[Controversial aspects of magnetic resonance imaging in sudden onset cochleovestibular diseases].
Sudden deafness and vertigo are a challenge for the otolaryngologist. With its high fluid content, the membranous labyrinth is best evaluated through Magnetic Resonance Imaging (MRI). Recently gadolinium-enhanced MRI has opened new perspectives in the imaging of the pathological labyrinth, able to directly detect labyrinthine lesions. To date the main role of MRI has been to rule out the presence of retrocochlear involvement in patients with sudden deafness and/or vertigo. However, in the past few years, several authors, reporting on gadolinium-enhanced MRI, have described better labyrinthine imaging, revealing direct labyrinth or nerve bundle involvement in all such patients. On the contrary, other studies have not revealed any enhancement of post-contrast labyrinthine images upon MRI but have shown an increase in signal intensity upon T2-weighted images. In this light, the purpose of the present study has been a) to evaluate the prevalence of labyrinthine abnormalities found upon MRI in consecutive patients with sudden deafness and vertigo and b) to assess the correlation between the severity of clinical and audiological findings and the MRI abnormalities encountered. Twelve consecutive patients with sudden hearing loss and/or vertigo were included in the study (age range 9-59 years; 6 males and 6 females). All subjects underwent complete otoneurological examination. MRI was performed with a 0.5 T superconducting magnet system allowing 2 mm-thick sections through the temporal bone. Within 29 days of onset of the complaints all patients were studied both before and after administration of the contrast medium (gadolinium-DTPA, 0.01 mmol/l, i.v.). Two of the 12 subjects had sudden deafness, 5 sudden deafness and vertigo while 5 had vertigo alone. Gadolinium enhancement and/or a high signal intensity upon T2-weighted images of the pathological labyrinth and nerve bundle was observed in 4 patients. The patients were divided into groups by etiology. MRI abnormalities were only found in the group where the etiology was viral. There was no correlation between the severity of clinical findings and the presence of MRI abnormalities nor between MRI and ABR findings. Analysis of such controversial data is discussed, stressing the importance of gadolinium-enhanced MRI of the labyrinth as a new diagnostic tool in sudden deafness and vertigo.
Comacchio
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Istituto di Clinica ORL, Università di Padova.
D'Eredità
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Marchiori
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D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D003639:Hearing Loss, Sudden / Q000209:etiology; D006801:Humans; D007759:Labyrinth Diseases / Q000150:complications / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014717:Vertigo / Q000209:etiology; D000159:Vestibulocochlear Nerve / Q000473:pathology*
Aspetti controversi della risonanza magnetica nucleare nello studio delle cocleovestibolopatie improvvise.