Acute Unilateral Audiovestibulopathy due to Embolic Labyrinthine Infarction

Abstract

IntroductionLabyrinthine infarction is a cause of acute audiovestibulopathy, but can be diagnosed only in association with other infarctions involving the brainstem or cerebellar areas supplied by the anterior inferior cerebellar artery (AICA) since current imaging techniques cannot visualize an infarction confined to the labyrinth. This case series aimed to establish embolic labyrinthine infarction as a mechanism of isolated acute audiovestibulopathy.MethodsWe analyzed clinical features, imaging findings, and mechanisms of embolism in 10 patients (8 men, age range: 38–76) who had developed acute audiovestibulopathy in association with an obvious source of embolism and concurrent acute embolic infarctions in the non-anterior inferior cerebellar artery territories. The presence of audiovestibulopathy was defined when bedside or laboratory evaluation documented unilateral vestibular (head-impulse tests or caloric tests) or auditory loss (audiometry).ResultsSix patients showed combined audiovestibulopathy while three had isolated vestibulopathy. One patient presented isolated hearing loss. Audiovestibular findings were the only abnormalities observed in nine patients. In all patients, MRIs documented single or multiple infarctions in the cerebellum (n = 5) or cerebral hemispheres (n = 5). Especially three patients showed single or scattered foci of tiny acute infarctions only in the cerebral hemispheres. Cardiac sources of embolism were found in eight, and artery-to-artery embolism was presumed in two patients.ConclusionSelective embolism to the labyrinth may be considered in patients with acute unilateral audiovestibulopathy and concurrent acute infarctions in the non-AICA territories.

Pearls & Oy-sters: Labyrinthine Infarction Mimicking Vestibular Neuritis

“…3 However, as in our patient, the auditory symptoms may not be striking in embolic labyrinthine infarction when the anterior vestibular artery is preferentially involved. 1,5 Indeed, laboratory evaluation showed predominant involvement of the HC. Given the normal angiogram, steno-occlusion of the proximal portion of the AICA and subsequent recanalization or embolism may be presumed as the mechanism.…”

Seltene Erkrankungen des vestibulären Labyrinths: von Zebras, Chamäleons und Wölfen im Schafspelz

“…Diagnosis of labyrinthine ischemia is complicated by several factors. First, isolated ischemia of the inner ear without brainstem or cerebellar involvement is not visible on MRI 70 71 75 76 . Diffusion restriction in the vestibular nerve on high-resolution DWI MRI of the temporal bone (1.4 mm instead of the usual 5 mm slice thickness) has only been described in some single cases so far 78 87 , while diffusion restriction limited to the inner ear labyrinth has not yet been shown 28 .…”

“…Die Diagnosestellung ist allerdings durch mehrere Faktoren erschwert. Erstens steht derzeit keine «beweisende» Bildgebung für einen isolierten Labyrinthinfarkt ohne Hirnstamm- oder Kleinhirnbeteiligung zur Verfügung 70 71 75 76 . So gibt es bislang nur wenige Fallberichte, bei denen der Nachweis einer Diffusionsrestriktion im Bereich des N. vestibulocochlearis mittels hochauflösendem DWI-MRT des Schläfenbeines gelang (1,4 mm anstatt wie üblich 5 mm Schichtdicke) 78 87 .…”

Clinical Characteristics of Patients With Dizziness/Vertigo Accompanied by Posterior Semicircular Canal Hypofunction

“…The following data were collected from patients' medical records: sex, age, current medical history (course of disease, symptoms during attack, duration of attack, factors induced the attacks, triggering factors, and accompanying symptoms), underlying diagnosis (including labyrinthine infarction, dizziness/vertigo of unclear origin, vestibular neuritis, autoimmune inner ear disease, Ménière's disease, vestibular migraine, otitis media, vestibular paroxysmia, labyrinthine concussion, intralabyrinthine hemorrhage) (Figure 1), results of physical examination upon admission, and auxiliary examinations (such as immune-related laboratory tests, MRI and CT of the brain). Regarding the diagnosis of the above-mentioned underlying diagnosis, labyrinthine infarction, vestibular neuritis, labyrinthine concussion and intralabyrinthine hemorrhage are diagnosed according to patients' medical history, cochleovestibular evaluation and neurovascular imaging (8)(9)(10)(11), vestibular migraine, Ménière's disease and vestibular paroxysmia are diagnosed based on the diagnostic criteria suggested by Barany society (12)(13)(14), autoimmune inner ear disease is diagnosed according the medical history, vestibulocochlear evaluation and immune-related laboratory tests (15,16), otitis media is diagnosed according to the criteria reported by Gates et al (17).…”