Session Information
Date: Tuesday, June 21, 2016
Session Title: Myoclonus
Session Time: 12:30pm-2:00pm
Location: Exhibit Hall located in Hall B, Level 2
Objective: To clarify the clinical picture of transient myoclonic state in elderly patients and to establish a position in the classification of myoclonus.
Background: Transient myoclonic state is composed of repetitive and brief shivering-like jerks at resting condition, occurring exclusively in the elderly. It was isolated from other types of myoclonus in 1992, but its characteristic features of involuntary movements have not been quantitatively analyzed. The myoclonic movement of this disorder is not identified in the category of myoclonus classified based on temporal profile.
Methods: We investigated 26 patients with transient myoclonic state (10 women and 16 men, ages 79.7 ± 9.9 years, mean and SD). Features of involuntary movements, brain images, laboratory data including electroencephalograms and electromyograms, medications and treatment were analyzed.
Results: The affected sites of the myoclonic jerks were predominantly the lower face, neck and upper extremities. The myoclonus appeared at conscious resting condition, slightly exaggerated by posturing or action. Asterixis was observed in eight patients. Single myoclonic bursts were 1.70 ± 0.94 sec long. The interval of myoclonic bursts was 4.47 ± 2.44 sec. Single myoclonic bursts were composed of 9.5 ±2.5 Hz myoclonic contractions, and single myoclonic contractions were 44.4 ± 12.3 ms in duration. Most of the patients suffered from chronic diseases, but they were basically independent in activities of daily living. Oral administration of clonazepam was effective.
Conclusions: Transient myoclonic state is characterized by the repetition of brief myoclonus bursts at rest, and its stereotyped feature contrasts with the continuous myoclonus by action and posture in some other myoclonic disorders. We propose a term, “trembling myoclonus,” as a new entity in the classification of myoclonus for this movement disorder.
To cite this abstract in AMA style:
T. Hashimoto, T. Doden, H. Sato. Transient myoclonic state in the elderly: A new entity in the classification of myoclonus [abstract]. Mov Disord. 2016; 31 (suppl 2). https://www.mdsabstracts.org/abstract/transient-myoclonic-state-in-the-elderly-a-new-entity-in-the-classification-of-myoclonus/. Accessed June 14, 2025.« Back to 2016 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/transient-myoclonic-state-in-the-elderly-a-new-entity-in-the-classification-of-myoclonus/