title: Morphometric magnetic resonance imaging and genetic testing in cerebellar abiotrophy in Arabian horses.
abstract: BACKGROUND
  Cerebellar abiotrophy (CA) is a rare but significant disease in Arabian horses caused by progressive death of the Purkinje cells resulting in cerebellar ataxia characterized by a typical head tremor, jerky head movements and lack of menace response. The specific role of magnetic resonance imaging (MRI) to support clinical diagnosis has been discussed. However, as yet MR imaging has only been described in one equine CA case. The role of MR morphometry in this regard is currently unknown. Due to the hereditary nature of the disease, genetic testing can support the diagnosis of CA. Therefore, the objective of this study was to perform MR morphometric analysis and genetic testing in four CA-affected Arabian horses and one German Riding Pony with purebred Arabian bloodlines in the third generation.
  
  
  RESULTS
  CA was diagnosed pathohistologically in the five affected horses (2 months - 3 years) supported by clinical signs, necropsy, and genetic testing which confirmed the TOE1:g.2171G>A SNP genotype A/A in all CA-affected horses. On MR images morphometric analysis of the relative cerebellar size and relative cerebellar cerebrospinal fluid (CSF) space were compared to control images of 15 unaffected horses. It was demonstrated that in MR morphometric analyses, CA affected horses displayed a relatively smaller cerebellum compared to the entire brain mass than control animals (P = 0.0088). The relative cerebellar CSF space was larger in affected horses (P = 0.0017). Using a cut off value of 11.0% for relative cerebellar CSF space, the parameter differentiated between CA-affected horses and controls with a sensitivity of 100% and a specificity of 93.3%.
  
  
  CONCLUSIONS
  In conclusion, morphometric MRI and genetic analysis could be helpful to support the diagnosis of CA in vivo.
authors.affiliation: Clinic for Horses, University of Veterinary Medicine Hannover, Bünteweg 9, 30559, Hannover, Germany. jessika.cavalleri@tiho-hannover.de
authors.forename: Jessika M V
authors.initials: JM
authors.lastname: Cavalleri
authors.forename: Julia
authors.initials: J
authors.lastname: Metzger
authors.forename: Maren
authors.initials: M
authors.lastname: Hellige
authors.forename: Virginie
authors.initials: V
authors.lastname: Lampe
authors.forename: Kathrin
authors.initials: K
authors.lastname: Stuckenschneider
authors.forename: Andrea
authors.initials: A
authors.lastname: Tipold
authors.forename: Andreas
authors.initials: A
authors.lastname: Beineke
authors.forename: Kathrin
authors.initials: K
authors.lastname: Becker
authors.forename: Ottmar
authors.initials: O
authors.lastname: Distl
authors.forename: Karsten
authors.initials: K
authors.lastname: Feige
mesh_terms: D000818:Animals; D002524:Cerebellar Ataxia / Q000175:diagnosis / Q000235:genetics / Q000473:pathology / Q000662:veterinary; D002526:Cerebellar Diseases / Q000175:diagnosis / Q000235:genetics / Q000473:pathology / Q000662:veterinary*; D002531:Cerebellum / Q000473:pathology; D005260:Female; D005820:Genetic Testing / Q000662:veterinary; D005838:Genotype; D006734:Horse Diseases / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D006736:Horses / Q000235:genetics; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D059906:Neuroimaging / Q000662:veterinary; D020641:Polymorphism, Single Nucleotide / Q000235:genetics