Recorded Lecture: Neuro Basics and Examination

What are the parts that make up the brainstem?

Midbrain, pons, medulla oblongota

How many lobes do you have in the brain?

4×2 = 8

What is the function of the frontal lobe? Lesion? Mneumonic?

“On top of” everything “A CEO”

• Aphasia: Broca’s (speech production)

• Controls plan, programming, movement

• Emotional, behavioral control, personality, olfaction

What is the function of the temporal lobe? Lesion?

• Hearing and language comprehension

• Aphasia: Wernicke’s (understanding)

What is the difference between Broca’s aphasia and Wernicke’s aphasia? Lobe affected and treatment?

• Broca’s aphasia “BEN”

  • Broken speech - difficulty saying what they actually want to say

  • Expressive aphasia

  • Non-fluent aphasia

  • Lobe: frontal lobe

  • Treatment: yes/no questions

• Wernicke’s aphasia

  • Unable to understand - difficulty understanding what you’re saying

  • Receptive aphasia

  • Fluent aphasia

  • Word salad → “wowsome", fantabulous”

  • Lobe: temporal lobe

  • Treatment: gestures/demonstrations

Which side of the brain is a lesion that affects language most common/is the dominant hemisphere?

Left

What is the function of the parietal lobe? Lesion?

• Perceptual disorders e.g. unilateral neglect → common w/ R brain, R parietal lobe lesion → neglecting left side i.e. only shaving the R side of the face

• Sensory loss

What is the function of the occipital lobe? Lesion?

Visual loss

How many cranial nerves do we have?

12×2 = 24

Name all cranial nerves and type.

1. Olfactory - S

2. Optic - S

3. Oculomotor - M

4. Trochlear - M

5. Trigeminal - B

6. Abducens - M

7. Facial - B

8. Vestibulocochlear - S

9. Glossopharyngeal - B

10. Vagus - B

11. Accessory - M

12. Hypoglossal - M

Which cranial nerves are sensory, motor, both?

• Sensory: I, II, VIII

• Motor: III, IV, VI, XI, XII

• Both: V, VII, IX, X

Where are the cranial nerves located?

“CE MI PONS MEDU”

• Cerebrum: I, II

• Midbrain: III, IV

• Pons: V, VI, VII, VIII

• Medulla oblongota: XI, X, XI, XII

Name, type, function, and effect of CN I.

• Olfactory

• Sensory

• Sense of smell

• Anosmia - loss of smell

Name, type, function, and effect of CN II.

• Optic

• Sensory

• Vision: color, acuity, peripheral vision, pupillary light reflex

• Blindness, myopia (short-sighted), presbyopia (far-sighted)

What is a normal pupillary ligth reflex?

Shine light in one eye and L&R constrict (L2 senses light “danger!” warns L3 and R3 to constrict)

What cranial nerve is affected if a light is shone in the L eye and L constricts, but R stays the same?

R3

What cranial nerve is affected if a light is shone in the L eye and L stays the same, but R constricts?

L3

What cranial nerve is affected if a light is shone in the L eye and L and R do not constrict?

L2

Name, type, function, and effect of CN III.

• Oculomotor

• Motor

• Function and if affected - all eye muscles except superior oblique (IV) and lateral rectus (VI)

  • Movement of eyeball → strabismus - lateral (lazy eye)

  • Opens eyeball → ptosis - drooping of eyelids

  • Constricts pupils → dilation of pupils

Name, type, function, and effect of CN IV.

• Trochlear

• Motor

• Look down and in (at nose) - superior oblique

Name, type, function, and effect of CN VI.

• Abducens

• Motor

• Look out (abducting) - lateral rectus

  • Lesion → medial strabismus

If there is a lesion to the glossopharyngeal and vagus, what other cranial nerve is likely to be affected?

“CE MI PONS MEDU”

11 (spinal accessory) or 12 (hypoglossal) because they are located in the medulla oblongota

Describe the cranial nerve and muscle action of each of the eye muscles

• superior rectus 3 up

• inferior rectus 3 down

• medial rectus 3 in

• lateral rectus 6 out

• superior oblique 4 down and in

• inferior oblique 3 up and out

Name, type, function, and effect of CN V.

• Trigeminal

• Both

• Function

  • Sensation to face

  • Corneal reflex - Afferent (closes eye to protect)

  • Sensation to anterior 2/3rd of tongue

  • Dampens sound (hyperacusis - whispering is too loud)

  • Jaw jerk

Name, type, function, and effect of CN VII.

• Facial

• Both

• Function

  • Movement of face

  • Corneal reflex - Efferent

  • Taste to anterior 2/3rd of tongue

  • Dampens sound

  • Lacrimation (crying), salivation (drooling)

What movements of the face does the facial nerve not perform? Which nerves do these actions?

• Opening eyelids - 3

  • Closing eyelids - 7

• Mastication - 5 “triCHEWminal”

What cranial nerve does smiling?

CN VII

What cranial nerve does chewing?

V

What cranial nerve does swallowing?

A lot - 9, 10 mainly

What cranial nerve moves the tongue?

CN XII

Name, type, function, and effect of CN VIII.

• Vestibulocochlear

• Sensory

• Balance and hearing

  • Hearing loss

    • Conductive - outer ear (putting finger in ear, noise cancelling headphones)

    • Sensorineural - inner ear

Describe the steps to diagnose hearing loss and which type and side.

• Step 1: Rinne’s test for type (conductive vs sensorineural) - tuning fork vibration at mastoid process BC → “cant hear it anymore” → tuning fork to ear AC

  • Normal: AC > BC

  • Sensorineural loss: AC > BC

  • Conduction loss: BC > AC

• Step 2: Weber’s test for side (right vs left) - tuning fork to top of head

  • Normal: heard equal on both sides

  • Sensorineural loss - heard louder in normal ear

  • Conduction loss - heard louder in affected ear

  • “CANS” → Conductive = louder to Affected; Sensorineural = louder in Normal ear

Determine the type of hearing loss and which ear if Rinne’s test showed BC > AC and Weber’s test showed louder R.

Conductive hearing loss in R side

Determine the type of hearing loss and which ear if Rinne’s test showed AC > BC and Weber’s test showed equal.

Normal

Determine the type of hearing loss and which ear if Rinne’s test showed AC > BC and Weber’s test showed louder R.

Sensorineural loss in L side

Determine the type of hearing loss and which ear if Rinne’s test showed BC > AC and Weber’s test showed louder L.

Conductive hearing loss in L side

Name, type, function, and effect of CN IX.

• Glossopharyngeal

• Both

• Function

  • Gag reflex - Afferent

  • Posterior tongue sensation and taste

Name, type, function, and effect of CN X.

• Vagus

• Both

• Gag reflex - Efferent

• Deviation of uvula

  • If R10 affected → uvula deviates L (MOVES OPPOSITE)

Name, type, function, and effect of CN XII.

• Hypoglossal

• Motor

• Moves tongue

  • Atrophy or “Lick your lesion” R12 affected → tongue moves to R

If a patient “talks normally but doesn’t make sense”, leans to the right when sitting and has difficulty lifting his right arm overhead, and becomes frustrated when given instructions and is fluent but nonsensical speech, what lobe is damaged?

• Left temporal lobe Wernicke’s area

What presentation indicates injury to the CN XI nerve?

Shoulder droop and weakness with shoulder shrug

What presentation indicates involvement of the left parietal lobe?

Impaired safety awareness, difficulty recognizing his right-sided weakness

Name, type, function, and effect of CN VI.

• Spinal accessory

• Motor

• Shoulder elevation → test SCM & traps (SB same side, rotate opposite) by shrugging shoulders

Give a summary of the functions of each brain lobe.

Give a cranial nerves summary of name, type, and action/test.

Give a lesion location summary of UMN, LMN, BG, and Cerebellum.