Idiopathic facial neuropathy in cats: clinical presentation, magnetic resonance imaging findings, and outcome.

Abstract

Background: Idiopathic facial neuropathy (IFN) is commonly described in dogs, but information in cats is lacking.

Hypothesis/objectives: Describe clinical presentation, magnetic resonance imaging (MRI) findings and outcome in cats diagnosed with IFN.

Animals: Thirteen cats with presumptive diagnosis of IFN.

Methods: Multicenter retrospective descriptive study with questionnaire-based follow-up. Magnetic resonance imaging was assessed by a single author blinded to clinical signs.

Results: Median age was 30 months (range, 6-142). Median time of onset to presentation was 6 days (range, 1-150). Facial paresis or paralysis was unilateral in 10 cases and bilateral in 3 (16 sides affected). Clinical signs included absent (11/16) or decreased (2/16) palpebral reflex; lip ptosis (5/16); absent or decreased ear movements (3/6 reported). Eight cats had vestibular signs, including head tilt (6/13), vestibular ataxia (6/13), head swaying (2/13), and horizontal nystagmus (3/13). Findings on MRI included thickened (4/16), or contrast-enhancing (7/16) facial nerve or both and smaller caudal belly of the digastricus muscle (9/16). Cerebrospinal fluid (CSF) was normal in 10 of 11 cats. Treatments included eye lubrication (11/13) and anti-inflammatory doses of prednisolone (3/13). Follow-up was available for 9 of 13 cats (median, 13 months; range, 2-91). Median time to maximal recovery was 20 weeks (range, 2-24). Recovery of spontaneous blinking was complete in 7 out of 12 eyes, partial in 2 out of 12 and absent in 3 out of 12. Three cats had persistent abnormalities of the lips, face, ears or some combination of these. All vestibular signs resolved but one cat was euthanized because of relapse.

Conclusion and clinical importance: Idiopathic facial neuropathy appears to affect mostly young cats, often unilaterally and frequently with vestibular signs. Spontaneous improvement is likely, but persistent neurologic deficits are possible.