The utility of positron emission tomography in the evaluation of autoimmune hearing loss.
OBJECTIVE
To evaluate positron emission tomography as an imaging tool in the diagnosis, evaluation, and management of autoimmune inner ear disease.


BACKGROUND
Autoimmune inner ear disease is a form of cochleovestibular disease associated with variable hearing loss and vertigo for which no reliable diagnostic tests are available.


METHODS
Pilot study of 10 patients with autoimmune inner ear disease and 5 sex-matched and age-matched control subjects without any history of autoimmune inner ear disease, who underwent limited positron emission tomography of the inner ear. Five patients with new or active autoimmune inner ear disease underwent serial positron emission tomography before and after 4 to 6 weeks of a high-dose tapering course of prednisone. The subjects had cranial magnetic resonance imagining, audiometric and vestibular studies, and heat-shock protein (HSP-70) measurements. Reading of the positron emission tomography scans was blinded.


RESULTS
Positron emission tomography was normal in 4 of 5 normal control subjects and abnormal in 1 with normal audiometric and vestibular studies and positive HSP-70. Of patients with established and stable autoimmune inner ear disease, 4 of 5 had no positron emission tomography abnormalities and negative HSP-70, and the one with abnormal positron emission tomography shortly thereafter manifested clinically active disease. Of the 5 patients with active autoimmune inner ear disease monitored serially, 4 had an initial abnormal positron emission tomography in at least one ear, which became normal in all but 1 patient after therapy. HSP-70 correlated with disease activity. Only 1 patient with clinically active autoimmune inner ear disease had a normal positron emission tomography before and after therapy (the HSP-70 was positive before therapy and negative after the therapy).


CONCLUSIONS
Positron emission tomography, especially when combined with HSP-70 determination, may be a useful technique for assessing disease in patients with autoimmune inner ear disease.
Mazlumzadeh
Mehrdad
M
Division of Rheumatology, Mayo Clinic, Rochester, Minnesota, USA.
Lowe
Val J
VJ
Mullan
Brian P
BP
Fabry
David A
DA
McDonald
Thomas J
TJ
Matteson
Eric L
EL
D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D000906:Antibodies / Q000276:immunology; D001327:Autoimmune Diseases / Q000150:complications* / Q000276:immunology; D003051:Cochlea / Q000033:anatomy & histology / Q000378:metabolism*; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology / Q000378:metabolism; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D010865:Pilot Projects; D011241:Prednisone / Q000627:therapeutic use; D015203:Reproducibility of Results; D014055:Tomography, Emission-Computed; D014722:Vestibule, Labyrinth / Q000033:anatomy & histology / Q000378:metabolism*
D000893:Anti-Inflammatory Agents; D000906:Antibodies; D018840:HSP70 Heat-Shock Proteins; D011241:Prednisone; D008727:Methotrexate