A mágneses rezonanciás képalkotás (MRI) diagnosztikai és differenciál diagnosztikai szerepe epilepsziás kutyák kivizsgálásában

Abstract

SUMMARY Background: Epilepsy is one of the most common neurologic disorders in dogs, presenting a prevalence up to 5,7 % in the canine population. The most impor tant factor in prognosis and therapy is the differentiation of primary, cryptogenic and secondary epilepsy, which is possible with magnetic resonance imaging (MRI) in most of the cases. Objectives: The aim of the present study was to determine the prevalence of primary and secondary epilepsy in dogs, and to find out the underlying causes of secondary epilepsy based on MRI findings. Furthermore, to evaluate the differ ences in lateral ventricle asymmetry and ventricular enlargement between the epileptic dogs and a control group of dogs. Materials and Methods: MRI of 83 epileptic dogs (31 females and 52 males; aged between 0.3–14 years, weighing between 1.8–72 kg) and 31 control dogs (7 females and 24 males; aged between 1–14 years, weighing between 3–42 kg) was performed with a 1.5T MR scanner. The imaging protocol included the fol lowing sequences: T2w in transversal, sagittal and paradorsal planes, FLAIR in transversal plane, thin sliced T1w 3D in sagittal plane followed by transversal and paradorsal reconstructions, and ToF angiography in transversal plane. Intrave nous contrast medium was applied in cases with structural lesions. Results and Discussion: Sixty three dogs (76%) showed no abnormalities in the MRI, and were classified as primary epilepsy. Twenty dogs (24%) showed structural brain lesions. In those cases the final MR diagnosis was intracranial neoplasia (n = 10), encephalitis and Chiari malformation (n = 4), porencephaly and hydrocephalus (n = 1). Asymmetry of the lateral ventricles was present in 11% in the primary epileptic group, 40% in the secondary epileptic group and 25% in the control group. Ventriculomegaly was mildly overrepresented in the epileptic group and showed a high prevalence in brachycephalic dogs independently from clinical subgroup. According to our findings lateral ventricle asymmetry and ven triculomegaly are most likely not epileptogenic phenomena.