Neuro/Sp_senses Flashcards
(164 cards)
Damage to which cranial nerve causes MEDIAL strabismus?
CN VI
What are the 4 physiologic compartments of the cranial space?
Blood, CSF, intracellular fluid, extracellular fluid
Where is most CSF formed and where is it drained?
Formed by ultrafiltration from blood vessels of the choroid plexus lining the ventricles
Drains into the subarachnoid space, where it is absorbed
What forms the motor unit?
Lower motor neurons, neuromuscular junction, skeletal muscle fibers
What is the most common cranial nerve to be affected by a nerve sheath tumor?
The trigeminal nerve
What is neuropraxia?
The loss of nerve conduction without structural changes. Can occur from transient loss of blood supply and usually resolves over weeks to months.
What is axonotmesis?
Axonal damage without loss of supporting structures. It requires regeneration of the axons toward its specific muscle target before functional recovery.
How quickly does axonal regeneration occur?
1 mm per day
What is neurotmesis?
The complete severance of the nerve. This is typically seen with severe trauma.
How do patients with toxoplasmosis or neospora typically present?
They initially have flaccid paraparesis that may progress to a chronic state of extreme extensor tone. Once hind limb rigidity has developed, clinical improvement no longer occurs.
List 3 drugs that may result in neuropathies
Vincristine, thallium, organophosphates
How is masticatory myositis confirmed?
Either by muscle biopsy or through serum titers for antibodies against type IIM muscle fibers
Which breeds of dogs are over-represented in cases of acquired myasthenia gravis?
German shepherds, Labs, Akitas
What is the difference between localized, generalized, and fulminant myasthenia gravis?
Localized: Typically show facial, laryngeal, or pharyngeal dysfunction without appendicular muscle involvement
Generalized: Appendicular muscle weakness with out without signs of facial, pharyngeal, or laryngeal dysfunction
Fulminant: Sudden, rapid, progression of severe appendicular muscle weakness resulting in recumbency, frequent regurgitation, and facial, pharyngeal, and laryngeal dysfunction
In what percent of dogs with acquired myasthenia gravis will detectable levels of antibodies to acetylcholine receptors be found?
80-90%
In what percentage of dogs with myasthenia gravis will the disease be related to a thymoma?
15%
How long will it take to see complete resolution of signs in a dog with botulism?
2 to 3 weeks
How long after attachment of a tick will signs of tick paralysis be seen? And how quickly will signs resolve after the tick is removed?
3 to 5 days after attachment, signs will resolve within 24-72 hours after the tick is removed.
What nerves can be safely biopsied to diagnose a neuropathy?
Fascicular biopsies of the ulnar or peroneal nerves
What makes up a lower motor neuron?
Cell bodies found in the brainstem or spinal cord, and their motor axons within the cranial or spinal nerves respectively. They terminate on skeletal muscle fibers at the neuromuscular junction.
Equation for cerebral perfusion pressure?
CPP=MAP-ICP
What types of factors affect the volume of the blood in the brain?
Altered vascular tone or blood viscosity, impaired venous outflow (head-down posture, jugular vein compression, increased intrathoracic pressure)
What is the normal ICP int he dog?
5-12 mm hg
T/F: The upper limit of ICP in which tx for ICH should be instituted has not been defined in dogs, but is 20 mm Hg in humans
True