Answer

Answer 21-10. Cluster headaches are severe, unilateral pain starting in the orbit area, often occurring on a regular and predictable schedule that may awaken the patient from sound sleep. Usually the eye is red and teary, and nose is congested on that side. HornerÕs syndrome may be present on that side. Patients are agitated and are often awakened from a sound sleep. Headaches are short, usually lasting less than 90 minutes but they may occur in clusters lasting weeks to months and then go away.