Treat Canis Meningoencephalomyelitis of unknown origin
ISSN 2398-2969      

Meningoencephalomyelitis of unknown origin

i  canis
Contributor(s):

Mark Lowrie

Nicolas Granger

Synonym(s): MUO, meningo-encephalo-myelitis, meningoencephalitis

Introduction

  • Inflammatory diseases of the central nervous system (CNS) are one of the common causes of neurological dysfunction in the dog. 
  • Inflammatory CNS disease can be grouped into two broad categories; those of a known infectious etiology and those causing meningoencephalomyelitis of unknown origin (MUO). 
  • The MUO group consists of diseases such as steroid responsive meningitis-arteritis (SRMA), eosinophilic meningoencephalomyelitis, and the numerous encephalitides including granulomatous meningoencephalomyelitis (GME) and the specific meningoencephalitides (ie necrotizing encephalitis (NE) including necrotizing meningoencephalomyelitis [NME] and necrotizing leucoencephalitis (NLE)). 
  • These conditions require histopathological confirmation of a CNS biopsy to form a diagnosis. However, limited tissue access, risks of morbidity and mortality together with its limited availability make it an impractical tool. 
  • The term ‘meningoencephalomyelitis of unknown origin’ has been coined to describe those cases in which MRI and cerebrospinal fluid (CSF) alterations indicate inflammatory non-infectious (immune-mediated) CNS disease but definitive histopathological analysis is lacking. 
  • In using the term MUO we have a more clinically useful group of dogs to analyze in order to ensure the best treatments are given in spite of our inability to establish a histopathological diagnosis. 
  • Small breeds, notably terriers are most commonly affected, although any breed can develop the disease. 
  • Highest incidence occurs in dogs between 4-8 years age although any age dog can be affected. 
  • Signs: generally, the disease causes multifocal lesions, causing a range of possible clinical presentations. 
  • Diagnosis: cerebrospinal fluid analysis, and CT/MRI scans. 
  • Treatment: corticosteroids at immunosuppressive doses, and/or other immunosuppressive drugs therapy. 
  • Prognosis: guarded to fair but relapses may occur. Dogs with multifocal signs, signs of raised intracranial pressure and/or herniation on MRI have a poorer prognosis.

Pathogenesis

Pathophysiology

  • MUO is assumed to have an autoimmune and genetic pathogenesis. 
  • In general, major factors that contribute to the development of autoimmunity are genetic susceptibility and environmental factors. 
  • Suspected agents include environmental or infectious antigenic triggers that might activate autoreactive cells in the CNS, although no such agent has yet been identified in the development of MUO. 
  • Susceptibility genes may confer susceptibility or protection for autoimmunity by influencing the maintenance of self-tolerance. Data from inbred rodent studies have identified a strong influence of genetic background as a competing influence in the variability of lymphocyte responses in clearing pathogens from the CNS and promoting neuroprotection. 
  • Histiocytes, or monocytes, which are derived from circulating monocytes → invade white matter following breakdown of blood-brain barrier → immune-mediated damage and general loss of structural detail and can develop into → discrete masses, especially cerebral white matter, thalamus, brain stem, cerebellum, spinal cord → increased production of intrathecal immunoglobulin. 

Timecourse

  • Multifocal GME Granulomeningoencephalitis typically is characterized clinically by sub-acute to acute onset and rapid progression of multifocal neurologic signs. 
  • Focal GME tends to have a more insidious or slower progression of neurologic signs that may suggest a space-occupying lesion. 
  • Ocular GME, clinically manifests with acute signs of blindness attributable to optic neuritis. 

Diagnosis

This article is available in full to registered subscribers

Sign up now to start a free trial to access all Vetlexicon articles, images, sounds and videos, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to start a free trial to access all Vetlexicon articles, images, sounds and videos, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to start a free trial to access all Vetlexicon articles, images, sounds and videos, or Login

Further Reading

Publications

Refereed Papers

  • Recent references from PubMed and VetMedResource.
  • Paušová T K, Tomek A, Šrenk P, Belašková S (2021) Clinical Presentation, Diagnostic Findings, and Long-term Survival Time in 182 Dogs With Meningoencephalitis of Unknown Origin From Central Europe That Were Administered Glucocorticosteroid Monotherapy. Top Companion Anim Med 44, 100539 doi.org/10.1016/j.tcam.2021.100539.
  • Brady S L, Woodward A P, le Chevoir M (2020) Survival time and relapse in dogs with meningoencephalomyelitis of unknown origin treated with prednisolone and ciclosporin: a retrospective study. Aust Vet J 98(10), 491-498 PubMed.
  • Stee K, Broeckx B J G, Targett M, Gomes S A, Lowrie M (2020) Cytosine arabinoside constant rate infusion without subsequent subcutaneous injections for the treatment of dogs with meningoencephalomyelitis of unknown origin. Vet Rec 187(11), e98 PubMed.
  • Cornelis I, Van Ham L, Gielen I, De Decker S, Bhatti S F M (2019) Clinical presentation, diagnostic findings, prognostic factors, treatment and outcome in dogs with meningoencephalomyelitis of unknown origin: A review. Vet J  244, 37-44 PubMed.
  • Lowrie M, Thomson S, Smith P, Garosi L (2016) Effect of a constant rate infusion of cytosine arabinoside on mortality in dogs with meningoencephalitis of unknown origin. Vet J 213, 1-5 PubMed.
  • Coates J R, Jeffery N D (2014) Perspectives on meningoencephalomyelitis of unknown origin. Vet Clin North Am Small Anim Pract 44(6), 1157-1185 PubMed.
  • Lowrie M, Smith P M, Garosi L (2013) Meningoencephalitis of unknown origin: investigation of prognostic factors and outcome using a standard treatment protocol. Vet Rec 172(20), 527 PubMed.
  • Granger N, Smith P M, Jeffery N D (2010) Clinical findings and treatment of non-infectious meningoencephalomyelitis in dogs: a systematic review of 457 published cases from 1962 to 2008. Vet J 184(3), 290-297 PubMed.
  • Cherubini G B, Platt S R, Anderson T J et al (2006) Characteristics of magnetic resonance images of granulomatous meningoencephalomyelitis in 11 dogs. Vet Rec 159, 110-115 PubMed.
  • Gnirs K (2006) Ciclosporin treatment of suspected granulomatous meningoencephalomyelitits in three dogs. JSAP 47, 201-206 PubMed. 
  • Benigni L & Lamb C R (2005) Comparison of fluid-attenuated inversion recovery and T2-weighted magnetic resonance images in dogs and cats with suspected brain disease. Vet Radiol Ultrasound 46, 287-292 PubMed. 
  • Adamo F P, O'Brien R T (2004) Use of cyclosporine to treat granulomatous meningoencephalitis in three dogs. JAVMA 225, 1211-1216 PubMed.  
  • Kitagawa M, Kanayama K, Satoh T et al (2004) Cerebellar focal granulomatous meningoencephalitis in a dog: clinical findings anf MR imaging. J Vet Med A Physiol Pathol Clin Med 51, 277-279 PubMed. 
  • Radaelli S T & Platt S R (2002) Bacterial meningoencephalomyelitis in dogs: a retrospective study of 23 cases (1990-1999). JVIM 16 (2), 159-163 PubMed. 
  • Burtch M (1998) Granulomatous meningitis caused by Coccidiodes immitis in a dog. JAVMA 212 (6), 827-829 PubMed. 
  • Kipar A et al (1998) Immunohistochemical characterization of inflammatory cells in the brains of dogs with granulomatous meningoencephalitis. Vet Pathol 35 (1), 43-52 PubMed.  
  • Muñana K R et al (1998) Prognostic factors for dogs with granulomatous meningoencephalomyelitis - 42 cases (1982-1996). JAVMA 212 (12), 1902-1906 PubMed. 
  • Sorjonen D C (1990) Clinical and histopathological features of granulomatous meningoencephalitis in dogs. JAAHA 26, 141-147.
  • Sisson A F (1989) Radiation therapy for granulomatous meningoencephalitis of dogs. J Vet Int Med 3 (2), 119.
  • Bailey C S  & Higgins R J (1986) Characteristics of CSF associated with canine granulomatous meningoecephalitis - a retrospective study. JAVMA 188 (4), 418-421 PubMed. 
  • Braund K G (1985) Granulomatous meningoencephalomyelitis. JAVMA 186 (2), 138-141 PubMed.  

RELATED ARTICLES

Arterial blood gas sampling

Ataxia

Biopsy: brain

Brain: neoplasia

Brain: tentorial herniation

Canine neural angiostrongylosis

Cerebrospinal fluid: cytology

Cerebrospinal fluid: protein

Cerebrospinal fluid: sampling

Ciclosporin

Cytarabine

Distemper disease

Ehrlichiosis

Encephalitis

Granulomatous meningoencephalomyelitis

Intracranial pressure measurement

Leishmaniosis

Magnetic resonance imaging: brain

Meningitis

Necrotizing (leuko-)encephalitis (Yorkshire Terrier)

Necrotizing meningoencephalitis (Maltese)

Neosporosis

Neurological examination

Niemann Pick disease

Optic neuritis

Prednisolone

Rocky Mountain Spotted Fever (RMSF)

Steroid-responsive meningitis-arteritis (SRMA)

Tick-borne encephalitis (TBE)

Toxoplasmosis

OWNER FACTSHEETS

Inflammatory CNS disease

RELATED DIAGNOSTIC TREES

Trismus

Want more related items, why not
contact us

RECENTLY ADDED

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

USA
  • 9789 Charlotte Hwy
  • Suite 400-179
  • Fort Mill
  • SC 29707
  • USA
  • +1 803 762 6130
HEAD OFFICE
  • Three Hills Farm
  • Bartlow
  • Cambridge
  • CB21 4EN
  • UK
CONTACT US
STAY CONNECTED
STAY CONNECTED WITH VETLEXICON VIA EMAIL

Receive latest Vetlexicon news and updates by signing up to our mailing list.

SUBSCRIBE
  • Vetstream Ltd © 2021
  • Registered in England No. 05575700
  • VAT No. GB 874037318