Neurologic Examination Flashcards
Tools for a neurologic examination
- Reflex hammer/Pleximeter
- Hemostat
- Lens
- Light
Things to assess when looking at the patient
- Mental status (Are they aware?)
- Posture (is head moving independently)
- Gait evaluation (ataxia?)
Conscious proprioception - describe how to do. What is normal?
- Make sure they’re square
- Flip the feet over, contact the floor, and replace the limb
- DO they have the ability to replace the limb?
- Normal is replacing within 1 sec; compare all 4 legs to each other
Conscious proprioception pathway
- Goes from the foot to the cortex and efferent motor pathway
Where could CP deficits possibly localize?
- Foot, leg, spinal cord, brain
What are other ways to test conscious proprioception?
- Hopping
- Hemiwalking
- Wheelbarrowing
What’s the difference between a reflex and a response?
- Responses go to the cortex, while reflexes do NOT
How many spinal cord segments are there for dogs and cats?
- 8 cervical
- 13 thoracic
- 7 lumbar
- 3 sacral
- 5 caudal
Thoracic intumescence - which SPINAL CORD segments?
- C6, C7, C8, T1, T2
Pelvic intumescence, which spinal cord segments?
L4, L5, L6, L7, S1
How many synapses are in the patellar reflex?
- Monosynaptic
Which spinal cord segments and nerves are involved in the patellar reflex (i.e. where could the lesion be if there’s an absent or decreased patellar reflex)?
- L4-6 spinal cord segments and nerve roots
- Also femoral nerve
Femoral nerve function
- Innervates the quadriceps for extension of the stifle
How many synapses are in the withdrawal reflex in both the forelimb and hindlimb?
- Polysynaptic for both
Which spinal cord segments and nerves are involved in the withdrawal reflex in the hindlimb (i.e. where could the lesion be if there’s an absent or decreased withdrawal reflex)?
- L6-S1
- Sciatic nerve
Which spinal cord segments and nerves are involved in the withdrawal reflex in the forelimb (i.e. where could the lesion be if there’s an absent or decreased withdrawal reflex)?
- C6-T2
- Multiple nerves
Function of sciatic nerve
- Innervates muscles for flexion of the limb
What does positive deep pain sensation require?
- CORTICAL response such as crying, biting, or trying to get away
Does intact withdrawal of the hind limb suggest that the patient can feel it?
- No
When is the only time you need to do deep pain testing?
- If there’s no motor in the hind limbs
What are the other spinal reflexes that are less reliable but can still be done?
- Biceps reflex
- Triceps reflex
- Extensor carpi radialis reflex
- Gastrocnemius reflex
- Cranial tibial reflex
Cutaneous trunci reflex - what should you see if it’s intact?
- Should see a BILATERAL CONTRACTION
- Travels up bilaterally
What is a pinch dermatome?
- The area of skin for an individual dorsal root
What is being tested with the cutaneous trunci reflex?
- Travels up bilaterally and exits at C8-T1
- Both lateral thoracic nerve (C8-T1)
CN I
- Which nerve?
- Sensory/Motor/Both
- What does it do?
- Olfactory nerve
- Sensory
- Smell!
CN II
- Which nerve?
- Sensory/Motor/Both
- What does it do?
- Optic nerve
- Sensory
- Vision!
CN III
- Which nerve?
- Sensory/Motor/Both
- What does it do?*
- Oculomotor nerve
- Motor
- Extraocular muscles: medial, dorsal, ventral rectus; ventral oblique; levator palpebrae; constrict muscles of the pupil (parasympathetic)
CN IV
- Which nerve?
- Sensory/Motor/Both
- What does it do?*
- Trochlear nerve
- Motor
- Contralateral dorsal oblique (skeletal muscle)
CN V
- Which nerve?
- Sensory/Motor/Both
- What does it do?
- Trigeminal nerve
- BOTH
- See separate flashcard for the different parts
CN VI
- Which nerve?
- Sensory/Motor/Both
- What does it do?*
- Abducens nerve
- Motor
- Lateral rectus and retractor bulbi
CN VII
- Which nerve?
- Sensory/Motor/Both
- What does it do?
- Facial nerve
- BOTH
- Sensory to middle ear, blood vessels of head; sensory to palate, rostral 2/3 of tongue for taste
- Motor to muscles of facial expression (ears, eyelid - orbicularis oculi, cheeks, lips, rostral digastricus; mandibular/submandibular salivary glands, lacrimal glands***, nasal glands)
CN VIII
- Which nerve?
- Sensory/Motor/Both
- What does it do?
- Vestibulocochlear nerve
- Sensory
- Hearing and vestibular system
CN IX
- Which nerve?
- Sensory/Motor/Both
- What does it do?
- Glossopharyngeal
- Both
- Sensory to the CAROTID body and sinus; caudal tongue and rostral pharynx
- Motor to pharyngeal muscles (skeletal); zygomatic/parotid salivary lands
CN X
- Which nerve?
- Sensory/Motor/Both
- What does it do?
- Vagus
- Both
- Sensory to AORTIC body/sinus, pharynx, larynx, thoracic/abdominal cavity; caudal pharynx and larynx
- Motor to the pharynx, larynx, esophagus; esophagus, organs of the thorax/abdomen
CN XI
- Which nerve?
- Sensory/Motor/Both
- What does it do?
- Accessory
- Motor
- Motor to esophagus, organs of thorax and abdomen via parasympathetic by joining the vagus; motor to the pharynx, larynx, esophagus by joining the vagus
- External branch is motor to the trapezius, sternocephalicus, brachicephalicus
CN XII
- Which nerve?
- Sensory/Motor/Both
- What does it do?
- Hypoglossal
- Motor to the tongue (skeletal)
Frontal lobe - which cortex?
- Motor cortex
Parietal lobe - which cortex?
- Somatosensory cortex
Occipital lobe - which cortex?
- Visual cortex
Temporal lobe - which cortex?
- Auditory cortex, behavioral cortex
Which CN are supratentorial?
- CN I and CN II (olfactory and optic)
Which CN are infratentorial?
- CN 3-12
An animal comes in with facial paralysis, difficulty swallowing, lateral strabismus - are you thinking supratentorial or infratentorial?
- Thinking infratentorial
Where do most CNs exit?
- Through some important holes in the bottom of the skull
Mnemonic for CNs
- Some
- Say
- Marry
- Money
- But
- My
- Brother
- Says
- Big
- Brains
- Matter
- More
CN I - where are cell bodies? Where do axons enter through?
- Cell bodies in olfactory epithelium of the ethmoid
- Axons enter through the cribriform plate to reach the olfactory bulb
CN II - where are cell bodies? Where do axons enter through?
- Cell bodies in the ganglionic layer of the retina
- Axon enters the optic canal
Pathway of CN II - and at what point does it become contralateral?
- Cell bodies in the ganglionic layer of the retina –> axon enters optic canal –> optic chiasm –> optic tract* –> optic radiation* –> occipital lobe (visual cortex)*
What are the three branches of CN V?
- Ophthalmic
- Maxillary
- Mandibular
Ophthalmic branch of CN V
- Sensory/Motor/Both
- What does it do?
- Sensory to the eyeball and MEDIAL canthus
Maxillary branch of CN V
- Sensory/Motor/Both
- What does it do?
- Sensory to the maxilla
- Lateral canthus maybe?
Mandibular branch of CN V
- Sensory/Motor/Both
- What does it do?
- Sensory to mandible
- MOTOR to the muscles of mastication (masseter, temporalis, caudal digastricus (skeletal)
Which cranial nerve is sensory to the carotid body?
- Glossopharyngeal
Which cranial nerve is sensory to the aortic body?
- Vagus
Which CNs have parasympathetic function?
- CN III (constricts pupil)
- CN VII (motor to mandibular/submandibular salivary glands, lacrimal glands, and nasal glands)
- CN IX (motor to zygomatic and parotid salivary glands)
- CN X (motor to esophagus, organs of the thorax and abdomen)
- CN XI (joins with vagus)
Which nerve is responsible for lacrimal secretions? What is the consequence if this nerve is damaged?
- Facial nerve
- If it’s damaged, the patient may have dry eyes, so you need to make sure that you’re providing artificial tears
Menace response: Which CN are being tested with the afferent and efferent pathways?
- Afferent: Optic nerve
- Efferent: Facial nerve (blink)
Optic nerve pathway for the menace response (remember it again and indicate which parts of the pathway are contralateral)
- Optic chiasm (ipsilateral)
- Optic tract*
- Thalamus (lateral geniculate)*
- Visual/occipital cortex*
- Motor/frontal cortex*
- Descending tracts (ipsilateral)
- Cerebellar influence (ipsilateral)
- I would draw this out too to help it make more sense
What should you check with pupil size?
- That they are symmetrical in normal room light
Pupillary light reflex - where should you be testing the reflex?
- In a dark room with a very bright light
Afferent and efferent pathways of pupillary light reflex
- Afferent: Optic nerve
- Efferent: Oculomotor nerve
Pathway of optic nerve for PLR
- Indicate which are contralateral
- Optic chiasm
- Optic tract*
- Pretectal area*
Does the PLR require a cortical response?
- No
What is a positive PLR response that you would expect?
- Bilaterally leads to direct and indirect pupillary constriction
Draw out the PLR pathway
- Just do it
What is the oculovestibular reflex?
- Doll’s eye reflex or physiologic nystagmus
Which CN are being tested with oculovestibular reflex?
- CN 8 (vestibular component)
- MLF (Medial longitudinal fasciculus)
- CN 3 (oculomotor nerve)
- CN 4 (trochlear nerve)
- CN 6 - abducent nerve
Positive response for ocular sensation
- Third eyelid retracting
- Feel the eyelid retract, blink, and eye goes up
Afferent and efferent pathways for ocular sensation
- Afferent: Trigeminal nerve (CN V - ophthalmic branch)
- Efferent: Facial nerve (blink) and abducent nerve (eyeball retraction and elevation of the third eyelid)**
Afferent and efferent pathways for the palpebral reflex
- Afferent: Trigeminal nerve (CN v) - maxillary and ophthalmic branches
- Efferent: Facial nerve –> blink
Which is sensory to medial and lateral canthus for trigeminal nerve branches?
- Medial canthus: ophthalmic branch
- Lateral canthus: maxillary branch
Afferent and efferent pathways for facial reflex
- Afferent: Trigeminal nerve (CN V for ophthalmic/maxillary/mandibular branches)
- Efferent: Facial nerve (CN VII) for blink and twitch
What is the facial response? How does it differ from the facial reflex?
- Should have a cortical jerking away response or trying to bite
- Different than twitching which is the facial reflex
Facial response afferent and efferent pathways
- Afferent is ophthalmic branch of the trigeminal nerve
- Descending pathway is to move the head/body away from the stimulus (pull-away response)
Facial response afferent pathway and which are contralateral?
- Thalamus*
- Somatosensory/parietal cortex*
- Motor cortex*
Which side is damaged if no facial response on the right side?
- Something wrong with the contralateral cortex, i.e. the left side
Which CN is responsible for jaw tone?
- Mandibular branch
- CN V
Which nerves responsible for facial symmetry?
- CN V (without it, atrophy of the mandibular muscles like the temporalis muscle, digastricus)
- CN VII (drooping)
Which nerves involved in the gag reflex?
- CN 9 and CN 10
Which nerve responsible for innervation of the tongue?
- CN 12
What are the last parts of the neurologic examination?
- Neck movement
- Spinal palpation
- Rectal examination
Describe the perineal reflex
- Constriction of the anus (anal tone)
2. Flexion of the tail
Which nerves involved with constriction of the anus with the perineal reflex?
- Pudendal nerve
- S1-S3
Which nerves involved in flexion of the tail for the spinal cord reflex?
- Caudal spinal cord segments
What does a positive response for deep pain sensation look like?
- CORTICAL response such as crying, biting or trying to get away
Who do you test deep pain sensation in?
- Paralyzed patients only
Prognosis for deep pain negative?
- Poor prognosis for recovery
Supratentorial brain regions?
- Cerebral hemisphere
- Thalamus
- Pituitary
Infratentorial brain regions?
- Cerebellum
- Brainstem
What are the spinal cord segments?
- C1-C5
- C6-T2
- T3-L3
- L4-S3
- Caudal
What are clinical signs in the thoracic limbs if you have a lesion cranial to the thoracic intumescence?
- UMN signs (i.e. hypermetria, decreased CPs, normal to increased reflexes)
What are clinical signs in the thoracic limbs if you have a lesion at the thoracic intumescence?
- LMN signs (i.e. decreased withdrawal reflexes, decreased CPs)
What makes up the lower motor neuron unit?
- Spinal cord segments (C6-T2, L4-sacral)
- Peripheral nerves - afferent and efferent
- Neuromuscular junction
- Muscle (effector organ)
What are the parts of the PNS with the LMN?
- Peripheral afferent and efferent nerves
- Neuromuscular junction
- Muscle (effector organ)
What are the CNS parts of the lower motor neuron unit?
- Spinal cord segments (i.e. C6-T2, L4-sacral)
UMN signs
- Reflexes
- Muscle tone
- Type of atrophy
- NORMAL to increased spinal REFLEXES
- Normal to increased muscle tone
- Disuse muscle atrophy
LMN signs
- Reflexes
- Muscle tone
- Type of atrophy
- Decreased to absent spinal reflexes
- Decreased to absent muscle tone
- Neurogenic muscle atrophy
How long does it take to have disuse muscle atrophy?
- Slowly over time
How long does it take to have neurogenic muscle atrophy?
- within 7-10 days (VERY ACUTE)
- Limbs are completely atrophied
- If muscle isn’t working, it’s LMN
How long does primary myopathic atrophy take?
- Variable amount of time
Clinical signs in thoracic limbs and pelvic limbs if lesion is in the brain?
- UMN to both
Clinical signs in thoracic limbs and pelvic limbs if lesion is in C1-C5?
- Thoracic: UMN
- Pelvic: UMN
Clinical signs in thoracic limbs and pelvic limbs if lesion is in C6-T2?
- Thoracic: LMN
- Pelvic: UMN
Clinical signs in thoracic limbs and pelvic limbs if lesion is in T3-L3?
- Thoracic: normal
- Pelvic: UMN
Clinical signs in thoracic limbs and pelvic limbs if lesion is in L4-S1/3?
Thoracic limbs: Normal
Pelvic limbs: LMN
Case:
CP deficits in both pelvic limbs
Normal patellar reflexes bilaterally
Normal withdrawal reflexes bilaterally
Lesion is where?
- T3-L3
- UMN problem to pelvis
Tone is normal to increased
Disuse atrophy
Case:
CP deficits to both pelvic limbs
Decreased patellar reflexes bilaterally
Decreased withdrawal reflexes bilaterally?
- LMN problem to pelvis
- L4-S1 or
bilateral femoral and sciatic nerves
- Tone is decreased to absent
- neurogenic atrophy
Case:
CP deficits to both pelvic limbs
Decreased patellar reflexes bilaterally
Normal withdrawal reflexes
L4-L6 or femoral nerve bilaterally
Case:
CP deficits to both pelvic limbs
Increased patellar reflexes bilaterally
Absent withdrawal reflexes bilaterally
- Bilateral sciatic nerve OR
- CNS lesion at L6-S1
Why increased patellar reflexes with sciatic nerve deficits or lesion at L6-S1?
- UMN –> T3-L3
OR Pseudohyperreflexia
Describe pseudohyperreflexia?
- Due to loss of antagonistic muscles from lack of sciatic/L6-S1 function
Case:
- CP deficits to all four limbs
- Normal spinal reflexes in all four limbs
- Brain (infratentorial or supratnetorial) or C1-C5
- Likely C1-C5 if no mentation changes or CN deficits
Case:
- CP deficits to all four limbs
- Normal spinal reflexes to the pelvic limbs
- Decreased withdrawal reflexes in the thoracic limbs
- C6-T2
Case:
CP deficits to all four limbs
Decreased patellar and withdrawal reflexes in the pelvic limbs
Decreased withdrawal reflexes in the thoracic limbs
- Diffuse LMN
- Either C6-T2 and L4-S1 OR
- ALl the peripheral nerves within the limbs
What is the name for all the peripheral limbs being affected?
- Polyneuropathy
