neuro

List the CNs

- CNN 1 - Olfactory

- CNN 2 - Optic

- CNN 3 - Oculomotor

- CNN 4 - Trochlear

- CNN 5 - Trigeminal

- CNN 6 - Abducent

- CNN 7 - Facial

- CNN 8 - Vestibulocochlear

- CNN 9 - Glossopharyngeal

- CNN 10 - Vagus

- CNN 11 - Accessory

- CNN 12 - Hypoglossal

True or false: Menace is a reflex

- False; It is a learned response

CNs of the menace response?

- Afferent: CNN II (Optic Nerve)

- Efferent: CNN VII (Facial Nerve)

Lesions affecting menace?

- Most common in forebrain lesions

- Cerebellar disease

Visual testing options?

- Exam room navigation

- History of any changes

- Maze

- Light vs. dark room

- Menace

CNs of PLR?

- Afferent: CNN II (Optic Nerve)

Efferent: CNN III (Oculomotor Nerve)

What factors can confound interpretation of PLR?

- Ophthalmologic disease (i.e., iris atrophy can cause asymmetry, retinal disease)

CNs of the palpebral reflex?

- Afferent: CNN V (Trigeminal Nerve)

- Efferent: CNN VII (Facial Nerve) -> Orbicularis oculi muscle

When performing the palpebral reflex on the medial canthus of the eye, which branch of CN V is stimulated? What about the lateral canthus?

- Medial: Ophthalmic

- Lateral: Maxillary

CNs of the retractor bulbi reflex?

- Afferent: CNN V (Trigeminal Nerve; Ophthalmic branch)

- Efferent: CNN VI (Abducens Nerve)

CNs involved in vestibulocochlear movement?

- Afferent: CNN VIII (Vestibulocochlear Nerve)

- Efferent: CNN III, IV, VI (Oculomotor, Trochlear and Abducent Nerves)

Which nerves innervate ocular muscles?

- Oculomotor: Dorsal, medial and ventral recti and ventral oblique

- Trochlear: Dorsal oblique muscle

- Abducens: Lateral rectus and retractor bulbi

Medial strabismus indicates dysfunction in which CN? What about ventrolateral strabismus?

- Medial: Abducens

- Ventrolateral: Oculomotor

Three types of pathologic nystagmus?

- Horizontal

- Rotary

- Vertical

Horizontal or rotary nystagmus that is non-changing implies __________ vestibular localization. Any nystagmus that changes with position or has a vertical character implies a more ________ lesion.

- Peripheral

- Central

Nystagmus is named for the fast or slow component?

- Fast

True or false: The Dolley's eye reflex is a physiologic nystagmus in which the slow phase is mediated by the brainstem and the oculocephalic component is mediated by the cerebrum.

- True (Normal reflex is present when moving the pt's head causes eyes to move in opposite direction to maintain the gaze fixed forward)

When is testing the oculocephalic/Doll's eye reflex most fruitful?

- Cases of head trauma

How is vestibular rebound tested?

- Turn head to either side 45 degrees and let the head fall after - the rebound occurs secondary to over compensation by the normal side (indicative of dysfunction)

How is cerebellar rebound tested?

- Hold head straight up and let fall

- Lack of cerebellar control results in dramatic acceleration of the head downward

CNs which mediate nasal/facial sensation?

- Afferent: CNN V (Trigeminal)

- CNN XI (Accessory n.; mediates body movement away from stimulus) and CNN VII (Facial n.; mediates twitching of skin)

What are the three branches of the trigeminal nerve?

- Ophthalmic (red)

- Maxillary (blue)

- Mandibular (green)

The motor component of the mandibular branch of the trigeminal nerve innervates what muscles?

- Innervates muscles of mastication (Masseter, temporalis, rostral digastricus, pterygoid, mylohyoid muscles)

Facial symmetry and signs such as drooping lips/drooling/dropping food are mediated by which CN?

- CN VII

How does one assess function of CNs IX, X, XI, and XII? If dysfunction is observed, one should beware of which disease?

- Through observation of swallowing, tongue movements, and atrophy of muscle groups; Can also palpate cervical muscle mass

- Rabies

Ideal space/factors in which to perform a neurologic exam?

- Quiet room

- Time (May be difficult to be thorough in a 30 min apt slot)

- Carpet or non slippery floor

- Area to observe gait

- Non obstructive areas (no where to hide) for cats

- +/- table for small dogs/cats

Instrumentation needed to perform a neurologic exam?

- Dark room

- Strong light source

- Indirect bio lens

- Hemostats

- Pleximeter/"Neuro Hammer"

*Components of the neurologic exam?

- Mentation/General Observation

- Body/head posture

- CNs

- Gait

- Proprioception

- Motor/spinal reflexes

- Sensory assessment

Two components of mentation and what they are mediated by?

- Level of consciousness (Brainstem; Ascending reticular activating system)

- Content of consciousness (Forebrain)

Categorizations of level of consciousness?

- Alert

- Dull/Obtunded

- Stuporous: Responds to noxious stimuli

- Comatose: No response to noxious stimuli

Categorizations of content of consciousness?

- Appropriate for surroundings

- Agitated or reticent (reserved)

- Aggressive vs. timid

- Changes in habits

- Pacing

- Inappropriate urination/defecation

- Changes in sleep/wake patterns

What is the difference between paresis and paralysis?

- Paresis: Weakness

- Paralysis: Lack of voluntary motor movement

Define Mono vs. Hemi vs. Para vs. Tetra.

- Mono: One limb

- Hemi: One side of the body (right or left limbs)

- Para: One half of the body (front or hind limbs)

- Tetra: All four limbs

What are the three forms of ataxia? Briefly describe them.

- Vestibular - Listing/leaning/rolling/veering

- Cerebellar - Dysmetria/hypermetria of one or all limbs

- Proprioceptive - Crossing over of front/hind limbs/evidence of nail wear/dragging of front or hind limbs

Postural reactions test the function of what?

- The proprioceptive tracts

- Sensory and motor involved

Which postural reactions require movement of the limb to correct for displacement? These reactions are accentuated by __________.

- Hopping, Wheel Barrow, Extensor Postural Thrust

- Weakness

Of hopping, wheel barrow, and extensor postural thrust, which is the most sensitive for minor deficits?

- Hopping

How does one interpret the results of a hopping test in which the pt has poor initiation? What about if the pt has poor follow through?

- Poor initiation: Proprioceptive deficit

- Poor follow through: Motor deficit (paresis)

Why are proprioceptive positioning/placing tests performed with some support of the animal's weight?

- So weakness has less of an influence

How does one perform proprioceptive positioning/placing tests?

- Gently turn animal's paw over and they should immediately replace (Watch out for withdrawal)

- Tactile placing test: Bring the animal to edge of platform/table without being able to visualize it and watch for proper placement

- Visual placing test: Repeat the test above but allow the animal to visualize normally; They should "reach" for the surface

How are withdrawal reflexes tested?

- Noxious stimulus applied to toe and entire limb should flex

- Test both medial and lateral toes

*Which nerves are involved in the withdrawal reflexes of the thoracic and pelvic limbs.

- Thoracic: Axillary, musculocutaneous, median, ulnar and radial nerves (C6-T2)

- Pelvic: Sciatic nerve (L6-S1)

True or false: Withdrawal reflexes require input from the brain.

- False

*The patellar reflex tests which nerve? It should result in what action?

- Femoral nerve (L4-L6)

- Extension of stifle

*The cranial tibial reflex tests which nerve? It should result in what action?

- Peroneal branch of the sciatic nerve (L6-7)

- Flexion of hock

*The extensor carpi radialis reflex tests which nerve? It should result in what action?

- Radial nerve (C7-T1)

- Slight extension of carpus

*How is the perineal reflex tested? What nerve is involved?

- Light stimulation of the perineum with forceps -> Should "wink"

- Pudendal nerve (S1-3)

*Nerves of the brachial plexus?

- SSMARMU

- Suprascapular

- Subscapular

- Musculocutaneous

- Axillary

- Radial

- Median

- Ulnar

How is vertebral palpation performed?

- Cervical: Ventral palpation starting at thoracic inlet (Too much muscle mass dorsally) with gentle flexion and extension

- Thoracolumbar: Over dorsal spinous processes or just lateral to them while supporting gently under the abdomen

Which nerve and muscle are involved in the cutaneous trunci/panniculus reflex? How can it be interpreted

- Lateral thoracic nerve (C8-T1) >> cutaneous trunci muscle

- As you perform caudal to cranial, if there is a deficit you will begin seeing rxn approximately 2 vertebral bodies caudal to the lesion

When is the Panniculus reflex most sensitive?

- When voluntary motor is lost

A pt walks into your clinic with a normal gait and a history of seizures. Should you test for superficial/deep pain during your neurologic exam?

- No (If pt is walking normally, do not need to check for pain)

True or false: When testing for deep or superficial pain, a withdrawal of the limb indicates the pt perceived the pain.

- False

What are the key divisions of the nervous system?

- Brain

- Spinal Cord: C1-C5 / C6-T2 / T3-L3 / L4-S2 segment

- Neuromuscular

What are the key divisions of the brain?

- Forebrain (Cerberum/Telencephalon)

- Thalamus (Diencephalon)

- Brainstem

- Cerebellum (Note it is in a very vulnerable location)

- Ventricles

What are the lobes of the forebrain?

- Frontal Lobe: Intellect and behavior

- Temporal Lobe: Emotion (Aggression, fear)

- Parietal Lobe: Proprioception and nociception

- Occipital Lobe: Vision

Which structure produces CSF?

- Choroid plexus

Obstruction of the ventricles of the brain can result in what?

- Hydrocephalus

What comprises white and grey matter?

- Grey matter: Nuclei

- White matter: Axons

Components of the neuromuscular division of the nervous system?

- Nerve root(s)

- Peripheral Nerve

- Neuromuscular junction

- Muscle

Disease of which component of the nervous system will result in change in the content of consciousness?

- Forebrain disease (Behavior, habits, intellect, personality, abnormal elimination habits, abnormal wake/sleep cycles, failure to recognize O, change in demeanor)

*Common signs of forebrain disease?

- Seizures (Focal/Partial/Generalized)

- Altered mental status (disorientation, change in routine, lethargy)

- Circling (Wide), pacing, obsessive or aimless wandering (All in the direction of the lesion, usually)

- Head pressing

- Proprioceptive ataxia

- Papilledema, irregular respiration

- Contralateral deficits: Partial CN deficits, CP deficits, hemiparesis, hemi-sensory loss, UMN reflexes, visual impairment with normal PLR

*Signs of thalamic disease?

- Normal or abnormal gait

- Altered mentation/behavior

- Aggression/excitability

- Circling/Pacing/Wandering/Head pressing

- Bilateral CNN II deficits (lesion at the level of the optic chiasm): Pupil dilation, visual loss, decreased PLR

- Abnormal temperature regulation (Hyper/hypothermia)

- Abnormal appetite (Increased or decreased)

Thalamic disesae can cause what other disorders?

- Endocrine disturbances: DI, DM, Cushings (I.e. pituitary macroadenoma), Addison's

- Seizures

Components of the brainstem?

- Midbrain

- Pons

- Medulla

*Main finding of brainstem disease?

- Change in level of consciousness (alert/obtunded/stuporous/comatose) but appropriate

*Other clinical findings of brainstem disease?

- Level of consciousness change

- Ipsilateral conscious proprioceptive deficits

- Spastic (UMN) weakness or paralysis of all four limbs or limbs on the ipsilateral side

- UMN reflexes ipsilateral to side of the lesion

- Ipsilateral multiple CNN deficits (III-XII) -> Complete LMN deficits

- Ventilatory/PLR changes

*Function of cerebellum?

- Functions to regulate the range, rate and force of a movement

- Inhibitory

*Dysfunction of the cerebellum results in what?

- Dysinhibition

*Signs of cerebellar disease?

- Dysmetria of the head (Intention tremor)

- Dysmetria of the eyes (Pendular or oscillatory nystagmus)

- Dysmetria of the limbs (Hypermetria, goose-stepping)

- Truncal/Cerebellar ataxia (Hypermetria to dysmetria, cerebellar rebound)

- Absence of behavior change (normal mentation)

- Absence of proprioceptive deficits/weakness

- Ipsilaterally absent menace

- Broad-base stance with preservation of strength

*Key features of vestibular disease?

- Head tilt (Only exception is bilateral otitis media-interna)

- Vestibular ataxia ("Drunken sailor")

- Pathologic nystagmus

What structures run within the middle ear?

- CN 7 and sympathetic tract (chorda tympani)?

Forms of physiologic nystagmus?

- Oculocephalic reflex - Forebrain (move head quickly side-side, eyes slow return to center)

- Doll's eye reflex - Brainstem (move head slowly side-side, eyes quickly return to center)

Forms of pathologic nystagmus?

- Sustained and non-positional

- Positional

- Horizontal/rotary/vertical downbeat

Describe peripheral vestibular nystagmus. What about central?

- Peripheral: Sustained, non-changing, rotary or horizontal nystagmus with fast phase away from side of head tilt

- Central: Changes with position, rotary, horizontal, or vertical downbeat

Peripheral vestibular disease can occur where? What about central?

- Peripheral: CNN VIII and its receptor

- Central: Flocculonodular lobe (cerebellum), vestibular nuclei, (medulla), MLF

*Signs of peripheral vestibular disease?

- Head tilt towards side of lesion

- Loss of balance, rolling, falling usually toward the side of the lesion

- Sustained, non-changing horizontal or rotary nystagmus (Fast phase away from lesion)

- Normal to increased myotatic reflexes

- +/- increased extensor tone on side opposite head tilt

- Normal strength/proprioception

- Normal CNN reflexes (Exception is CNN VII/Horner's Syndrome if otitis media)

- Strabismus of affected side

*Signs of central vestibular disease?

- Head tilt away from lesion (if paradoxical) or towards the lesion

- Loss of balance/falling/rolling

- Positional/changing nystagmus away from lesion

- Other brainstem signs: Ventrolateral strabismus, complete LMN deficits of CN I, VI, VII, +/- cerebellar signs, change in level of consciousness, hemiparesis/CP deficits ipsilateral, vomiting/nausea

*Signs of a C1-C5 lesion?

- +/- tetraparesis/plegia in severe cases

- Hyperpathia (pain) of the neck

- Ipsilateral CP deficits or bilateral in fore/hindlimbs

- +/- Ipsilateral hemiparesis/plegia

- UMN fore- and hindlimb reflexes

- Neck fasciculations

- Normal withdrawal reflexes in all four limbs

- +/- intact pain perception

- +/- diaphragmatic paralysis (Phrenic nerve involvement in C4-C6)

- Abnormal head carriage

- Root signature (Lameness associated with nerve root impingement)

*Signs of a C6-T2 lesion?

- Ipsilateral hemiparesis/plegia (if severe)

- Ipsilateral CP deficits fore/hind limbs

- LMN signs (hyporeflexia) fore limb(s)

- UMN signs (hyperreflexia) hind limb(s)

- +/- Horner's Syndrome (T1 - T3)

- Abnormal head carriage +/- cervical pain

- +/- loss of conscious pain perception

What disease affecting C6-T2 are Dobermans predisposed to?

- Disc-associated low cervical spinal cord compression

*Signs of a T3-L3 lesion?

- Ipsilateral or bilateral paraparesis/paraplegia

- CP deficits one or both hind limbs

- UMN reflexes in hind limbs

- +/- UMN tone fore limbs if T13-L2 lesion severe (Border cells)

- Spinal hyperpathia (thoraco-lumbar area or referred)

- +/- panniculus loss

- +/- loss of conscious pain perception hind

*Signs of a L4-S2 lesion?

- Ipsi- or bilateral paraparesis/paraplegia

- Normal fore limb myotatic reflexes, strength

- Hind limb LMN reflexes and diminished withdrawal reflexes unilateral or bilateral (L4 -L6 vs. L7 - S2)

- CP deficits unilateral or bilateral hind limbs

- Urinary/fecal incontinence

- Decreased anal tone, perineal reflex

- Change in tail carriage

- L-S hyperpathia on palpation +/- rectal exam

Caudal cervical spondylomyelopathy is typically a lesion of what spinal cord segment? Signs?

- Typically a C6-T2 lesion

- Hindlimb signs (>forelimb signs) with progressive improvement over time

Signs of a radiculopathy (Nerve root disease)?

- Spinal hyperpathia/hyperesthesia

- Root signature

- Generalized weakness/paralysis

- Voice change

- LMN signs to one limb/multiple limbs dependent on cause

- Normal mentation

- +/- Horner's Syndrome

- Muscle atrophy (focal or generalized)

- +/- Sensory loss

*Signs of a motor neuropathy?

- Flaccid paresis or paralysis of innervated structures (limb, facial muscles, esophagus, anus)

- Neurogenic muscle atrophy

- Reduced or absent reflexes and muscle tone

- Muscle fasciculations/voice change

Signs of a sensory neuropathy?

- Decreased pain response or sensation

- Proprioceptive deficits

- Abnormal sensation or sensitivity (paresthesia) of face, trunk or limbs

- Self-mutilation

- Reduced or absent reflexes without muscle atrophy

Signs of an autonomic (+/- sensorimotor) neuropathy?

- Anisocoria or dilated pupils

- Decreased tear secretion

- Decreased salivation

- Bradycardia

*Signs of a neuromuscular junctionopathy?

- Normal mentation

- +/- palpebral/menace deficits

- Generalized motor weakness or paralysis dependent upon the cause

- Episodic or continual signs

- Normal or hyporeflexic myotatic and withdrawal reflexes

- +/- voice change

Signs of myopathies?

- Generalized weakness

- Exercise intolerance

- Stiff, stilted gait

- Localized or generalized muscle atrophy

- Generalized muscle hypertrophy

- Dimple contracture

- Muscle pain on palpation

- Limited joint movement (i.e., contracture)

- +/- voice change (if severe)

- +/- trismus (inability to open the mouth)

When is neurosurgical intervention an option for an animal with brain trauma?

- Extradural hemorrhage

- Depressed skull fracture(s)

- Worsening neurologic status despite aggressive conservative management

Steps to consider in management of brain trauma?

- BP measurement

- Serial BG measurement

- Serial neuro exams

- Fluid therapy

- +/- steroids (Controversal)

What is spinal cord injury?

- SCI comprises primary and secondary injury along with sustained compression

What is primary spinal cord injury?

- Occurs at impact

- Parenchyma/vasculature directly damaged by compression, contusion, shearing, laceration or stretching

What is secondary spinal cord injury?

- Depletion of neuronal ATP

- Intracellular accumulation of calcium and sodium

- Formation of oxygen free radicals

- Increases in cytokine production/extracellular levels of glutamate, lactic acid, nitric oxide

T3-L3 radiculopathy signs?

- Recurrent back pain

- Positive response to steroids/NSAIDS then relapse once off the drugs

When do pts with T3-L3 radiculopathy need referral?

- Side effects to the drugs

- Recurrence of signs are decreasing quality of life

- Possibility of regression to myelopathy signs

L4-S2 myelopathy/radiculopathy signs?

- Recurrent back pain with minimal neurologic deficits

- Short, choppy gait

- Holding tail down

- Changes in urination/defecation

- Pain on tail extension

- Signs can be recurrent and intermittent

- Intermittent response to NSAIDS or steroids

Indications for immediate referral in pts with T3-L3 signs?

- Signs progress over a period of hours

- Signs are immediate

Indications for immediate referral in pts with C1-C5 or C6-T2 signs?

- Signs progress over a period of hours to days

- Signs are immediate