Eye
If a patient had a negative/abnormal Corneal Reflex test, what cranial nerves are damaged?
a) CN II, CVII
b) CN V, CN VI
c) CN III, CN IV, CN VI. CN VIII
d) CN V and CN VII
CORRECT: CN V, CN VI (trigeminal, ophthalmic branch senses / Abducens retracts) *see neuro sheet
b) CN II, CVII (menace response)
c) CN III, CN IV, CN VI. CN VIII (vestibular-ocular reflex / strabismus)
d) CN V and CN VII (palpebral reflex)
Are Vestibular syndromes Motor or Sensory disorders?
Sensory
(this is why they affect conscious or unconscious pathways, but not directly UMN “EPS or PS” and LMN pathways) they can affect them secondarily
What eye tests/responses would still be present in a cortically blind (damage to visual cortex/occipital lobe) patient?
a) Dazzle reflex and PLR
b) Menace response and PLR
c) Maze test and visual tracking
d) Maze test and Corneal reflex
CORRECT: Dazzle reflex (retina, optic nerve, optic tract, visual reflex center, CN VII) and PLR (retina, optic nerve, optic tract pectenum, CN III, constrictor pupillae)
b) Menace response (visual cortex not there to perceive the threat) and PLR
c) Maze test and visual tracking
d) Maze test and Corneal reflex (does not need visual cortex)
Would you expect to see Glial scarring in the CNS or PNS?
CORRECT: CNS (permanent damage)
PNS (wallerian degeneration if endoneurium is intact)
When evaluating muscle tone on a dog, what system would you be concerned with if you observed flaccidity of muscles?
CORRECT: LMN (flaccidity)
UMN (rigidity)
A cat comes into your clinic with its pupils facing inward (medial strabismus). What muscle and cranial nerve is damaged?
a) Ventral Oblique, Oculomotor nerve
b) Medial rectus, Oculomotor nerve
c) Dorsal Oblique, Trochlear nerve
d) Lateral rectus, Abducens nerve
CORRECT: Lateral rectus, Abducens nerve
b) Medial rectus, Oculomotor nerve
c) Dorsal Oblique, Trochlear nerve
d) Ventral Oblique, Oculomotor nerve
If an animal is showing signs of head tilting and occasional loss of balance while standing still, what structure of the inner ear is damaged?
a) 3 Semicircular canals
b) Vestibule
c) Ossicles
d) Spinal organ
CORRECT: Vestibule (static equilibrium - "standing still")
b) 3 Semicircular canals (dynamic equilibrium)
c) Ossicles (in middle ear, contributes to sound)
d) Spinal organ (responsible for sound)
A cat was attacked by a dog and sustained a deep laceration along the right cranial thoracic wall. Neurological testing shows that the cutaneous trunci reflex is absent on the right side but normal on the left side. All other spinal reflexes are normal. Which spinal cord segments are most likely damaged, and why does this produce the described cutaneous trunci reflex pattern?
a) Bilateral damage to L4–S1 segments — disrupts afferent sensory input from the flank
b) Right-sided damage to C8–T1 segments — interrupts the lateral thoracic nerve motor output
c) Right-sided damage to T10–T12 segments — interrupts ascending afferent input from caudal areas
d) Left-sided damage to C6–C8 segments — interrupts proprioceptive sensory tracts
CORRECT: b) Right-sided damage to C8–T1 segments — interrupts the lateral thoracic nerve motor output
Which type of cerebral edema results from ATP failure causing ischemia and leading to cell swelling?
CORRECT: Cytotoxic edema (Intracellular accumulation in neuron, glial cells, endothelial cells)
Vasogenic edema (EC accumulation in white matter due to breakdown of BBB)
If a dog had Paradoxical/Cerebellar Vestibular Syndrome, what pathway would be affected? (think about how symptoms present)
Unconscious Proprioceptive Pathway "ascending pathway"
(this is the reason they have delayed/exaggerated postural reactions on the ipsilateral side of the lesion)
A 6-year-old dog is presented with bilateral ocular redness, mucopurulent discharge, and frequent blinking. The owner reports the dog’s eyes appear dry and have been slowly worsening over the past few months. On examination, you notice corneas have superficial vascularization, but there is no evidence of ocular pain. Based on these findings, what is the most likely type of keratoconjunctivitis sicca?
a) Cherry Eye
b) Qualitative KCS
c) Quantitative KCS
d) Neurogenic KCS
CORRECT: Quantitative KCS (idiopathic, aqueous tear film deficiency, caused by immune-mediated destruction of lacrimal gland)
b) Qualitative KCS (lipid or mucous layer abnormality)
c) Neurogenic KCS (unilateral, dry nostrils or xeromycteria, failure of parasympathetic innervation to lacrimal gland)
d) Cherry Eye
A 5-year-old Cocker Spaniel is presented with chronic ear scratching, head shaking, and a malodorous, dark discharge from both ears. The owner mentions the dog swims frequently during summer and has a history of seasonal itching. On examination, the external ear canals are erythematous, edematous, and have some crusts, with a thick, brown discharge. Cytology reveals cocci bacteria and Malassezia yeast. The owner admits they often forget to administer the prescribed ear medications.
What are the Predisposing, Primary, Perpetuating, and Secondary factors to this dog developing Otitis Externa?
Predisposing: cocker spaniel, frequent swimming
Primary factors: seasonal itching (atopic dermatitis flare ups)
Perpetuating: Pathologic changes, owner non-compliance
Secondary factors: bacterial and yeast infections
A 5-year-old dog is presented after a minor trauma. On examination the left eye shows miosis and ptosis. There is also found to be damage to the spinal cord segments T1-T3. What disorder does this describe?
a) LMN hindlimb paralysis
b) Facial nerve paralysis
c) Blindness
d) Horner’s syndrome
CORRECT: Horner’s syndrome (hypothalamus is 1st order bodies, T1-T3 is 2nd order bodies, cranial cervical ganglion in tympanic bulla is 3rd order bodies, CN V causes Mydriasis)
b) Facial nerve paralysis
c) Blindness
d) LMN hindlimb paralysis
What microscopic change occurs in neurons by lysosomal storage diseases?
a) Accumulation of lipofuscin pigment
b) Enlargement of cell body
c) Central chromatolysis
d) Intraneural inclusions
CORRECT: Enlargement of cell body
b) Accumulation of lipofuscin pigment (aging)
c) Central chromatolysis (axonal injury, degenerative, viral, or inherited conditions)
d) Intraneural inclusions (viral infections)
During the Correction of Imbalance reflex, the vestibular receptors detect head movement and send a signal through CN VIII to the vestibular nuclei in the brainstem. From there, the output goes to the Cerebellum for coordination/fine tuning and the Vestibulospinal tracts for postural reflexes. This tract descends to the spinal cord to influence LMNs of anti-gravity extensor muscles.
Can you list some of the major extensors in the limbs of quadrupeds and give their functions? (I listed only 4 major ones)
Gluteal muscles (extend hip)
Quadriceps femoris (extend stifle)
Gastrocnemius/other distal limb extensors (extend hock and stabilize stance)
Triceps brachii (extend the elbow)
A 3 yr old cat is presented because the owner reports that it bumps into furniture and seems to ignore her ball when it’s thrown past her. The cat’s pupils constrict normally when a bright light is shone in either eye and the corneas appear clear. However, the menace response is absent in both eyes. Based on these findings, where is the most likely location of the lesion?
a) Optic nerve
b) Oculomotor nerve
c) Thalamus (LGN)
d) Retina
CORRECT: Thalamus (LGN) (deficits affect vision only, optic nerve still works but signal cannot travel to visual cortex for animal to perceive the threat so menace response not triggered)
b) Retina (PLR in tact)
c) Optic nerve (visual info still traveling though to allow for PLR)
d) Oculomotor nerve (PLR intact)
A dog comes into your clinic with suspected vestibular disease. Upon observation you note the right eye is constricted, while the left eye appears to be a normal dilation. There is also fast phase nystagmus to the left. You perform a hemiwalking test and hopping test on both the thoracic and pelvic limbs. The results come back unremarkable. Where can this lesion be localized to? (location and side)
a) Peripheral, right
b) Peripheral, left
c) Central, right
d) Central, left
CORRECT: Peripheral, right (normal postural reactions, horner’s syndrome to affected eye, nystagmus is contralateral)
b) Peripheral, left
c) Central, right
d) Central, left
A 3-year old dog is presented after a minor fall. The dog is showing signs of tetraparesis, but the problem seems to worsen in the rear limbs. On neurological examination, you find spinal reflexes are slightly increased, pain perception is intact, increased tone, and delayed postural reactions in all limbs. Cranial nerves are also found to be normal. Based on these findings, where is the dog’s lesion?
a) C1-C5 spinal cord
b) C6-T2 spinal cord
c) T3-L3 spinal cord
d) L4-S2 spinal cord
CORRECT: C1-C5 spinal cord (UMN signs to all limbs)
b) C6-T2 spinal cord (LMN signs to forelimbs and UMN signs to hindlimbs)
c) T3-L3 spinal cord (UMN signs to hindlimbs)
d) L4-S2 spinal cord (LMN signs to hindlimbs)
A 5-month old puppy presents with depression, fever, and stumbling when walking. On a neurological exam, you notice circling and head pressing. Analysis of CSF shows an increased number of white blood cells. A necropsy of another affected littermate shows multiple foci of gliosis and perivascular cuffing within the brain and spinal cord gray matter. What general type of neurological disease does this describe?
a) Neoplasia
b) Degenerative diseases
c) Metabolic-toxic diseases
d) Inflammatory disease
CORRECT: Inflammatory disease
(encephalitis or meningioencaphalitis - e.g. canine distemper)
A 10-year-old dog has chronic joint pain, stiffness, and pain at rest, sometimes affecting areas beyond the affected joints. The clinician notes that peripheral sensitization (hyperexcitable joint nerves) and central sensitization (spinal cord and brain neurons amplifying pain signals) are contributing to the dog’s discomfort. Which condition is most likely?
a) Osteopetrosis
b) Osteogenesis imperfecta
c) Osteoarthritis
d) Chondrodysplasia
CORRECT: Osteoarthritis (chronic joint degeneration causing persistent pain that spreads and occurs at rest)
a) Osteopetrosis (genetic disorder of bone resorption/osteoclasts deficiency - usually painless - causes bone marrow/neurological issues)
b) Osteogenesis imperfecta (genetic disorder of bone formation/osteoblasts with genes coding for type I collagen - acute pain)
d) Chondrodysplasia (genetic disorder of endochondral ossification, Disproportionate dwarfism - Dachshund - not painful)
An owner has you look at her 7-year old Horse for a gradually enlarging, slightly red eye with increased corneal diameter. The dog does not seem to be in any pain, and the owner reports that this has been noticed over the past several weeks. Upon gonioscopy, you notice the iridocorneal angle is normal-appearing, but aqueous humor outflow seems to be impaired. Based on these findings, what is the most likely type of glaucoma?
a) Acute secondary glaucoma from uveitis
b) Congenital glaucoma
c) Open-angle glaucoma
d) Closed-angle glaucoma
e) Lens-induced glaucoma
CORRECT: Open-angle glaucoma (w/ buphthalamus)
b) Closed-angle glaucoma
c) Acute secondary glaucoma from uveitis
d) Congenital glaucoma
e) Lens-induced glaucoma
An 11-year old dog is brought by its owner after suddenly developing a pronounced head tilt to the left, vomiting, and horizontal nystagmus. The owner reports that the dog was fine yesterday and there have been no other signs of illness. On neurological examination, you note postural reactions are normal and there are no cranial nerve deficits. Based on this information, what should your top differential be?
a) Idiopathic Vestibular disease
b) Otitis Media
c) Neoplasia
d) Vascular Infarction
CORRECT: Idiopathic Vestibular disease (peripheral)
b) Otitis Media (peripheral, would have something with the ear)
c) Neoplasia (central/cerebellar)
d) Vascular Infarction (aka stroke - central/cerebellar)
A 2-year old dog is presented with generalized weakness that worsens with exercise. The owner reports that the dog tires quickly when playing fetch and collapses after running. On neurological examination, the reflexes are reduced but present, muscle tone is slightly decreased, and there appears to be no sensory deficits. Based on these findings, which type of disorder is most likely?
a) Upper motor neuron disease
b) Vestibular disorder
c) Junctionopathy
d) Myopathy
CORRECT: Junctionopathy (neuromuscular junction disorder, LMN signs to all limbs, e.g. Myasthenia gravis)
b) Vestibular disorder (no head tilt, nystagmus, ataxia)
c) Upper motor neuron disease (would have increased muscle tone, hyperreflexia, slow/stiff gait)
d) Myopathy (weakness is not exercise dependent)
You’re asked to take a farm call because the owner is concerned that his cows have started exhibiting sudden onset of incoordination, blindness, and dull mentation. Upon observation, you see that several cows are affected. None have a fever, and CSF analysis is normal. On necropsy, both cerebral hemispheres show soft, pale areas of necrosis that are bilaterally symmetrical. Microscopic examination reveals spongy degeneration of the gray matter and neuronal necrosis. What general type of neurological disease does this describe?
a) Metabolic-toxic diseases
b) Idiopathic diseases
c) Degenerative diseases
d) Vascular diseases
CORRECT: Metabolic-toxic diseases (polioencephalomalacia or lead poisoning)
It was mentioned that you can see specific peripheral nerve deficits in a L4-S2/3 spinal cord segment lesion.
1. Can you list the 2 peripheral nerves?
2. What specific segments are involved for each?
3. What clinical signs would you see when each nerve is not working? (*hint* think about the muscles they innervate, what the function of that muscle is, and the reflexes associated with those nerves)
1. Femoral nerve and Sciatic nerve
2. Femoral (L4-L6) / Sciatic (L6-S2)
3. Femoral n. damage = atrophy of quadriceps muscles, weak stifle extension (cannot support weight), and reduced/absent patellar reflex
3. Sciatic n. damage = atrophy of hamstrings and distal limb muscles, weak hip extension, hock, and digit movements, reduced/absent flexor (withdrawal) reflex of pelvic limb