Disappearing palatal Myoclonus

Abstract

Two patients had palatal myoclonus that disappeared. In one, the palatal myoclonus disappeared completely during all stages of natural sleep only to return again when he awoke, persisting as long as he remained awake. In the other patient, palatal myoclonus was continuous for 2 years, became erratic for 6 months, and then disappeared completely, although she could induce it voluntarily. These cases demonstrate that palatal myoclonus is not always: independent of the sleep-waking cycle, persistent throughout life, and independent of cortical control.

Palatal tremor suppressed by mouth opening

“…A) at rest: tremor bursts involve the genioglossal (traces 1,3,5,7) but not the digastric muscle (traces 2,4,6,8); B) active jaw opening: during the task sustained voluntary tonic activation of the digastric muscle is associated with tremor bursts stop in the genioglossal muscle (black arrows), which reappear after jaw closure (dotted arrows); C) passive jaw opening: between two brief voluntary phasic muscle contractions of the digastric muscle (arrows), necessary to allow insertion and removal of a small object to bite, muscle relaxation replaces tremor bursts in the genioglossal muscle. In each panel time base is 200 ms/div (each horizontal trace 4s); sensitivity 500 µV/div It has been reported that EPT can be modified by different manoeuvres including mental processing [2,11,15,22,25], neck position [23], speaking [4,11], singing [4] or mouth opening [2,25]. The findings observed in our patients confirm that mouth opening and other situations that imply mouth opening may completely suppress PT.…”

“…In fact, even though many uncertainties still exist about the pathophysiology of both EPT and SPT, some evidence suggests a cortical influence on the generator of PT. Indeed, PT may be voluntarily influenced by simply concentrating on it [11,15,22], without performing any movement. In addition, transcranial magnetic stimulation of the motor cortex may modulate PT [1].…”

“…An interesting, although just occasionally reported and emphasized feature of PT is that sometimes it may be influenced by several manoeuvres [2,4,11,23,24].…”

Isolated Episodic Lingual Myoclonus

“…The fact that myoclonus was episodic is a unique feature, to our knowledge, although 2 cases of disappearing palatal myoclonus have been reported [10]. In all reported cases, poor response to or ineffectiveness of treatment have been emphasized.…”

Palatal myoclonus

“…[6] Esansiyel palatal miyoklonus, spontan düzelme bildirilen birkaç olgu dışında genellikle yaşam boyu devam eden bir durumdur. [18,19] Palatal miyoklonusa bağlı objektif tinnitus ile orta kulak miyoklonusuna bağlı objektif tinnitusun birbirinden ayrılması önemlidir. Orta kulak miyoklonusunda palatal tremor görülmezken, kulaktaki tıklama sesi ile senkronize timpan membran hareketi görülebilir.…”