Lecture 7: Common Diseases in Veterinary Neurology

Idiopathic epilepsy: signalment

- Young dogs (6m-6y)

- Purebred, large breed (labs common)

Idiopathic epilepsy: signs

- Partial or generalized seizures

- Single or cluster seizures

- Normal between seizures

Idiopathic epilepsy: diagnosis

- Diagnosis of exclusion

Idiopathic epilepsy: treatment

- Goal is to decreases the frequency and severity of seizures

- Medications (not all required drugs) if seizures closer together / cluster

Old dog vestibular disease: signalment

- Geriatric dogs (10+ years)

- Large breeds

Old dog vestibular disease: signs

- Peracute onset

- IDIOPATHIC

- Peripheral vestibular signs (severe healed tilt*, ataxia, nystagmus, rolling, falling)

- NO CP deficits! No seizures.

Old dog vestibular disease: treatment

- Symptomatic and supportive (fluids, anti-emetics, +/- anti-anxiolytics)

- Brain MRI is unremarkable

- move them around slowly! they're dizzy!

what is MUE (meningoencephalitis of unknown etiology)?

- A non-infectious inflammatory process in the CNS

- Immune-mediated

- Can occur anywhere in the CNS

MUE (meningoencephalitis of unknown etiology): signalment

- Young, middle aged dogs

- Small toy and terrier breeds

- female > male

MUE: diagnosis

- Rule out infectious causes

- MRI affected area

- CSF analysis

MUE: treatment

- Corticosteroids

- Immune modulatory drugs

- Other drugs as needed

IVDD: two types?

- Type 1: chondrodystrophic dogs; acute disc extrusion (nucleus hits cord)

- Type 2: large breed dogs; chronic disc protrusion (annulus presses on cord)

IVDD: location

Anywhere you have a disc

where is IVDD most common?

C2 to tail

common at T11-L3

IVDD: diagnosis

- CT or MRI (can see the spinal cord being pressed on)

IVDD: treatment

- Medical management

- Surgery if they go down (excellent prognosis if pain perception present, 50% if paraplegic with absent pain perception)

what is fibrocartilagenous embolism?

disk --> blood supply --> ischemic injury

Fibrocartilagenous embolism: location

Anywhere along spinal cord (but usually T3-L3)

Fibrocartilagenous embolism: signs

- Peracute

- Asymmetric signs

- Non-painful on exam

Fibrocartilagenous embolism: diagnosis

- Cross-sectional imaging (MRI) —> look for focal area of ischemia

(NOT CT)

Fibrocartilagenous embolism: treatment

- PT

- Pain management

Degenerative myelopathy: signalment

- German shepherds*, corgis, boxers

- ~7 years old

- Progressive over 6-18 months

Degenerative myelopathy (DM): location

- Starts at T3-L3 non-painful

- Can descend to L4-S3 and cause fecal/urinary incontinence

- Can then ascend to affect the TLs

Degenerative myelopathy: diagnosis

- MRI T3-L3 spine

- SOD-1 test: look for mutation (Homozygous mutation means at risk/affected)

Degenerative myelopathy: treatment

- No definitive treatment

- PT prolongs functional time

Most common cause of inflammatory disease in cat CNS.

FIP (Coronavirus mutation)

FIP: diagnosis

- MRI

- CSF analysis (high neutrophils and protein)

CNS FIP is a ? form

dry

- No effusion, +/- ↑globulins

FIP: treatment

New drug (nucleoside analog)?

poor prognosis

T/F: it is easy to clear toxoplasma gondii.

False — once infected, almost impossible to clear (recurrent episodes), it's in the environment (protozoal organism)

Toxoplasmosis: diagnosis

4-fold rise in serum antibody titer

Can affect the CNS anywhere

Toxoplasmosis: treatment

Clindamycin

Meningioma: signalment

Geriatric cat (12+ years old)

Meningioma: signs

Slowly progressive forebrain signs (behavior changes*, circling)

Meningioma: diagnosis

MRI >> CT

Meningioma: treatment

Surgery (>2 years to return of signs)

Most common cause of spinal disease in dogs.

IVDD

describe equine wobblers syndrome

- osseous associated

- Abnormal gait and cervical hyperesthesia

- many names

wobblers diagnosis

imaging (difficult)

Most common cause of spinal disease in horses.

Equine protozoal myelitis

EPM most common organism?

Sarcocystis neurona

EPM: signs

- Asymmetrical proprioceptive ataxia

- LMN involvement —> lameness and asymmetrical muscle atrophy ****

EPM: treatment

- Folic acid inhibition

- Ponazuril (antiprotozoal)

what is EEE/WEE/VEE?

Regional mosquito-borne viruses that still occur despite effective vaccines

EEE/WEE/VEE: signs

Forebrain signs, very high mortality

EEE/WEE/VEE: diagnosis

IgM ELISA

what is WNV (west nile virus)?

Encephalomyelitis due to a mosquito borne flavivirus

WNV signs?

Subclinical to fulminating -- Fever, paresis, ataxia, vestibular, cerebellar, behavior changes

WNV: diagnosis

IgM ELISA

regional and seasonal

WNV: treatment

supportive

equine herpes myelopathy from EHV1?

- Mostly respiratory, can cause neurologic signs

- Urinary bladder paralysis & urine dribbling!!

- Fever, paresis and ataxia. Decreased tail and anal tone, fecal retention

EHV1: diagnosis

PCR of respiratory secretions

Temperohyoid osteoarthropathy: signalment

Adult horses w/ ankylosis of the temporohyoid joint

Temperohyoid osteoarthropathy: signs

- Vestibular

- Ataxia

- Facial nerve paralysis (—> corneal ulcers)

- Fractures cause acute deteriorations

Temperohyoid osteoarthropathy: diagnosis

- Radiographs

- Endoscopy

- CT

Temperohyoid osteoarthropathy: treatment

Ceratohyoidectomy

what is listeriosis?

- Listeria monocytogenes --> microabscesses

- ruminants!!

- Rhombencephalitis

listeriosis: signs

progressive, multifocal!

Ataxia Tetraparesis Opisthotonus Tremors, hyperexcitability Compulsive movements Convulsions Stupor Vestibular signs Cranial nerve deficits

Listeriosis: diagnsois

CSF —> monocytic pleocytosis

what is horners syndrome?

Loss of sympathetic innervation in face and eye

Horner's syndrome: signs

- Ptosis

- Prolapsed 3rd eyelid

- Miosis

- Enophthalmos

cause of horners in dog

Idiopathic - Golden retrievers

Horner's syndrome: signs (horses)

- Ptosis (eyelashes point down)

- Unilateral sweating

- Increase temperature face/neck/shoulder

cause of horners in cat

Otitis media

No other signs!

thiamine deficiency in ruminants?

- Polioencephalomalacia

- Cerebrocortical necrosis --> forebrain signs

- Sulfur toxicity?

thiamine deficiency in carnivores?

- Seizures & blindness

- Focal areas of hemorrhage in the brain

- Cats fed solely cold water fish