Otitis media/interna with or without polyp in cats : Does meningeal enhancement on postcontrast MRI and/or inflammatory CSF change our perspectives?

Otitis media/interna (OMI) is a frequent aetiology in cats with
peripheral vestibular syndrome (PVS) with or without a polyp.
Magnetic resonance imaging (MRI) in combination with cerebrospinal
fluid (CSF) examination is perceived as the gold standard
diagnostic approach. They provide information about meningeal
enhancement (MgE) and CSF abnormalities, which suggest concurrent
meningitis. However, the relationship between MgE and
abnormal CSF in cats with OMI has not yet been investigated.
Study's objectives were to establish the association between MgE
and CSF findings, their individual correlation with bacteriology
results from affected ear samples, and with clinicians' therapeutic
choice in cats with OMI. MRI and CSF analyses of 58 cats with
PVS diagnosed with OMI were retrospectively evaluated. MgE
was reported in 26/58 cases of which 7 had an increased total
ABSTRACT 349
nucleated cell count (TNCC) in CSF; 9/32 cases had abnormal
TNCC without MgE. There was no association between bacteriology
results (external ear canal or bulla) and MgE or abnormal CSF
results. Prednisolone was prescribed in 10/16 cases with
increased TNCC. Among the 42 cases with normal TNCC, 15/42
received prednisolone, and 13/42 received NSAIDs. Various antibiotics
were prescribed in 53/58 cats. When given, treatment
duration was similar regardless of positive bacterial culture (5.58
vs 4.22 weeks), increased TNCC (6.13 vs 4.72 weeks) or MgE
(5.33 vs 4.90 weeks). No association was found between MgE,
CSF or bacteriology findings. In addition, CSF results seem to only
influence the choice of anti-inflammatory drugs but not the antibiotic
therapy length. The latter was not influenced by the bacteriology
results or MgE.