The primary factor in the proper treatment of a headache is making the right diagnosis, so it is important to review the differences in evaluating headache patients in the Emergency Department compared to an outpatient clinic, according to the Department of Neurology at Dartmouth-Hitchcock Medical Center.
The Emergency Department (ED) and an outpatient clinic are inherently different. For example, ED providers have limited time to spend with patients, and one of the main goals is to rule out headaches that are life-threatening. In an outpatient clinic, providers are able to follow up with patients over time, rather than having a single encounter, so they can develop a headache management plan with the patient.
Understanding the nature of each setting may lead to better outcomes. For example, a Canadian study evaluating the diagnostic accuracy of neurological complaints in the ED found that in 35.7% of cases, the initial diagnosis in the Emergency Department did not match up with the ﬁnal diagnosis eventually made by a neurologist. And primary headaches — migraines, clusters, etc. — were among the most commonly misdiagnosed headaches. This is compared to secondary headaches, which are due to an underlying cause, such as an infection or mass lesion.2
Still, the majority of headaches seen in both the ED and outpatient clinics are migraine or tension-type headaches.3 All diagnoses should begin with a thorough history and a determination whether the headache is secondary. The SNOOP method is effective in catching red flags:4
Systemic symptoms: this includes fever, chills, weight loss, HIV infection, or a history of cancer;
Neurological signs or symptoms: confusion, change in mental status, seizure, asymmetric reﬂexes or other rel evant abnormalities on ex amination;
Onset: acute, sudden or split-second ;
Older patient: ≥50 years old with new onset or progressive headache;
Previous headache history: ﬁrst headache or different headache (change in attack frequency, severity, or clinical features.
Emergency Department Evaluation
Diagnoses of patients with headaches in the ED must be made quickly and efficiently, and arrangements should be made for a follow-up when the patient is discharged. In the ED, it is crucial to determine if a headache is secondary, as there could be dangerous causes, such as trauma to the head or neck — particularly including a concussion.
CT scanning may be used to detect blood, and scanning of the cervical spine is typically performed at the same time. Epidural and subdural hematoma, subarachnoid hemorrhage, and fracture are common diagnoses.
A CT scan without contrast is particularly effective in detecting subarachnoid blood, approaching 100% if performed within 6-12 hours of the initial onset of symptoms.
Outpatient Clinic Evaluation
The evaluation and management of headache patients in a clinic is typically a much more relaxed pace than in the ED, with ongoing follow-ups to consider and adjust treatment. The provider should take a history, examine the patient, and then make a preliminary diagnosis about the types of headache the patient has.
The patient will usually present with red flags, perhaps indicating migraine. The assessment of the patient can be divided into 4 categories: initial history, examination, follow-up assessment, and diagnostic testing when appropriate.
Headache calendars or journals are extremely helpful in the assessment of patients. They help with the establishment of the headache pattern and determining the actual frequency of headaches. Often, a patient complains of a limited number of headaches each month, but when asked to document the headache frequency, discovers that the headaches are much more frequent. This insight can lead to a change in the diagnosis as well as the management of the patient.
Chronic migraine is one of the most common forms of headache that many providers see. Non-modifiable risk factors for chronic migraines include age, female gender, white race, low educational level, low socioeconomic status, and genetic factors.
Modifiable risk factors include: anemia or polycythemia, anxiety or depression, caffeine overuse, hyperthyroidism and hypothyroidism, medication overuse, obesity, and psychiatric comorbidities.
Nye BL, Ward TN. Clinic and Emergency Room Evaluation and Testing of Headache. Headache 2015 Sep 30. doi: 10.1111/head.12648.
Moeller JJ, Kurniawan J, Gubitz GJ, Ross JA, Bhan V. Diagnostic accuracy of neurological problems in the emergency department. Can J Neurol Sci. 2008;35:335-341.
Rasmussen BK, Jensen R, Schroll M, Olesen J. Epidemiology of headache in a general population — A prevalence study. J Clin Epidemiol 1991;44:1147-1157.
Dodick DW. Clinical clues and clinical rules: Primary vs secondary headache. Adv Stud Med. 2003;3:S550-S555.
Bigal M. Migrane chroniﬁcation – Concept and risk factors. discovery medicine 2009;8:145-150.