Peripheral Neuropathy Flashcards
Motor unit includes
Lower motor neuron
Neuromuscular junction
Muscle fibers
Functional signs of diffuse motor unit disease
Paresis
Weakness
Gait abnormalities
Exercise induced weakness
Reduced reflexes
Postural alterations (cervical ventroflexion)
Dysphonia
Regurgitation
Dysphagia
Dyspnea
Megaesophagus
Dilation of esophagus
Common with generalized motor unit disease
Development of megaesophagus in cats/dogs
Skeletal muscle distribution in
2/3 in dogs
1/3 in cats
Classic sign of weakness in cats
Cervical ventroflexion
Cats don’t have a Nuchal ligament and will sit back on haunches bc they can’t lift their head
Testing for diffuse neuromuscular disease
Signalment, History, Physical exam, Neurologic Exam
• CBC, Chemistry (including CK), Urinalysis
• Metabolic/Endocrine and infectious disease testing as appropriate
• Thoracic Radiographs, Abdominal Ultrasound
• ACh antibody titer (will be discussed further)
Advanced testing for for NMD
Electro diagnostics
Muscle/nerve biopsy
CT/MRI
CSF sampling
Neuropathy
Primary injury to cell body, secondary demyelination
Axonopathy
Primary injury to axon, secondary demyelination
Demyelination
Primary loss of myelin, no change to axon
DAMNITV
Degenerative
Anomalous
Metabolic
Nutritional
Neoplastic
Idiopathic
Inflammatory
Infectious
Trauma
Toxin
Vascular
Degenerative polyneuropathy
Laryngeal paralysis
Could be hereditary or acquired
Hereditary laryngeal paralysis
Young animals
Huskies, Rottweilers
Varying severity & nerve involvement
Acquired laryngeal paralysis
Older dogs
Large breeds, Labrador retrievers**
Prognosis and treatment for laryngeal paralysis
Generally poor for both hereditary and aquired
Exercise restrictions, avoid stress & heat
Arytenoid lateralization surgery
Diabetic polyneuropathy
Occurs in dogs and cats
Bilateral pelvic limb paresis & abnormal reflexes
Could occur bc the axons are dying or have abnormal Schwann cell function
Diagnosis and treatment of diabetic polyneuropathy
Documented/diagnosed diabetes
Rule out other causes for polyneuropathy
No specific treatment - just control the diabetes
Prognosis is guarded
Neoplastic polyneuropathy
Lymphoma
Some tumors have a predilection for nerves
Paraneoplastic polyneuropathy
Insulinoma
Clinical signs vary and can be severe
Treat underlying neoplasia - will help neuropathy
Inflammatory polyneuropathy
Infectious or immune mediated
Infectious inflammatory polyneuropathy
Neospora canium, toxoplasma gondii
Immune mediated inflammatory polyneuropathy
Immune mediated in cats
Acute polyradiculoneuritis
Trigeminal neuritis
Signalment in immune mediated PN in cats
Young, males more than females
Weakness, tetraparesis, reduced withdrawals
Acute polyradiculoneuritis
Coonhound paralysis
Most common polyneuropathy in dogs
Progressive paresis with reduced reflexes
Diagnosing & treating acute polyradiculoneuritis
Signalment, history, clinical sings, muscle biopsy, CSF eval
Prognosis is good - takes time
Supportive therapy during recovery
Differentials for acute flaccid paralysis
Acute polyradiculoneuritis
Botulism
Tick paralysis
Fulminant myasthenia gravis
Dysautonomia
Degenerative disease
Common in young dogs and cats
Clinical signs are compatible with autonomic dysfunction
