From the Guidelines
Red flags for headache diagnosis include sudden onset of severe headache, headache with fever or neck stiffness, headache after head trauma, and headache with neurological symptoms, which may indicate a serious underlying condition requiring immediate medical attention. According to the 2023 guideline for the management of patients with aneurysmal subarachnoid hemorrhage, specific red flags for headache diagnosis include age ≥40 years, neck pain or stiffness, witnessed loss of consciousness, onset during exertion, thunderclap headache, and limited neck flexion on examination 1. These red flags are critical in identifying patients who may require additional investigation for subarachnoid hemorrhage (SAH).
The Ottawa SAH Rule is a useful tool in screening out individuals with a low likelihood of SAH, and it requires patients who present with a severe headache and meet any of the criteria outlined in the rule to undergo additional testing 1. The rule has been validated in several studies, including a prospective study of 1153 patients, which found it to be 100% sensitive and 13.6% specific 1.
It is essential to note that the presence of any new red flag symptoms should prompt immediate medical evaluation, as they could indicate life-threatening conditions such as subarachnoid hemorrhage, meningitis, brain tumor, stroke, or increased intracranial pressure. Urgent evaluation with neuroimaging (CT or MRI), lumbar puncture, or other diagnostic tests may be necessary, depending on the clinical presentation 1.
In addition to the red flags outlined in the Ottawa SAH Rule, other warning signs that may indicate a serious underlying condition include headache with systemic symptoms (weight loss, night sweats), headache that progressively worsens, and headache in immunocompromised patients 1. These symptoms warrant prompt medical attention, and patients should be evaluated thoroughly to determine the underlying cause of their headache.
Key points to consider in headache diagnosis include:
- Sudden onset of severe headache (thunderclap headache)
- Headache with fever or neck stiffness
- Headache after head trauma
- Headache with neurological symptoms (weakness, numbness, vision changes, speech difficulties, confusion)
- Headache that worsens with coughing or exertion
- New headache in patients over 50 years old
- Headache with systemic symptoms (weight loss, night sweats)
- Headache that progressively worsens
- Headache in immunocompromised patients
- Age ≥40 years
- Neck pain or stiffness
- Witnessed loss of consciousness
- Onset during exertion
- Thunderclap headache
- Limited neck flexion on examination
These red flags and warning signs should be taken seriously, and patients who present with any of these symptoms should be evaluated promptly to determine the underlying cause of their headache and to initiate appropriate treatment.
From the Research
Red Flags for Headache Diagnosis
The following are red flags that should be considered when diagnosing headaches:
- Sudden and severe headache
- Headache with fever, stiff neck, or vomiting
- Headache with confusion, seizures, or loss of consciousness
- Headache with weakness, numbness, or tingling
- Headache with visual disturbances or blindness
- Headache with neck stiffness or pain
Secondary Headache Disorders
Secondary headache disorders can be life-threatening and require immediate attention. These include:
- Subarachnoid hemorrhage
- Reversible cerebral vasoconstriction syndrome
- Elevated intracranial pressure
- Hydrocephalus
- Cerebral venous sinus thrombosis
- Arterial dissection
- Central nervous system infection
- Inflammatory vasculitis 2
Patient Evaluation
A thorough history and physical examination are essential in evaluating headache patients. This includes:
- A detailed history of the current headache
- A focus on dynamics, phenotype, and trigger factors
- A possible preexisting headache
- A complete neurological examination
- Consideration of neuroimaging and serum/spinal fluid analysis if indicated 3, 4
High-Risk Patients
Certain patients are at higher risk for secondary headache disorders, including: