Endplate dysfunction causing respiratory failure in a patient with prior paralytic poliomyelitis

Area of Science:

• Neurology
• Respiratory Medicine
• Clinical Electrophysiology

Background:

• Poliomyelitis survivors can develop late sequelae, including respiratory muscle weakness.
• Progressive dyspnea in postpolio syndrome can necessitate mechanical ventilation.
• Autoimmune myasthenia gravis is a common cause of neuromuscular junction dysfunction.

Observation:

• A 56-year-old male with postpolio syndrome presented with progressive dyspnea requiring intensive care unit admission and mechanical ventilation.
• Repetitive nerve stimulation studies revealed a significant decrement in trapezius muscle response, characteristic of neuromuscular transmission defects.
• The muscle response decrement was notably reversed by edrophonium, an acetylcholinesterase inhibitor.

Findings:

• Anticholinesterase therapy led to considerable and sustained improvement in the patient's ventilatory function.
• The absence of serological markers for autoimmune myasthenia gravis suggested an alternative etiology.
• Endplate dysfunction, potentially linked to postpolio syndrome, was proposed as the underlying mechanism.

Implications:

• Repetitive nerve stimulation is a valuable diagnostic tool for identifying treatable neuromuscular junction dysfunction in postpolio syndrome.
• Anticholinesterase treatment should be considered for postpolio syndrome patients with respiratory compromise and electrophysiological evidence of neuromuscular transmission defects.
• This finding expands therapeutic options for managing respiratory insufficiency in the late stages of poliomyelitis sequelae.