RESUMO
Optic neuritis (ON) is a recognized condition, yet factors influencing recovery of vision are currently unknown. The purpose of this study was to identify prognostic factors for recovery of vision in canine ON of unknown etiology. Clinical databases of three referral hospitals were searched for dogs with presumptive ON based on clinicopathologic, MRI/CT, and fundoscopic findings. Twenty-six dogs diagnosed with presumptive ON of unknown etiology, isolated (I-ON) and MUE-associated (MUE-ON), were included in the study. Their medical records were reviewed retrospectively, and the association of complete recovery of vision with signalment, clinicopathologic findings, and treatment was investigated. Datasets were tested for normality using the D'Agostino and Shapiro-Wilk tests. Individual datasets were compared using the Chi-squared test, Fisher's exact test, and the Mann-Whitney U-test. For multiple comparisons with parametric datasets, the one-way analysis of variance (ANOVA) was performed, and for non-parametric datasets, the Kruskal-Wallis test was performed to test for independence. For all data, averages are expressed as median with interquartile range and significance set at p < 0.05. Twenty-six dogs met the inclusion criteria. Median follow-up was 230 days (range 21-1901 days, mean 496 days). Six dogs (23%) achieved complete recovery and 20 dogs (77%) incomplete or no recovery of vision. The presence of a reactive pupillary light reflex (p = 0.013), the absence of fundoscopic lesions (p = 0.0006), a younger age (p = 0.038), and a lower cerebrospinal fluid (CSF) total nucleated cell count (TNCC) (p = 0.022) were statistically associated with complete recovery of vision. Dogs with I-ON were significantly younger (p = 0.046) and had lower CSF TNCC (p = 0.030) compared to the MUE-ON group. This study identified prognostic factors that may influence complete recovery of vision in dogs with ON. A larger cohort of dogs is required to determine whether these findings are robust and whether additional parameters aid accurate prognosis for recovery of vision in canine ON.
RESUMO
CASE SUMMARY: A 12-year-old domestic shorthair cat was presented with acute non-painful hindlimb proprioceptive ataxia localising to T3-L3 spinal cord segments. MRI revealed paravertebral muscular hyperintensity on T2-weighted images at the level of T7-T8 vertebrae. The cat improved on conservative management but deteriorated 3 months later. Repeated MRI showed meningeal enhancement at the same level and hyperintensity of the paravertebral musculature extending to the right thoracic wall and pleural space on short tau inversion recovery images. Thoracic CT showed mineralised lesions of the right lung, restricted pleural effusion and expansile bone lesions affecting multiple ribs. The cat had been treated for pyothorax 5 years earlier but manifested no current respiratory signs. Cerebrospinal fluid (CSF) examination showed lymphocytic pleocytosis but no neoplastic cells. Biopsy of the affected muscles and cytology of the lung and pleural lesions suggested a malignant epithelial cell tumour. Post-mortem examination confirmed a pulmonary adenocarcinoma locally infiltrating the thoracic wall, T7-T8 vertebrae and the spinal cord white matter. Meningeal carcinomatosis was detected with neoplastic cells invading the ventral median fissure of the spinal cord. No metastases were observed in other organs, indicating that neoplastic cells reached the spinal cord by direct extension. RELEVANCE AND NOVEL INFORMATION: Spinal meningeal carcinomatosis has not been reported in dogs or cats with extraneural tumours but is a well-recognised condition in humans. A metastatic cause of meningeal enhancement should be considered in patients with neurological signs of unknown origin. Imaging findings and CSF results can be non-specific.
