Audiovestibular findings in patients with pseudotumor cerebri

Pseudotumor cerebri syndrome is characterized by benign intracranial hypertension. This syndrome can be manifested by audiological and vestibular complaints. The aim of thisstudy is to determine the audiovestibular pathologies in this syndrome by performing current audiovestibular tests. The study was conducted at Başkent University Otorhinolaryngology Head and Neck Surgery Department and designed as a prospective, controlled and blind clinical study. Study group subjects were 20 pseudotumor cerebri patients diagnosed in our hospital. Control group consists of 20 healthy, age and sex matched volunteers. Pure tone audiometry, timpanometry, electronystagmography (ENG) and vestibular evoked myogenic potentials tests (VEMP) were performed to both groups and study group results were compared with the control group. As a result, dizziness and/or vertigo, hearing loss, tinnitus, aural fullness and pressure sensation symptoms were realised to be detected in the pseudotumor cerebri patients. The audiological tests showed significant low tone hearing loss in the study group, compared to the control group. Electronystagmography tests revealed pathologies indicating central nervous system defects (saccadic latency delay, optokinetic asymetry, tracking test abnormalities) in the study group. Results were significantly higher in the study group (50% of the patients in the study group had central disorders according to the ENG test, while only 5% of the control group manifests such abnormality). According to the VEMP tests, study group had significantly higher abnormality rates compared to the control group ( 40% of the study group (amplitude changes, prolonged latency and absence of VEMP responses), 5% of the control group had abnormal results in this test). We propose that, the pathophysiology of hearing loss in patients with pseudotumor cerebri syndrome may be due to increased perilymphatic pressure by transmission of cerebrospinal fluid pressure through the coclear aqueduct. İncreased perilymphatic pressure may directly or indirectly affect the endolymphatic system; or, since the sac is composed of two dural plates, it may affect the endolymphatic sac itself by decreasing the vascular supply of the sac or putting the sac under pressure directly. The same pathophysiological principles may also be valid for the involvement of the iner ear vestibular apparatus.