RESUMO
OBJECTIVES: The pathophysiologic mechanisms of idiopathic tinnitus remain unclear. Recent studies demonstrated focal brain activation in the auditory cortex of patients with chronic tinnitus. Low-frequency repetitive transcranial magnetic stimulation (rTMS) is able to reduce cortical hyperexcitability. STUDY DESIGN: Fusing of the individual PET-scan with the structural MRI-scan (T1, MPRAGE) allowed us to identify exactly the area of increased metabolic activity in the auditory cortex of patients with chronic tinnitus. With the use of a neuronavigational system, this target area was exactly stimulated by the figure 8-shaped magnetic coil. In a prospective study, rTMS (110% motor threshold; 1 Hz; 2000 stimuli/day over 5 days) was performed using a placebo controlled cross-over design. Patients were blinded regarding the stimulus condition. For the sham stimulation a specific sham-coil system was used. Fourteen patients were followed for 6 months. Treatment outcome was assessed with a specific tinnitus questionnaire (Goebel and Hiller). SETTING: Tertiary referral medical center. RESULTS: Increased metabolic activation in the auditory cortex was verified in all patients. After 5 days of verum rTMS, a highly significant improvement of the tinnitus score was found whereas the sham treatment did not show any significant changes. The treatment outcome after 6 months still demonstrated significant reduction of tinnitus score. CONCLUSION: These preliminary results demonstrate that neuronavigated rTMS offers new possibilities in the understanding and treatment of chronic tinnitus.
Assuntos
Córtex Auditivo/fisiopatologia , Neuronavegação , Zumbido/terapia , Estimulação Magnética Transcraniana/uso terapêutico , Adulto , Doença Crônica , Estudos Cross-Over , Dominância Cerebral/fisiologia , Método Duplo-Cego , Metabolismo Energético/fisiologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuronavegação/instrumentação , Lobo Parietal/fisiopatologia , Satisfação do Paciente , Tomografia por Emissão de Pósitrons , Retratamento , Inquéritos e Questionários , Lobo Temporal/fisiopatologia , Zumbido/diagnóstico , Zumbido/fisiopatologia , Resultado do TratamentoRESUMO
BACKGROUND: Langerhans' cell histiocytosis (LCH) is a rare disease with variable clinical appearance. The etiology of LCH remains unclear to date. It is currently believed that clonal accumulation and proliferation of CD1a-positive Langerhans' cells are causative. METHODS: A 2-year-old boy presented with hypacusis and disturbance of balance. Auditory brainstem-evoked responses (ABRs) revealed severe bilateral labyrinthine hearing loss. Magnetic resonance imaging (MRI) showed inflammatory changes with bone erosion in both temporal bones including labyrinthine systems and mastoid processes. RESULTS: During bilateral surgical exploration, fragile slightly yellowish tissue with necrotic areas was found that turned out to be LCH on histology. Chemotherapy with vinblastine and prednisone was subsequently initiated, leading to continuing complete remission. CONCLUSIONS: The initial presentation of LCH with bilateral temporal bone involvement is a very rare condition. The signs and symptoms of otologic histiocytosis can mimic those of acute and chronic infectious ear disease. Only a surgically obtained biopsy leads to definitive diagnosis and appropriate therapy.
