Bronchial involvement in the cramp-fasciculation syndrome

Cramp-fasciculation syndrome (CFS) is an acquired, chronic, usually benign and rather heterogeneous condition with isolated fasciculations and muscle cramps generally induced by physical exercise. They commonly involve calf and quadriceps muscles. The pathophysiology of CFS is related to peripheral nerve hyperexcitability, most often located at the motor nerve terminal or intramuscular arborization.

A 21-year-old man presented with a progressive syndrome of bronchospasm, cramps and muscle twitches related to physical exercise. Spirography showed bronchial hyperresponsiveness, so he received inhaled corticosteroids and beta2-agonists that improved respiratory symptoms. Electrodiagnostic studies were consistent with CFS. Gabapentin was then introduced.

Both respiratory and muscle symptoms improved. A new spirogram after all inhaled medication had been discontinued was normal.

This picture suggests a concomitant involvement of the peripheral motor nerves of both skeletal and airway autonomic smooth muscle, a presentation not previously reported in CFS.