Reduced olfactory bulb volume in post-traumatic and post-infectious olfactory dysfunction

Neuroreport. 2005 Apr 4;16(5):475-8. doi: 10.1097/00001756-200504040-00011.


The olfactory bulb is a highly plastic structure the volume of which partly reflects the degree of afferent neural activity. In this study, 22 patients with post-infectious olfactory deficit, nine participants with post-traumatic olfactory deficit, and 17 healthy controls underwent magnetic resonance volumetry of the olfactory bulb. Patients presented with significantly smaller olfactory bulb volumes than controls; significant correlations between olfactory function and bulb volume were observed. Patients with parosmia exhibited smaller olfactory bulb volumes than those without parosmia. Findings indicate that smell deficits leading to a reduced sensory input to the olfactory bulb result in structural changes at the level of the bulb. Reduced olfactory bulb volumes may also be considered to be characteristic of parosmia.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Analysis of Variance
  • Case-Control Studies
  • Female
  • Functional Laterality / physiology
  • Humans
  • Image Processing, Computer-Assisted / methods
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Olfaction Disorders / classification
  • Olfaction Disorders / pathology*
  • Olfactory Bulb / pathology*
  • Severity of Illness Index