Lingual protrusion dystonia: frequency, etiology and botulinum toxin therapy.

The purpose of this study was to examine lingual protrusion dystonia (LPD); its frequency, etiology and response to botulinum toxin therapy. Previous literature suggests that LPD is more frequently the result of heredodegenerative disease and that the use of botulinum toxin therapy in LPD is associated with significant adverse effects. This is a retrospective database and record review from a movement disorder clinic. Of 421 dystonia patients, we identified 17 with LPD (4%). Of these cases, the diagnoses were: primary cranial dystonia (5), primary generalized dystonia (2), tardive dystonia (7), heredodegenerative disease (1), multifactorial (1) and post-infectious (1). All primary cases had concomitant oromandibular dystonia. In some secondary cases the LPD was the only cranial feature. Nine received botulinum toxin injections and 55.6% sustained moderate or marked improvement. Of 89 total botulinum toxin sessions, 66.3% had an excellent response, and 92.1% had some response. 97.8% of the sessions resulted in no significant adverse effects. On one occasion one patient developed severe dysphagia requiring placement of a percutaneous gastrostomy (PEG) tube. We conclude that LPD is rare, most commonly the result of tardive and primary dystonia. Botulinum toxin therapy may be very effective but needs to be utilized with care because of the possibility for the development of dysphagia.