Quantitative myotonia assessment: an experimental protocol.
Severe clinical myotonia can be physically disabling and socially impairing but as yet there is no standardized treatment regimen. The aim of our study is to present a protocol to measure myotonia using quantitative muscle assessment measures. The proposed protocol addresses two main issues. Muscle strength is assessed in 8 muscles on the right and on the left using a myometer (QMA, quantitative muscle assessment) and by testing strength manually using the 5-point MRC scale (5 = normal) in 15 muscles on the right and on the left. Grip myotonia is assessed by: (a) measuring 1/2 and 3/4 relaxation times (RT) after maximum voluntary contraction (MVC) using QMA apparatus; (b) functional tests (time to open a fist 10 times, time to open and squeeze the eyes 10 times, time to climb 10 steps starting from a seated position, time to protrude the tongue 10 times, time to step onto a chair 10 times; (c) subjective measures of the severity of myotonia using an arbitrary 4-point scale (0 = absent, 4 = severe); and (d) electromyography (EMG) relaxation times after MVC. Although QMA seems to be a reliable tool to measure myotonia, there are still a number of unsolved issues. Further studies are needed to ensure the ability of QMA to quantify myotonia and to guarantee the reliability of the results for clinical research purposes.
Sansone
V
V
Department of Neurology, University of Milan, Istituto Policlinico San Donato, Via Morandi 30, I-20097 San Donato Milanese (MI), Italy.
Marinou
K
K
Salvucci
J
J
Meola
G
G
D002985:Clinical Protocols; D004185:Disability Evaluation; D006801:Humans; D018908:Muscle Weakness / Q000175:diagnosis / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology*; D009222:Myotonia / Q000175:diagnosis* / Q000503:physiopathology