Exploring Respiratory Involvement in Oculopharyngeal Muscular Dystrophy

Case Diagnosis: A 55 year old female with Oculopharyngeal Muscular Dystrophy (OPMD) develops chronic respiratory failure.

Case Description or Program Description: The patient who had a chronic tracheostomy due to OPMD was admitted for Acute Hypoxemic Respiratory Failure secondary to influenza A pneumonia with bilateral basilar pneumonia. The patient was mechanically ventilated through chronic tracheostomy, but worsening clinical status resulted in two subsequent cardiac arrests. Patient was ultimately stabilized and discharged to our Inpatient Rehabilitation Hospital for further medical care and functional recovery.

Setting: Inpatient Rehabilitation Hospital

Assessment/Results: Initial assessment was conducted by physiatrists with physical, occupational and speech therapists to gauge baseline functionality. The patient participated in 3 hours of therapy daily for three weeks under the guidance of physical, occupational and speech therapists in order to improve strength, mobility and overall functionality. Upon initial evaluation, the patient presented with proximal greater than distal weakness as well as requiring ACVC ventilatory support. She progressed to ambulate 160 feet under contact guard assist with the use of a rolling walker, but was unable to be fully weaned from ventilatory support due to intermittent episodes of apnea.

Discussion (relevance): Although, the current literature suggests that OPMD does not directly affect life expectancy, it is evident from this case that this patient population is at increased risk of clinical deterioration due to underlying bulbar muscle weakness. While there is no evidence of respiratory muscle weakness associated with OPMD, there have been published case reports that suggest recurrent aspiration pneumonia secondary to dysphagia may induce respiratory muscle weakness and reduced lung compliance7. In this case, the patient has required a tracheostomy for approximately two years due to frequent hospitalizations secondary to aspiration pneumonia. Another case study from 2013 reported a patient with OPMD who developed cor pulmonale and respiratory failure subsequently. This was suggested to be a result of chronic hypoventilation and was attributed to the underlying muscle disease and malnutrition with respiratory muscle weakness. As such, it is evident that OPMD can cause significant respiratory failure.

Conclusions: Further research is required to assess the extent of atrophic changes extending beyond bulbar involvement, including but not limited to muscles of respiration in patients with OPMD.