"Background According to ICHD-II, and as proposed for ICHD-III, non-hemiplegic migraine aura (NHMA) symptoms last between five and 60 minutes whereas hemiplegic migraine aura can be longer. In ICHD-III it is proposed to label aura longer than an hour and less than a week as probable migraine with aura. We tested whether this was appropriate based on the available literature.Methods We performed a systematic literature search identifying articles pertaining to a typical or prolonged duration of NHMA. We also performed a comprehensive literature search in order to identify all population-based studies or case series in which clinical features of NHMA, including but not restricted to aura duration, were reported, in order to gain a complete coverage of the available scientific data on aura duration.Results We did not find any article exclusively focusing on the prevalence of a prolonged aura or more generally on typical NHMA duration. We found 10 articles that investigated NHMA features, including the aura duration. Five articles recorded the proportion of patients in whom whole NHMA lasted for more than one hour, which was the case in 12%–37% of patients. Six articles reported some information on the duration of single NHMA symptoms: visual aura disturbances lasting for more than one hour occurred in 6%–10% of patients, sensory aura in 14%–27% of patients and aphasic aura in 17%–60% of patients.Conclusions The data indicate the duration of NHMA may be longer than one hour in a significant proportion of migraineurs. This seems to be especially true for non-visual aura symptoms. The term probable seems inappropriate in ICHD-III so we propose reinstating the category of prolonged aura for patients with symptoms longer than an hour and less than one week" http://cep.sagepub.com/content/33/7/483.abstract
I have had visual auras, not associated with my persistent migraine auras, last longer than an hour before the migraine started and sometimes into the migraine itself. Sensory such as tingling does not seem to last more than an hour but I have never clocked it, the numbness on the other hand definitely does. The hearing aura, of going in and out, or muffled definitely can last longer. I think we all know the aphasic aura can last longer. It really seems to depend on how the migraine develops. Some migraines are very fast onset and you fly through the initial stages and some are not. I think an hour is just that typical guideline they give.