The failure to properly diagnose the patient with headache remains one of the most common diagnostic errors in neurology, and that has not improved over the past three decades despite significant advances in neuroimaging.
There are various reasons for this recurrent error: a significant number of patients with brain tumors have an unremarkable presentation; many patients with secondary headache present with the features of a migraine or tension headache; certain tumors mimic particular headache syndromes; and the inexperienced, poorly trained or hurried neurologist may overlook the subtle warning signs of a secondary headache.
However, the failure is at least partially attributable to the United States Headache Consortium guidelines which state that neuroimaging is not warranted in patients with migraine and a normal examination. These guidelines were based on a very small number of retrospective, flawed and outdated studies incorrectly reporting a 0.2% incidence of intracranial abnormalities in patients with headache and a normal exam. The guideline authors considered this incidence too low to warrant an MRI for these patients.
But James C. Johnston, MD, JD summarized more recent data extrapolated from thousands of MRIs demonstrating the true incidence of intracranial abnormalities actually ranges from 3 - 5% depending on age and other factors. These abnormalities included brain tumors, cysts, aneurysms, vascular changes and a number of other conditions, some benign but others requiring further investigation, monitoring or treatment.
Unfortunately, many physicians continue to follow the outdated guidelines, perpetuating the misdiagnosis of headaches. Some neurologists have even recommended further restricting MRIs in the name of cost containment, failing to recognize the enormous cost of headache misdiagnosis.
Drs. Johnston and Zebenigus recommend deleting the outdated guidelines until imaging protocols are prudently refined through well designed prospective studies focused on improving patient care. In the intervening time, more aggressive imaging of the patient with headache is warranted. They have published these recommendations in several peer reviewed journal articles in Neurologic Clinics; Headache; Neurology; and Medical Law; as well as several chapters in leading textbooks including Legal Medicine and Medical Ethics and Legal and Forensic Medicine.
James C. Johnston, MD, JD is the founding partner of GlobalNeurology® and works closely with Professor Mehila Zebenigus, both serving as Directors of Global NeuroCare®, a nonprofit dedicated to advancing neurology services in developing regions. They are currently performing a prospective study on imaging in the patient presenting with new onset headaches, and anticipate discussing the data at the 2020 World Congress of Medical Law.