"Anosmia" is a condition characterized by a complete or partial lack of smell. While it is most associated with the elderly, significant head and neck trauma can cause a tearing of the nerves in the nose responsible for smell and result in anosmia.
Earlier this year, a case study was published in the Annals of Vertebral Subluxation Research described a 53-year-old woman who came to a chiropractor seeking help with her high blood pressure. They found that she had also lost her sense of smell after an auto accident 9 years earlier. After taking x-rays, the doctors saw that she had an irregular "S-shape" in the curve of her neck (versus a normal "C shape") which is typical of a whiplash injury.
After 5 months of chiropractic care focused on correcting vertebral subluxation, or misalignments of the spine that cause tension and interference on the nervous system, and restoring proper structure and motion to the spine, the woman saw improvements in the curve of her neck and reported that she could smell again!
Carney, C. L., DC, MacCarthy, M., DC, & Girdis, C., DC. (2017). Resolution of Post-Traumatic Anosmia Following Network Spinal Analysis Care: A Case Study. A. Vertebral Subluxation Res., 2017(1), 8-14.