Lesson 48/49
Where could a lesion be located if the patient is experiencing intention tremors?
Paradoxical/cerebellar
What cranial nerve tests are only for retinal function not vision?
Pupillary light reflex (CN lll) and Dazzle light reflex (CN Vll)
A patient presents with seizures and behavioral changes, immediately what part of the brain should you suspect has a lesion?
Cerebral lesion
How does glaucoma develop?
Production of aqueous humor (AH) exceeds drainage leading to increased intraocular pressure
What are the different spinal cord segments for neurolocalization?
C1-C5
C6-T2 (brachial plexus)
T3-L3
L4-S2/3 (lumbosacral plexus)
What disease causes facial nerve paralysis in yearling heifers?
Listeriosis
What test is performed to ensure the eyes are producing an adequate amount of tears?
Schirmer tear test
A patient presents with a lesion on the brainstem, what clinical signs could one expect to see?
Decreased mentation, Cranial nerve (3-12) signs, UMN reflexes, ipsilateral signs and tetraparesis
What are the 3 different types of corneal dystrophy?
Epithelial (upper layers of all breeds)
Stromal (middle layer in younger dogs (cocker spaniels, bearded collies, weimaraners))
Endothelial (deepest layer in Boston terriers, boxers, cockers, chihuahuas, dachshunds, dalmatians, and poodles)
What are clinical signs of an UMN injury? What about LMN?
UMN- Paresis or paralysis, normal or exaggerated spinal reflexes, increased muscle tone (rigidity, spasticity), mild muscle atrophy (disuse)
LMN- Paresis or paralysis, weak or absent spinal cord reflexes, decreased muscle tone (flaccid), early muscle atrophy
What does CHANG stand for?
Cyst, hematoma, abscess, neoplasia, and granuloma
What ophthalmic tool is used to test intraocular pressure and what drug should be used?
Tonometer and topical anesthetic (proparacaine)
What are the three main functions of the cerebellum highlighted in lecture?
Coordination of movement and posture, regulation of body tone, and maintenance of equilibrium
What is the difference between corneal dystrophy and corneal degeneration?
Corneal dystrophy: Inherited non-inflammatory deterioration in the function and structure of the cornea leading to white spots on the cornea which are full of triglyceride, cholesterol and calcium
Corneal degeneration: In older dogs the cornea becomes water-logged and swollen generally secondary to other ocular disease or systemic conditions
(painful if ulcers develop and deposits may be present)
What is the clinical sign progression of loss of function (hint: that picture with the arrow of loss and gain and their clinical signs)...
Proprioception -> ataxia -> voluntary motor -> voluntary urination -> superficial pain -> deep pain
Gain is the order of these clinical signs backwards!
What structures suspend the lens of the eye and control its shape?
Ciliary body
What eye staining technique is used in large animal ophthalmic exams to visualize damaged corneal and conjunctival cells. This practice has been increasingly replaced with lissamine staining because this technique has been known to be cytotoxic and causes irritation?
Rose bengal
What signs will you NOT see if the patient has cerebellar dz?
Weakness/paresis, inability to initiate movement, and mentation changes
What are 3 types of abnormalities of the cilia that can be reported in animals? Describe each.
Ectopic cilia – eyelash growing from underside of eyelid and contacts the cornea
Distichiasis – eyelashes growing from the Meibomian gland on the eyelid margin behind normal eyelashes
Trichiasis – outer eyelid “flips in” and the hair on the eyelid contacts the cornea
A 5yr MN Golden Doodle presents to your clinic with ataxia of the pelvic limbs. Upon examination you notice paresis, exaggerated spinal reflexes and spasticity of the pelvic limbs. There are no abnormalities associated with the thoracic limbs. What is the neurolocalization of the lesion?
T3-L3
(UMN deficits to the hindlimb and no effect to the forelimbs)
What four muscles of the eye are controlled by Cranial nerve 3?
Superior rectus, inferior rectus, medial rectus and inferior oblique
What test examines the patency/integrity of the nasolacrimal tear duct?
Jones test
A patient presents with seizures, altered behavior, and contralateral blindness. The owner notes that she noticed Sparky only eats half of his bowl of food. Where is the lesion located that can explain these findings?
Diencephalic syndrome (clinically grouped with cerebral lesions)-hemineglect
Describe Horner’s syndrome. What is it? What are clinical signs associated with it? What is it associated with?
It is a disruption of sympathetic innervation to the eye which is normally not harmful
Clinical signs include: protrusion of the third eyelid is the most noticeable sign normally, miosis, ptosis (droopy upper eyelid), enophthalmos (sunken eyeball)
It is associated with otitis media and inflammation of the inner ear.
What are clinical signs seen with myasthenia gravis (a type of junctionopathy)?
Paresis, decreases spinal reflexes, and flaccid thoracic and pelvic limbs
You can also see neck and facial weakness, excessive drooling, and difficulty breathing