Make the Diagnosis: Does This Patient With Headaches Have a Migraine or Need Neuroimaging?
Headaches are ubiquitous with a lifetime prevalence of >94%.1 When a patient has headaches frequently, and the headaches are unrelated to underlying conditions, he or she has a primary headache disorder. Neuroimaging for primary headache disorders (tension, migraine, or cluster) rarely reveals important intracranial pathology. Thus, the physicians must identify patients at risk for serious disorders to avoid unnecessary studies.
Who Should Be Assessed for Migraine?
All headaches create the perception of pain through nociceptive stimulation of the trigeminal nerve, so differentiating the primary headache disorders is difficult. The population prevalence for tension-type headaches is 38%, migraine 6%-17%, and cluster headache 0.4%.2 Some experts consider migraine and frequent tension-type headaches to coexist or overlap in many patients.
Assessing the Likelihood of Migraine Headache
The presence of photophobia with the headache (likelihood ratio [LR], 5.8; 95% confidence interval [CI], 5.1-6.6) or phonophobia (LR, 5.2; 95% CI, 4.5-5.9) does not provide more information than the easily remembered POUNDing mnemonic (Table 68-1).
Table 68-1POUNDing Mnemonic for Diagnosing Migraine Headachesa |Favorite Table|Download (.pdf) Table 68-1 POUNDing Mnemonic for Diagnosing Migraine Headachesa
|POUNDing Mnemonic Questions ||Diagnosis ||Number of Positive Responses ||LR (95% CI) |
1. Is it a Pulsating headache?
2. Does it last between 4-72 hOurs without medication?
3. Is it ever Unilateral?
4. Is there Nausea?
5. Is it Disabling?
|Definite or possible migraine || |
| ||Definite migraine || |
Among Patients With Headaches, Who Should Have Neuroimaging?
Significant intracranial neuroimaging abnormalities appear in only 1.2% (95% CI, 0.77%-1.8%) of patients with headaches significant enough that they undergo evaluation in specialty headache clinics.4 In the general population, including those presenting to a primary care clinician, the prevalence should be much lower.
Patients with the sudden onset of an extremely severe headache (so severe that they immediately seek medical attention) have a “thunderclap headache.” These patients are quite different from those with primary headache disorders in that they have a high risk for a subarachnoid hemorrhage (prevalence 43%; 95% CI, 20%-68%).
Assessing the Likelihood of a Significant Neuroimaging Intracranial Abnormality
Table 68-2Findings for Identifying Patients With Significant Neuroimaging Intracranial Abnormalities |Favorite Table|Download (.pdf) Table 68-2 Findings for Identifying Patients With Significant Neuroimaging Intracranial Abnormalities
| ||LR+ (95% CI) ||LR- (95% CI) |
|Cluster-type headache ||11 (2.2-52) ||0.95 (0.84-1.1) |
|Abnormal findings on neurological examination ||5.3 ...|