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The medical records of 29 dogs unable to close their mouths due to flaccid paralysis or paresis of the muscles innervated by the mandibular branch of the trigeminal nerve, were reviewed. Idiopathic trigeminal neuropathy was diagnosed in 26 dogs based on complete resolution of clinical signs and lack of any long-term neurological disease. Of these dogs, golden retrievers were over-- represented. No age, sex, or seasonal predispositions were identified. Trigeminal sensory innervation deficits were observed in 35% (9/26), facial nerve deficits were observed in 8% (2/26), and Horner's syndrome was observed in 8% (2/26) of dogs. Electromyographic examination of the muscles of mastication revealed abnormalities in seven of nine dogs. Results of cerebrospinal fluid analysis were abnormal in seven of eight dogs. Corticosteroid therapy did not affect the clinical course of the disease. Mean time to recovery was 22 days. Lymphosarcoma, Neospora caninum infection, and severe polyneuritis of unknown origin were diagnosed in three of 29 dogs at necropsy. J Am Anim Hosp Assoc 2002;38:262-270.
Key
C
Case Report--describes one or more cases that may be unusual or contribute new ideas to the literature.
O
Original Article-describes a prospective study involving original research or multiple cases. The idea for the study was established prior to the research or seeing the cases.
RS
Retrospective Study-summarizes the data from evaluation of case records and brings out significant information. The idea for the study was established after the cases were seen.
R
Review Article-reviews the literature and summarizes current thoughts and ideas on a specific topic.
RS
Introduction
The trigeminal nerve is the largest cranial nerve in dogs and humans and contains both motor and sensory fibers. The cell bodies of the motor neurons are located in the trigeminal motor nucleus in the pons. The sensory cell bodies of the general somatic afferent fibers are located in the trigeminal ganglion within the trigeminal canal. As the nerve emerges from the trigeminal canal, it divides into three branches. The mandibular branch contains both motor and sensory fibers. The motor fibers innervate the masseter and temporalis muscles that close the mouth. The sensory fibers of the mandibular branch innervate the buccal cavity, tongue, teeth of the lower jaw and skin of the mandible, caudal buccal region, and craniolateral...