Cribriform Plate Foramina Count in Patients With Acquired and Congenital Anosmia.

Background: Cribriform foramina provide the openings for olfactory nerve fibers to cross from the nasal cavity to the olfactory bulb. Disruption of the olfactory nerve fibers is known to affect olfactory function, but little is known about the potential effects on the number of cribriform foramina in congenital anosmia.

Objective: This pilot study aimed to investigate whether there was a reduction in foramina in patients with acquired and congenital anosmia (including both Kallmann syndrome and isolated congenital anosmia) compared to controls with normal olfactory function.

Methods: Paranasal CT image stacks were analyzed from 20 patients with congenital anosmia (n = 6), acquired anosmia (n = 6), or normal olfactory function (n = 8). Cribriform foramina were counted by three observers from the slice revealing the crista galli and the ethmoidal slits. The two closest values for each subject were analyzed in comparison across the three groups using one-way analysis of variance.

Results: Patients with congenital, but not acquired, anosmia had significantly fewer cribriform foramina (x̄ ± SE = 10.17 ± 1.23) compared to healthy, normosmic controls (x̄ ± SE = 19.88 ± 2.01). There was no significant difference in foramina count between congenital and acquired anosmics (x̄ ± SE = 15.83 ± 3.47).

Conclusion: In this pilot study, a reduced number of cribriform foramina was found in individuals with congenital anosmia. Examination of cribriform foramina could be helpful in counseling patients with olfactory loss. Further investigation in larger studies with additional cohorts is warranted.