As promised, here are two papers relevant to this morning’s discussion of transient monocular visual loss in patients with no evident cerebrovascular disease.
C. Miller Fisher first described the phenomenon that he termed late-life migraine accompaniment in 1980. Six years later, he published a follow-up paper, which is worth reading. With respect to transient monocular visual loss, he wrote:
Cases of benign transient monocular blindness occurring in the absence of detectable cerebrovascular disease, although widely accepted as “migrainous” are not included in the present series. This is not to diminish their potential importance as a migrainous phenomenon. Unaccompanied visual symptoms were at one time regarded as evidence of basilar artery ischemia but it continues to be our experience that this is rarely so and late-life migraine is a much more common cause.
Another good paper, looking specifically at visual phenomena, is this one by Christine Wijman, et al. They looked at data from the Framingham cohort. Among 2110 cohort members who fit their inclusion criteria, 186 had a first-ever spontaneous visual defect (8.8%). Of these 186, 19 (10%) were classified as “transient monocular blindness”, which they lumped with stroke and TIA. 26 (14%) were classified as “migrainous visual symptoms”. Overall, 1.23% of the cohort had migrainous visual symptoms.
Almost all of the visual events described had some positive features and only 1 had exclusively negative symptoms. However, they don’t address in this paper the possibility that some of their “transient monocular blindness” cases may have been migraines as well. As Fisher stated in the papers above, he didn’t even include them in his series not because they were clearly vascular in nature but because he felt them to be clearly migrainous (and thus non-controversial and not worthy of detailed study).