Survival time and relapse in dogs with meningoencephalomyelitis of unknown origin treated with prednisolone and ciclosporin: a retrospective study

Survival in dogs with meningoencephalomyelitis of unknown etiology with and without lesions detected by magnetic resonance imaging

BACKGROUND

The prognosis of individual dogs with meningoencephalomyelitis of unknown etiology (MUE) remains difficult to predict. MUE cases with no lesions detected by magnetic resonance imaging (MRI) occur, but it is unknown whether this finding is associated with prognosis.

HYPOTHESIS

MUE cases without detectable lesions on MRI have a better outcome than cases with detectable lesions.

ANIMALS

Study included 73 client-owned dogs with MUE presenting to Purdue University Veterinary Hospital from 2010 to 2020.

METHODS

Retrospective study. Dogs with a clinical diagnosis of MUE were identified by medical record search. MRI reports were reviewed for presence or absence of lesions consistent with MUE. Clinical findings at presentation, treatment, disease-specific survival, and outcomes including rates of remission and relapse were compared between cases with normal MRI or abnormal MRI.

RESULTS

Overall, 54 dogs (74%) were classified as abnormal MRI, and 19 dogs (26%) were classified as normal MRI cases. Death caused by MUE occurred in 1/19 (5%) normal MRI dogs and 18/54 (33%) abnormal MRI dogs (P = .016). Median survival was >107 months in both groups, but survival was significantly longer in the normal MRI group (P = .019). On multivariate analysis, abnormal MRI was significantly related to death (hazard ratio, 7.71; 95% confidence interval 1.03-58.00, P = .0470), whereas significant relationships with death were not identified for either the use of secondary immunosuppressive medications or cerebrospinal fluid nucleated cell count.

CONCLUSIONS

MUE dogs with no detectable lesions on MRI have reduced disease-related death compared with dogs with abnormal MRI. The presence or absence of MRI lesions in MUE dogs is prognostically relevant.

Clinical features, treatment, and outcome of juvenile dogs with meningoencephalitis of unknown etiology

BACKGROUND

The information relating to the outcome specifically for juvenile dogs with meningoencephalitis of unknown etiology (MUE) is lacking.

OBJECTIVES

To describe the clinical presentation, diagnostic findings, treatment, and outcome in a cohort of dogs with MUE <52 weeks old.

ANIMALS

Thirty-four client-owned dogs.

METHODS

Multicenter retrospective case series. Records from 5 referral centers were searched. Data was extracted from the medical records and referring veterinarians were contacted for survival data if this was not available from the record.

RESULTS

The mean age was 31 weeks; the youngest dog was 11 weeks and 3 dogs were <16 weeks old. Altered mentation (71%), ataxia (44%), seizures (29%), and circling (26%) were the most common presenting complaints. Neuroanatomical localization was to the forebrain (38%), multifocal (35%), brainstem (18%), and cerebellum (12%). Corticosteroid monotherapy (n = 15) and corticosteroid plus cytosine arabinoside (n = 15) were used in equal proportions. Outcome data was available for 26 dogs, 8 (31%) were alive at the time of data collection with a follow-up range of 135 to 2944 days. Death or euthanasia was related to MUE in 17/18 dogs that died during the study period. Kaplan-Meier survival analysis demonstrated a median survival time for all-cause death of 84 days.

CONCLUSION

The prognosis for MUE in this subset of dogs was considered poor.

Investigation of side effects to treatment and cause of death in 63 Scandinavian dogs suffering from meningoencephalitis of unknown origin: a retrospective study

BACKGROUND

Meningoencephalitis of unknown origin is a common cause of severe neurological disease in dogs. The term covers a heterogeneous group of noninfectious inflammatory diseases, with immune dysregulation widely accepted as the underlying disease mechanism. Current treatment consists of immunosuppression, with corticosteroids being the mainstay of virtually all treatment regimens. However, side effects of corticosteroids can be severe, and might be the cause of death in some patients. This retrospective, multi-centric study aimed at describing a population of Scandinavian dogs with meningoencephalitis of unknown origin in regards to reported side effects and cause of death, and to highlight possible differences in survival, when comparing corticosteroid monotherapy with other treatment regimens.

RESULTS

Within the 5-year study period, 63 dogs were included. Of these, 35 (49.3%) died or were euthanized during the study period. Median survival time from time of diagnosis based on Kaplan-Meier curves for the overall population was 714 days (equivalent to around 25 months, range 0-1678 days). There was no statistically significant difference (P = 0.31) in survival between dogs treated with corticosteroid monotherapy (n = 26, median survival time 716 days, equivalent to around 25 months, range 5-911 days), dogs receiving a combination of corticosteroids and ciclosporin (n = 15, median survival time 916 days, equivalent to around 31 months, range 35-1678 days), and dogs receiving corticosteroids combined with either cytosine arabinoside, leflunomide, or a combination of 2 or more add-on drugs (n = 13, median survival time 1186 days, equivalent to around 40 months, range 121-1640 days). Side effects were registered for 47/63 dogs. Polyphagia (n = 37/47), polyuria/polydipsia (n = 37/47), diarrhea (n = 29/47) and lethargy (n = 28/47) were most frequently reported. The most common cause for euthanasia was relapse (n = 15/35, 42.9%), followed by insufficient or lack of treatment response (n = 9, 25.7%). Side effects were the direct cause of euthanasia in 2/35 dogs (5.7%).

CONCLUSIONS

A large proportion of dogs in the overall population were euthanized due to relapse, emphasizing a need for treatment regimens aimed at specifically preventing relapse for an improved long-term survival. Side effects in dogs receiving corticosteroid monotherapy were rarely a direct cause of death, but were reported for all dogs. No statistically significant difference in survival was found when corticosteroid monotherapy was compared to other treatment regimens.

Predictive Value of Acute Phase Proteins for the Short-Term Outcome of Meningoencephalitis of Unknown Origin in Dogs

Meningoencephalitis of unknown origin (MUO) is one of the most common inflammatory diseases of the central nervous system (CNS). The study evaluates the possible increase and the potential role of acute phase proteins (APPs) and other inflammatory serum parameters as biomarkers predicting the short-term outcome of dogs with meningoencephalitis of unknown origin (MUO). A retrospective cohort study was designed. The APP profile and other markers of systemic inflammation of forty-eight client-owned dogs with a new diagnosis of MUO were compared between 7-day survival and non-survival dogs diagnosed with MUO. Thirty-nine (81%) dogs were alive at the end of the 7-day follow-up period, while 9 (19%) dogs died or were euthanized because of MUO. None of the 11 markers of inflammation studied were different between the survived and non-survived dogs; for this reason, none of them could be used as a predictor of the short-term outcome based on the results of the present study. This confirms that even though MUO is often associated with a severe inflammatory status of the central nervous system (CNS), this condition is probably isolated exclusively to the CNS.

Off-Label Use of Crisdesalazine (GedaCure) in Meningoencephalitis in Two Dogs

An 8-year-old, castrated male Shih-tzu dog (Case 1) showing ataxia and gait disorder was referred for neurological examination and magnetic resonance imaging. Through comprehensive examinations, the patient was tentatively diagnosed with meningoencephalitis of unknown origin (MUO) and treatment with prednisolone and cytosine arabinoside was started. The symptoms were improving with immunosuppressive treatment. However, severe bacterial cystitis occurred and we could not avoid tapering off prednisolone. Then, neurological signs recurred. Therefore, we added crisdesalazine, which allowed us to reduce the daily dosage of immunosuppressants easily. In another case, a 4-year-old, spayed female Yorkshire terrier dog (Case 2) was referred to our hospital showing a head tilt, circling, and loss of the menace reflex. The patient was tentatively diagnosed with MUO and treatment with some immunosuppressants was attempted. The clinical symptoms improved, but the alleviation was inadequate. Thus, we added crisdesalazine. The neurological signs then markedly improved. Moreover, the drugs could be tapered off more easily than before. Crisdesalazine is a novel drug that has antioxidant and anti-inflammatory action in brain disease and is used particularly for dementia. In this paper, we tried an off-label use of this drug in canine MUO patients, and found that it had, in these two patients, additional therapeutic effects on the MUO.

Perspectives on pharmacologic strategies in the management of meningoencephalomyelitis of unknown origin in dogs

There are many non-infectious inflammatory diseases, assumed to be immune-mediated in origin, recognized to affect the nervous system in canine patients. Concentrating on meningoencephalomyelitis of unknown origin, we will discuss the medications used to treat the underlying disease process, focusing on their adverse effects, therapeutic monitoring when necessary and effectiveness. The literature overwhelmingly supports the use of a steroid/ Cytosar® or steroid/ cyclosporine treatment protocol with the steroid tapered after the acute phase of the disease, leaving the secondary medication to control the disease long term. The decision on when and how quickly to taper the steroid is clinician dependent as a best practices has not been established in the literature. Also discussed will be the supportive care treatments often needed in the acute phase of these patients' diagnosis and treatment such as anti-edema and anti-epileptic agents.

New insights into the treatment of meningoencephalomyelitis of unknown origin since 2009: A review of 671 cases

“Meningoencephalomyelitis of unknown origin” (MUO)—a collective term for a group of clinically-indistinguishable (but pathologically distinct) autoimmune diseases of the CNS—has become increasingly commonly recognized throughout the world. In the 1960s−1980s the focus was primarily on the pathological description of these conditions and, largely anecdotally, their response to glucocorticoids. The subsequent availability of magnetic resonance imaging for companion animals led to a focus on imaging characteristics and response of MUO to various immunosuppressive medications. Previous reviews have not found clear evidence of superiority of any specific treatment regimen. Here, we review outcomes in a further 671 dogs treated with various combinations of glucocorticoids and immunosuppressive drugs and reported since 2009, aiming to determine whether recommendations can be drawn from the material published during more recent decades. We observe that: (i) there is more complete information on outcome of MUO-affected dogs solely receiving glucocorticoids and these reports provide evidence to undermine the dogma that MUO inevitably requires treatment with glucocorticoids plus an immunosuppressive drug; (ii) there is far more information on the pharmacokinetics of cytarabine delivered by a variety of routes, revealing that previous dosing and duration of administration in dogs with MUO may not have been optimal; and, (iii) there is a large number of cases that could be available for entry into multi-institutional randomized controlled trials. Finally, we suggest new research avenues that might aid future clinical trials in MUO through improved understanding of etiological triggers and individual patterns of immune response, such as the impact of the gut microbiome, the potential of CSF flow cytometry, and the establishment of robust clinical scores for evaluation of treatment success.

Treatment With Cytarabine at Initiation of Therapy With Cyclosporine and Glucocorticoids for Dogs With Meningoencephalomyelitis of Unknown Origin Is Not Associated With Improved Outcomes

Meningoencephalomyelitis of unknown origin (MUO) is a common disorder of dogs that results in significant morbidity and mortality. The ideal treatment regimen is not known but a second immunosuppressive agent is often utilized in combination with glucocorticoids to increase efficacy and reduce side effects. Recently, a benefit to using a cytosine arabinoside (CA) constant rate infusion (CRI) at the time of diagnosis has been demonstrated. Here, a retrospective study was performed to determine if administration of CA at the time of diagnosis would alter prognosis in dogs receiving cyclosporine and prednisone for treatment of MUO. Medical records of 51 client-owned dogs diagnosed with MUO at one institution were reviewed (2009-2019). All dogs were treated with cyclosporine and a tapering course of prednisone. Twenty-one dogs received a single initial 200 mg/m² treatment with CA either as a CRI or subcutaneously. Significantly more patients in the CA treatment group were obtunded on presentation but all other baseline parameters were similar between groups. No differences in success (defined as sustained improvement on neurological exam with owner perceived good quality of life), relapse, or death were identified at 1-, 3-, 6-, 9-, 12-, 18-, or 36-month time points. These results do not support treatment with CA (either as a CRI or subcutaneously) at the time of diagnosis in dogs treated with cyclosporine and prednisone.