Neurology 3 Flashcards
1
Q
What 5 things can occur to cause tetraparesis/tetraplegia?
A
- Diskospondylitis
- Neoplasia
- Fractures
- Luxations
- FCE
2
Q
Spinal cord lesions between C1-T2: Cervical disc disease
A
- 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
3
Q
What are the signs of cervical disc disease (C1-T2)?
A
- 8yrs (2-16)–neck pain (90%); 45% acute
- Won’t move head–brain fine, hyperreflexia
- Tetraparesis–64% - rear worse
- Hemiparesis and tetraplegia (3%)–rare
4
Q
How do you diagnose cervical disc disease?
A
Myelogram, calcified discs on rads (can find old calcified discs that aren’t causing the current problem, however–need myelogram to confirm)
5
Q
What is the treatment for cervical disc disease?
A
- 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
6
Q
Cervical spondylomyelopathy
A
- Canine wobblers
- Cervical malformation-malarticulation syndrome
- Caudal cervical spondylopathy, etc x 14
- Spinal cord compression - esp. > C5/6
7
Q
What are some specific causes of cervical spondylomyelopathy?
A
- 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
8
Q
Etiology of cervical spondylomyelopathy?
A
- 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
9
Q
What are the signs of cervical spondylomyelopathy?
A
- 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
10
Q
How do you diagnose cervical spondylomyelopathy?
A
- Rads, myelogram (much better)
- Tipping
- Stenosis
- Rounding
- Dec. disc spaces
- Degeneration in articular facets
11
Q
What will be seen on the myelogram/MRI of a dog with cervical spondylomyelopathy?
A
- 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
12
Q
Cervical sponylomyelopathy treatment/prognosis?
A
- 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
13
Q
What drugs are used for a UMN bladder in dogs with cervical spondylomyelopathy? LMN bladder?
A
- UMN bladder
- Phenoxybenzamine–musc. relaxant
- Prazosin tamsulosin
- Valium/dantrolene
- LMN bladder
- Phenylpropanolamine
- Bethanecol
14
Q
Prognosis of cervical spondylomyelopathy
A
- 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
15
Q
Atlanto-axial subluxation
A
- 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
16
Q
What is the best diagnosis for atlanto-axial subluxation?
A
- Don’t manipulate the neck!!
- Rads best–vd esp. for absence
17
Q
Signs of atlant-axial subluxation
A
- Congenital
- Toy/mini breeds
- 6-18 ms (dd cerv discs)
- Neck pain to tetraplegia (resp paralysis)
- Insidious in onset + progressive
- Large breeds: trauma
18
Q
What is the treatment for atlanto-axial subluxation?
A
- Hemilaminectomy + wiring/screwing
- 30% failure rate–bones aren’t very strong + small breeds
19
Q
Caudal occipital malformation syndrome: tell me all the things
A
- 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%
20
Q
Muscle and end-plate conditions: general
A
- Myopathies
- Weakness (exercise)
- Stilted stiff gate (short strides)
- Sometimes pain, CPK
- Normal CP and reflexes except flexor withdrawal reflex
21
Q
What are the main causes of inflammatory myopathies?
A
- Infectious (20%)
- Toxoplasma
- Neosporum
- Lyme
- Hepatozoan
- FeLV, FIV
22
Q
Canine idiopathic polymyositis–all ze thingzzz
A
- 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)
23
Q
Masticatory muscle myositis
A
- 2M fibers–large breeds, < 4yr
- Waxing and waning
- Painful swollen muscles
- Pseudotrismus
- Fever
- Inn
- Chronic–atrophy
24
Q
How do you diagnose masticatory muscle myositis? What’s the treatment?
A
- Biopsy/serology
- Prednisone–good response, even chronics
- Taper dose slowly
- With azathioprine–steroid sparing
25
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
26
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)
27
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
28
Limber tail
* Paralyzed tail after long day of working/running after long period of inactivity
* Usually gets better w/o treatment
29
What are the 4 degenerative/developmental myopathies?
1. Dystrophic myopathies
2. Non-dystrophic myopathies
3. Metabolic myopathies
4. Miscellaneous conditions
1. Myotonia
2. Dermatomyositis
30
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
31
Non-dystrophic myopathies
* Central core-like
* Nemaline rod
* Congenital degenerative myopathies
* Probably genetic--labs, great danes
* Entire litters affected
* Start seeing muscle wasting, degeneration
32
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
33
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
34
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
35
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
36
Myasthenia gravis
* Congenital--Jack russels, foxies (rare, musc. weakness)
* Acquired--autoantibodies to AchR
* Stops receptors from working--\> weakness
37
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
* Antibody test exists
38
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)
39
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**
40
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
41
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
42
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
43
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
44
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
45
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
46
Protozoal polyradiculoneurititis
* Toxo/*Neosporum caninum*
* Transplancental--subclinical
* Prog post paresis
* Serology?
* Organisms - biopsy
* TMS--pyrimeth or clindamycin
* Prog. dependent on contracture
47
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
