Intoxications and Infections of the CNS Flashcards

1
Q

Where does the tetanus toxin come from?

A

Tetanus is an exotoxin produced from Clostridium tetani

It is either produced anaerobically in dirty wounds or from a non-sterile needle or drug abusers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How does the tetanus toxin produce an effect?

A

After hours to weeks, the exotoxin binds to interneurons of the CNS, preventing release of inhibitory glycine and GABA —> motor disinhibition

(generalized seizures, painful spasms etc)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How is a tetanus diagnosis made?

A

Clinically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is tetanus treated?

A

ICU care, neuromuscular blockade, sedation, anticonvulscents, tetanus immune globulins and antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where does the botulism toxin come from?

A

Exotoxin of clostridium botulinum- produced anaerobically in improperly canned or prepared food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does the botulinum toxin produce an effect?

A

The botulinum exotoxin binds to presynaptic nerve terminals preventing the release of ACh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Administration of what aids in the release of ACh from the pre-synaptic cleft?

A

Guanidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How is botulism diagnosed?

A

Clinical picture, EMG tests, bioassay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does lead poisoning manifest in adults?

A

Peripheral neuropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does lead poisoning manifest in children?

A

Encephalopathy, abdominal pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does organic solvent toxicity manifest in patients?

A

Encephalopathy or peripheral neuropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are symptoms associated with CO poisoning?

A

Early: headache, vomiting, blurred vision
Later: coma, seizures, or cardiopulmonary arrest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Survivors of CO poisoning may have what lasting effects?

A

Amnesia and parkinsonianism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What drugs cause stroke syndromes in atypical patients?

A

Cocaine (most common), amphetamines, PCP, and LSD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the neurological symptoms caused by acute alcohol intoxication?

A

social disinhibition, impaired consciousness, cerebellar dysfunction
secondary head trauma
very high levels may lead to coma, death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the neurologic symptoms caused by alcohol withdrawal?

A

early, hypersympathetic stage (tremulous, sweaty, tachycardic);
limited number of convulsive seizures 12 hrs-3 days after drinking stopped;
later stage of delirium tremens, 3-4 days after drinking stopped, with fluctuating motor and autonomic activity, confusion, hallucinations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do we treat alcohol withdrawal?

A

treat with benzodiazepines for sedation and seizure control, provide hydration and metabolic support, thiamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is acute Wernicke Encephalopathy?

A

nystagmus, ophthalmoplegia, gait ataxia, confusion…acute phase of Wernicke-Korsakoff syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is wernike encephalopathy corrected?

A

thiamine supplimentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is korsakoff psychosis?

A

Korsakoff psychosis (amnesia, confabulation) is the chronic phase of Wernicke-Korsakoff syndrome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where does alcoholic cerebellar degeneration occur?

A

Anterior superior cerebellar vermis

22
Q

What are the symptoms of alcoholic cerebellar degeneration?

A

gait ataxia and dysmetria of the lower limbs (inability to judge distance/scale –> discoordination)

23
Q

Define meningitis

A

Inflammation of the leptomeninges due to blood, foreign material, or infection within the subarachnoid space.

24
Q

What agents cause acute meningitis vs chronic meningitis?

A

Acute: bacterial, viral
Chronic: unusual organisms

25
Q

How are the CSF white counts and glucose affected by typical bacterial meningitis?

A

White count; increased neutrophils

Glucose: decreased

26
Q

How should the patient be treated if bacterial meningitis is suspected?

A

1) Look for primary source of infection
2) Give broad spectrum antibiotics
3) Narrow antibiotics once culprit is identified
4) Observe for complications +/- DEX to minimize risk of complications

27
Q

Name 4 complications of bacterial meningitis

A

1) Hydrocephalus (from pus obstructive CSF pathway)
2) Secondary inflammation and edema of cortex (meningoencephalitis)
3) Infarction from thrombosis of inflamed superficial vessels
4) Deafness (monitor hearing in children)

28
Q

who is most susceptible to chronic meningitis?

A

Elderly, malnourished, and immunosuppressed patients

29
Q

What are the symptoms of chronic meningitis?

A

subtle symptoms of mild headache, confusion, no obvious meningeal signs

30
Q

What usually causes encephalitis?

A

Viral infection

31
Q

How do you usually acquire viral encephalitis?

A

Viral transmission by seasonal arthropods (ticks, mosquitoes), inhalation or reactivation (herpes simplex)

32
Q

What are the symptoms of encephalitis?

A

High fever and headache (like with meningitis)

Seizures, focal neurologic deficits, changes in behavior and consciousness (more specific for encephalitis)

33
Q

Which strain of herpes causes herpes encephalitis?

A

HSV-1 (cause of oral herpes)

34
Q

The herpes virus has a predilection for which lobes of the brain? How does this correlate to neurologic symptoms?

A

Frontal and temporal

* aphasia, behavioral changes and memory impairment

35
Q

What is the treatment for herpes encephalitis?

A

acyclovir: reduces mortality from 40-70% to 20%

36
Q

What are the symptoms of west nile virus?

A

Encephalitis –> fever, headache, rash

Weakness from affected peripheral nerves or anterior horn cells

37
Q

Which cells are targeted by the polio virus?

A

motor neurons in the brain stem, spinal cord

38
Q

Survivors of polio suffer from what long term effects?

A

Asymmetrical atrophy and weakness in one limb

39
Q

What are shingles?

A

Reactivation of chicken pox (varicella zoster), which lies latent in the dorsal root ganglia

Causes a vesicular rash in 1 or 2 dermatomes

40
Q

HIV destroys which WBCs?

A

T4 helper lymphocytes

41
Q

HOw is the nervous system affected by HIV?

A

Direct viral invasion (dementia, meningitis)
Indirect damage from cell lysis, inflammation
Complications of an immunodeficient state

42
Q

How is AIDS dementia diagnosed?

A

Clinical diagnosis of exclusion

MRI shows nonspecific atrophy or white matter alterations

43
Q

Progressive Multifocal Leukoencephalopathy (PML) is an opportunistic infection in immunodeficient patients caused by what virus?

A

papovavirus

44
Q

What cells of the CNS are infected by the papovavirus in PML? What is the outcome?

A

Oligodendrocytes

Leads to patchy demyelination in the CNS and focal deficits. It is untreatable

45
Q

What is the causative agent in prion disease?

A

Infectious protein

46
Q

What is the most common prion disease?

A

Creutzfeldt-Jakob Dementia (CJD)

47
Q

How is prion disease transferred?

A

human graft tissue or neurosurgical instruments

Other prion diseases are hereditary in nature

48
Q

How do prions cause disease?

A

Infectious proteins induce conformational changes in normal proteins –> neuronal death WITHOUT inflammation

49
Q

What is the timing of Creutzfeldt-Jakob Disease?

A

Rapidly progressive, untreatable, fatal in weeks to months

50
Q

What are the symptoms of Creutzfeldt-Jakob Disease?

A

Dementia with prominent myoclonus

Often corticospinal, extra-pyramidal, cerebellar or LMN signs