Peripheral Neuropathies Flashcards
1
Q
What are the etiologies for peripheral neuropathies?
A
- Degenerative
- Neoplastic
- Metabolic
- Nutritional
- Inflammatory
- infectious
- Traumatic
2
Q
What signs are common in Neruopathic syndromes?
A
- Neruogenic muscle atrophy
- Flaccid paresis/paralysis
- Reduced or absent reflexes
- Decreased pain response
- Proprioceptive deficits
3
Q
Examples of Degenerative, Metabolic, Neoplastic, Infectious, and Inflammatory Peripheral Neruopaties?
A
- Degenerative:
- Giant axonal neuropathy
- Hypertrophic neuropathy
- Birman Cat distal neuropathy
- Metabolic:
- Diabetic neuropathy
- Hyperchylomicronemia
- Hypothyroidism
- Neoplastic
- Nerve sheath tumor
- Leukemia
- Infectious
- Bostulism, Tetanus
- Tick paralysis
- Toxoplasma, Neospora
- Inflammatory
- Coonhound paralysis
- Idiopathic Polyradiculoneuritis
- Idiopathic, immune-mediated
4
Q
What is the diagnostic pathway for peripheral neruopaties?
A
- Accurate localization based on examination
- Reference access
- Clinical features and characteristics alone
- Electromyography and nerve conduction velocity studies
- Fibrillation potentials; positive sharp waves
- Complex repetitive disharges; myotonic discharges
- MNCV, SNCV, RNS
- MRI
- Nerve and muscle biopsy
5
Q
What are the signs of Traumatic Neuropathy? how is it Dx? Tx?
A
- Nomoparesis
- Traction, compression, missile, bite, injection, surgical, ischeia
- LMN signs
- Variable return of function
- Axon intact
- Axon disrupted, support intact
- Severed axon and support
- Dx: history, clin signs, EMG, NCV
- Tx:
- Surgical
- Conservative care
- Amputate if non-functional or no improvement
- 4-6 weeks in most
- Rare recovery after 4 months
- Axons regrow at 1-4mm/day
- Very common
- Even worse is when they are iatrogenic (injection site, compression from leg ties during surgery)
- Cautiously pessimistic prognosis for most patients
6
Q
What is Facial Nerve Paralysis? Dx? Tx?
A
- Mononeuropathy
- Etiology
- Otitis media
- Hypothyroidism
- Trauma
- Idiopathic (75% of dogs, 25% of cats)
- Dx:
- clinical
- eliminate differentials
- EMG
- Tx: supportive
- Poor prognosis for recovery
- Incredibly common, often goes unrecognized, may be an “old lesion”
7
Q
What is Trigeminal Neuritis?
A
- Idiopathic, bilateral
- Acute onset jaw paralysis
- Some clients will present the dog for polydipsia
- Concurrent neuropathy
- CN7, Sensory CN5
- Horner’s
- Dx: Clinical
- Tx: Supportive
- Good Prognosis
- DDx: leukemia, mononuclear cell neoplasia, rabies
8
Q
What is Coonhound Paralysis/Idiopathic Polyradiculoneuritis?
A
- Hunting dogs (CP) or any breed (IP)
- Common polyneuropathy
- Clinical presentation
- onset 7-11 days post exposure
- Progressive over 12 hours or up to 10 days
- LMN signs
- Normal from neck up
- Persists up to 3 months
- Severe- affect facial nerve, voice, breathing
- Dx:
- Clinical
- EMG/MNCV- may be normal
- CBC/Chem - normal
- Tx:
- supportive
- Mechanical ventilation in some cases
9
Q
What is Tick Paralysis?
A
- A NM jjunction disorder (NOT a neuropathy)
- 5-9 days post-attachment
- Progressive over 1-3 days
- Clinical signs:
- Diffuse LMN signs
- Voice change, cough, dysphagia
- Normal cranial nerves
- Respiratory paralysis
- Tx:
- Tick removal ⇢ rapid recovery
- Isoxazolone preventatives to prevent
10
Q
What is Botulism?
A
- A NM junction disease (Type C toxin)
- Progressive ascending LMN paralysis
- Additional Findings
- Megaesophagus
- KCS
- Dysphagia
- Cranial nerve dysfunction
- Uncommon
- Tx: supportive
- No C antitoxin
- 14-24 days for spontaneous recovery
11
Q
What is Botulism?
A
- A NM junction disease (Type C toxin)
- Progressive ascending LMN paralysis
- Additional Findings
- Megaesophagus
- KCS
- Dysphagia
- Cranial nerve dysfunction
- Uncommon
- Tx: supportive
- No C antitoxin
- 14-24 days for spontaneous recovery
12
Q
What is Infectious polyradiculoneuritis?
A
- Protozoal disease
- Neospora caninum
- Toxoplasma gondii (?)
- Puppies <3mo
- Clinical Signs:
- extensor rigidity of pelvic limbs
- Meningoencephalomyelitis, myositis
- Dx: Serology, Cytology, histopathylogy
- Tx:
- Clindamycin, TMS, pyrimethamine
- Ponazuril, toltrazuril
13
Q
What is Chronic Inflammatory Demyelinating Polyneuropathy / Chronic Relapsing Polyneuropathy / Idiopathic Unclassified Demyelinating Polyneuropathy?
A
- Poorly classified and spontaneous
- Variable onset of symptoms and peripheral nerve dysfunction
- Paresis or paralysis involving all 4 limbs is the expected
- Recovery is spontaneous in many
- Immunosuppression helps with some forms
- One of the main differentials for Idiopathic polyradiculoneuritis.
- Biopsy is the only wat to confirm
14
Q
What are some breed specific polyneuropathies?
A
- Idiopathic polyneuropathy of alaskan malamutes (IPAM)
- Boxer dog progressive anonopahty
- Birman cat distal polyneuropathy ( and bengal cat polyneuropathy)
- Laryngeal paralysis polyneuropathy compled of Dalmation and Rottweiler
- Sensory neruopathy of Pointer dogs
- Sensory neuropathy of longhaired dachshunds
- Dancing Doberman Disease
- Giant axonal neuropathy of German shepherd dogs
- Golden retriever hypomyelinating polyneuropathy
- Hypertrophic neuropathy of Tibetan
- Rottweiler distal sensorimotor polyneuropathy
- Neuroaxonal dystrophy of Spanish water dogs
- Polyneuropathy in Black Russian Terrier dogs
15
Q
What issues does Tetanus cause? How?
A
- Tetanospasmin from C. tetani
- Inhibits glycine and GABA release
- Protected from anti-toxin in neuron
- Generalized muscle stiffness, sardonic grin, laryngeal spasm
- Infected wounds or surgery sites
- Develop over 2-7 days
- Takes 30-45 days to resolve
