Etiological evaluation of sensorineural hearing loss in children

The research presented in this thesis has the aim to contribute to the optimal diagnostic work up and counseling of children with (U)SNHL and their parents, with a focus on the etiological diagnosis of imaging of the temporal bone and inner ear. An additional focus is on the diagnosis and prognosis of an enlarged vestibular aqueduct, one of the most prevalent structural abnormalities causing SNHL in children. Chapter 2 describes the identification of causative genetic, structural and acquired etiologies in a large cohort of patients with uni- or bilateral SNHL, in relation to age at diagnosis and hearing loss severity, using a stepwise etiological diagnostic work-up. Chapter 3 reports the evaluation of the clinically relevant abnormalities as visualized on CT and MR imaging in children with symmetric and asymmetric SNHL, in relation to age and the severity of hearing loss. Chapter 4 describes the evaluation of causal abnormalities identified on CT and MR imaging in children with USNHL. Chapter 5 is a systematic review of the literature on sudden drops in hearing level after minor head trauma in patients with an EVA. In chapter 6 the long-term ipsi- and contralateral hearing of patients with a EVA is evaluated. Chapter 7 consists of a summary and conclusions of this thesis, and a proposal for an etiologic diagnostic flowchart for children with (U)SNHL. Further, the recent developments and future perspectives are addressed.