Related Experiment Video
Updated: Mar 3, 2026
Author Spotlight: Translational Applications of Stimulated SFEMG in Rodent Models
Published on: March 8, 2024
Facial twitches in ADCY5-associated disease - Myokymia or myoclonus? An electromyography study
Sinem Tunc1, Norbert Brüggemann1, Magdalena K Baaske1
1Institute of Neurogenetics, University of Lübeck, Germany; Department of Neurology, University of Lübeck, Germany.
Objective:
A clinical feature in patients with ADCY5 gene mutations are perioral muscle twitches initially described as facial myokymia.
Methods:
Five patients with ADCY5-associated disease with facial twitches and truncal jerks underwent electrophysiological investigations of the orbicularis oris and trapezius muscles to delineate neurophysiological characteristics of these phenomena.
Results:
Electromyography (EMG) recordings showed a complex electrophysiological pattern with brief bursts of less than 100 ms and longer bursts with a duration of 100-300 ms up to several seconds in keeping with myoclonus and chorea, respectively, as key findings. None of the patients had EMG patterns of myokymia.
Conclusions:
In this series of five ADCY5 mutation carriers, perioral twitches and truncal jerks do not represent myokymia. In view of characteristic clinical signs and electrophysiological patterns with a combination of myoclonus and chorea it might be preferable to refer to these phenomena as myoclonus-chorea.
Related Concept Videos
01:15Myasthenia Gravis: Diagnostic Tests
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
01:26Chemical Synapses
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
01:26Chemical Synapses
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
01:28Disorders of the Skeletal Muscle
Musculoskeletal disorders
Musculoskeletal disorders involve injuries and conditions affecting the skeletal muscles and associated connective tissues. These disorders can arise from acute biomechanical stresses or chronic overuse and can occur across different age groups. Common injuries include sprains, fractures, and muscular strains, often resulting from...
01:20Myasthenia Gravis: Overview and Treatment
These antibodies interfere with the function of the nicotinic receptors in three ways: by binding to the receptor and disrupting acetylcholine binding; by causing cross-linking of receptors which...
01:10Muscle Contraction