Presentation
Intellectual deficit is also present in adult cases. Balding may occur in affected males and females and infertility may be present. Late-onset disease after 40 years of age involves mild myotonia and weakness, daytime sleepiness, and cataracts. [orpha.net]
Ophthalmoplegia as the presenting muscle-related manifestation of myotonic dystrophy. Rev Neurol. 2010;166(5):538-541. ↑ Versino M, Rossi B, Beltrami G, Sandrini G, Cosi V. Ocular motor myotonic phenomenon in myotonic dystrophy. [eyewiki.aao.org]
The initial presentation is usually not muscle weakness, rather patients present with bilateral cataracts, arrhythmias, or infertility. DM 1 has broad range of clinical symptoms which are summarized below. [hindawi.com]
Presentation, clinical course, and outcome of the congenital form of myotonic dystrophy. Pediatr. Neurol. (1994). doi:10.1016/0887-8994(94)90104-X Van Vliet, J. et al. Hearing impairment in patients with myotonic dystrophy type 2. [mda.org]
○ Include a pediatric or neonatal specialist present at delivery; intensive neonatal care is recommended for neonates that may have DM1; anticipate need for feeding tube and ventilator support. ▪ Access to a pediatric or neonatal specialist is recommended [cp.neurology.org]
Entire Body System
- Weakness
In childhood onset cases (with the age of onset between 1 and 10 years of age), the main clinical manifestations involve muscle weakness (including both proximal and distal muscle group, facial weakness, respiratory and gastrointestinal complications [orpha.net]
DM causes weakness of the voluntary muscles, although the degree of weakness and the muscles most affected vary greatly according to the type of DM and the age of the person with the disorder. [mda.org]
Typical facial features include ptosis, weak eyelid closure, and weak smile. Muscle weakness is progressive but slow and correlates with disease duration and CTG repeat expansion size [31]. [hindawi.com]
In DM2, muscle weakness, pain, and myotonia are common, while other systemic features tend to be less frequent and milder in severity. [eyewiki.aao.org]
The muscle weakness associated with type 1 particularly affects muscles farthest from the center of the body (distal muscles), such as those of the lower legs, hands, neck, and face. [medlineplus.gov]
- Congestive Heart Failure
Less commonly, cardiomyopathy and congestive heart failure may occur. There is also an increased incidence of septal defects and valvular abnormalities, including mitral valve prolapse. [hindawi.com]
Gastrointestinal
- Diarrhea
[…] only for recurring pneumonia or severe dysphagia causing weight loss or causing inability to swallow safely without recurrent aspiration ▪ Mexiletine can be considered to treat diarrhea or constipation. [cp.neurology.org]
- Nausea
(f)Gastrointestinal: Smooth muscle involvement may result in dysphagia, nausea, vomiting, reduction in rate of gastric emptying, and early satiety. [hindawi.com]
- Vomiting
(f)Gastrointestinal: Smooth muscle involvement may result in dysphagia, nausea, vomiting, reduction in rate of gastric emptying, and early satiety. [hindawi.com]
Musculoskeletal
- Muscular Atrophy
Dystrophy Association, Myotonic Dystrophy Foundation, Spinal Muscular Atrophy Foundation, and CureSMA; and receives royalty payments for DM2 genetic testing and SCA5 genetic testing from Athena Diagnostics. [cp.neurology.org]
Psychiatrical
- Behavior Disorder
[…] related abnormalities (e.g., fluid-attenuated inversion recovery hyperintensities, particularly in the temporal poles, and dilated perivascular spaces, often colocalizing) and track over time. ○ Refer patients with psychiatric or behavioral disorders, [cp.neurology.org]
Workup
▪ Inquire about erectile dysfunction; consider further workup and medications to treat erectile dysfunction. [cp.neurology.org]
Treatment
Management and treatment No specific targeted treatment is currently available. Management primarily includes monitoring for complications and supportive care (assistive devices, hormone therapy, pain medication). [orpha.net]
Treating muscular dystrophy There's no cure for MD, but a range of treatments can help with the physical disabilities and problems that may develop. [nhs.uk]
Comprehensive evidence-based guidelines do not currently exist to guide the treatment of DM1 patients. [cp.neurology.org]
Ophthalmic Management Ophthalmic management of DM consists largely of treatment of ocular sequelae. Cataracts that are visually significant, for example, should be treated with surgical cataract extraction. [eyewiki.aao.org]
It is recommended to avoid use of opioids in recovery room if possible and consider multimodal treatment for pain. [hindawi.com]
Prognosis
Prognosis Some cases are severe and may have an impact on life expectancy, particularly early-onset cases caused by massive gene expansions. The prognosis in adult-onset cases is mainly dependent on the severity of cardiac manifestations. [orpha.net]
Etiology
Etiology The disease is due to abnormal CTG expansion in the non-translating region of the DMPKgene (19q13.3). Disease severity generally correlates with the number of DNA repeats. More than 2000 CTG repeats may be found. [orpha.net]
In one study, ciliary body detachment was observed in all DM1 patients studied, suggesting a possible etiology for hypotony in this population.[12] Fuchs’ Endothelial Corneal Dystrophy The association between DM1 and Fuchs’ endothelial corneal dystrophy [eyewiki.aao.org]
Epidemiology
The Epidemiology of Myotonic Dystrophy in Northern Ireland. Public Health Genomics (2003). doi:10.1159/000016209 Siciliano, G. et al. Epidemiology of myotonic dystrophy in Italy: Re-apprisal after genetic diagnosis. Clin. [mda.org]
Summary Epidemiology It is the most frequent adult muscular dystrophy and has an estimated prevalence ranging from 1/215,000 in Taiwan to 1/5,500 in Croatia. [orpha.net]
Epidemiology The prevalence of DM has previously been estimated in European populations at around 1 in 8000. [eyewiki.aao.org]
Eymard), Groupe Hospitalier Pitié-Salpêtrière, Institut de Myologie, France; Department of Anesthesia and Perioperative Care (MF), University of California, San Francisco; Clinical Genetics Branch (SMG), Division of Cancer Epidemiology and Genetics, National [cp.neurology.org]
Pathophysiology
Miosis Miosis, usually evident as impaired pupillary dilation following administration of pharmacologic dilating agents, has been observed in DM patients.[9] Although the pathophysiology has not been fully elucidated, it has been theorized to be due to [eyewiki.aao.org]
Prevention
The NCARDRS helps scientists look for better ways to prevent and treat MD. You can opt out of the register at any time. Page last reviewed: 20 July 2021 Next review due: 20 July 2024 [nhs.uk]
These changes prevent muscle cells and cells in other tissues from functioning normally, which leads to the signs and symptoms of myotonic dystrophy. [medlineplus.gov]
Prophylactic insertion of pacemaker has been performed in patient with some conduction defects to prevent sudden cardiac death [1, 35]. [hindawi.com]
Julie Bolen and Natalie Street of the US Centers for Disease Control and Prevention for invaluable advice and Paul Formaker, Pam Lewis, and Margaret Wahl, R.N., for exemplary support. Author affiliations Stanley H. [cp.neurology.org]