Olfactory dysfunction in patients with idiopathic intracranial hypertension

OBJECTIVE: Although accumulating evidence suggests that a malfunction of the CSF system in idiopathic intracranial hypertension (IIH) may give rise to olfactory dysfunction, little objective knowledge is available at present about the olfactory capacity of patients with this condition.

METHODS: Seventeen patients with IIH and 17 age- and sex-matched controls were included. The extended Sniffin' Sticks procedure was used to test odor threshold, discrimination, and identification (TDI).

RESULTS: Median (interquartile range) values of the composite TDI score (29 [26.5-35.5] vs 35 [34-37], p = 0.003) were reduced in patients with IIH. Furthermore, Spearman correlation revealed reduced TDI values in patients with a recent clinical deterioration of IIH (r = 0.66, p = 0.004).

CONCLUSIONS: Our pilot study provides new evidence that olfaction is impaired in patients with IIH, especially in those who have been newly diagnosed or who have experienced a recent clinical deterioration.