Treatment of Essential Palatal Myoclonus in a 10-Year-Old Girl with Botulinum Neurotoxin

Palatal myoclonus (PM) is a rare neurotological disorder but is being reported with increasing frequency. Two forms, symptomatic and essential PM, have been identi- fied as separate clinical entities and probably also have sepa- rate etiologies. In essential PM, brain imaging is unremarkable and a clicking noise caused by peritubal muscle contractions and often audible by the examiner usually is the patients' chief complaint. The treatment of essential PM with systemic appli- cation of anticonvulsants and related substances as well as by destructive surgical means has yielded unsatisfactory results. Recently, the use of botulinum neurotoxin has emerged as a new treatment option that seems particularly attractive due to its safety, complete reversibility, very few side effects, and minimal invasiveness. We report the case of essential PM in a 10-year-old girl who was successfully treated with bot- ulinum toxin injections under eletromyographic guidance and we review the literature on the use of botulinum toxin in PM. Myoclonus of the palatal muscles is rare and reports on its treatment scarce and mostly based on small numbers of patients. In the essential form, the pathomechanism is still poorly understood; some evidence points to the involve- ment of the inferior olivary nuclei. Contractions of the palatal muscles including M. levator veli palatini and M. tensor veli palatini cause rapid opening and closing of the Eustachian tube, producing an objective clicking tinnitus clearly audible by the examiner. Destructive surgery and pharmacological treatment with anticonvulsants have been used in the past to treat this disorder but did not reach the desired effectiveness and safety. In recent years, the use of botulinum toxin has been extended to this disease entity and shows promising results.