[Frequency of hearing disorders in children with langerhans' cell histiocytosis].
ABSTRACT The aims of the study were to find out the frequency of hearing disorders in children with Langerhans' cell histiocytosis (LCH) and to find out possible risk factors for hearing disorders due to the disease itself and the therapy.
30 patients with LCH were examined audiologically by using standard audiometric procedures. In cases of central nervous system (CNS) lesions, brainstem evoked response audiometry (BERA) was done additionally. A significant hearing disorder was defined as a hearing impairment affecting speech, thus being characterized by the following features: Both ears should present either conductive and/or sensorineural hearing loss of at least moderate degree. The frequencies important for speech development (1 - 4 kHz) had to be affected. Also, prolongation of BERA interpeak latencies was regarded as a significant hearing impairment, because those children had an increased risk for a central auditory and speech processing disorder.
In our study 3 patients had a significant hearing disorder according to our definition. The prevalence of a significant hearing disorder is increased in patients with LCH compared to the prevalence of permanent hearing disorders in German children. We found the following risk factors for the development of a significant hearing disorder: LCH of the temporal bone, CNS lesions.
We recommend periodical audiological follow up examinations for LCH patients with lesions of the temporal bone and/or the brain. BERA is indicated in cases with CNS lesions, because central auditory and speech processing disorders are possible in those patients.