Neuro

Question 1

Why is there so much variability in the expression of mitochondrial diseases?

Answer 1

normal and abnormal diseases are randomly distributed between daughter cells in mitosis (heteroplasmy)

Question 2

Name three mitochondrial syndromes

Answer 2

1. Leber hereditary optic neuropathy
2. Myoclonic epilepsy with ragged-red fibers
3. mitochondrial encephalomyopathy with lactic acidosis and stroke like episodes (MELAS)

Question 3

child
cognitive impairment
behavioral problems
mild anemia
lives in old house

Answer 3

lead poisioning

Question 4

Enzymes most sensitive to lead inhibition

Answer 4

delta-aminolevulinate dyhydrase and ferrochelatase (zinc containing)
Causes delta-ALA and proroporphyrin IX to accumulate, decreased production of heme

Question 5

Pathway that N. meningitidis uses to colonize CNS:

Answer 5

Nasopharynx-> mucosal epithelium -> bloodstream -> choroid plexus ->CNS via BBB

Question 6

Location of Foramen of Monro

Answer 6

between lateral ventricles and third ventricle

Question 7

Location of cerebral aqueduct

Answer 7

between third ventricle and fourth ventricle

Question 8

Openings between fourth ventricle and subarachnoid space:

Answer 8

lateral foramina of Luschka and medial foramen of Magendie

Question 9

How does CSF return to venous circulation

Answer 9

arachnoid villi

Question 10

Noncommunicating hydrocephalus

Answer 10

caused by obstruction of CSF flow

Question 11

Communicating hydrocephalus

Answer 11

blockage of subarachnoid space, not within brain or brainstem
from fibrosis following inflammation

Question 12

Normal pressure hydrocephalus

Answer 12

CSF is not absorbed by arachnoid villi

Question 13

Hydrocephalus ex vacuo

Answer 13

Increased CSF volume occurring in conditions of brain atrohpy

Question 14

Psuedotumor cerebri

Answer 14

increased intracranial pressure in overweight young women. Related to decreased CSF outflow at arachnoid villi

Question 15

Causes of progressively weakening diaphragmatic contractions (intact phrenic nerve stimulation)

Answer 15

NMJ pathology (myasthenia gravis) or rapid diaphragmatic muscle fatigue (restrictive lung disease)

Question 16

fever and muscle rigidity after surgery under general anathesia
tachycardia, hypertension, hyperkalemia, myoglobinemia

Answer 16

Malignant hyperthermia. Caused by excess free calcium in the cytoplasm of muscle fibers (defect in ryanodine receptor). Ramps of action of sarcoplasmic reuptake of Ca (ATP dependent-> generates heat)

Question 17

What drug is used to reverse malignant hyperthermia?

Answer 17

Dantrolene- muscle relaxant that acts of ryanodine receptors preventing further release of Ca into the cytoplasm.

Question 18

Tetrodotoxin

Answer 18

neurotoxin in pufferfish. Binds to voltage gate sodium channels in nerve and cardiac tissue, preventing depolarization

Question 19

Most common symptoms of MS

Answer 19

optic neuritis
internuclear opthalmoplegia
sensory deficits
Worsen with heat exposure

Question 20

Enzyme deficiency in Niemann-Pick

Answer 20

sphingomyelinase

Question 21

Urinary incontinence
ataxic gait
dementia

Answer 21

Normal pressure hydrocephalus (wacky, wobbly, wet)

Question 22

CT findings in normal pressure hydrocephalus

Answer 22

symmetric dilitation of ventriculi

Question 23

Light reflex findings when one optic nerve is damaged

Answer 23

Light in effected eye will not cause contstriction of either pupil (optic nerve can’t carry info away)
Light in unaffected eye will cause constriction of both pupils (occulomotor nerves still function)

Question 24

What happens at sites of irreversible neuron injury?

Answer 24

Astrocytosis (glial cells that form scar that compensates for volume loss)

Question 25

Which vitamins are fat soluble?

Answer 25

ADEK

Question 26

Which vitamin deficiency causes neuromuscular disease and hemolytic anemia?

Answer 26

Vitamin E (functions to protect fatty acids from oxidation. Deficiency allows damage to neurons and RBCs)

Question 27

Cerebellar ataxia Telangectasia increased risk of sinopulmonary infections

Answer 27

ataxia telangiectasia: AR defect in ATM (DNA repair) gene Causes IgA deficiency

Question 28

Function of kinesin

Answer 28

transport of neurotransmitter containing secretory vesicles to synaptic terminals

Question 29

Spastic rigidity hyperreflexia paresis

Answer 29

Upper motor neuron lesions. Can be located in corticospinal tract, internal capsule (posterior limb), and primary motor cortex.

Question 30

hemiballism

Answer 30

wild, flinging movements of the extremities on one side (contralateral to lesion) of the body. Occurs due to damage of the subthalamic nucleus (part of basal ganglia)

Question 31

What comprises the wall of a cerebral cystic cavity?

Answer 31

astrocytes (gliosis)

Question 32

Cause of neonatal tetanus

Answer 32

infected umbilical stump

Question 33

When can a child get their first tetanus vaccine?

Answer 33

Two months

Question 34

What molecules are derived from POMC?

Answer 34

beta-endorphins ACTH MSH

Question 35

How does tetanospasmin (tetanus toxin) travel through the body?

Answer 35

motor neuron (retrograde transport) -> spinal cord-> inhibition of inhibitory interneurons -> unregulated firing on primary motor neurons

Question 36

Two brain tumors that arise in the cerebellum

Answer 36

pilocytic astrocytomas and medullobastomas

Question 37

tumor composed of sheets of small cells with basophilic nuclei and scant cytoplasm (small, round, blue). Abundant mitoses

Answer 37

Primitive neuroendocrine tumors. Include Medullobastomas

Question 38

Amniocentesis findings in neural tube defect

Answer 38

High Alpha-fetoprotein and acetylcholinesterase.

Question 39

Confusion/apathy/inattentiveness ataxia opthalmoplegia (horizontal nystagmus) damage to mamillary bodies

Answer 39

Wernicke encephalopathy | Caused by glucose infusion in a patient with a thiamine deficiency

Question 40

``` flu-like prodrome agitation disorientation pharyngospasm photophobia followed by flaccid paralysis Exposure to wild mammals ```

Answer 40

Rabies encephalitis

Question 41

How do rabies viruses bind to cells?

Answer 41

Bind to nicotinic acetylcholine receptors

Question 42

Signs of acute Vitamin A toxicity

Answer 42

nausea vomiting vertigo blurred vision

Question 43

Signs of chronic Vitamin A toxicity

Answer 43

``` alopecia dry skin hyperlipidemia hepatotoxicity HSM visual difficulties intracranial hypertension ```

Question 44

Signs of niacin deficiency

Answer 44

3D's of pellagra: dementia, dermatitis, diarrhea

Question 45

Schizophrenic symptoms lasting 1-6 months

Answer 45

Schizophreniform disorder

Question 46

Substance that causes the most overdose deaths in the US

Answer 46

Opioid analgesics

Question 47

Vertical diploplia

Answer 47

Double vision when looking towards the nose. USually caused by palsy of trochlear nerve (CNIV)

Question 48

Total sensory loss on one side of the body (no motor dysfunction)

Answer 48

Contralateral thalamic syndrome

Question 49

Cause of lacunar infarcts

Answer 49

small vessel lipohyalinosis and atherosclerosis involving penetrating vessels supplying deep brain structures

Question 50

Risk factors for lacunar infarcts

Answer 50

DM and uncontrolled hypertension

Question 51

Stimulus for release of acetylcholine into NMJ

Answer 51

Calcium influx into nerve terminal

Question 52

Blotchy red fiber on Gomori trichrome stain

Answer 52

mitochondrial myopathies. Because abnormal mitochondria accumulate under the sarcolemma

Question 53

Tumor at cerebellopontine angle S-100 positive around cranial nerve (especially VIII)

Answer 53

Schannoma

Question 54

What two types of cancers are S-100 positive

Answer 54

Schwannoma and Melanoma