Clinical features associated with ictal osmophobia in migraine

Olfactory hypersensitivity may occur during migraine attacks and has been found to be very specific for this form of headache. Aim of this study was to investigate if migraineurs with ictal osmophobia have particular clinical features comparing to patients without ictal osmophobia. We recruited 200 consecutive migraineurs. Other primary headaches comorbidity and migraine prophylaxis were exclusion criteria. Each patient was interviewed following a structured questionnaire including general features about migraine, depression and anxiety symptoms. Migraine triggers both spontaneously and selecting from a specific list. Allodynia during the migraine attack was measured using the Allodynia symptoms check-list 12 (ASC-12). Eighty four (42 %) patients are non-osmophobic vs. 116 patients (58 %) who are osmophobic. After a logistic regression analysis, pain intensity (OR 1.391; p = 0.008) and anxiety (OR 1.099; p = 0.047) were significantly higher while aura (OR 0.421; p = 0.028) is less frequent in osmophobic migraineurs. We found significant differences in clinical features of osmophobic patients in respect to non-osmophobic ones. Ictal osmophobia seems being related to a broader sensorial hypersensitivity that could lead to a more florid clinical presentation.