What tests are done for people with cluster headaches?

Doctors reach a diagnosis of cluster headache entirely on the basis of the signs (what doctors find on examination) and symptoms (what patients report) of the condition. Rarely, the signs and symptoms caused by tumors or other masses mimic those of cluster headaches. In these uncertain cases, doctors will order a CT scan or MRI (which shows images of the inside of the body).

Sometimes, a lumbar puncture (spinal tap) is needed. This procedure may help confirm if an individual's cluster headaches are caused by an infection or by bleeding in or around the brain.

These tests are necessary, because people with the following medical problems can have signs and symptoms that may be mistaken for those of cluster headaches:

• Meningiomas of the cavernous sinus (a benign [relatively harmless] tumor in a certain part of the brain)
  
  
• Arteriovenous malformations (blood vessel defects)
  
  
• Pituitary adenomas (benign tumors of the pituitary gland)
  
  
• Nasopharyngeal carcinoma (cancer in certain parts of the nasal passages and neck)
  
  
• Vertebral artery aneurysms (bulging in certain arteries of the head and neck)
  
  
• Metastatic carcinoma of the lung (spreading lung cancer)
  
  
• Subarachnoid hemorrhage (bleeding in the membranes of the brain