Factors influencing HINTS exam usage by Canadian Emergency Medicine Physicians.

OBJECTIVES: The HINTS examination (head impulse, nystagmus, test of skew) is a bedside physical examination technique that can distinguish between vertigo due to stroke, and more benign peripheral vestibulopathies. Uptake of this examination is low among Emergency Medicine (EM) physicians; therefore, we surveyed Canadian EM physicians to determine when the HINTS exam is employed, and what factors account for its low uptake. METHODS: We designed and tested a 26-question online survey, and disseminated it via email to EM physicians registered with the Canadian Association of Emergency Physicians (CAEP), with 3 and 5-week reminder emails to increase completion. This anonymous survey had no incentives for participation, and was completed by 185 EM physicians, with post-graduate medical training in either Emergency Medicine or Family Medicine. The primary outcomes were the frequencies of various responses to survey questions, with secondary outcomes being the associations between participant characteristics and given responses. RESULTS: 88 respondents (47.8%) consistently use the HINTS examination in the work-up of vertigo, and 117 (63.7%) employ it in scenarios where its clinical utility is limited. The latter is more common among physicians working in non-academic settings, without 5-year EM residency training, and with greater years of practice (p < 0.01). The most frequent explanations for non-use were a lack of need for the HINTS examination, the lack of validation of the exam among EM physicians, and concerns surrounding the head-impulse test. CONCLUSIONS: Though HINTS exam usage is common, there is a need for education on when to apply it, and how to do so, particularly as concerns the head-impulse test. Our attached rubric may assist with this, but quality-improvement initiatives are warranted. Low uptake is partly due to the lack of validation of this examination among EM physicians, so effort should be made to conduct well-designed HINTS trials exclusively involving EM physicians.

RéSUMé: OBJECTIFS: L'examen HINTS (head impulse, nystagmus, test of skew) est une technique d'examen physique au chevet du patient qui permet de distinguer les vertiges dus à un accident vasculaire cérébral des vestibulopathies périphériques plus bénignes. Cet examen est peu pratiqué par les médecins en médecine d'urgence (MU). Nous avons donc mené une enquête auprès des médecins d'urgence canadiens afin de déterminer quand l'examen HINTS est utilisé et quels sont les facteurs qui expliquent sa faible utilisation. MéTHODES: Nous avons conçu et testé une enquête en ligne de 26 questions, et l'avons diffusée par courriel aux médecins urgentistes inscrits à l'Association canadienne des médecins d'urgence (ACMU), avec des courriels de rappel de trois et cinq semaines pour augmenter le taux de réponse. Cette enquête anonyme, qui ne comportait aucune incitation à la participation, a été remplie par 185 médecins de médecine d'urgence ayant suivi une formation médicale postuniversitaire en médecine d'urgence ou en médecine familiale. Les résultats primaires étaient les fréquences des diverses réponses aux questions de l'enquête, les résultats secondaires étant les associations entre les caractéristiques des participants et les réponses données. RéSULTATS: 88 répondants (47,8 %) utilisent systématiquement l'examen HINTS dans l'évaluation des vertiges, et 117 (63,7 %) l'emploient dans des scénarios où son utilité clinique est limitée. Cette dernière est plus fréquente chez les médecins travaillant dans des établissements non universitaires, n'ayant pas suivi une formation de 5 ans en résidence en médecine d'urgence et ayant un plus grand nombre d'années de pratique (p < 0,01). Les explications les plus fréquentes de la non-utilisation étaient le manque de nécessité de l'examen HINTS, le manque de validation de l'examen parmi les médecins de médecine d'urgence et les préoccupations concernant le test d'impulsion de la tête. CONCLUSIONS: Bien que l'utilisation de l'examen HINTS soit courante, il existe un besoin d'éducation sur le moment où il faut l'appliquer et sur la manière de le faire, en particulier en ce qui concerne le test d'impulsion de la tête. Notre rubrique ci-jointe peut vous aider à cet égard, mais des initiatives d'amélioration de la qualité sont justifiées. Le faible taux d'utilisation est en partie dû au manque de validation de cet examen parmi les médecins de la médecine d'urgence. Il faut donc s'efforcer de mener des essais HINTS bien conçus impliquant exclusivement des médecins de la médecine d'urgence.

Novel Vascular Anastomoses and Moyamoya Disease in a Woman with Down Syndrome.

A 56-year-old woman with Down syndrome presented with right-sided weakness and dysarthria, and was found on CT/CTA to have a left middle cerebral artery infarct secondary to moyamoya disease. Her left posterior inferior cerebellar artery (PICA) was fed both by the left vertebral artery, and the left ascending pharyngeal artery (APA), with a variant origin from the internal carotid artery (ICA), then passing through the jugular foramen (Figure 1). Her right PICA originated exclusively from her right occipital artery, also via the jugular foramen (Figure 2). The left vertebral artery originated directly from the aortic arch, whereas the right vertebral artery originated from the brachiocephalic trunk. In addition, she had a trifurcated anterior cerebral artery (ACA), and just prior to this trifurcation, her left ACA was partially supplied by the left ICA, via a superior hypophyseal artery. This case is noteworthy for several reasons. First, though it is exceedingly rare to have the PICA supplied by the jugular branch of the APA, this is the first reported case with an ICA origin of that APA.1,2 The fact that both PICAs in this patient originate from the anterior circulation should remind clinicians that in unexplained posterior circulation infarctions, vascular anatomy should be explored, as carotid-vertebrobasilar anastomoses such as these are rare, but possible. Lastly, the conjunction of moyamoya disease and anomalies of the vertebrobasilar system in a patient with Down syndrome raises interesting questions about the influence of trisomy 21 on the developing vasculature. Connections from the APA to the vertebrobasilar system are hypothesized to result from a lack of regression of an embryological anastomosis, in line with the more common persistent trigeminal and persistent hypoglossal arteries.1 Patients with moyamoya disease have a significantly higher rate of persistent carotid-vertebrobasilar anastomoses than the general population,3 and are also 26 times more likely to have Down syndrome.4 Correspondingly, patients with Down syndrome have significantly higher levels of moyamoya disease, and are more than 10 times as likely as the general population to have abnormalities of the Circle of Willis5 and vertebral arteries.6 Several genes on chromosome 21 are known to affect angiogenesis, namely collagen XIII/endostatin (COL18A1), DYRK1A, and Down syndrome candidate region 1 (DSCR1), possibly through inhibition of VEGF activity.7 Whether additional copies of these genes are responsible for the anomalous vascular development seen in Down syndrome, in turn predisposing to the development of moyamoya disease, could benefit from further exploration.