Use of ICHD-3 Increases Specificity When Diagnosing Migraine With Aura and Typical Aura

Researchers determined that new diagnostic criteria in the International Classification of Headache Disorders, 3rd edition (ICHD-3) is significantly more specific than that included in ICHD-3 beta when it comes to diagnosing migraine with aura and with typical aura, according to a study published in The Journal of Headache and Pain.

In emergency departments (EDs), it can be difficult for physicians to distinguish between a migraine with aura and a transient ischemic attack (TIA), a brief stroke. Misdiagnoses can lead to adverse patient outcomes, like an unnecessary expensive diagnostic work-up or prescriptions for antiplatelet and lipid-lowering therapy. In addition, mistaking a TIA for a migraine could result in an avoidable stroke.

“The ICHD-3 is a highly useful tool for the clinical neurologist in order to distinguish between a migraine with aura and a TIA, already at the first point of patient contact, such as in the emergency department or a TIA clinic,” the researchers said.

To determine this, data were collected from 128 patients suspected of suffering TIA who visited the ED of the University Hospital of Lübeck, Germany, between August 2016 and January 2017.

Interviews were conducted by a member of the study team either while the patient was still in the ED or within 8 hours of presentation. Questions focused on the ICHD-3 and ICHD-3 beta diagnostic criteria of migraine with aura and migraine with typical aura “in order to determine and compare the specificity of the old and new classification system.”

The researchers determined specificity by calculating the number of true negatives relative to the total number of subjects actually being negative for the specific analysis. The “diagnostic gold standard” used in the study was the opinion of a senior neurologist at a German tertiary hospital, who was blinded to the interview results.

“Patients with symptoms of a TIA as well as a migraine, however, often initially present to doctors less experienced in the treatment of neurological disorders, such as their general practitioner or an ophthalmologist in case of visual symptoms. Here, even more than for the tertiary sector, a clinically oriented classification system is important to guide further diagnostic and therapeutic work-up,” the researchers said.

Patients’ symptom duration lasted a median of 47.5 minutes, and the symptom duration of patients ultimately discharged with TIA lasted a median of 30 minutes. Of the 128 patients included in the study, 78 were classified as having suffered a TIA; 31, an ischemic cerebral infarction; 4, migraine with aura; 3, an epilepsy; 2, a somatoform disorder; and 1 each, abducens nerve palsy, syncope, benign paroxysmal positional vertigo, Ménière’s disease, Parkinson’s disease, inflammatory CNS disease, transient global amnesia, cancer of unknown primary origin syndrome, keratitis, and hypertensive encephalopathy.

Weighing the diagnosis of a single migraine attack, or probable migraine with aura when only 1 attack occurred, the researchers found, “The ICHD-3 beta results in a false-positive rate of 53.2% of our TIA patients (specificity of only 41%), while the ICHD-3 has a lower false-positive rate of only 24.2% (79% specificity). The specificity of the ICHD-3 for a single attack of migraine with aura was significantly greater than that of the ICHD-3 beta (P <.001).”

The results showed a similar trend when analyzing diagnostic criteria of a single attack of migraine with typical aura. In this cohort, the ICHD-3 beta had a false-positive rate of 16.9% (specificity of 72%), and the ICHD-3 had a rate of 10.5% (specificity of 86%). “The specificity of the ICHD-3 for single attack migraine with typical aura is thus significantly greater than that of the ICHD-3 beta (P =&thinsp;.002),” the authors said.

In a subgroup analysis, they found that patients with migraine were significantly younger than patients with a TIA (P = .0042).

“If the patient presents with a first episode, it becomes even more challenging to decide whether this is a migraine attack or a TIA (a previous similar episode makes the diagnosis of a migraine far more likely). Hence it is these patients, where a precise (ie, specific) diagnostic classification system is most important in clinical practice,” the researchers said.

Reference:

Göbel CH, Karstedt SC, Münte TF, et al. ICHD-3 is significantly more specific than ICHD-3 beta for diagnosis of migraine with aura and with typical aura. J Headache Pain. 2020;21(1):2. doi: 10.1186/s10194-019-1072-2.