Computed Tomography of the Hyoid Apparatus in Equine Headshaking Syndrome.
Abstract: Headshaking is a common condition in horses, most cases are presumed idiopathic/trigeminal-nerve mediated. Diagnostic work-up of a headshaking horse may involve computed tomography (CT) of the head to exclude causative structural pathology. The relevance of the presence and severity of hyoid apparatus findings at CT to headshaking is unknown. A retrospective analysis of CT changes in the hyoid apparatus in horses was carried out. Comparisons were performed between horses with signs of headshaking and a control population and a subgroup of horses with signs of headshaking and no other 'likely relevant findings' to headshaking and the control population. The grade of temporohyoid joint sheath ossification, mineralisation of the tympanohyoid cartilage, and widening and narrowing of the temporohyoid joint all showed significant correlation with age. Findings of the remaining hyoid apparatus (fracture, deformation, or arthropathy) showed significant correlation with temporohyoid joint grade. Centres of ossification of the epihyoid, thyrohyoid, and lingual processes were described. No consistent association of headshaking to hyoid changes was found. Odds ratios were increased in many cases, particularly in comparisons of the subgroup with no 'likely relevant findings'; however, statistical significance was not reached. CT findings of the temporohyoid joint are not consistently associated with clinical signs of headshaking.
Publication Date: 2025-05-23 PubMed ID: 40559747PubMed Central: PMC12197519DOI: 10.3390/vetsci12060511Google Scholar: Lookup
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- Journal Article
Summary
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The study explores the association between headshaking in horses and deformities in the hyoid apparatus, a bony structure in their neck. The research found no clear link between these two parameters.
Significance of the Study
- The research offers valuable insights into the condition of headshaking in horses, a common issue whose cause is typically unknown and assumed to be linked to the trigeminal nerve.
- The study investigates potential structural pathologies, specifically pertaining to the hyoid apparatus in horses, which could potentially contribute to this headshaking condition.
- The hyoid apparatus is a key area of study, given its significance in physical functioning, and any changes or abnormalities here could have far-reaching impacts on the animal’s health.
Methods of the Study
- Researchers used computed tomography (CT) scans of horses that were headshaking, as well as a control group of horses, to gain a visual understanding of the structure and changes in the hyoid apparatus.
- These scans were reviewed retrospectively, comparing horses with symptoms of headshaking against a control group.
Findings of the Study
- A significant correlation was revealed between the age of the horse and changes like the grade of temporohyoid joint sheath ossification (calcification), mineralisation of the tympanohyoid cartilage, and widening or narrowing of the temporohyoid joint.
- Other conditions such as fractures, arthropathy or deformation showed a significant correlation with the grade of temporohyoid joint.
- The results didn’t show a clear or consistent connection between CT findings of the temporohyoid joint and clinical signs of headshaking in horses.
Conclusions of the Study
- While the study described components of the hyoid apparatus like the epihyoid, thyrohyoid, and lingual processes, it concluded that these structures and any changes to them did not necessarily correlate with headshaking.
- In many cases, the odds ratios were elevated, particularly when comparing the subgroup of horses with the headshaking condition and without any ‘likely relevant findings’; however, statistical significance was not reached in these comparisons.
Cite This Article
APA
Lloyd-Edwards RA, Mulders E, Sloet van Oldruitenborgh-Oosterbaan MM, Veraa S.
(2025).
Computed Tomography of the Hyoid Apparatus in Equine Headshaking Syndrome.
Vet Sci, 12(6), 511.
https://doi.org/10.3390/vetsci12060511 Publication
Researcher Affiliations
- Diagnostic Imaging, Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands.
- VET.CT, Broers Building, 21 JJ Thomson Avenue, Cambridge CB3 0FA, UK.
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands.
- Internal Medicine, Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands.
- Eikenlust Equine Consultancy, Kees Boekelaan 8, 3723 BA Bilthoven, The Netherlands.
- Diagnostic Imaging, Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands.
Conflict of Interest Statement
The authors declare no conflicts of interest.
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