Neuro6

Question 1

What do we see histopathologically/grossly in Huntington Disease? (3)

Answer 1

• -Degeneration of the GABAergic neurons of the caudate nucleus –> expansion of lateral ventricles
• -Also degenerative changes in the putamen and cortex
• -decreased levels of GABA and ACh in the brain

Question 2

What are the clinical characteristics of Huntington Disease?

Answer 2

• -Chorea
• -writhing movement (athetoid)
• -progressive dementia
• -behavioral disorders

**sometimes Huntington disease is initially mistaken for substance abuse

Question 3

60% of abscesses in the brain are caused by what primary disease process?

Answer 3

otitis media (middle ear infection)

cerebellar and temporal lobe abscesses are associated with otitis media

Question 4

Cerebellar abscesses are specifically associated with what disease?

Answer 4

otitis media (middle ear infection)

Question 5

What bacteria are most commonly responsible for otitis media?

Answer 5

Haemophilus influenzae

Streptococcus pneumoniae

Question 6

What is a subdural empyema?

Answer 6

A collection of pus between the dura and the arachnoid. This is usually a complication of bacterial meningitis.

Question 7

Where in the brain would sinusitis cause abcesses?

Answer 7

frontal and temporal lobe

Question 8

What is a ring-enhancing lesion in the brain on CT indicative of?

Answer 8

a brain abscess

Question 9

Unlike injury to the lateral geniculate nucleus or optic radiations, why do we observe macular sparing with a lesion to the occipital cortex?

Answer 9

This is because the most posterior region of the occipital cortex, which is where the macula is represented, has a bilaterally redundant blood supply. It is supplied by the PCA (posterior cerebral artery) and a branch of the middle cerebral artery.

Question 10

What blood vessel pathology would lead to a bitemporal hemianopia?

Answer 10

The anterior communicating artery is located in the vicinity of the optic chiasm. Aneurysm of the anterior communicating artery can therefore compress the optic chiasm, producing a bitemportal hemianopia.

Question 11

What artery gives rise to the ophthalmic artery?

Answer 11

Internal carotid artery

Question 12

How would occlusion of the ophthalmic artery manifest clinically?

Answer 12

This artery perfuses the optic nerve and the retina. Occlusion of this artery would lead to monocular blindness in the affected eye.

Question 13

What would be the ophthalmologic deficit that results from aneurysm of the posterior communicating artery?

Answer 13

The posterior communicating arteries overlie CN III. Aneurysm of these arteries can lead to a CN III palsy. Because the parasympathetic fibers of CN III are located peripherally, the first sign of compression of this nerve would manifest as mydriasis (pupil dilation) on the affected side. If the aneurysm grows to impinge the centrally located motor fibers, extraocular eye movement will be impaired: lateral strabismus, with the affected eye pointing down and out on primary gaze.

Question 14

What blood vessel pathology would lead to a binasal hemianopia?

Answer 14

The internal carotid arteries also run next to the chiasm on their outside; calcification of these vessels could compress the non-decussating fibers of the chiasm, leading to a binasal hemianopia. (The nasal visual field projects to the temporal retina; the optic nerve fibers of the temporal retina do not decussate.)

Question 15

What is PrP sc?

Answer 15

PrP sc is a prion protein that is responsible for the spongiform changes seen in Creutzfeldt-Jakob Disease (CJD)

Question 16

What is mutation in zinc-copper superoxide dismutase associated with?

Answer 16

It is associated with some hereditary forms of Amyotrophic Lateral Sclerosis (ALS)

Question 17

What are neurofibrillary tangles composed of?

Answer 17

Hyperphosphorylated tau proteins. Tau proteins are microtubule-associated proteins that normally bind to and stabilize microtubules.

The hyperphosphorylated tau proteins form insoluble paired helical filaments (PHF)

Question 18

Where is the facial nucleus located?

Answer 18

The lower pons

Question 19

What cranial nerve nuclei are located in the medulla?

Answer 19

the motor nuclei for CNs 9, 10, 11, and 12

Question 20

What cranial nerve nuclei are located in the midbrain?

Answer 20

3 and 4

Question 21

What type of information does each branch of the trigeminal nerve carry?

Answer 21

ophthalmic - sensory
maxillary - sensory
mandibular - motor and sensory

Question 22

Where is the motor nucleus of the trigeminal nerve located?

Answer 22

In the mid-pons

Question 23

What is apraxia?

Answer 23

An inability to perform a task or a movement when asked, even though the command was understood

Question 24

Where is the hippocampus located?

Answer 24

In the medial temporal lobe

Question 25

What brain structure is exquisitely sensitive to anoxic injury, and can be selectively affected by anoxic injury?

Answer 25

The hippocampus. This would result in anterograde amnesio--an inability to acquire new information (form new memories).

Question 26

With what disorder do we see violent flinging of the proximal limb muscles?

Answer 26

hemiballismus

Question 27

What nerve lies in the tonsillar fossa?

Answer 27

the glossopharyngeal nerve

Question 28

What information is carried by the glossopharyngeal nerve?

Answer 28

The glossopharyngeal nerve carries general sensory information from the mucosa of the pharynx, and general sensory and taste sensation from the posterior 1/3 of the tongue. This nerve also innervates the stylopharyngeus muscle, which helps to elevate the palate. However, this innervation occurs proximal to the point at which the nerve crosses the tonsillar fossa

Question 29

What nerve innervates the constrictor muscles of the pharynx?

Answer 29

The vagus

Question 30

What nerve innervates the muscles of the soft palate?

Answer 30

Most are innervated by the vagus nerve. The tensor palati is innervated by the mandibular branch of the trigeminal nerve

Question 31

What nerve innervates the muscles of the tongue?

Answer 31

The hypoglossal nerve innervates the hypoglossus, geniooglossus, and styloglossus. The only tongue muscle not innervated by CN12 is the palatoglossus, which is innervated by the vagus

Question 32

What is the order of layers through which a needle passes for a lumbar puncture (LP)?

Answer 32

``` skin superficial fascia deep fascia supraspinous ligament interspinous ligament ligamentum flavum epidural space dura arachnoid subarachnoid space ```

Question 33

Where would you administer local anesthetic in an epidural?

Answer 33

in the epidural space

Question 34

Where would you administer local anesthetic in spinal anesthesia?

Answer 34

into the CSF in the subarachnoid space

Question 35

Between which vertebra is a needle typically inserted for an LP?

Answer 35

Between L4 and L5

Question 36

What are the characteristics of a subdural hematoma on imaging?

Answer 36

- -cresent-shaped - -cross suture lines - -don't cross the midline

Question 37

What is the Cushing reflex?

Answer 37

Hypertension and bradycardia in response to increased intracranial pressure (ICP).

Question 38

Explain why we see hypertension in the Cushing reflex

Answer 38

- -This reflex is triggered in response to a decrease in cerebral perfusion pressure (CPP), which is the difference between MAP and ICP, when that change is due to significantly increased ICP. - -Initially when ICP increases, cerebral arteries will dilate maximally to decreased cerebral vascular resistance and therefore maintain cerebral vascular pressure. However, if the increase in ICP overwhelms this response, the hypothalamus will activate the sympathetic nervous system, which will increase cardiac output and stimulate peripheral vasoconstriction in an attempt to increase MAP.

Question 39

Why do we paradoxically observe bradycardia in the Cushing reflex?

Answer 39

The hypothalamus activates the sympathetic nervous system, which will increase cardiac output and stimulate peripheral vasoconstriction, leading to increased MAP. However, this increased MAP will be sensed by the baroreceptors in the carotid and aortic arches, leading to a vagal response that leads to a reduction in heart rate, often to the point of bradycardia.

Question 40

Sensory innervation of the laryngeal mucosa above the vocal folds

Answer 40

Internal branch of the superior laryngeal nerve

Question 41

Sensory innervation of the laryngeal mucosa below the vocal folds?

Answer 41

Recurrent laryngeal nerve

Question 42

Sensory innervation of the pharyngeal mucosa?

Answer 42

glossopharyngeal nerve

Question 43

Motor innervation of the cricothyroid muscle

Answer 43

External branch of the superior laryngeal nerve

Question 44

Motor innervation of the lateral cricoarytenoid muscle

Answer 44

recurrent laryngeal nerve

Question 45

What artery accompanies the interal branch of the superior laryngeal nerve in the larynx?

Answer 45

superior laryngeal artery