Neurology 3 Flashcards
What 5 things can occur to cause tetraparesis/tetraplegia?
- Diskospondylitis
- Neoplasia
- Fractures
- Luxations
- FCE
Spinal cord lesions between C1-T2: Cervical disc disease
- Type I–explosive
- 75% chondrodystrophics and Poodles C3-C4
- 25% large breeds (labs, GSD, rott, dob) C5/C7
- Type II
- Dobes/rott at C6/C7 – wobblers
What are the signs of cervical disc disease (C1-T2)?
- 8yrs (2-16)–neck pain (90%); 45% acute
- Won’t move head–brain fine, hyperreflexia
- Tetraparesis–64% - rear worse
- Hemiparesis and tetraplegia (3%)–rare

How do you diagnose cervical disc disease?
Myelogram, calcified discs on rads (can find old calcified discs that aren’t causing the current problem, however–need myelogram to confirm)
What is the treatment for cervical disc disease?
- No deficits–cage rest
- Give time for annulus to repair itself
- NSAIDs/pred
- NSAIDs don’t work very well
- Only use pred when animal is in pain–will slow healing
- Can add diazepam on top of pred as musc. relaxant
- Up to 33% recur
- No improvement/neuro signs = surgery
- 8% recur, 99% walk unassisted
- Much faster recovery than back surgery
- Can fenestrate vertebral body on both sides to lessen chance of recurrence
Cervical spondylomyelopathy
- Canine wobblers
- Cervical malformation-malarticulation syndrome
- Caudal cervical spondylopathy, etc x 14
- Spinal cord compression - esp. > C5/6
What are some specific causes of cervical spondylomyelopathy?
- Stenosis–craniodorsal ridge
- Problem with development, often in Dobermans (most Dob’s have some degree of stenosis)
- Front of vertebra grows more than back–> tipping
- Osteophytes from malformed articular processes
- Instability from vertebrae –> joints move side-to-side –> ligaments tear from bone –> pressure on spinal cord –> dysfunction
- Hansen type II disk: increased lig. flavum
- Dob’s have thicker discs and stenosis –> greater risk
Etiology of cervical spondylomyelopathy?
- Genetics (dob’s, great danes)
- Congenital stenosis/lig laxity
- Rapid growth, over-nutrition
- Abnormal stresses/straint, joint motility/symmetry, cartilage
- Calcitonin
- Static and/or dynamic compression
What are the signs of cervical spondylomyelopathy?
- Great danes 3-18mo: congenital spinosis
- Dobes 5-8 yrs: older–cartilage changes
- Head guarding (won’t move head side-to-side)
- Pelvic signs esp. paresis
- Wobbling, scuffing
- Hypermetria of hind limbs (long strides)
- Front legs can also be affected but might look normal compared to back legs–why postural rxns important
- Thoracic limbs
- Dysmetria, mild CP def.–stiff gait
- Atrophy infra-/supraspinatus, w/drawal
- Can w/draw carpus, can flex elbow; might not be able to operate shoulder
- Neck pain (15%)–nerve roots
- Front legs can become pigeon-toed
How do you diagnose cervical spondylomyelopathy?
- Rads, myelogram (much better)
- Tipping
- Stenosis
- Rounding
- Dec. disc spaces
- Degeneration in articular facets

What will be seen on the myelogram/MRI of a dog with cervical spondylomyelopathy?
- MRI more helpful when have mult. lesions–will show sc edema
- Dorsal comp–lig flavum
- Ventral comp–disc
- Lateral comp–artic facets
- Vertebral tipping–>lesions disappear
- Single <50%
- Multiple <80%
- Traction rads
- No standards, hit or miss, can’t really estimate improvement
Cervical sponylomyelopathy treatment/prognosis?
- Varies–each case is different
- Medical
- Palliative–40, 30, 20
- Condition is progressive
- Surgery
- Decompression
- Distraction-stabilization
- About 1/2 will get better, ~30% will stay the same, and ~20-30% will get worse
- Can’t guarantee surgery will help–can try cage rest first
- Dorsal approach much more difficult w/ more complications than ventral–dogs tend to worsen after sx
What drugs are used for a UMN bladder in dogs with cervical spondylomyelopathy? LMN bladder?
- UMN bladder
- Phenoxybenzamine–musc. relaxant
- Prazosin tamsulosin
- Valium/dantrolene
- LMN bladder
- Phenylpropanolamine
- Bethanecol
Prognosis of cervical spondylomyelopathy
- Disc only = good
- Tetra- = poor
- Guarded in others
- Surgery–80-90% success (?)
- Recurrence/domino 20-40%, 2-3yr
- Must warn owners of more surgery and nursing care
Atlanto-axial subluxation
- Spinal cord compression due to dorsal displacement of the axis
- Large breeds–trauma
- Small breeds–lack of development
- Toy breed dogs: see progressive tetraparesis
- Ligaments can rupture –> spinal cord crushed –> death

What is the best diagnosis for atlanto-axial subluxation?
- Don’t manipulate the neck!!
- Rads best–vd esp. for absence

Signs of atlant-axial subluxation
- Congenital
- Toy/mini breeds
- 6-18 ms (dd cerv discs)
- Neck pain to tetraplegia (resp paralysis)
- Insidious in onset + progressive
- Large breeds: trauma
What is the treatment for atlanto-axial subluxation?
- Hemilaminectomy + wiring/screwing
- 30% failure rate–bones aren’t very strong + small breeds
Caudal occipital malformation syndrome: tell me all the things
- Chiari 1 malformation syndrome
- Malform caudal occip bone–crowding in caudal fossa
- Signs 3-6 yrs (from 6m)
- Neck/face scratching
- CP deficits
- Vestibular signs
- Spinal hyperesthesia
- Gabapentin and pred
- FMD–foramen magnum decompression
- 70% successful
- Recurrence 20-40%

Muscle and end-plate conditions: general
- Myopathies
- Weakness (exercise)
- Stilted stiff gate (short strides)
- Sometimes pain, CPK
- Normal CP and reflexes except flexor withdrawal reflex
What are the main causes of inflammatory myopathies?
- Infectious (20%)
- Toxoplasma
- Neosporum
- Lyme
- Hepatozoan
- FeLV, FIV

Canine idiopathic polymyositis–all ze thingzzz
- Normal neuro exam except for flexor withdrawal reflex
- Immune mediated
- Large, mature, acute or chronic
- Weakness/stiff/rapid fatigue/atrophy
- Some have pyrexia, pain, regurge, bark, dysphagia
- Patterns of necrosis–lots of lymphs and neutrophils
- Prednisone +/- azathioprine
- 25% recover; 50% lifelong
- Biopsy for definitive diagnosis (take multiple since patchy)
Masticatory muscle myositis
- 2M fibers–large breeds, < 4yr
- Waxing and waning
- Painful swollen muscles
- Pseudotrismus
- Fever
- Inn
- Chronic–atrophy

How do you diagnose masticatory muscle myositis? What’s the treatment?
- Biopsy/serology
- Prednisone–good response, even chronics
- Taper dose slowly
- With azathioprine–steroid sparing
Extraocular myositis–all the things
- Diagnose with biopsy/ultrasound
- Not very common, tend to be in golden retrievers (young)
- Autoimmune
- Eyes bulge out due to muscles being inflamed
- Pred–resolves in weeks
- Some need chronic pred

Exertional myopathy
- Post exercise
- Massive CPK
- Renal failure (myoglobin gets blocked up in kidneys)
-
Hypokalemia (cats)
- CRF
- Acid diets
- Conn’s
- Hyperthyroid
- Oral supplementation
- Normal neuro exam–normal reflexes, just have exreme muscle weakness/exhaustion
- Can sometimes get hyperalosteronism (ext. rare)
Feline idiopathic inflamatory myopathy
- Cat with droopy head, everything else normal
- Diagnosis of exclusion
- Usually improve with immunosuppressive dose of pred
- 10mg/day w/ no side effects
Limber tail
- Paralyzed tail after long day of working/running after long period of inactivity
- Usually gets better w/o treatment
What are the 4 degenerative/developmental myopathies?
- Dystrophic myopathies
- Non-dystrophic myopathies
- Metabolic myopathies
- Miscellaneous conditions
- Myotonia
- Dermatomyositis
Dystrophic myopathies
- Molecule on outside that binds actin to myosin
- Alpha-2 laminin deficiency
- Dystrophin normally surrounds muscle –> patchy instead –> muscle doesn’t contract properly –> tears; Ca leaks in, etc.
- Look normal at birth, develop strange gait
- Progressive til ~6mo, then relatively stable til ~2yrs
- Heart is then affected –> death

Non-dystrophic myopathies
- Central core-like
- Nemaline rod
- Congenital degenerative myopathies
- Probably genetic–labs, great danes
- Entire litters affected
- Start seeing muscle wasting, degeneration

Metabolic myopathies
- Hypo- hyperthyroid–lack of metabolism in muscles
- Hyperadrenocorticism
- Overproduce glucocorticoids –> tear into muscles
- Dogs usually brought in for PU/PD
-
Enzyme deficiencies
- Glycogen storage disease
- Phosphofructokinase deficiency
- Exercise induced collapse (EIC) in labradors (< 3yrs)
- < 1% population; working dogs/pets
- Rocking horse gait (LMN in hind limbs)
- Limp, 5-25 min. recovery (get better w/ rest)
- Metabolic cocktail
- Phenobarb
- Dynamin gene (DNM1)–neuromuscular transition
Myotonia
- Chows, Westies, Danes, cats, fainting goats
- Cl channelopathy
- Dimpling
- Tap muscles–> contract and forms dimple that slowly disappears
- Can check on tongue
- Stiff gait, CP slow
- Reflexes chronic
Dermatomyositis
- Sheep dogs, collie breeds
- Skin lesions 2-6m then weakness
- megaesophagus
- Resolves or chronic wax/wane.
- Pentoxifylline–makes RBCs more bendy
- Autoimmune disease, damage to capillaries; usually goes away w/in a year

Feline hyperesthesia syndrome
Inclusion body myopathy
- Multifactorial condition
- 5-8 yr pure breeds
- Intermittent twitching, grooming, agitation (self-trauma), vocalizing, running, aggression
- Allergies, SC lesions, myositis, behavior, seizures
- Can respond to pred
- If doesn’t respond, can try phenobarb
- Inclusion body myopathy
- Muscle cells degenerate
- Protein from cell breakdown cause hypersensitivity rxn
- No treatment/cure–>only gets worse
- Muscle cells degenerate
Myasthenia gravis
- Congenital–Jack russels, foxies (rare, musc. weakness)
- Acquired–autoantibodies to AchR
- Stops receptors from working–> weakness
What are the 3 forms of myasthenia gravis? How do they differ?
- Classically–weak following exercise
- Look normal, get weaker and weaker until eventually collapse from exercise
- Tensalon esterase inhibitor
- Given IV, stops breakdown of Ach–> dog fine in about 15 min
- Focal–36% (esoph, face, pharynx, larynx)
- Skeletal muscles fine; localized
- Sign: regurgitation
- Generalized muscle involvement + weakness
- Acute fulminating 16%
- Not assoc. w/ exercise–weak all the time plus severe megaesophagus (–> severe regurg.)
- Die of resp. failure
- Chronic generalized 48%
- 80% megaesophagus (clinical sign = regurg)
- 50% exercise-induced
- Acute fulminating 16%
- Antibody test exists
Tests/treatment/prognosis for masthenia gravis?
- Cats–rare, generalized, thymoma (26%)
- Weak with exercise
- Tensilon test–anticholinesterase (only picks up ~1/4 of dogs with it)
- AchR antibody test/immune complex
- Support (gastrostomy + cisapride)
- Increased tone of esoph. sphincter
- Can get muscle atrophy (disuse)
- Pyridostigmine–play w/ dose to avoid PNS acitivity
- +/- prednisolone (aza/cyclo)–avoid if poss.; start w/ low dose (will worsen pneumonia and musc. weakness)
- +/- thymectomy–thymoma
- Poor drug response
- Prognosis: 6 months, resolution in 90%
- Bad–congenital + fulminant
- Vaccine–anergy (overwhelm immune system)
Botulism
- Dogs-outbreaks when hunted animals aren’t bled out properly
- Blocks Ach presynaptically
- Tetraparesis, cranial nerves, esophagus, parasympathetic and sympathetic signs
- Respiration
- Slow improvement over 2-3 weeks
- Need major physiotherapy–turn often
- Exotoxin in feces/serum
- Antisera (not effective after), support, neostig
- If have LMN on all 4 limbs–think of things working on outside peripheral nerves
Tick paralysis
- Toxins–Dermacentor + Ixodes + 58 species
- Unpredictable
- Block nerve conduction or decrease Ach
- Stop AP’s–> stop Ach from being released
- Not all ticks/dogs
- Can be relatively acute progression
- Hard to differentiate from botulism–must find the tick
What are the major signs of tick paralysis?
- Tetraparesis - plegia
- LMN signs (all 4 limgs)
- Cranial nerves, sensation, continence spared
- Recovery after tick removed
- Check ext. ear canal/interdigital spaces
- *Botulism suspect–make sure aren’t any ticks
Tetanus
- Dogs–rarely cats–anaerobic wounds
- Often only affects one limb
- Puncture wounds where there’s no blood supply
- Toxin enters wound –> enters nerves –> spinal cord –> animal becomes stiff
- Sardonic–facial expression of skepticism/disdain
What is the diagnosis and treatment of tetanus?
- Diagnosis–clinical signs
- Treatment
- Temperature
- Antitoxin IV (not useful)
- Pen/peroxide (if find the wound)
- Val/ace/pent
- Muscle relaxants***
- Turn regularly, give fluids, etc. for maintenance
- Feeding tubes; hernias
- Slow improvement, sometimes have deficits later on due to nerve damage

Acute canine polyradiculoneuritis
- AKA Coonhound paralysis
- Inflammation/demyelination ventral roots
- Raccoon saliva/viruses/drugs–hapten
- Ascending LMN paralysis and tetraplesia
- Start going off back legs, then front w/in 24 hours
-
Cranial nerves + sensory + continence spared
- Looks like tick paralysis and botulism–treatment the same
- Pred not helpful–demyelination only there for a few hours, then just left with the damage
What is the recovery/treatment/prognosis of acute canine polyradiculoneuritis?
- Spontaneous recovery–weeks to months
- Diagnosis–clinical signs + EMG (not normally done–would need to biopsy nerve roots)
- Glucocorticoids don’t help
- Inflammation is gone relatively quickly and animal heals itself–adding steroids would only slow down healing process (w/ PU/PD, immunosuppression)
- Supportive therapy
Protozoal polyradiculoneurititis
- Toxo/Neosporum caninum
- Transplancental–subclinical
- Prog post paresis
- Serology?
- Organisms - biopsy
- TMS–pyrimeth or clindamycin
- Prog. dependent on contracture
Miscellaneous neuropathies
- Diabetic
- Hypothyroid
- Trigeminal/brachial plexus neuritis
- Masticating muscles
- Paraneoplastic
- Idiopathic facial nerve
- Venom
- Salinomycin (used in chickens to kill coccidia)
- Inherited/familial neuropathies