comparative effects of these strategies on learners' understanding of neurology. For example, we omitted reflex testing from the hypothesis-driven strategy to increase its utility for non-neurologists such as emergency physicians and hospitalists, who often do not carry reflex hammers. This has pedagogical ramifications, because students must at some point develop the ability to accurately test and interpret reflexes, which can be critical in certain clinical scenarios, such as the acute presentation of Guillain-Barré syndrome. Furthermore, our results emphasize that the quality of a neurologic examination depends on properly obtaining a history, establishing a neuroanatomical localization, and formulating a differential diagnosis; these areas are thus important topics for further study.
The findings of this study should be interpreted in light of several limitations of its design. Some may disagree with our choice of examination maneuvers for specific situations. We created the algorithm for hypothesis-driven examinations on the basis of our own clinical experience and the limited evidence available10–15
; certainly, more high-quality research on the utility of examination findings in specific settings is required. In addition, it may be argued that physicians learn through experience to appropriately focus their neurologic examinations. However, if this is the case, early teaching of an explicit approach may instill more robust examination skills and confidence in younger trainees. Conversely, we anticipate that some neurologists will disagree with such a focused and algorithmic approach and view it as yet another blow against the art of the neurologic examination. In response, we would stress that we are not proposing to change or abandon the screening neurologic examination, which all physicians should learn, not least because it involves a laying on of hands that is of timeless value but increasingly endangered. Instead, we wish to add a supplemental approach that our results suggest is superior in acute settings. From a pedagogical perspective, further studies will be required to determine the optimal time to introduce this approach into the neurology curriculum. Furthermore, our study emphasized acute, focal presentations of neurologic disease, thereby limiting our ability to comment on the utility of hypothesis-driven examinations outside this setting. Finally, the students in our study were given printed checklists to aid them during their examinations, and it may be argued that this does not replicate real-world conditions. However, we primarily wished to compare the actual performance of the 2 methods of examination and not students' ability to absorb them in a single 30-minute session. With the increasing use of electronic aids in medicine, such printed checklists may become more practical to use, at least until students have internalized them. Nevertheless, future studies should examine the teachability and ease of memorization of the 2 methods.
In the meantime, physicians will continue to face difficult and urgent diagnostic decisions in patients presenting with acute neurologic symptoms. The neurologic examination is indispensable in these situations, but it is a complex tool that can be difficult to master. Our study suggests that its performance and usability can be improved by supplementing traditional teaching with a focused, hypothesis-driven approach.