title: [A case of progressive supranuclear palsy presenting mouth opening difficulty with tonic contraction of the orbicularis oris muscle].
abstract: A 72-year-old man developed supranuclear ophthalmoplegia, bradykinesia, rigidity, unsteady gait, dementia, dysphagia, retrocollis, grasp reflex and apraxia of eyelid opening. These findings were compatible with progressive supranuclear palsy (PSP). At the age of 66, he presented a peculiar phenomenon characterized by simultaneous tonic contraction of the orbicularis oris muscle (OOM) and the palatal muscles elicited by pronouncing "pa", which resulted in difficulty of voluntary opening of the mouth and the rhinopharynx. Therefore, the respiration air reciprocated between the lung and the closed mouth. The expiratory pressure puffed out the cheeks, while the lips remained tightly closed. While the respiratory movements and the pressure increased by degree, the OOM contracted more strongly in proportion to the pressure. Sixty to ninety seconds after the elicitation, the pressure overcame the contraction of the OOM and the course of the phenomenon was completed. The electromyograms showed that the OOM activity was prolonged after initial voluntary contraction, remaining thus after a tracheostomy for pneumonia at the age of 72, and that it increased in response to the pressure. Apraxia of eyelid opening, one of the other symptoms, resembled this phenomenon in terms of the aspect of difficulty of voluntary mouth opening. The "holding" phase of grasp reflex, yet another symptom, resembled it in the recruitment of the OOM activity. The phenomenon is not common in patients with PSP. However, we concluded that it may be included among the symptoms of PSP because it has similar characteristics to apraxia of eyelid opening and grasp reflex, which are not uncommon in patients with PSP.
authors.affiliation: Department of Nurology, Tokyo Metropolitan Neurological Hospital.
authors.forename: M
authors.initials: M
authors.lastname: Hayashi
authors.forename: E
authors.initials: E
authors.lastname: Isozaki
authors.forename: M
authors.initials: M
authors.lastname: Suga
authors.forename: S
authors.initials: S
authors.lastname: Horiguchi
authors.forename: T
authors.initials: T
authors.lastname: Hayashida
mesh_terms: D000368:Aged; D006801:Humans; D008297:Male; D009055:Mouth / Q000503:physiopathology*; D009119:Muscle Contraction / Q000502:physiology; D013494:Supranuclear Palsy, Progressive / Q000503:physiopathology*