Cranial Nerves and Neurological Functions Quiz

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Questions and Answers

Which cranial nerve is responsible for motor function of the trapezius muscle?

CN XII

CN XI (correct)

CN V

CN VII

What is the function of the baroreceptor reflex?

Stimulates salivation

Regulates blood pressure (correct)

Controls muscle movement

Controls breathing rate

Which cranial nerve pair is NOT routinely tested during a neurologic examination?

CN III

CN XI (correct)

CN I

CN II

Which cranial nerve is associated with the menace response?

CN II and CN VII (B) Signup and view all the answers

What is the primary function of the vagus nerve (CN X)?

Regulates parasympathetic functions (C) Signup and view all the answers

What is the purpose of the 'explode-the-hand' technique used in the menace response test?

To avoid stimulating the whiskers or eyelashes (A) Signup and view all the answers

Which of the following is NOT a cranial nerve routinely tested in a neurological examination?

Olfactory nerve (CN I) (B) Signup and view all the answers

What is the main function of the hypoglossal nerve (CN XII)?

Controls tongue movement (B) Signup and view all the answers

What is the main characteristic that distinguishes an overreaching, long-strided, floating gait caused by an UMN lesion from a gait caused by cerebellar hypermetria?

The degree of flexion or extension of the elbow joint. (B) Signup and view all the answers

Which cranial nerve is responsible for sensory input from the inner pinnae of the ear?

Facial nerve (VII) (B) Signup and view all the answers

What is the primary function of the trochlear nerve (IV)?

Motor control of the dorsal oblique muscle. (A) Signup and view all the answers

Which of the following is NOT a sign of a C6-T2 myelopathy?

Bilateral elbow osteoarthritis. (A) Signup and view all the answers

Which cranial nerve, when damaged, can lead to difficulties with chewing and swallowing?

Glossopharyngeal (IX) (B) Signup and view all the answers

The dorsal, medial, and ventral rectus muscles, as well as the ventral oblique muscle, are all associated with:

The movement and function of the eyes. (B) Signup and view all the answers

Which of the following is NOT a component of the physical examination that should be performed before evaluating cranial nerves?

Assessing pupillary light reflex. (D) Signup and view all the answers

What is the function of the levator palpebrae dorsalis muscle?

Raising the upper eyelid. (D) Signup and view all the answers

Which of the following is a reliable indicator of vestibular dysfunction?

A history of gagging, retching, or coughing while eating or drinking (C) Signup and view all the answers

What is a possible cause of bilateral atrophy of the masticatory muscles?

Masticatory muscle myositis (C) Signup and view all the answers

Which cranial nerve does the author explicitly state is NOT routinely tested during a neurologic examination?

CN I (Olfactory) (A) Signup and view all the answers

What is a potential drawback of using the gag reflex to evaluate CN IX (Glossopharyngeal) and CN X (Vagus)?

It can be unreliable because some normal dogs may not swallow. (D) Signup and view all the answers

Which of these is NOT a characteristic of pathologic nystagmus?

It is always associated with vestibular dysfunction. (C) Signup and view all the answers

What muscles are potentially affected by a CN XI (Accessory) deficiency?

Trapezius and sternocephalicus (A) Signup and view all the answers

Why do the authors not routinely evaluate olfaction, taste, or hearing?

The results can be subjective in animals and difficult to interpret. (D) Signup and view all the answers

What condition can be indicated by difficulty opening the jaw and bilateral atrophy of the masticatory muscles?

Masticatory muscle myositis (C) Signup and view all the answers

What is the term used to describe weakness in one limb of a dog?

Monoparesis (A) Signup and view all the answers

Which condition describes a dog that cannot walk on its own but has voluntary motor control in the pelvic limbs?

Nonambulatory paraparesis (C) Signup and view all the answers

What is the best surface for observing a dog's gait?

Grass (A) Signup and view all the answers

How should a clinician describe a dog's gait if both pelvic limbs are affected?

Paraplegia (D) Signup and view all the answers

Which term refers to the lack of voluntary movement in all four limbs of a dog?

Tetraplegia (B) Signup and view all the answers

What does ataxia refer to in regards to canine gait?

Incoordination of movements (A) Signup and view all the answers

If a dog exhibits symptoms of weakness in both hind limbs but can still move its front limbs normally, which term is appropriate?

Paraplegia (C) Signup and view all the answers

When walking a dog for gait analysis, the leash should ideally be:

Short and taut (D) Signup and view all the answers

What two cranial nerves are tested during the pupillary light reflex?

Cranial nerves II and III (A) Signup and view all the answers

The menace response is considered a learned response in dogs and cats, developing around what age?

10-12 weeks (C) Signup and view all the answers

Which part of the central nervous system (CNS) can be directly evaluated during a fundic examination?

Optic disc (B) Signup and view all the answers

Why do the authors prefer an indirect fundic examination?

It avoids the observer being too close to the patient’s mouth (B) Signup and view all the answers

What two cranial nerves are assessed during the palpebral reflex?

Cranial nerves V and VII (D) Signup and view all the answers

Which of the following is NOT a function assessed during the palpebral reflex?

Pupillary light reflex (D) Signup and view all the answers

What is the primary role of the cerebellum in relation to the menace response?

Exerting some influence over the response (A) Signup and view all the answers

A dog with cerebellar dysfunction may exhibit what abnormal neurological sign?

Absent menace response ipsilateral to the lesion (A) Signup and view all the answers

Which cranial nerves are tested when examining corneal sensation and globe retraction?

CN V, VI, VII (C) Signup and view all the answers

What is the normal response when testing corneal sensation with a cotton swab?

Eyelid closure and eyeball retraction (B) Signup and view all the answers

Why should you not perform a gag reflex on aggressive or nervous dogs?

It may cause additional trauma. (A) Signup and view all the answers

Which cranial nerve is evaluated by assessing jaw tone?

CN V (B) Signup and view all the answers

What indicates a normal nystagmus response during the head turning test?

Fast phase in the direction of head movement (C) Signup and view all the answers

What is the appropriate method to test for tongue deviation or atrophy?

Observing resting tongue position (C) Signup and view all the answers

Which cranial nerves are involved in the action of swallowing?

CN IX and X (B) Signup and view all the answers

What is the role of CN VII during the menace response test?

Eyelid closure (D) Signup and view all the answers

Study Notes

Neurologic Examination

Five main sections: mental status, gait analysis and body posture, cranial nerves, postural reactions, and spinal and withdrawal reflexes
Additional tests: muscle tone, muscle atrophy, perineal reflex, cutaneous trunci reflex, and nociception and neck/back pain
Routine is important to prevent errors
Using a neurologic examination form is recommended

Mental Status

Assess mental status throughout the examination, and patient should be alert and responsive at all times
Note interactions with humans and environment, including:
- Full alertness and responsiveness
- Difficulty navigating corners or tight spaces
- Circling behavior
- Response to name

Gait Analysis & Body Posture

Early analysis is essential, especially for nervous or stressed cats
Assess gait and posture for weakness (paresis) or paralysis (plegia), ataxia, and lameness
Evaluate ambulation (ambulatory or non-ambulatory) and affected limbs/degree of weakness (mono-paresis, para-paresis, tetra-paresis, hemi-paresis)
Observe for ataxia (proprioceptive, cerebellar, vestibular)
- Proprioceptive ataxia: scuffing paws, knuckling, crossing over, or interference (limbs hitting each other)
- Vestibular ataxia: leaning or falling to one side, uses wall for support
- Cerebellar ataxia: dysmetria (unequal range/force of each step) or hypermetria (overflexion)
Examine for postural abnormalities: head tilt, head turn, torticollis

Cranial Nerve Examination

Performed after gait and mental status
Method: numerical order or by location (eyes, nose/face, ears, mouth)
Twelve pairs of cranial nerves (CNs)
Not all are routinely tested
Include:
- Olfactory (I)
- Optic (II)
- Oculomotor (III)
- Trochlear (IV)
- Trigeminal (V)
- Abducens (VI)
- Facial (VII)
- Vestibulocochlear (VIII)
- Glossopharyngeal (IX)
- Vagus (X)
- Accessory (XI)
- Hypoglossal (XII)

Cranial Nerve Examination (Step-by-Step)

Step 1 (Menace Response): CN II and VII; cover one eye, menace other eye, and check for blinking response
Step 2 (Pupillary Light Reflex): CN II and III; use a strong light and check for pupil constriction
Step 3 (Fundic Examination): CN II; visual exam of the optic disc
Step 4 (Palpebral Reflex): CNs V and VII; tap the medial/lateral canthus of both eyes to check for blinking response
Step 5 (Physiologic Nystagmus): CNs III, IV, and VI; turn head from side to side and up/down; check if there's abnormal nystagmus (irregular eye movement)
Step 6 (Masticatory Muscles): CN V; palpate for pain or atrophy in the masticatory muscles
Step 7 (Sensory/Motor): CN V and VII; stimulate different areas of the head for sensation/motor response
Step 8 (Nasal Mucosa): CN V; touch nasal mucosa to check for head withdrawal
Step 9 (Jaw Tone): CN V; open and close mouth to observe jaw tone
Step 10 (Gag Reflex): CN IX and X; gently touch the oropharynx/laryngopharynx to induce swallowing (use caution with nervous/aggressive animals)

Postural Reactions

Assess general proprioception of the limbs
Paws are positioned, and patient returns to normal position
Additional tests: hopping/wheel-barrowing and extensor postural thrust (additional proprioception testing)
- For proprioception, failure to return the paw to normal position can be due to the use of a muzzle or owner distraction

Spinal Nerve Reflexes

Testing patellar reflex (femoral nerve) by striking straight patellar tendon.
Withdrawal reflex using hemostats to induce flexion of all joints in the limb
Test for crossed extension (UMN lesion) of contralateral limb

Ancillary Tests

Muscle tone and atrophy, cutaneous trunci reflex, perineal reflex, or anal tone, nociception, and neck/back pain
Evaluate for conscious nociceptive stimulus (e.g., turning, biting, respiratory rate changes).
Palpate along the vertebral column for possible pain/problems; observe neck/tail movement

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Description

Test your knowledge on cranial nerves and their functions with this quiz. Explore the roles of different cranial nerves in motor and sensory activities, reflexes, and neurological examinations. Ideal for students studying neuroscience or veterinary neurology.