Upper Arm Tremble and Ultrasonography of Deltoid Vibration in a Patient With an MYBPC1 Variant

A 35-year-old man presented with exercise intolerance and muscle trembling since childhood. Muscle trembling appeared during muscle contraction and disappeared during relaxation. B-mode ultrasonography showed irregular vibration of muscle bundles under contraction in both longitudinal and transverse sections of the deltoid muscle, while the subcutaneous tissue maintained a relative static state. Genetic testing revealed a pathogenic heterozygous variant (T-to-G substitution at nucleotide c.788) in the MYBPC1 gene. To our knowledge, this is the first reported ultrasound image of the so-called myogenic tremor. The noninvasive dynamic visualization of muscle ultrasonography is helpful for its wider application in the differential diagnosis of neuromuscular diseases. Click https://ja.ma/40p5y9t for full case details.

Видео Upper Arm Tremble and Ultrasonography of Deltoid Vibration in a Patient With an MYBPC1 Variant канала JAMA Network