Role of Diffusion Tensor Imaging in the Diagnosis and Management of Post-Traumatic Anosmia

Brain Inj. 2017;31(13-14):1964-1968. doi: 10.1080/02699052.2017.1346293. Epub 2017 Aug 17.

Abstract

Introduction: Anosmia is a possible complication of Traumatic Brain Injury (TBI). Psychometric and electrophysiological methods of olfaction measure and Magnetic Resonance Imaging (MRI) are the tools to evaluate the post-traumatic olfactory loss. Diffusion Tensor Imaging (DTI) provides useful data for a better understanding of etiopathogenesis TBI-related anosmia, in particular the loss of neural connections and their eventual recovery over time.

Materials and methods: This study describes a case of TBI-related anosmia. The olfactory function was evaluated by Sniffin' Sticks Test (SST), Olfactory Event-Related Potentials (OERPs), MRI and DTI at baseline (T0) and after one year (T1).

Results: At baseline, SST highlighted a functional anosmia. The OERPs showed the presence of a small N1-P2 complex. MRI confirmed the presence of a scarring involved in the right orbitofrontal cortex (OFC). DTI detected a reduction in the average length and the number of neuronal fibre pathways of right OFC. At T1, a recovery of olfactory function was confirmed by SST and OERPs.

Conclusion: While MRI images are unchanged from T0, DTI showed an increase in average length and number of fibre tracts in the right OFC. DTI could be a valid tool to display a post-traumatic loss of neural connections and to better understand TBI-recovery mechanisms.

Keywords: Diffusion tensor imaging; magnetic resonance imaging; olfactory event-related potentials; sniffin sticks test; traumatic brain injury.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Brain / diagnostic imaging
  • Brain Injuries, Traumatic / complications*
  • Diffusion Tensor Imaging*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Nerve Fibers, Myelinated / pathology
  • Olfaction Disorders* / diagnostic imaging
  • Olfaction Disorders* / etiology
  • Olfaction Disorders* / therapy
  • Psychometrics