A 45 year old male met with a road traffic accident and suffered a head injury. On examination, he was drowsy and his blood pressure is high. Which reflex is responsible for elevated BP in this condition?

Reflex responsible for elevated BP in head injury patient is Cushing reflex. When intracranial pressure is increased, the blood supply to rostral ventrolateral neurons is compromised, and the local hypoxia and hypercapnia increase the discharge of the central chemoreceptors. The resultant rise in systemic aerial pressure (Cushing reflex) tends to restore the blood flow to the medulla. Cushing reflex causes a triad of symptoms: Reflex bradycardia ( aerial baroreceptors) Hypeension (With widened pulse pressure) Irregular respiration (bradypnea) Ref: Ganong&;s review of Medical Physiology 26th edition Pgno: 582