Abstract
In classical textbooks on Otolaryngology, involuntary movements of soft palate are described as myoclonus or myorrhythmia. Neurophysiologists describe the phenomenon as a soft palate tremor for the predominantly regular frequency.
Two forms of the tremor are differentiated: essential and symptomatic. The cause of essential tremor remains unclear,whereas the symptomatic tremor originates in disorders of the function of nucleus olivae and nucleus dentatus cerebelli.
No changes of density were observed in MRI examination in the essential tremor, while hyperdensity was noted in T-weighted images in ventral part of medulla oblongata, i.e. in the area of nucleus olivae. In the case of essential tremor, involuntary movements of soft palate were observed, based especially on contractions of m. tensor veli palatini, whereas involuntary contractions of m. levator veli palatini occurred in the symptomatic tremor.
It is particularly the essential tremor, which is accompanied with objective tinnitus, originating during opening of the orifice of Eustachian tube in contractions of m. tensor veli palatini. Involuntary contractions of m. tensor veli palatini and the resulting objective tinnitus were repeatedly favorably influenced by administration of botulotoxin into m. tensor veli palatini.
Essential tremor was observed in two patients. The frequency was irregular in both of them.
No neurological finding suggesting that the symptomatic tremor is based on an organic defect was detected in either of them. At the same time, one of the patients, a 41-year man was affected by contractions of m. tensor veli palatini on both sides with extension of soft palate, being accompanied by objective registration of clattered tinnitus.
The other patient, a 51-year woman was affected by contractions of m. tensor veli palatiniwith symmetrical elevation of soft palate. Botox, 10 units,was administered into soft palate muscles (into m. tensor veli palatini in the 41-year man and into m. levator veli palatini in the 51-year woman) on both sides.
In the male patients, where the tremor was induced by contractions of m. tensor veli palatini, there was a significant improvement of tinnitus, but it reappeared after 4 weeks. After 4 months of Botox, 7 units, was administered again into both m. tensor veli palatini muscles with subsequent deterioration of tinnitus, which was not registered by objective examination.
Twitching occurred in m. sternocleidomastoideus as well as dyspnoa attacks, accompaniedwith marked changes in behavior and the patient was recommended for psychiatric therapy. In the 51-year woman, there was a diminution of tinnitus which finally almost dissappeared.
After deterioration of the previously manifested complaints with locomotion of cervical spine and pains the contractions of soft palate and its elevation with objective registration of clattering tinnitus reappear during movements of the head into outer position and back to the middle position. Involuntary movements of soft palate at rest occur only exceptionally being accompanied by tinnitus of low intensity and not registered by objective examination.
Etiological mechanism of the origin of involuntary movements of soft palate with objective tinnitus in the two patients proved to be completely different. It was apparently a manifestation of psychosomatic disease in one of them, whereas in the other patient the motor involuntary stereotype was apparently induced by reflex mechanism on the basis of disorders in cervical spine dynamics.
Botulotoxin, by virtue of its effect, entered the motor involuntary stereotype induced by various etiological mechanisms.