Duration of migraine aura

We have read with great interest the review article by PJ Goadsby and colleagues on typical duration of migraine aura: A systemic review (1), in which they identified that the duration of non-hemiplegic migraine aura (NHMA) lasts for over an hour in a significant proportion of patients. The clinical implication of their work proposes that the term ‘prolonged’ rather than ‘probable’ migraine with aura (MA) should be re-established in International Classification of Headache Disorders, third edition (ICHD-III), as it is both clinically and diagnostically more accurate. Their review prompted an assessment of the incidence of prolonged non-hemiplegic migraine aura (PNHMA) among patients referred with headaches to the outpatient headache clinic at our local hospital.

We examined the incidence of PNHMA among 276 paediatric patients (160 female, with mean age of 11.8 years) who had been diagnosed with MA according to ICHD II classification. The incidence of PNHMA (defined as aura lasting for more than one hour), was investigated prospectively from headache diary entries and headache clinic sessions over a mean follow-up period of 11.3 months.

PNHMA was identified in 12/276 (4.4%) patients. Of these, 10 patients were female, 11 white Caucasian, and one patient was Pakistani, and their ages ranged from 4.9 to 18.1 years (mean 12.3 years). Migraine was chronic (n = 6) and episodic (n = 6). The duration of headache history ranged from six months to seven years (mean = 1.6 years). There was no history of seizure, head injury or central nervous system infection. All patients had a magnetic resonance imaging scan (MRI) which had been reported as normal.

Five of 12 (41.7%) experienced PNHMA in some of their migraine attacks, and the remaining seven of 12 patients experienced PNHMA in most or all attacks. Migraine aura included sensory aura (n = 6), vision (n = 4) and both sensory and visual aura (n = 2). Duration of sensory aura lasted for >1–2 hours (n = 1), >2–4 hours (n = 2), >4–6 hours (n = 1), two days (n = 1), and 10 days (n = 1). Visual aura lasted for three to four hours (n = 3) and one day (n = 1). The remaining two patients experienced both a sensory aura lasting four and six hours, respectively, and visual aura lasting two and three hours, respectively.

Our findings on typical duration of migraine aura among children with migraine reflect those reported in literature (2–4), as 4.4% of our patients known to have MA had aura symptoms lasting over an hour. Sensory aura is the most frequently reported prolonged aura subtype, occurring in 67% of patients, with a duration of ≥6 hours in four of eight patients (57%). Prolonged visual aura occurred in 30% patients with symptoms lasting most commonly for three hours in three of four patients (75%).

We agree that the term probable MA in ICHD-II classification does not adequately categorise the prolonged aura phenotype, and have identified 4.4% of our local population who suffer with symptoms that are not suitably recognised in current taxonomy. Re-establishing migraine with prolonged aura in ICHD-III categorisation will help diagnosis for the clinician and patient, and allow for more structured sub-classification as the research into PNHMA evolves.