Usefulness of neurological assessment scales in prognosis of meningoencephalitis of unknown origin in Yorkshire Terriers.

backgroundAttempts to determine the prognostic factors that affect the survival time of canine patients with meningoencephalitis of unknown origin (MUO) have produced highly variable results. Scaled complex ratings to predict general outcomes are required. Scaled rating was recently proven to help predicting prognosis in general MUO population of dogs. However, Yorkshire Terriers (YST) are predisposed to necrotizing meningoencephalitis, especially necrotizing leukoencephalitis, which more frequently manifests itself with forebrain lesions and may exhibit a distinct disease course compared to granulomatous meningoencephalitis. This study aimed to determine the usefulness of neurological assessment scales in the prognosis of YST with MUO. The study population comprised 127 YST which met inclusion criteria for a highly probable diagnosis of MUO. This multicentre, cohort study was designed as a retrospective review of medical records. Based on documented neurological examinations, animals were scored on three scales: the Modified Glasgow Coma Scale, Neuro Disability Scale 1 (Smith et al.), and Neuro Disability Scale 2 (Gonçalves et al.). The association between the scores and survival time was investigated over three periods of time - 7 days, 100, and 365 days (1 year) after onset of clinical signs.

resultsAll scales were significantly associated (p < 0.001) with MUO-specific survival and death of MUO within the first 7 days and had high prognostic accuracy in terms of short-term prognosis. None of the scales was significantly associated with the probability of survival after 100 or 365 days. Dogs with unilateral lesions on magnetic resonance images (MRI) had approximately 12- and threefold higher odds of surviving up to 100 and 365 days, respectively, than dogs with bilateral lesions on MRI. Dogs heavier than 3.2 kg at presentation had approximately sixfold higher odds of survival up to day 365.

conclusionsThe study provides strong evidence for a high short-term prognostic accuracy of the three neurological assessment scales in YST with MUO - the scales seem to be very useful in predicting death within the first week of the onset of MUO. However, the scales do not appear to have prognostic value in the longer time frame. However, the presence of unilateral MRI changes and dog's body weight may assist with medium- and long-term prognosis.