Consejos para diagnosticar un accidente cerebrovascular en el síndrome vestibular agudo: examen oculomotor de tres pasos al lado de la cama más sensible que la resonancia magnética temprana ponderada por difusión

Abstract

Background and purpose

Acute vestibular syndrome (AVS) is often due to vestibular neuritis but can result from vertebrobasilar strokes. Misdiagnosis of posterior fossa infarcts in emergency care settings is frequent. Bedside oculomotor findings may reliably identify stroke in AVS, but prospective studies have been lacking.

Methods

The authors conducted a prospective, cross-sectional study at an academic hospital. Consecutive patients with AVS (vertigo, nystagmus, nausea/vomiting, head-motion intolerance, unsteady gait) with >or=1 stroke risk factor underwent structured examination, including horizontal head impulse test of vestibulo-ocular reflex function, observation of nystagmus in different gaze positions, and prism cross-cover test of ocular alignment. All underwent neuroimaging and admission (generally <72 hours after symptom onset). Strokes were diagnosed by MRI or CT. Peripheral lesions were diagnosed by normal MRI and clinical follow-up.

Results

One hundred one high-risk patients with AVS included 25 peripheral and 76 central lesions (69 ischemic strokes, 4 hemorrhages, 3 other). The presence of normal horizontal head impulse test, direction-changing nystagmus in eccentric gaze, or skew deviation (vertical ocular misalignment) was 100% sensitive and 96% specific for stroke. Skew was present in 17% and associated with brainstem lesions (4% peripheral, 4% pure cerebellar, 30% brainstem involvement; chi(2), P=0.003). Skew correctly predicted lateral pontine stroke in 2 of 3 cases in which an abnormal horizontal head impulse test erroneously suggested peripheral localization. Initial MRI diffusion-weighted imaging was falsely negative in 12% (all <48 hours after symptom onset).

Conclusions

Skew predicts brainstem involvement in AVS and can identify stroke when an abnormal horizontal head impulse test falsely suggests a peripheral lesion. A 3-step bedside oculomotor examination (HINTS: Head-Impulse-Nystagmus-Test-of-Skew) appears more sensitive for stroke than early MRI in AVS.

Kattah JC, Talkad AV, Wang DZ, Hsieh YH, Newman-Toker DE. HINTS to diagnose stroke in the acute vestibular syndrome: three-step bedside oculomotor examination more sensitive than early MRI diffusion-weighted imaging. Stroke. 2009 Nov;40(11):3504-10. doi: 10.1161/STROKEAHA.109.551234.

Comentario del experto

En este estudio se realizó un estudio prospectivo en el que pacientes que acudieron de a Urgencias por síndrome vestibular agudo y que tuvieran algún factor de riesgo vascular fueron evaluados de manera estructurada.

En todos los pacientes, se realizó una prueba de neuroimagen. Los pacientes fueron hospitalizados y seguidos posteriormente en consulta.

Se incluyeron 101 pacientes con síndrome vestibular agudo de alto riesgo de los que 25 tuvieron una causa periférica y 76 una causa central.

La realización de una evaluación clínica meticulosa, incluyendo evaluación de Head Impulse Test, evaluación de Nistagmo o presencia de desviación en Skew (los componentes del HINTS) tuvo mayor sensibilidad que la neuroimagen en la detección de vértigo de causa central.

Dr. David García Azorín
Servicio de Neurología.
Hospital Clínico Universitario de Valladolid