Cranial Nerve lesions DSA

Question 1

what is the first step in a mental status examination?

Answer 1

determine the patient’s ability to relate to himself and to his environment. aka consciousness

Question 2

In general, what is arousal?

Answer 2

refers to the activation of the cerebral cortex by the brainstem reticular formation and the content of consciousness alludes to the higher cortical functions that may result

Question 3

Define arousal

Answer 3

the state of wakefulness of the patient

dependent on RAS

Question 4

Define attentiveness.

Answer 4

ability to attend to a specific stimulus without being distracted by extraneous environmental stimuli
It is a balance b/w ascending (recticulocortical) activation and descending cortical modulation

Question 5

What are the 4 levels of consciousness?

Answer 5

Alertness
Lethargy
Stupor/ Semicoma
Coma

Question 6

_______ is a basic state of arousal in which the pt is able to respond to any stimulus in a meaningful way.

Answer 6

Alertness

Question 7

_______ is defined as pt is not fully alert and tends to drift off to sleep when not specifically stimulated.

Answer 7

Lethargy

Question 8

In a ________ state the pt responds only to persistent and vigorous stimulation.

Answer 8

Stupor/ Semicoma

and when aroused the pt os only able to groan and move restlessly in bed

Question 9

______ is defined as completely unarousable.

Answer 9

Coma

Question 10

______ ____ ____ is a common method of assessing changes in levels of consciousness.

Answer 10

Glasgow Coma Scale

scores range from 15-3 and are scored based on eye opening, best motor, and best verbal responses.

Question 11

______ _____ _____ is used to assess the severity and progression of cognitive impairment.

Answer 11

Mini-Mental Status Exam

Question 12

Explain the Doll’s eye maneuver

Answer 12

Test CN 3 and 6 in an unconscious patient w/o cervical injury, side-to-side movement of the head results in horizontal movement of the eyes in the opposite direction

Question 13

Doll’s Eye maneuver: head turns left (responds and indicates)

Answer 13

horizontal gaze to left=normal finding
right adduct, left neutral= left VI palsy
right neutral, left abduct= right III palsy
no response=possible midbrain damage

Question 14

Doll’s Eye maneuver: head turns right (responds and indicates)

Answer 14

horizontal gaze to right= normal finding 
left adducts, right neutral= right VI palsy
left neutral, right abducts=left III palsy 
no response (both neutral)=possible midbrain damage

Question 15

Describe the Oculocaloric testing for the vestibuloocular response.

Answer 15

in an unconscious patient injection of cold water into the external auditory meatus results in horizontal gaze towards the side of the stimulus.

Question 16

Oculocaloric testing: Stimulus into Right Ear (Rt and lf eye and indicates)

Answer 16

Rt abducts, lf adducts= normal finding
Rt abducts, lf no response= Left III nerve palsy
Rt no response, lf adducts= right VI nerve palsy
Rt and Lf no response= right VIII nerve palsy (midbrain damage)

Question 17

Oculocaloric testing: Stimulus into Left Ear (Rt and lf eye and indicates)

Answer 17

Lf abduct, rt adducts= normal findings
lf abducts, rt no response= Right III nerve palsy
Lf no response, rt adducts= left VI nerve palsy
rt and lf no response= left VIII nerve palsy (midbrain damage)

Question 18

What are the 3 types of onsets and progression of symptoms?

Answer 18

Abrupt: sudden onset of symptoms followed by gradual improvement ( cerebral hemorrhages, vascular disease and infection or head traumas)

Relentlessly progressive: linear progression

Intermittent, relapsing episodes: cycle of remission and symptoms (MS or vascular diseases)

Question 19

What cranial nerve is located in the telencephalon?

Answer 19

CN I olfactory nerve

Question 20

What cranial nerve is located in the diencephalon?

Answer 20

CN II optic nerve

Question 21

What cranial nerves are located in the midbrain?

Answer 21

CN II oculomotor nerve

CN IV trochlear nerve

Question 22

What cranial nerves are located in the Pons?

Answer 22

CN V trigeminal

Question 23

What cranial nerves are located in the pontomedullary Sulcus?

Answer 23

CN VI abducens
CN VII facial
CN VIII vestibulocochlear nerve

Question 24

What cranial nerves are located in the medulla?

Answer 24

CN IX glossopharyngeal nerve
CN X vagus nerve
CN XII hypoglossal nerve
CN XI spinal accessory nerve

Question 25

Describe the clinical presentation of a lesion of the optic nerve.

Answer 25

diencephalon or upper midbrain may involve one of these

structures and result in a specific pattern of visual field blindness.

Question 26

Describe the clinical presentation of a lesion of the oculomotor nerve.

Answer 26

midbrain lesion may destroy the fibers of the oculomotor nerve, and result in external
strabismus, pupillary dilation and complete ptosis.

Question 27

Describe the clinical presentation of a lesion of the trochlear nerve.

Answer 27

The patient is not able to look in (adduct) and down (depress) the affected eye. The eye is
passively directed down and out, and the patient will complain of diplopia when attempting to look straight
ahead. To compensate the patient usually tilts his head away from the affected eye to maintain binocular
vision.

Question 28

Describe the clinical presentation of a lesion of the trigeminal nerve.

Answer 28

Lesions of the nerve in this area results in ipsilateral loss of sensations from half of the face; paralysis and atrophy of the ipsilateral muscles of mastication When the patient opens his mouth wide, the chin deviates toward the
side of the lesion.

Question 29

Describe the clinical presentation of a lesion of the abducens nerve.

Answer 29

Central lesions of the abducens nerve result in ipsilateral paralysis of lateral gaze and internal strabismus.

Question 30

Describe the clinical presentation of a lesion of the facial nerve.

Answer 30

Central lesions of the nerve result in ipsilateral facial (Bell’s) palsy; loss of taste sensations from the anterior 2/3 of tongue; and hyperacusis.

Question 31

Describe the clinical presentation of a lesion of the vestibulocochlear nerve.

Answer 31

Central lesions of VIII result in ipsilateral deafness; problems with equilibrium and
posture; and nystagmus.

Question 32

Describe the clinical presentation of a lesion of the glossopharnygeal nerve.

Answer 32

Central lesions of the glossopharyngeal nerve result in decreased sensations from the palate and pharynx (diminished gag reflex); and a loss of taste from the posterior 1/3 of tongue

Question 33

Describe the clinical presentation of a lesion of the vagus nerve.

Answer 33

Central lesions of the vagus nerve result in dysphagia, dysarthria, hoarseness, paralysis or paresis of the muscles of the palate; uvula may deviate to the side opposite the lesion; and transient parasympathetic effects

Question 34

Describe the clinical presentation of a lesion of the spinal accessory nerve.

Answer 34

ipsilateral paresis of the sternocleidomastoid. The patient has difficulty in turning his head away from the affected side and bending the head forward at the same time and shrugging his shoulders.

Question 35

Describe the clinical presentation of a lesion of the hypoglossal nerve.

Answer 35

paralysis and atrophy of the ipsilateral intrinsic muscles of the tongue. The patient may also complain of dysphagia and dysarthria.
The protruded tongue deviates toward the side of the lesion.