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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The very rare case of palatal myoclonus manifesting in objective tinnitus was discussed. Options of surgical and pharmacological treatment were analysed with particular emphasis of therapeutic success with application of muscle-relaxant--Baclofen.
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PMID:[A case of objective tinnitus caused by palatal myoclonus]. 1135 86

We report on two patients with an objective tinnitus. In the first one, the objective tinnitus was unique as it was due to bilateral rhythmic contractions of the vocal cords. In the second, the objective tinnitus arose from Eustachian tube contractions and was associated with up and down movements of the larynx. In both patients, the abnormal laryngeal movement shared most of the characteristics of palatal or palatolaryngeal myoclonus and was thought to be laryngeal myoclonus. Its origin remained essential as all the investigations were negative.
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PMID:Objective tinnitus associated with essential laryngeal myoclonus: report of two cases. 1183 71

A quantitative analysis of two rat syndromes of myoclonus are presented, modeling myoclonic epilepsy and postanoxic myoclonus. Like the human conditions, both of the models benefit therapeutically from drugs that act on the serotonin system. The rat model of myoclonic epilepsy is associated with a profound loss of serotonin throughout the brain (except in the striatum) and is generated by an oscillator that is synchronized around the midline. The rat model of posthypoxic myoclonus does not demonstrate a significant reduction in serotonin in any location of its brain and is generated by a non-oscillating circuit in the medulla. Although some forms of myoclonic epilepsy may benefit from serotonin drugs because they are caused by a decrease in brain serotonin, our data indicate that posthypoxic myoclonus is not caused by a decrease in the serotonergic innervation of any region of the brain. That the raphe nuclei do not degenerate after global brain ischemia was noted by C. David Marsden in a discussion of the histologic findings of three of his human cases of posthypoxic myoclonus (page 117 of reference 10) and led him to question the hypothesis that posthypoxic myoclonus was due to a loss of serotonin neurons. Our data confirm his observation in the rat, but also indicate that density of serotonin fibers and terminals throughout the brain is not reduced by the brain ischemia that produces posthypoxic myoclonus. It remains to be determined whether the physiologic responsiveness of serotonin neurons is altered by global brain ischemia and whether changes in serotonin release or serotonin receptor properties are associated with posthypoxic myoclonus. The stability of the serotonin system in posthypoxic myoclonic rats is remarkable when one considers the wide range of disorders that is produced by the prolonged brain ischemia. The inability of the most severely posthypoxic myoclonic rats to perform 7-Hz tongue protrusions indicates substantial physiologic disruption of brainstem motor function. Moreover, the posthypoxic myoclonic rat suffers from ataxia, seizures, retrograde amnesia, and impaired ability to learn. The wide spectrum of these deficits is sharply constrasted by its apparently intact serotonin system. We have identified the inferior olive as a locus that may generate the rhythmic components of tremor and myoclonus in syndromes that are truly associated with a dramatic loss of brainstem serotonin. Serotonin acts within the inferior olive to constrain its rhythmic firing. Without intraolivary serotonin, olivary neurons are predisposed to oscillate continuously, providing a substrate upon which sustained rhythmic spiking may be superimposed. It is clear that such unconstrained rhythmicity produces synchronized whole-body tremor at 10 Hz (33, 41-43). The effects of serotonin to suppress olivocerebellar rhythmicity are mediated by postsynaptic 5-HT2 receptors that reduce the magnitude of the low-threshold calcium conductance, IT. It is notable that dysregulation of this conductance has been associated with hyper-rhythmic states in the thalamus underlying cognitive disorders ranging from depression to tinnitus (49), indicating a common mechanism underlying a variety of neurologic conditions. The identification of a specific brainstem locus (inferior olive), serotonin receptor 5-HT2, and ionic current IT involved in a form of rhythmic myoclonus may provide multiple clues toward which future pharmacotherapies can be directed.
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PMID:The serotonin hypothesis of myoclonus from the perspective of neuronal rhythmicity. 1196 57

Objective tinnitus may be caused by many etiologies-palatal myoclonus being one of them. We report one patient of voluntary palatal myoclonus presenting with objective tinnitus treated with botulinum toxin injection. Five units of botulinum toxin A were injected into each side of the soft palate at the palatal muscles (levator veli palatini and tensor veli palatini muscle). The tinnitus disappeared within two days of injection and no side effect was observed.
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PMID:Botulinum toxin injection for objective tinnitus from palatal myoclonus: a case report. 1211 33

Myoclonus of the middle ear is a very rare condition. We present the case of a 20-year-old soldier who was exposed to intense artillery noise during a fierce battle and immediately afterward complained of an incapacitating tinnitus in both ears. Microscopic examination of the ears demonstrated rapid rhythmic movements of the tympanic membrane coinciding with the tinnitus, which was also easily heard by the examiner. There was no evidence of palatal myoclonus, and thus the diagnosis of middle ear myoclonus was made. Exploratory tympanotomy confirmed the diagnosis of stapedial muscle myoclonus. Bilateral sectioning of the stapedial tendons brought immediate relief of the tinnitus to the patient. We review the literature of middle ear myoclonus and discuss the symptoms, evaluation, and management of this rare condition.
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PMID:Stapedius muscle myoclonus. 1283 20

The cause of objective tinnitus provoked by palatal and middle-ear myoclonus may be identified by magnetic resonance imaging of the central nervous system in the Guilliain-Mollaret triangle or it may be idiopathic. The idiopathic cases are rare. From the literature, one can perceive the following unanswered questions: (1) Are palatal and middle-ear myoclonus different entities or do they usually appear together? (2) Are the clicks being produced by the palatal myoclonus (walls of the eustachian tube slapping together) or by the tensor tympani muscle contractions or by both? (3) Is stapedius muscle myoclonus important in the production of the clicks? (4) What should be the treatment for palatal and middle-ear myoclonus? We present two cases of idiopathic palatal and middle-ear myoclonus and discuss these cases in light of the literature and of some ideas of our own.
Int Tinnitus J 2003
PMID:Palatal and middle-ear myoclonus: a cause for objective tinnitus. 1476 28

Tinnitus is a common otological symptom. Usually it is subjective (perceived only by the patient); very rarely is it objective (heard by both the patient and the examiner) Objective tinnitus due to middle-ear myoclonus is extremely rare, with only a few case reports published in the literature. We present three cases of objective tinnitus caused by middle-ear myoclonus. All patients were cured by tympanotomy with stapedial and tensor tympani tendon section.
Int Tinnitus J 2003
PMID:Bilateral tinnitus due to middle-ear myoclonus. 1476 31

Tinnitus produced by middle-ear myoclonus is a rare condition. In this article, a rare case of unilateral continuous high-frequency objective tinnitus caused by middle-ear myoclonus is described. This condition appears to be the second case reported in the literature. Otoscopic examination revealed visible rhythmic movements of the tympanic membrane. Weak clicking sounds were heard around the right ear by auscultation. Direct stimulation of the soft palate showed no evidence of palated myoclonus. Tympanometry confirmed rhythmic changes in the middle-ear compliance. The condition was effectively treated with a muscle relaxant (orphenadrine citrate).
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PMID:Objective high-frequency tinnitus of middle-ear myoclonus. 1506 24

Subjective tinnitus (heard only by the patient) is a common otological complaint. Objective tinnitus (heard by the examiner as well as the patient) is extremely rare. There are only a few cases of objective tinnitus, secondary to middle-ear myoclonus, described in the literature. We present the case of a child with bilateral, congenital, objective tinnitus, secondary to middle-ear myoclonus, with otherwise normal hearing thresholds (250 Hz-8 kHz), and with no evidence of intra-cerebral or systemic disorders. No similar case has been reported in the world literature.
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PMID:Bilateral objective tinnitus secondary to congenital middle-ear myoclonus. 1599 81

Palatal tremor (formerly palatal myoclonus) is an extremely rare, but potentially treatable cause, of objective tinnitus. The tinnitus is thought to be secondary to rhythmic involuntary movements of the soft palate. Its aetiology is variable and it remains difficult to treat. Many different medical and surgical remedies have been tried but none have demonstrated reproducible success. Botulinum toxin has been used in sporadic cases and seems to produce good results. Ten patients with palatal tremor have presented to this department over the last three years. After discussion with the patients with regard to the management of this condition and possible complications, five opted for botulinum toxin therapy and five declined further intervention. Clinical diagnosis was made on the confirmation of soft palate movements synchronous with an audible clicking noise. Five patients underwent botulinum toxin injection into the insertion of the levator and tensor veli palatini muscles. Of the five that were treated with toxin, four showed complete resolution of symptoms after a course of treatment. Only one patient reported transient side effects. This would suggest that botulinum toxin is a safe and effective first line treatment for palatal tremor.
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PMID:Botulinum toxin is effective and safe for palatal tremor: a report of five cases and a review of the literature. 1684 71


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