Type 1 myotonic dystrophy (MD) is a rare inherited disease that presents with skeletal muscle weakness and myotonia. Involvement of smooth muscles is also common and mainly manifests in the gastrointestinal tract. We report a case of type 1 MD who presented with dysphagia and was found to have unique esophageal manometry findings.
A 57-year-old Caucasian male patient presented with progressive dysphagia to solids and liquids for the last few months. The patient had a history of type 1 myotonic muscular dystrophy diagnosed at the age of 34. Past medical history was also significant for gastroesophageal reflux disease, diaphragmatic paralysis, and obstructive sleep apnea. Last upper endoscopy showed a small hiatal hernia and a normal esophagus, stomach, and duodenum. His only home medication was omeprazole. Past surgical history was insignificant. Both his father and brother died in their 50s because of unclear respiratory problems. He was a former smoker and did not drink alcohol. Review of systems was unremarkable. On physical exam, the patient was alert, oriented, and in no acute distress. Vital signs were within normal limits. Cardiovascular, lung, abdominal, and skin exams were unremarkable. Neurological exam was significant for bilateral facial muscle weakness and mild ptosis. His other cranial nerves were intact. He had atrophy and weakness of the distal upper and lower extremities. Deep tendon reflexes were absent. Sensory, cerebellar, and gait exams were unremarkable. Upper endoscopy showed mild hyperemia of the stomach, but a normal esophagus and no hiatal hernia. Esophageal biopsies were normal and showed no evidence of eosinophilic esophagitis. After two weeks of being off omeprazole, the patient underwent a 24-hour esophageal pH testing which showed no significant acid reflux. Esophageal manometry revealed elevated lower esophageal sphincter (LES) pressure, elevated upper esophageal sphincter (UES) pressure, and very week peristalsis of the esophageal body.
Esophageal involvement is common in type 1 MD manifesting with dysfunction of UES, esophageal body, and LES. Manometry usually describes a reduced resting tone of the UES and LES. Our patient had elevated LES pressure and week peristalsis of the esophageal body consistent with esophageal achalasia. He also had an elevated UES pressure consistent with cricopharyngeal achalasia. This is the opposite of what is expected in type 1 MD.