Inability to close mouth and dysphagia caused by pseudobulbar palsy: trial treatment by vibration-induced mastication-like movement

摘要

An 84-year-old man suddenly developed dysphagia following repeated transient ischaemic attacks. He could not close his mouth, swallow food, or speak. Dislocation of the jaw, atrophy of the tongue, or gag reflex was not seen, but the snout reflex and jaw jerk were exaggerated, and the patient was able to walk. Radiological findings showed occlusion of the right internal carotid artery, leukoaraiosis and atrophy of anterior operculum. The patient's condition was diagnosed as Foix-Chavany-Marie syndrome, a type of pseudobulbar palsy. His mouth was kept half-open due to inability to close mouth. We used a bandage to prevent jaw dislocation and stretch the jaw closing muscles. Under nutritional control with gastric fistula, swallowing training was started, but dysphagia did not improve. However, vibration stimulation of the mouth with an electric toothbrush induced mastication-like movement in a reflex manner ( ). After 2 weeks of reflex movement training, the patient was able to close his mouth voluntarily. However, adding swallowing training to the reflex movement training using an electric toothbrush failed to improve dysphagia. The mastication-like movement was analysed with surface electromyogram (EMG) by placing electrodes on the masseter, suprahyoid (digastricus) and orbicularis oris muscles ( ). Voluntary masticatory movements were similar to the vibration-induced movements, but did not lead to swallowing movement. Although dysphagia of pseudobulbar palsy is difficult to treat, range of movement exercise of the mandibular joint and stimulation of the trigger point have been reported to be useful for opening the mouth and facilitating swallowing in patients with pseudobulbar palsy. Because of relatively abundant muscle spindles in the masseter and temporal muscles, the vibratory stimuli from an electric toothbrush probably trigger the jaw closing reflex and facilitate voluntary mastication. Stimulation with an electric toothbrush may be a plausible method for treating dysphagia caused by pseudobulbar palsy.