Neurite idiopática do nervo trigêmeo em um cão / Idiopathic neuritis of the trigeminal nerve in a dog

ABSTRACT

Background: Idiopathic trigeminal neuropathy is a peripheral neuropathy whose clinical signs include inability to close themouth. A neurological examination reveals mainly flaccid paralysis of the masticatory muscles, which may be accompaniedby atony/hypotonia of the masseter and temporalis muscles. Altered sensitivity may also be present in very rare cases.This article reports a case of idiopathic trigeminal neuropathy with involvement of the motor and sensory nerve fibers in adog, describing the clinical symptoms, neurological findings, exclusion of other diseases, and evolution of the condition.Case A 5-year-old bitch showing signs of difficulty in picking up food, swallowing water, and hypersalivation was takento a veterinary clinic. According to her owner, these signs had started spontaneously 2 days earlier. A physical examinationof the animal revealed only a persistently open mouth, although the mouth opening and closing movements could be performed manually by manipulating the jaw. The patient showed swallowing ability, and her tongue movements were intact.The neurological examination revealed that the animal also presented bilateral absence of nasal sensitivity and absenceof palpebral reflex. The animal’s blood test results showed changes only in the CK and AST levels, which were 1,182.60U/L (reference 1.5 to 28.4 U/L) and 87.1 IU/L (reference 6.2 to 13 IU/L), respectively. The animal tested negative fordistemper, leishmaniasis, toxoplasmosis and neosporosis. Abdominal ultrasound and thoracic radiography were performedto investigate neoplasia, as well as radiography of the temporomandibular joints, and none of these imaging tests revealedany alterations. A cerebrospinal fluid (CSF) analysis was also within the normal range of reference parameters. In view ofthe possibility of idiopathic trigeminal neuropathy, prednisolone...