Neurologic Exam

Question 1

CN I - Name

Function

Answer 1

CN I - Olfactory

Sensory- smell, projects into the nasal mucosa and synapses within olfactory regions of the brain

Question 2

CN II

Answer 2

CN II - Optic
Sensory- vision acuity/visual fields, projects to the lateral geniculate nucleus (LGN) and superior colliculus

Lesions can cause homonymous hemianopsia (LGN, optic radiations, or contralateral occipital lobe), superior homonymous quadrantanopsia (axons of Meyer’s loop in contralateral posterior temporal lobe), bitemporal hemianopsia (chiasmatic lesion such as pituitary adenonma)

Question 3

CN III

Answer 3

CN III - Oculomotor
Motor- medial/upward/downward eye movement, pupillary constriction, eyelid retraction; projects from the midbrain to the iris and 5 of the extraocular muscles (EOMs)

Compression of CN III can cause fixed and dilated (blown) pupil, diagonal diplopia, or marked pupillary constriction (pinpoint pupil) in the case of drug effects (morphine)

Question 4

CN IV

Answer 4

CN IV - Trochlear
Motor- superior oblique muscle; rotation of eye; projects from midbrain to the superior oblique muscle of the eye

Compression of CN IV can cause suppression of the eye, with vertical diplopia

Question 5

CN V

Answer 5

CN V - Trigeminal
Motor and Sensory- mastication muscles and facial sensation; projects from pons into 3 divisions (ophthalmic, maxillary, mandibular) that innervate upper, middle, and lower face.
Lesion may cause jaw to deviate to the side of weakened muscle innervation.

Question 6

CN VI

Answer 6

CN VI - Abducens
Motor- lateral eye movement; projects from the pons to the lateral rectus.

Compression of CN VI causes failure to adduct (look in lateral direction), with horizontal diplopia

Question 7

CN VII

Answer 7

CN VII - Facial
Motor and Sensory- originates from lower pons/upper medulla, controls upper and lower face motor functions and salivary glands, tear glands, nasal mucosa

Taste from anterior 2/3 of tongue.
Motor func. assessed by watching for unequal elevation of pt’s mouth corners, inability to close both eyes or wrinkle brows symmetrically

Question 8

CN VIII

Answer 8

CN VIII - Vestibulocochlear
Sensory- hearing; originates in cochlea, projects via medulla to medial geniculate nucleus.

Tested tested by rubbing fingers lightly together at external auditory canal; a Rinne’s test uses a tuning fork to the mastoid bone; unilateral conduction deficit causes sound to be perceived as louder on impaired side.

Vestibular func. tested via Dix-Hallpike maneuver- pt sits upright and lies back with head extended over exam table edge- pt’s head is rotated. Vertigo w/ nystagmus suggests dysfunction lateralized to downward ear side

Question 9

CN IX

Answer 9

CN IX - Glossopharyngeal
Mostly sensory with some motor- projects from medulla to pharynx, middle ear, and posterior tongue.

Taste from posterior 1/3 of tongue.
Induce gage reflex, typically by touching uvula; unilateral nerve dysfunction causes uvula to retract to stronger side

Question 10

CN X

Answer 10

CN X - Vagus
Motor and Sensory- soft palate movement and vocal cord innervation; originates from several nuclei in medulla, projects to points in viscera including the gut, heart, and lungs; mediates gage reflex along w/ CN IX
Vagus nerve palsy- pt unable to produce a high-pitched sound

Question 11

CN XI

Answer 11

CN XI - (Spinal) Accessory
Motor- projects from cervical spinal cord to sternocleidomastoid muscle and trapezius.

Tested by having pt shrug shoulders- asymmetric suggests dysfunction on side that is lower. Also tested with hand against pt’s jaw and asking pt to rotate head against examiner’s hand

Question 12

CN XII

Answer 12

CN XII - Hypoglossal
Motor- originates from medulla, projects to tongue muscles.

Tongue deviates toward side of hypoglossal nerve weakness. Subtle dysarthria may be noted in challenging phrases

Question 13

What is “pronator drift”?

What type of neuron involvement does it indicate?

Answer 13

When pt stands with feet together and arms extended with palms facing upward, pronator drift is when the hand or arm gradually rotates downward. It is associated with UMN involvement, & tested in differentiating peripheral from central tract/UMN problems.

Question 14

What is dysdiadochokinesia vs. dysmetria?

Answer 14

Dysdiadochokinesia = impaired ability to smoothly alternate movements.
Dysmetria = inaccuracy in coordinated movements such as in finger-to-nose test.
Both suggest cerebellar dysfunction ipsilateral to the more affected side.

Question 15

paresis vs. plegia

Answer 15

Weakness that is mild to moderate (paresis) or complete (plegia)

Question 16

What do hyperactive vs. hypoactive Deep Tendon Reflexes (DTRs) indicate

Answer 16

Hyperactive DTRs are generally indicative of CNS injury w/ corticospinal tract damage. Hypoactive DTRs occur in PNS injury.

Question 17

What is Babinski sign?

Answer 17

Plantar stimulation causes great toe to move upward, rather than downward (normal). Pathologic reflexes (not normally elicitable beyond infancy) signal CNS damage.

Question 18

How do atrophy, fasciculations, reflexes, and tone distinguish UMN from LMN lesions?

Answer 18

UMN= weakness, increased reflexes, increased tone, NO atrophy or fasciculations.

LMN= weakness, decreased reflexes, decreased tone, atrophy, and fasciculations.

Question 19

What is the Romberg Test?

Answer 19

Assesses cerebellar and posterior column func. mediating truncal stability. Pt stands with feet together, eyes closed, to bring out instability.

Question 20

What elements of gait are assessed in a neurologic exam?

Answer 20

Stance (how far apart feet are), posture, stability, how high the feet are raised off the floor, trajectory or leg swing, circumduction (abnormal arced trajectory in the medial-to-lateral direction), leg stiffness and degree or knee bending, arm swing, tendency to fall or swerve in any particular direction, rate and speed, difficulty initiating or stopping gait, turns, and involuntary movements brought out by walking.

Question 21

What is tandem gait?

Answer 21

A test where the pt is asked to walk straight while touching the heel of one foot to the toe of the other with each step. Difficulty to do this occurs in cerebellar ataxia or higher motor dyscontrol.

Question 22

What is scissoring of gait?

Answer 22

Lower extremities have reduced knee flexion, indicating corticospinal dysfunction.

Question 23

What characterizes parkinsonian gait?

Answer 23

Narrow-based, short-stepped, accompanied by difficulty stopping and tendency to fall backward. Usually accompanied by hand tremors.

Question 24

What sensory modalities are tested in a neurologic exam (and how)?

Answer 24

Touch- cotton swab or light finger touch; two-point discrimination.
Pain- safety pin/sharp point.
Position- minimally moving a digit and asking pt to specify direction (with eyes closed).
Vibration- tuning fork.
Sometimes includes temperature testing

Question 25

What does a typical mental status screening entail in neurologic exams?

Answer 25

Alertness, attention, & cooperation
Orientation (person, place, and time)
Language (spontaneous, comprehension, naming, repetition, reading, writing)
Memory (immediate, remote)
Praxis (ideomotor apraxia)
Constructions & neglect
Sequencing (& frontal release signs)
Reasoning (logic, abstraction)
Delusions, hallucinations, mood

Question 26

What is clonus?

Answer 26

Repetitive, involuntary vibratory movements.

Question 27

What is dyskinesia?

Answer 27

Impaired voluntary movement.

Question 28

What is graphesthesia?

Answer 28

Ability to identify letters or numbers traced on the skinl

Question 29

What is stereognosis?

Answer 29

Ability to identify forms of solid objects by touch.

Question 30

Cranial nerve exams, which CN is/are involved vision?

Answer 30

CN II

Test for visual acuity, color vision, visual fields, & visual extinction

Question 31

Cranial nerve exams, which CN is/are involved in pupillary responses?

Answer 31

CN II and CN III
Afferent pupillary defects have decreased direct response due to decreased visual function (CN II), but pupillary constriction is spared (CN III) when elicited through the consensual response (contralateral pupil is illuminated)

Question 32

Cranial nerve exams, which CN is/are involved in extraocular movements?

Answer 32

CN III, IV, and VI
Test for smooth pursuit, convergence movements, saccades, nystagmus, rotation of eye with head tilt (CN IV)
Deviation of affected eye laterally (CN III) versus deviation of affected eye medially (CN VI)

Question 33

Cranial nerve exams, which CN is/are involved in facial sensation?

Answer 33

CN V

Facial touch and pain test CN V, though the corneal reflex involves both CN V and VII

Question 34

Cranial nerve exams, which CN is/are involved in taste?

Answer 34

CN VII and IX
CN VII innervates anterior tongue and perception is predominantly for sweet.
CN IX innervates the posterior tongue involves perception of sour tastes.

Question 35

Cranial nerve exams, which CN is/are involved in gag reflex and palate elevation?

Answer 35

CN IX and X

Question 36

Cranial nerve exams, which CN is/are involved in articulation?

Answer 36

CN V, VII, IX, X, and XII
V- jaw jerk reflex
VII- facial muscles
IX- palate
X- soft palate and vocal chords, vocal quality
XII- muscles of the tongue

Question 37

Cranial nerve exams, which CN is/are involved in auditory function?

Answer 37

CN VIII
Test sound perception as well as vestibular sense if vertigo is reported. A tuning fork can help distinguish neural from mechanical conductive hearing problems.