Prolonged migraine aura: new insights from a prospective diary-aided study

DOI: https://doi.org/10.1186/s10194- 018- 0910- y

Abstract-Summary There is limited literature on prolonged aura (PA—defined as an aura including at least one symptom for > 1 h and < 7 days), and there are no prospective studies.

Two hundred and twenty-four patients suffering from migraine with aura were

recruited from the Headache Centers of Pavia and Trondheim.

Patients prospectively described, on an ad hoc diary, each aura symptom (AS),

the duration of AS and headache, and headache features.

Seventy-two patients recorded three consecutive auras in their diaries. We obtained similar results when we compared auras with at least one symptom with a duration of > 2 h (n  =  23) or > 4 h (n  =  14) with the others (n  =  193 and n = 202 respectively).

They do not differ from the other auras (even when their duration extends to 2

and/or 4 h) with the exception of a higher number of non-VS.

Extended: Our findings indicate the need to reconsider the use of the term “pro- longed aura” and the duration of aura symptoms that should be classed as a typical or prolonged auras.

Introduction All of the first three editions of the International Classification of Headache Disorders [16, 17, 156] (ICHD) have considered the individual symptoms of aura to be typical if the duration is more than five and less than 60 min.

The first version of the ICHD included migraine with prolonged aura (PA) and defined it as migraine with one or more aura symptoms lasting more than 60 min and less than a week, occurring in the presence of normal neuroimaging find- ings [156].

A prolonged non-hemiplegic migraine with aura (NHMA) is classified as ‘per-

sistent aura without infarction’ if the duration is equal or longer than 7 days.

The term “probable” used in such classification indicates suspicion as to whether the symptom is migraine aura and from our clinical experience we feel it does not help to categorise auras of a longer duration.

Methods Inclusion criteria were: patients suffering from migraine with aura for at least 1 year which met the ICHD-2 criteria for 1.2.1 [G43.10] typical aura with migraine head- ache,1.2.2 [G43.10], typical aura with non-migraine headache, 1.2.3 [G43.104] typical aura without headache, excluding point 3 of C criteria (“each individual aura symptom lasts 5-60 mins”) and where only one of point C1 or C2 had to be verified to fulfill C criteria; (2) age between 16 and 65 years.

3.2 Medical history

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The diary allowed the patients to—describe each visual (VS), sensory (SS) and dysphasic (DS) aura symptom in their own words, highlight the main characteristics of their migraine and record the duration of the aura symptoms and headache.

Follow up visits were arranged with a neurologist for patients who had com- pleted three recordings and the content of their diaries was discussed, specifically to verify if the described symptoms (2) were typical of previous auras experienced by the patient ii) were not premonitory symptoms (i.e. photophobia, difficulty with concentration/speech).

Findings When comparing PAs with the other auras (n = 178) we found PAs were character- ized by a higher total number of symptoms (p < 0.001), a higher frequency of SSs (p < 0.001) and a higher frequency of DSs (p < 0.001).

The only differences found was a higher frequency of SSs and a higher number

of aura symptoms in PA > 2 (p = 0.001 and p = 0.005, respectively).

In the second comparison auras with a minimum of one symptom lasting for >

4 h (PA > 4, n = 14) were compared with the others (n = 202).

The only difference was a higher number of aura symptoms in PA > 4 (p = 0.043).

Discussion Our findings show that phenotypically PAs are similar to non-PAs and are fairly common with 17% of all auras being PA and with 26% of patients experiencing at least one.

This can be expected if we consider the pathophysiology of auras and recognize that aura symptoms with a longer duration are likely to be related to a cortical spreading depression (CSD) proceeding across a longer path on the respective brain area.

The similarity in phenotypes of PAs and the other auras continues to be signifi- cant when the maximum duration is increased to 2 and/or 4 h. A key limitation of this research is that the study population was recruited from tertiary headache cen- ters and therefore it can be argued that the population is not representative as they are likely to be more difficult cases.

From a purely statistical point of view, it would be correct to raise the time limit

of aura symptoms up to 4 h to be considered a PA.

Conclusions Prolonged auras are quite common, being 17% of all auras, occurring at least once in 26% of patients.

Our findings indicate the need to reconsider the use of the term “prolonged aura” and the duration of aura symptoms that should be classed as a typical or pro- longed auras.

Acknowledgement A machine generated summary based on the work of Viana, Michele; Sances, Grazia; Linde, Mattias; Nappi, Giuseppe; Khaliq, Farihah; Goadsby, Peter J.; Tassorelli, Cristina. 2018 in The Journal of Headache and Pain

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3 Diagnosis

Headache Gauge: a real-life calendar-based tool for headache monitoring