Further research is required to determine if combined strength and aerobic training at moderate intensity is safe for people who have neuromuscular diseases, however the combination of aerobic and strength exercises may increase muscle strength. Aerobic exercise via stationary bicycle with an ergometer may be safe and effective in improving fitness in people with DM1. Cardiovascular impairments and myotonic sensitivities to exercise and temperature necessitate close monitoring of people and educating people in self-monitoring during exercise via the Borg scale, heart rate monitors, and other physical exertion measurements. Orthotics
Muscular weakness of dorsiflexors (dorsiflexion) hinders the ability to clear the floor during the swing phase of gait and people may adopt a steppage gait pattern or ankle-foot-orthotics may be indicated. Factors such as hand function, skin integrity, and comfort must be assessed prior to prescription. Neck braces can also be prescribed for neck muscle weakness. Mobility aids and adaptive equipment
Upper and lower limb weakness, visual impairments and myotonia may lead to the need for mobility aids and functional adaptive equipment such as buttonhooks and handled sponges for optimal hand function. If assistive devices and home adaptations are needed, physical therapists may refer on to occupational therapist(s) for further assessment. Prognosis
Life expectancy in non-congenital late-onset or adult onset DM1 is in the early 50s, with pulmonary complications being the leading cause of death, followed by cardiac complications. DM2 life expectancy has yet to be studied. Epidemiology
The prevalence of DM1 ranges from 5 to 20 per 100,000 (1:20,000–1:5000).
Research directions
Altered splicing of the muscle-specific chloride channel 1 (ClC-1) has been shown to cause the myotonic phenotype of DM1 and is reversible in mouse models using Morpholino antisense to modify splicing of ClC-1 mRNA.Some small studies have suggested that imipramine, clomipramine and taurine may be useful in the treatment of myotonia. However, due to the weak evidence and potential side effects such as cardiac arrhythmias, these treatments are rarely used. A recent study in December 2015 showed that a common FDA approved antibiotic, Erythromycin reduced myotonia in mice. Human studies are planned for erythromycin. Erythromycin has been used successfully in patients with gastric issues. References
External links
Myotonic dystrophy at Curlie