6/17- Toxic/Metabolic Disorders of the Nervous System Flashcards Preview

Term 5: Neuro > 6/17- Toxic/Metabolic Disorders of the Nervous System > Flashcards

Flashcards in 6/17- Toxic/Metabolic Disorders of the Nervous System Deck (25):
1

Outline/hierarchy of toxic and metabolic disorders

A image thumb
2

What is the result of Vitamin B12 deficiency (loss of what?)

Combined system degeneration:

- Dorsal columns

- Corticospinal tract (lateral and anterior) 

A image thumb
3

What other conditions look similar to Vitamin B12 deficiency?

- Nitrous oxide toxicity

- Vacuolar myelopathy of HIV

4

What does this show? 

Q image thumb

Mammillary body hemorrhage

- Memory disturbances, disrupted short-term memory

- Causes vascular proliferation and atrophy

- Involved in thiamine deficiency/Wernicke's encephalopathy (?)

5

Thiamine deficiency results in what?

Wernicke's encephalopathy

- Mammillary body impaired, causing decreased memory (can still retrieve old, but short-term impaired); confabulation

- Midbrain affected, so change in vertical gaze, nystagmus, ataxia 

A image thumb
6

T/F: Wernicke's encephalopathy is reversible?

True at first, but if you don't treat quickly enough it may become irreversible

7

What is it called when Wernicke's encephalopathy becomes irreversible?

Korsakoff's psychosis

8

What is confabulation?

May not remember information from the past few days and so replacing it with other possessed memories (without realizing)

9

Vitamin B6 is involved in the synthesis of what? Deficiency results in what?

GABA

- Deficiency results in increased incidence of seizures

10

What is Wilson's Disease? Symptoms?

Copper metabolism disorder with deposition in:

- Liver: (normally excretes Cu in bile) cirrhosis

- Brain: movement disorders (Cu tends to go to basal ganglia); chorea, athetosis, psychosis (may look like Huntington's)

- Eye: Kayser-Fleischer rings around cornea

May present with CNS manifestations, liver manifestations, or both

This is treatable!

- Restrict copper in diet

- Use chelators to bind Cu and prevent absorption or promote clearance from blood 

A image thumb
11

What is hepatic encephalopathy?

- Gross pathology

- Microscopic

Will have increased levels of ammonia, affecting levels of consciousness

Gross pathology: possibly cerebral edema

- Ammonia appears to affect function of astrocytes (trouble sustaining BBB)

Microscopic: Alzheimer type II astrocytosis*

- Enlarged, often paired, pale nuclei with nuclear chromatin peripheralized

*NOT seen in Alzheimer's disease; not related at all, just same scientist

12

What is this? 

Q image thumb

Alzheimer type II astrocytes seen in hepatic encephalopathy

- No cytoplasm (similar to a normal astrocyte)

- Nucleus is very large with peripheralized chromatin; large and pale

13

__ in __ hospitalizations is alcohol-related, with __% of MVAs involving alcohol consumption

1 in 25 hospitalizations is alcohol-related, with 50% of MVAs involving alcohol consumption

14

What is this? What could cause this? Symptoms? 

Q image thumb

Vermal cerebellar atrophy (see much space between folia)

- Could by caused by chronic alcohol consumption

- Would result in trunkal ataxia (wide-based stance when walking, etc.); higher likelihood of falling

15

What is Marchivava-Bignami syndrome? What causes it?

- Demyelination and necrosis of corpus callosum

- Seen with rapid correction of hyponatremia

- First described in alcoholics

16

What is this? 

Q image thumb

Demyelination and necrosis of corpus callosum seen with rapid correction of hyponatremia

17

What is this? What causes it?

Q image thumb

Central pontine myelinolysis

- Also seen with rapid correction of hyponatremia (although not technically part of Marchivava-Bignami syndrome?)

18

What is the mechanism of methanol intoxication damage? Symptoms?

Converted by liver to formic acid and formaldehyde

- Toxic to retinal ganglia cells -> blindness

- Hemorrhagic necrosis of basal ganglia

- Necrosis of the putamen -> movement disorder

19

What is this?

Q image thumb

Necrosis of the putamen caused by methanol intoxication (bilateral)

20

What is this? 

Q image thumb

Bilateral necrosis of the globus pallidum due to carbon monoxide intoxication

21

What is the mechanism of carbon monoxide intoxication damage? Symptoms? Result of?

- Bilateral globus pallidum necrosis (likely due to binding of iron in this tissue??)

- Depressed levels of consciousness (may go to sleep)

May result from:

- Auto exhaust

- Gasoline engines

- Coal stoves without adequate ventilation

22

Intoxication with ___ causes necrosis of ____: - Methanol: - Carbon monoxide:

- Methanol: Putamen (1 word-1 word)

- Carbon monoxide: Globus pallidus (2 words-2 words) 

A image thumb
23

What is this? Caused by? 

Q image thumb

Diffuse cerebral edema from heavy metal (lead) intoxication

24

What are the most common heavy metal intoxication elements?

- Lead

- Arsenic

- Thallium

25

What is this? Caused by? Results in? 

Q image thumb

Vascular necrosis in lead poisoning

- Central area used to be a BV

- Breakdown of BBB -> cerebral edema

- May result in LOC