Clinical Neuro Exam Flashcards
what is an Upper Motor Neuron (UMN)?
descending axons from cortex to brainstem
OR
from brainstem to spinal cord
what is a Lower Motor Neuron (LMN)?
axons exiting the CNS and innervating peripheral nerves
motor divisions of cranial nerves
is weakness a sign of an UMN or LMN Lesion?
Both
is atrophy a sign of an UMN or a LMN lesion?
LMN lesion
are fasiculations a sign of an UMN or LMN lesion?
LMN
are increased reflexes a sign of an UMN or a LMN lesion?
UMN lesion
(LMN have decreased reflexes)
is decreased tone a sign of an UMN or a LMN lesion?
LMN lesion
(increased tone = UMN lesion)
What are the 6 components of the whole clinical neurological exam?
- Mental Status
- Cranial Nerves
- Motor Exam
- Sensory Exam
- Reflexes
- Coordination/Gait
Which cranial nerves are pure sensory nerves?
- Olfactory (CN 1)
- Optic (CN 2)
- Auditory (CN 8)
which cranial nerves are pure motor nerves?
- Trochlear (CN 4)
- Abducent (CN 6)
- Accessory (CN 11)
- Hypoglossal (CN 12)
which cranial nerves are mixed nerves (both motor and sensory)?
- Trigeminal (CN 5)
- Facial (CN 7)
- Glossopharyngeal (CN 9)
- Vagus (CN 10)
- Occulomotor (CN 3)
Th test for olfaction (CN 1) includes what 2 tests?
- Tests for discrimination (contrast odors)
- Tests for arousal (noxious stimulant)
T/F: the CN 1 test is not often included in the cranial nerve screen
TRUE
this nerve tends to be spared from a lot of issues unless there is a specific pathology that impacts this sense
If a patient presents with unilateral or bilateral loss of smell but can still distinguish the smell what is the differential diagnosis?
a local nasal disease rather than a neural condition
When testing CN 1, what would suggest to you that there might be a neural pathology invovled?
if the pt has a distorted sense of smell for a neutral scent
List some possible mechanisms of injury to the olfactory nerve
- Parkinson’s disease
- chronic meningeal inflammation
- tumors in sub frontal region
- head injuries
- heavy smoking
What tests are included in the CN 2 exam?
- Visual acuity
- Color discrimination
- Field Cuts
- Pupillary response to light accommodation
- Visual Extinction
What is visual acuity? How do we test it?
ability to see clearly
Snellin chart
What is a visual field cut?
blindness in one of the 4 quadrants of the eye
this is due to damage to the optic nerve and is NOT the same as visual neglect
What is the visual extinction test?
a visual neglect test
helpful to include in testing the optic nerve and ruling out visual neglect over a visual field cut
what cranial nerves are responsible for innervating the extraoccular muscles?
CN III
CN IV
CN VI
CN III innervates extraoccular muscles that perform what movements?
elevation
depression
ADDuction
(PSNS: pupil constriction - efferent limb of pupillary reflex)
CN IV innervates extraoccular muscles that perform what movements?
Depression/intorsion
CN VI innervates extraoccular muscles that perform what movements?
ABDuction
what test is performing the examination of CN 3, 4, and 6?
Big H test
if a patient presents with a gaze palsy in which both eyes are skewed in the same direction, what type of lesion are you suspecting?
UMN Lesion
(both eyes have dysconjugate gaze)
if a pt presents with a gaze palsy in which both eyes are dysconjugate but are skewed in different directions, what lesion do you suspect?
LMN lesion
if a pt presents with a gaze palsy in which only one eye has a dysconjugate gaze in a specific direction, what type of lesion are you suspecting?
LMN lesion
The trigeminal nerve is a mixed sensory and motor nerve. What afferent/efferent info does it carry?
Afferent:
- pain
- temperature
- joint position
- vibration
- anterior 2/3 tongue (somatosensory)
- nasal sinuses
Efferent
- muscles of mastication
- tensor tympani
How would you test the trigeminal nerve?
- Light tough to face
- for all branches (V1, 2, 3)
- Bite strength
- for muscles of mastication
- Corneal reflex
- tests both V and VII
when is the corneal reflex test most often performed?
if a pt is obtunded
not commonly performed if a pt is alert
the facial nerve is a mixed sensory and motor nerve. What are it’s afferent and efferent branches?
afferent
- taste afferents for anterior 2/3 of tongue
- somatosensory for proprioception of facial muscles
- somatosensory for skin sensation of posterior ear and external auditory meatus
- motor for facial expression muscles
- autonomic motor to lacrimal and salivary glands
What is/are the methods for testnig CN VII?
- Observation
- Motor
- smile, raise eyebrows, puff out cheeks, purse lips, close eyes tightly
- Sensory
- taste (not typically done)
- secretomotor function
- Reflexes
- corneal reflex (CN V and VII)
- nasopalpebral reflex
why is taste not typically tested specifically?
pts wil often complain about it and will let you know if they have lose some taste
what is the formal way to test the salivary glands?
give the pt something spicy and then compare the either side of the inside of their mouth.
look for saliva secretion either side
When testing CN 7 how can you distinguish between an UMN and a LMN lesion?
look at the forehead
UMN = intact forehead muscle function
LMN = entire side of face will lose motor function
how is CN IX assessed/tested?
Palatal activation
inspect for symmetry → with a lesion, one side will deviate to uninvolved side
Gag reflex (sensory limb)
The gag reflex tests which cranial nerves?
CN IX (sensory afferent limb)
CN X (motor efferent limb)
how would you expect a pt with CN 9 and 10 dysfunction to sound?
hoarse
difficulty with speech production
how is CN 11 assessed?
Shoulder Shrug (UTrap)
Side bend and rotate (SCM)
how would an UMN lesion impact CN 11?
pt will present with trapezius weakness
BUT the SCM will be spared
how would a LMN lesion impact CN 11?
both the trapezius and SCM would be impacted
how is CN 12 assessed?
Stick out tongue (tongue protrusion)
direction may indicate UMN vs LMN
how will a pt present with an UMN lesion of CN 12?
tongue will deviate away from the side of the lesion
(picture on the right)
how will a pt present with a LMN lesion of CN 12?
tongue will deviate toward the side of the lesion
atrophy and fasciculations will also be observed
(left picture)
T/F: you can performm the motor exam part of the clincial neurological exam without even toughing the pt?
TRUE
what are the components of the Motor Exam?
- Inspection at rest
- Task Based observation
- Tone assessment
- MMT
what are you looking for during the inspection at rest portion of the Motor Exam?
- Muscle atrophy
- Fasiculation
- Hypertrophy
- Tremors
- Involuntary movements
- posturing
What is posturing?
occurs when a pt picks up a very specific position of their UE and LE base don where their inujury was
What are the 2 main kinds of posturing?
- Decorticate posture
- Decerebrate posture
Describe decorticate posture
pt has full flexion of the UE and they hold it there
full extension of LE
What type of damage would result in decorticate posturing?
damage to brainstemm above the red nucleus
Describe decerebrate posture
pt has full extension of UE and LE
might still have some finger flexion
What type of damage would result in decerebrate posture?
damage underneath/lower than the red nucleus in the brainstem
ex: pontine lesion
T/F: posturing has no prognostic value
FALSE
it is an indicator that the pt might not progress/get that much better
What is the distinction between the tone assessment and MMT?
tone assessment = resitance against passive movement
MMT = greater resistance, helps ID patterns of weakness
What is assessed during the Sensory Exam?
- Pain
- Temperature
- Vibration
- Proprioception
- Light touch/2 pt discrimination
How are reflexes graded?
0-5
0 = absent
1 = trace
2 = normal
3= brisk
4 = non-sustained clonus
5 = sustained clonus
If reflexes are abnormally increased this is indicative of what?
UMN lesion
if reflexes are abnormally decreased, this is indicative of what?
LMN lesion
but could be muscle, nerve fiber and NMJ
