myotonic pattern

Disfunción Mioneural Periférica Como Único Elemento Para el Diagnóstico de la Distrofia Miotónica Tipo I. Myoneural Disfunction For The Diagnosis Of Myotonic Dystrophy Type I

Myotonic dystrophy type 1, also known as Steinert’s disease, is a mulsystemic disorder that primarily affects the skeletal and smooth muscle, as well as the eye, heart, endocrine system and central nervous system. This pathology is uncommon and is characterized by generalized myotonia and multiorgan damage. Its clinical expression is variable, but in most cases, there is a variable degree of muscle weakness, cardiac arrhythmias and other conduction disorders, endocrine disorders, sleep disorders, cataracts and baldness. This is a hereditary disease with three recognizable phenotypes: mild, classic and congenital. Depending on the presentation, it may show poor prognosis and a usually rapid progression, which lacks of effective treatment. Case presentation: 54-year-old female patient who enters the Traumatology service of San Vicente de Paul Hospital in Ibarra, Ecuador for presenting a left femur fracture resulting from a fall of her own height. During hospitalization, the patient presented with type II respiratory failure without apparent cause, so she was admitted to the ICU for ventilatory support. The patient had difficulty achieving ventilatory weaning due to distal and proximal muscle weakness. Electromyography reveals a myopathic pattern compatible with the diagnosis of myotonic dystrophy type I. A tracheotomy was performed, and she was discharged for follow-up by the Internal Medicine service. The performance of a molecular diagnostic study was suggested. Conclusions: The molecular study is the diagnostic gold standard to determine with certainty the presence of myotonic dystrophy type I, besides allowing to determine its severity depending on the number of repeated. However, resource limitations in the present case forced evidence to be sought for diagnosis through electromyography. The treatment remains symptomatic. Because of its inheritance pattern being autosomal dominant, due to the expansion of trinucleotides, family members must be evaluated because they may have the diagnosis even though asymptomatic.