Acute evaluation of the acute vestibular syndrome: differentiating posterior circulation stroke from acute peripheral vestibulopathies

Abstract

This review article aims to provide an evidence-based approach to evaluating the patient who presents with acute prolonged, spontaneous vertigo in the context of the acute vestibular syndrome (AVS). Differentiation of posterior circulation stroke (PCS) presenting as an AVS has been regarded as an important diagnostic challenge for physicians involved in acute care. Current evidence suggests that a targeted approach to history taking and physical examination with emphasis on the oculomotor examination, more specifically the HINTS (Head Impulse/Nystagmus/Test-of-skew) examination battery, yields a higher sensitivity for the diagnosis of PCS than even standard magnetic resonance imaging with diffusion-weighted imaging. However, most studies have only validated the utility of the HINTS examination when performed by experts, who interpret the most powerful component of HINTS, namely the head impulse test (HIT), considerably different to the novice. Several investigations useful in the differentiation of the AVS are becoming more accessible and portable, such as videooculography with Frenzel goggles and video head impulse testing (vHIT), which allows for the quantitative assessment of the HIT. In clinical practice, vHIT has already become accepted as standard of care in the evaluation of AVS.

Alexander’s law in vestibular neuritis

“…Acute vestibular syndrome is vertigo, nausea or vomit that appears acutely over seconds to hours and lasts for days to weeks. 1 It is important to distinguish between peripheral vertigo such as vestibular neuritis and central vertigo such as cerebellar infarction. 1 Alexander's law refers to spontaneous nystagmus that occurs after an acute unilateral vestibular loss.…”

“…1 It is important to distinguish between peripheral vertigo such as vestibular neuritis and central vertigo such as cerebellar infarction. 1 Alexander's law refers to spontaneous nystagmus that occurs after an acute unilateral vestibular loss. In the case of peripheral nystagmus, intensity of nystagmus is enhanced when staring in the direction of fastphase otherwise reduced when staring at the opposite side of the fast-phase.…”

Patología vestibular en el primer nivel de atención

“…o Protocolo HINTS: llamado HINTS, por sus siglas en inglés (Head Impulse Nystagmus Type and Skew Test) corresponde a un protocolo para utilizar en los departamentos de urgencias para identificar los síndromes vestibulares de origen central con potencial riesgo de mortalidad, particularmente útil para identificar un ECV, con una sensibilidad del 95% . El protocolo HINTS es la combinación de tres pruebas que se deben interpretar para diferenciar de una patología vestibular periférica de una central (11,16,19). Las pruebas son:…”

“…-Head Impulse Test -Nistagmo -Test of Skew En enfermedades de origen periférico, el HIT esta anormal, el nistagmo es horizontal rotatorio unidireccional y el e588 Test Skew es normal (no hay desviación de la mirada). En las enfermedades de origen central (como en ECV), el HIT es normal, el nistagmo es de dirección cambiante o vertical; y el Test Skew presenta desviación ocular oblicua (7,19).…”

“…En pacientes con mareos o vértigo, de franco origen vestibular, es poco frecuente que los laboratorios estén alterados. (10,19).…”