Migraine causes significant disability but is underdiagnosed and undertreated. Making an accurate diagnosis is key to improving outcomes for patients. At AAN 2021, Professor Hope O’Brien, University of Cincinnati College of Medicine, OH, provided expert tips on diagnosing migraine and differentiating it from potentially life-threatening secondary headache disorders.
Migraine causes significant disability but is not life-threatening. As a result, it is underdiagnosed and undertreated worldwide.1
Migraine is underdiagnosed worldwide1
Primary headache vs secondary headache
"Headaches are common", said Professor O’Brien, "and almost 50% of adults have had at least one headache in the previous year".2 They are classified by the International Classification of Headache Disorders, 3rd edition as:
90% of headaches are primary headaches
- Primary — eg, migraine, tension-type headache, trigeminal autonomic cephalalgia
- Secondary due to a structural lesion or underlying disease
- Painful cranial neuropathies, other facial pain and other headaches3
In 90% of cases, a headache is a primary headache, and the examination is normal.4
SNOOP is a screening mnemonic to exclude secondary headache5
"Secondary headaches may be life-threatening, however", noted Professor O’Brien," and need further investigation and neuroimaging.5 They must be excluded when diagnosing migraine". SNOOP is a helpful screening mnemonic highlighting the red flags, which are:
- Systemic signs and disorders
- Neurologic symptoms
- Onset that is new or changed and over 50 years of age
- Onset as a thunderclap headache
- Papilledema, pulsatile tinnitus, positional provocation, precipitated by exercise5
Neuroimaging is not indicated for typical uncomplicated episodic or chronic migraine
Neuroimaging is also required for headaches diagnosed as:
- Episodic or chronic migraine without aura accompanied by an abnormal neurologic examination
- Migraine with aura accompanied by an atypical or complex aura
- Trigeminal autonomic cephalalgia
- Traumatic headache6
Professor O’Brien also noted the importance of the physical examination and paying attention to extracranial structures to exclude other diagnoses, for example sensitive scalp arteries suggesting temporal arteritis and impaired neck mobility suggesting meningeal irritation.7
Diagnosing migraine — the history is key
Stress is a common trigger7
"A thorough history is key in the diagnosis of migraine", said Professor O’Brien.
Important clinical features include its temporal pattern, location and radiation, nature (eg, throbbing), severity and intensity, associated features (eg, nausea, vomiting, aura), and aggravating factors (eg, light, sound, activity).7
Professor O’Brien highlighted that although usually unilateral, migraine headaches can be bilateral, and may be associated with cranial autonomic symptoms,3 and that stress is a common trigger.8
If two of the three PIN predictors are present, the positive predictive value for a diagnosis of migraine is 93%9
She also highlighted the “PIN” screening test for migraine9 based on the following three important predictors of migraine:
- Photophobia
- Impairment/intensity
- Nausea
When two of these three “PIN” predictors are present, the positive predictive value for a diagnosis of migraine is 93%.9
Additional diagnostic clues for a diagnosis of migraine include the presence of comorbid medical conditions with potentially shared pathophysiologic factors, for example asthma10 and a family history of migraine or other primary headache.7
AAN : American Academy of Neurology
OH : Ohio
SNOOP: Systemic signs and disorders; Neurologic symptoms; Onset new or changed & patient > 50 years old; Onset in thunderclap presentation; Papilledema, Pulsatile tinnitus, Positional provocation, Precipitated by exercise
BE-NOTPR-0127; approval date : 2/2022
