SRMA and MUE

Question 1

describe steroid responsive meningitis-arteritis (SRMA)

Answer 1

1. aberrant immune response
   -autoimmune/immune mediated
   -non-infectious
   -unknown trigger
2. Th2, Th17, B cell mediated which results in:
   -vasculitis
   -neutrophilic inflammation in CSF
3. must have a genetic component bc affects certain breeds

Question 2

describe signalment of SRMA

Answer 2

1. young
   -range is 4 months to 7 years
   –typically 8 months to 2 years: okay to make as a presumptive diagnosis if in this range
2. common breeds: medium to large!
   3Bs most common
   -beagle
   -bernese mountain dog
   -boxer

Question 3

describe clinical features of SRMA

Answer 3

1. acute and progressive
2. neck pain! kyphosis (arched back) along with the neck pain
   -other neuro deficits uncommon
   -but remember there are other/many sources of pain in the neck! (infection, muscle abscess, etc.)
3. neutrophilic leukocytosis and fever in many
4. +/- polyarthritis

Question 4

describe diagnostic testing for SRMA (4)

Answer 4

1. minimum database: neutrophilic leukocytosis common
2. MRI:
   -often normal but do this to rule out other diseases/infection
3. CSF!!:
   -marked neutrophilic pleocytosis
   -NO organisms, NEGATIVE culture!
4. at minimum, do rads to rule out bony lesions! (discospondylitis) in private practice when not/before refer

Question 5

describe treatment of SRMA (3)

Answer 5

1. prednisone/prednisolone: 1-2 mg/kg/day (steroid responsive!!)
   -taper every 6-8 weeks over 6 months
2. recheck before taper to make sure patient is normal/no pain (if still hurts probs no taper)
   -can consider rechecking CSF before tapering but this is rarely done
3. secondary immunosuppressive agents have been reported but rarely used
   -may allow faster tapering of steroids if steroid side effects not tolerated
   -may help in chronic, non-responsive cases or with relapses
   -make a neurologist prescribe these!

Question 6

describe prognosis of SRMA

Answer 6

1. fair to good if diagnosed quickly
2. guarded if chronic or if relapses
   -especially because of inconsistent steroid admin as “resistance” can develop
3. relapse rates range from 16-60% (really low!!!)
4. mortality rates range from 4.6-8.1% (very low!!)

Barber: “good disease, easy to treat”

Question 7

describe meningoencephalitis of unknown origin/etiology (MUE/MUO)

Answer 7

1. aberrant immune response
   -autoimmune/immune mediated
   -non-infectious
   -genetic!
2. similar to SRMA: seems to be overactivity of B and T cells causes
   -mononuclear (not neutrophilic) inflammation in the meninges and brain and/or spinal cord
3. clinically diagnosed as
   -non-suppurative (mononuclear), non-infectious CNS inflammation in small and toy breeds

Question 8

describe signalment of MUE/MUO

Answer 8

key to making diagnosis!!

1. SWF: SMALL, white fluffy
2. young to middle aged
   -6 months to 7 years
   -less commonly 8-12 years
3. CAN happen in other breeds but is rare and you canNOT make a presumptive diagnosis if not SWF breed

Question 9

describe clinical features of MUE/MUO

Answer 9

1. typically acute and progressive
2. less commonly chronic
   -can be progressive or wax and wane
3. signs for less than 3 months
4. anything brain or spinal cord! (signalment is key)
   -typically MULTIFOCAL, ASYMMETRICAL in the brain; but can be focal brain
   -can be optic neuritis: bilaterally mydriatic pupils with no menace and no PLR
   -can just be spinal cord (T3-L3 myelopathy)
   -can just be neck pain (potentially just back pain)
5. any signs of an affected CNS:
   -seizures, mentation change, visual deficits, central vestibular signs, cerebellar signs, difficulty walking from myelopathy, neck or back pain

Question 10

describe diagnosis of MUE/MUO

Answer 10

1. signalment!!
2. MRI: multifocal asymmetrical hyperintensities
3. CSF: mononuclear pleocytosis
   -lymphocytes
   -large mononuclear cells
   -neutrophils and eosinophils rare
4. negative infectious disease titers appropriate for geographic region
   -Georgia: toxoplasma gondii, neospora caninum, cryptococcus spp., +/- tick borne (RMSF)

Question 11

describe treatment of MUE/MUO

Answer 11

1. mainstay: prednisone
   -1-2 mg/kg/day
   -taper by 25% every 2 weeks
   -infectious disease testing first!!!!!
2. second agent long term to allow reduction/discontinuation of prednisone

Question 12

describe prognosis of MUE/MUO

Answer 12

1. 1/3 do well long term and can come off meds
2. 1/3 will die no matter what we do
3. 1/3 initially respond and then relapse
   -some respond well to med adjustment
   -some struggle with multiple relapses and then are euthanized