In contrast to subjective tinnitus, objective tinnitus can be heard by the examiner as well as by the patient. It can be triggered by, among many other etiologies, idiopathic muscular tremor in the soft palate, the essential palatal tremor (EPT). Many treatment modalities have been investigated, of which only Botulinum toxin (BT) injections have shown promising results.
The aim of this study was to evaluate the effect of BT treatment on objective tinnitus due to EPT by a systematic review of the literature.
In accordance with PRISMA guideline a systematic literature search in three databases was performed.
Twenty-two studies fulfilled the inclusion criteria, mainly case reports and case series. A total of 51 BT treated patients diagnosed with EPT were identified in the literature. The studies were evaluated with focus on diagnostics, injection technique and BT dose, follow-up, effect on objective tinnitus, complications, and adverse effects.
The included studies suffer from an extremely low evidence level with several sources of bias. When optimally injected, BT seems to be an effective treatment of objective tinnitus due to EPT, with few adverse effects and complications. We suggest BT injections as first choice in case of EPT and present a guideline regarding diagnostics, treatment, and follow-up.