Improved ventilatory response during exercise over time after concussion: A case report

This case study reports the exercise ventilatory responses of a 17-year-old female who sustained a traumatic brain injury (TBI) which resulted in loss of consciousness. Subsequently, she suffered from post-concussion syndrome accompanied by orthostatic and exercise intolerance. A cardiopulmonary exercise test (CPET) was performed 2 years post-TBI. The results demonstrated significant hypoventilation with elevated PetCO₂ and ventilatory equivalents, progressive desaturation, and pre-syncope symptoms limiting exercise capacity. A repeat CPET 4 years post-TBI demonstrated a similar exercise capacity limited by pre-syncope symptoms. However, there was a marked improvement in the ventilatory response, with appropriate ventilation, PetCO₂, and ventilatory equivalents, and only minor desaturation near peak exercise. Hypoventilation during exercise has been reported in subjects with post-concussion syndrome; however, with time the exercise ventilatory response can potentially normalize as observed in this subject.