Congenitally anosmic patients do have fewer olfactory foramina
Reviewed by Joanna Stephens

It has been previously established that patients with Kallman’s syndrome (very much associated with anosmia) have a similar number of cribriform plate foramina when compared to controls. As non-invasive CT assessment of the cribriform plate is now possible in cadavers, the authors sought to assess the brains of patients with congenital or acquired anosmia and compare them to healthy controls in the cadaveric state. The authors found that those patients with congenital anosmia had significantly less foramina in the cribriform plate than the normal controls. In the study, of the six patients with congenital anosmia, only two were diagnosed with Kallman’s syndrome and the remaining four patients had isolated congenital anosmia; this potentially accounts for the fewer foramina identified, in contrast to previous studies. Whilst the numbers were small and therefore not statistically significant, differences were found in the number of foramina between healthy controls and acquired anosmia. The authors hypothesise that either patients with acquired anosmia are equipped with fewer olfactory nerves and, hence, are more susceptible to olfactory loss; or perhaps acquired olfactory loss is due to atrophy of olfactory fibres followed by a decrease in olfactory nerves, resulting in bony appositions to the cribriform plate and, therefore, fewer foramina. Both are interesting ideas. 

Cribriform plate foramina count in patients with acquired and congenital anosmia.
Juratli JH, High B, Hummel T, et al.
AM J RHINOL ALLERGY
2025;39(1):58–62.