We report the case of a 36-year-old male in 2014 with no personal or family history of interest, who reported loss of strength in both hands documented from 33 years of age with a history of traumatic ulnar fracture and reduced sedation.
To determine the origin of the loss of strength in the hands, the family physician requests a consultation to Neurology to exclude a compressive neuropathy, specifically a syndrome of the tunnel syndrome.
The area neurologist performed an electromyographic (EMG) study in May 2011 without finding signs of neuropathy of the right median and bilateral ulnar nerves and identified a CPK of 281 mU-174).
In July 2012, due to the worsening of weakness in the hands, and again at the request of the family physician, the same neurologist repeats the EMG, identifying this time a myopic pattern in diagnostically confirmed myotonic extensor discharges.
In February 2013 a biopsy of the deltoid was performed to exclude myopathy, without obtaining a definitive diagnosis by insufficient sample for pathological diagnosis, with analytical in which only highlights CPK of 343 506 mU/dl and IgG of 700 mU/ml.
In April 2013, a molecular genetic study was carried out, identifying an expansion of the 3'UTR end of the DMPKt gene with 120 malformations confirming the diagnosis of myotonic dystrophy type 1 or Steiner's disease
The patient was referred to Cardiology, where in June 2013 a transthoracic echocardiography (TTE) was performed, in which a mild left ventricular hypertrophy (LVH) was identified, and a left ventricular ejection fraction (LVEF) of 50 was predicted.
In July 2013, conventional electrocardiogram (ECG) showed a first-degree atrioventricular (AVB) block with PR 270 ms, QRS 130 ms and repolarization abnormalities compatible with LVH.
In August 2013, the Holter ECG showed the existence of first-degree AVB with a maximum PR of 360 ms, maximum heart rate of 124 beats per minute (lpm), minimal nocturnal ventricular pause of 33 bpm.
Follow-up in cardiology consultations in six months is recommended.
During the September 2013 neurological follow-up, a ptosis affecting the limbs was identified, but without pupillary balance, bilateral weakness of the orbicularis oris, and elevation of the eyelids, and a mild motor sample.
At this time, genetic counseling is provided by Neurology, written information about the disease is provided, it is suggested to exclude other cases in the family and prenatal study is recommended if the patient wishes to have offspring.
A loss of proximal and distal muscle strength is also observed, such that, together with myotonia, prevent the patient from performing fine or rapid movements with the hands or carrying weights, so the corresponding total incapacity starts in February 2014.
In the assessment performed in January 2014, incipient bilateral cataracts were identified.
In March 2014, TTE and Holter ECG were repeated and an ejection fraction was found at the lower limit of normal and first-degree AVB with a maximum PR of 360 ms; a new electrophysiological study was performed within six months.
In September 2014, in a hospital that was different from the reference center, the patient underwent an electrophysiological study (EFS) to assess the atrioventricular conduction system, and identified the absence of left ventricular dysfunction with normal cardiac arrhythmias and low cardiac function.
A week later, the patient was implanted with DDDR bilayer in the right atrium and right ventricle and a cardioemisor device was supplied for home monitoring.
