What is the emergency department (ED) workup for a patient with an intractable headache?

From the Guidelines

The emergency department workup for intractable headache should begin with a thorough history and physical examination, focusing on red flags that suggest serious underlying pathology, and a non-contrast head CT as the initial imaging study to rule out hemorrhage, mass, or hydrocephalus, as recommended by the 2023 guideline for the management of patients with aneurysmal subarachnoid hemorrhage 1. The initial evaluation should include the application of the Ottawa SAH Rule to identify patients who require additional testing, including those with age ≥40 y, neck pain or stiffness, witnessed loss of consciousness, onset during exertion, thunderclap headache, or limited neck flexion on examination 1. Key aspects of the workup include:

• Obtaining vital signs and performing a complete neurological examination to assess for meningeal signs
• Using the Ottawa SAH Rule to determine the need for additional testing
• Ordering a non-contrast head CT as the initial imaging study
• Considering lumbar puncture if subarachnoid hemorrhage is suspected but CT is negative, especially if the patient presents > 6 hours from ictus 1
• Considering MRI brain with and without contrast if there are concerning neurological findings or if the patient has risk factors for venous sinus thrombosis
• Basic laboratory tests, including complete blood count, basic metabolic panel, and inflammatory markers like ESR and CRP if temporal arteritis is suspected The goal of this comprehensive approach is to ensure proper evaluation of potentially life-threatening causes while providing effective symptom relief, prioritizing morbidity, mortality, and quality of life as the outcome, as supported by the most recent and highest quality study available 1.

From the Research

Intractable Headache ED Workup

• The workup for intractable headache in the emergency department (ED) often involves ruling out subarachnoid hemorrhage (SAH) as a potential cause 2, 3, 4, 5, 6.
• A combination of negative computed tomography (CT) result and negative lumbar puncture (LP) result is often used to rule out SAH 2.
• Studies have shown that this combination has a high sensitivity and specificity for ruling out SAH, with a sensitivity of 100% and a specificity of 67% in one study 2.
• However, other studies have suggested that a negative CT result alone may be sufficient to rule out SAH in certain cases, such as when the headache occurs more than 6 hours after symptom onset 4, 5.
• The decision to perform a lumbar puncture in these cases is a matter of debate, with some studies suggesting that it may not be necessary in all cases 4, 5.
• A systematic review and meta-analysis found that the diagnostic utility of lumbar punctures in CT-negative suspected SAH is still warranted despite the sensitivity of modern CT scanners 6.

Diagnostic Tests

• CT scans are often used as the initial diagnostic test for suspected SAH, with a sensitivity of ≥97% for detecting SAH 6.
• Lumbar puncture is often used as a follow-up test to rule out SAH in cases where the CT result is negative 2, 3, 4, 5, 6.
• The sensitivity of LP in the context of a negative CT result is estimated to be around 38% in one study 6.

Clinical Decision-Making

• The decision to perform a lumbar puncture in cases of suspected SAH with a negative CT result should be made on a case-by-case basis, taking into account the patient's clinical presentation and risk factors 4.
• Shared decision-making between the patient and the emergency physician may be an appropriate approach in these cases 4.