[Controversial aspects of magnetic resonance imaging in sudden onset cochleovestibular diseases]. / Aspetti controversi della risonanza magnetica nucleare nello studio delle cocleovestibolopatie improvvise.

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.

MRI evidence of labyrinthine and eighth-nerve bundle involvement in mumps virus sudden deafness and vertigo.

Enhanced MRI has recently become an even more useful diagnostic tool in the study of the labyrinth in sudden deafness and vertigo. A 22-year-old male who experienced a right-sided sudden deafness and vertigo due to mumps virus underwent labyrinthine MRI examination with gadolinium, and both labyrinthine and nerve bundle involvement was demonstrated. The relationship between mumps virus and the sudden deafness in humans has not been completely established and the path of labyrinthine infection and the possible eighth-nerve involvement is discussed. In vivo evidence of labyrinthine and cochleovestibular-nerve involvement, in mumps virus sudden deafness and vertigo has not been previously demonstrated. MRI findings may represent a new contribution in the evaluation of the etiopathogenesis of mumps virus deafness and vertigo.

Hemangiopericytoma of the skull base and Collet-Sicard syndrome: a case report.

Hemangiopericytoma (HP) is a mesenchymal tumor that originates from the pericytes of the capillary walls. This is a rare neoplasm, particularly in the head and neck; the skull base is involved exceptionally. We report a case of a large HP located in the jugular foramen. The last four cranial nerves were involved, causing a Collet-Sicard syndrome associated with facial palsy. Only one case of HP and Collet-Sicard syndrome is reported in the literature. The clinical course of the disease is described, emphasizing the long period of elapsed time between onset of the complaints and the final diagnosis. Diagnostic procedures and immunohistochemical evaluation are analyzed, along with the possible differential diagnosis with other pathological processes that more frequently involve the jugular foramen.

[Value of TC99m-Nanocolloid spect in diagnosis and follow-up of necrotizing external otitis]. / La spect TC99m-nanocolloide nella diagnosi e follow up delle otiti esterne necrotizzanti.

Necrotizing external otitis (NEO), or malignant external otitis, a severe penetrating infection of the ear canal and the temporal bone, which occurs almost exclusively in diabetic or immunodepressed elderly patients, is caused in most cases by Pseudomonas aeruginosa while Staphylococcus epidermidis and Aspergillus fumigatus have been described as other possible agents. Recently bone scintigraphy, carried out above all employing SPECT, has been considered an important tool in diagnosis and follow-up of NEO. Many Authors confirm the role taken by Technetium99m-methylene-diphosphonate (MDP) and Gallium67-citrate bone scanning. Benecke suggested that response to therapy could be monitored with Ga67 or In111 scans. Two cases of NEO in which diagnosis and follow-up were made using Tc99m-nanocolloid (NC) SPECT are presented in this paper. The Authors discuss the advantages of this latter radiotracer, compared to those obtained with Ga67-citrate, in the follow-up evaluation of therapy efficacy. Tc99m-NC, in fact, is a better inflammation index in that its fixation on bone tissue is determined by the permeability of the basal membrane of vessels. Furthermore, with Tc99m-NC antibiotic therapy may be continued as long as necessary. Bone scintigraphy with other radiotracers may infact result positive for a long period after disease remission in that their fixation is linked to the one remodelling process.