LAS VEGAS – Even in a neurologist's office, every headache patient merits a general history and a physical examination, which may be the best tools with which to differentiate secondary from primary headaches, John G. Edmeads, M.D., said at a symposium sponsored by the American Headache Society.
“The headache never walks alone” when it is secondary to a general medical condition, said Dr. Edmeads of Sunnybrook Medical Centre, Toronto.
“There's always something on history or physical to give you a clue that there's a general medical disease going on. And once you have this clue you can diagnose them through a focused work-up that won't cost an arm and a leg,” he explained.
Dr. Edmeads offered the following suggestions:
▸ Neurologists can't assume that patients have had a thorough evaluation before reaching their offices. Dr. Edmeads said that he has had patients ask about the blood pressure cuff as if they had never seen one before.
▸ Be suspicious if the patient's signs and symptoms don't clearly meet International Headache Society criteria for primary headache. Any patient whose headache doesn't meet the society's criteria deserves additional investigation.
▸ If it's not clearly migraine or tension-type headache, look for evidence of central nervous system involvement, either in the brain or its coverings. If there's any indication of CNS involvement, the next step includes neuroimaging and possibly examination of the patient's cerebrospinal fluid.
▸ If there are no signs or symptoms of CNS involvement, then conduct a general medical screen. This should include a CBC; an erythrocyte sedimentation rate; electrolytes, including calcium and phosphate; BUN and creatinine; liver enzymes and bilirubin; thyroid function studies, including TSH, T3, and T4; and a chest x-ray. Answers will come back within a day or two and will cost less than a couple of hundred dollars, Dr. Edmeads said.
▸ If those studies are negative, consider serum protein electrophoresis and arterial blood gases. In winter, consider carbon monoxide poisoning and test for carboxyhemoglobin. Carbon monoxide poisoning from poorly maintained heaters will often present as daily, diffuse, nocturnal headaches that clear up in the morning when patients get out into the fresh air.
▸ If all results are still negative, but you still have a strong suspicion that the headache is the result of a general medical condition, consider a consultation with a general internist.