Muscle ultrasound measurements and functional muscle parameters in non-dystrophic myotonias suggest structural muscle changes.

Abstract

Patients with non-dystrophic myotonias, including chloride (myotonia congenita) and sodium channelopathies (paramyotonia congenita/potassium aggravated myotonias), may show muscular hypertrophy in combination with some histopathological abnormalities. However, the extent of muscle changes has never been assessed objectively in a large group genetically confirmed patients. This study quantitatively determines echo intensities, thicknesses, ranges-of-motion and force of four skeletal muscles in 63 genetically confirmed patients. The main findings revealed elevated echo intensities in all muscles except the rectus femoris (+1.3-2.2SD, p<0.0001), and hypertrophy in the arms (+0.5-0.9SD, p<0.01). Muscle echo intensities were inversely correlated to the corresponding ranges-of-motion (biceps brachii: r= -0.43; p<0.001, forearm flexors: r= -0.47; p<0.001, rectus femoris: r= -0.40; p=0.001, and tibial anterior: r= -0.27; p=0.04) and correlated positively to age (r=0.22; p=0.05). The echo intensity of the forearm flexors was inversely correlated to their muscles' force (r= -0.30; p=0.02). Together, these data suggest that non-dystrophic myotonias may lead to structural muscle changes.

• Authors: J Trip, S Pillen, C G Faber, B G M van Engelen, M J Zwarts, G Drost
• Journal: Neuromuscular disorders : NMD (Neuromuscul Disord) Vol. 19 Issue 7 Pg. 462-7 (Jul 2009) ISSN: 1873-2364 [Electronic] England
• PMID: 19540760 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Adult
• Aged
• Arm (diagnostic imaging, pathology, physiopathology)
• Channelopathies (diagnostic imaging, pathology, physiopathology)
• Cohort Studies
• Disease Progression
• Female
• Humans
• Leg (diagnostic imaging, pathology, physiopathology)
• Male
• Middle Aged
• Muscle Contraction (physiology)
• Muscle Fibers, Skeletal (diagnostic imaging, pathology)
• Muscle Strength (physiology)
• Muscle Weakness (diagnosis, etiology, physiopathology)
• Muscle, Skeletal (diagnostic imaging, pathology, physiopathology)
• Myotonic Disorders (diagnostic imaging, pathology, physiopathology)
• Predictive Value of Tests
• Prognosis
• Sensitivity and Specificity
• Severity of Illness Index
• Ultrasonography (methods)
• Young Adult