During the surgical removal of an invasive glioma from the base of the skull, cranial nerves IX and X are accidentally cut bilaterally. What would be the immediate change in the patient's hemodynamic condition?
The glossopharyngeal nerve (CN IX) and the vagus nerve (CN X) carry afferent information to the medulla from the carotid sinus and aoic arch baroreceptors, respectively. The firing rate of these neurons increases with increasing blood pressure. Therefore, severing these nerves sends the medulla a false signal that the patient has suddenly lost all blood pressure. This elicits a baroreceptor reflex, resulting in an increase in sympathetic outflow and leading to tachycardia and hypeension.
Bradycardia with hypeension
Bradycardia with hypotension
Sinus arrhythmia with hypotension
Tachycardia with hypeension