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Flashcards in Intoxications/Infections Deck (32):
1

Tetanus

Tetanospasmin binds to cortical, brainstem, and interneurons, preventing the release of GABA (glycine and gamma aminobutyric acid)
(2 weeks after exposure)
Symptoms: painful muscle spasms
-spread of exotoxin through the bloodstream produces diffuse muscle spasms and generalized convulsive seizures from cortical disinhibition
(trismus, risus sardonicus, opisthotonus)
-may impair swallowing and breathing

2

Botulism

improperly canned or contaminated food
-exotoxin binds to presynaptic nerve terminals and prevents the release of acetylcholine from lower motor neurons and parasympathetic nerves
(within 12 hours)
Symptoms:
initially
1. ptosis
2. diplopia
3. pupillary dialysis
followed by:
4. dysphagia
5. facial and limb weakness
6. respiratory paralysis

guanidine helps facilitate release of acetylcholine

3

Lead Poisoning

Adults: peripheral neuropathy with focal neuropathies like wrist drop
children: encephalopathy and abdominal pain

4

Organic solvent

peripheral neuropathy or encephalopathy or both

5

glue

periphearl neuropahty

6

CO

headache vomiting and blurry vision-->coma, seizures, and cardiopulmonary arrest

survivors: deficits of memory or cognition or show signs of parkinsonism

7

illicit drugs and the brain

1. intracranial hemorrhage from head trauma

2. drug induced seizures

3. drug induced vasoconstriction or hypertension leading to ischemic infarction or brain hemorrhage-->stroke syndrome in young healthy adult --->cocaine

4. ischemic infarction from IV drug use from vasculitis-immune mediated vascular reaction to the drug or its filler material

8

acute alcohol toxicity

social disinhibition, impairment of consciousness, and cerebral dysfunction(dysarthria, dysmetria, nystagmus, and ataxia)
-head trauma secondarily
-very high levels coma and death

9

Alcohol withdrawal syndrome

Initially
Hypersympathetic stage-tremulous, sweating, tach, jitteriness

12 hours- 3-days
Cluster of generalized tonic-clonic seizures

3-4 days
Delirium tremens
-fluctuating motor and autonomic activity, confusion and hallucinations
-delirium tremens or any complications such as infections or head trauma may become fatal if untreated

10

What is the treatment for alcohol withdrawal?

1. hydration and metabolic care (thiamine)
2. benzodiazepines provide sedation and seizure control*

11

Wernicke-Korsakoff syndrom

-deficiency of thiamine in patients with malnutrition or malabsorption-most described in alchololics

12

Wernicke's encephalopathy

acute phase of the syndrome
-nystagmus
-ophthalmoplegia
-gait ataxia
-confusion

may resolve within hours to days of thiamine administration

13

Korsakoff's psychosis

severe or recurrent thiamine deficiency
-chronic memory deficit
-amnestic syndrome
-confabulation

(tiny petechial hemorrhages and gliosis occur in the vicinity of the third and fourth ventricle and connecting aqueduct, involving mammillary bodies, fornix, and dorsomedial thalamus)

14

Alcoholic cerebellar degneration

anterior superior vermis--> ataxic gait and dysmetria of the lower limbs

15

central pontine myelinolysis

occurs in alcoholic who undergo rapid correction of severe hyponatremia
-demyelination of the corticospinal and corticobulbar tracts of the pons occur

16

Acute meningitis
Symptoms
Treatment

symptoms: fever, headache, nuchal rigidity( meningeal irritation and inflammation-Kernig or Brudzinski sign) malaise, lethargy, nausea and vomiting, lethargy to coma
-may be fatal

Treatment: ceftriaxone plus vanco
amp for elderly or neo for list
IV dexamethasone-given just before antibiotics reduces neurological complications such as deafness and cognitive deficits and lowers mortality

17

What can substantial amounts of purulent exudate lead to?

hydrocephalus by obstructing csf pathways

-pus in subarachnoid space may lead to inflammation and edema of cortex (meningoencephalitis) or cause infarction of the underlying brain or spinal cord when local superficial blood vessels become inflamed or thrombose

-young children may have deafness

18

Lumbar puncture bacterial meningitis

Polymorphonuclear WBC and low CSF glucose

19

Chronic meningitis

more subtle symptoms over weeks or months
-Tb, fungus, syphilis, parasites
Symptoms: confusion, low grade fever, mild headache, without obvious nuchal rigidity
-PCR CSF

20

Encephalitis

brain primary site of infection
symptoms: headache and fever, seizures, focal neurological deficits, behavior changes and impairment of consciousness

-patchy demyelination, edema, and tiny petechial hemorrhages
-neuronal destruction by proliferating microglia, perivascular lymphocytes, and viral inclusions within neurons

-arthropods(west-nile), viral infection (polio), rabies, herpes

21

What happens to patients with encephalitis

ICU-raised intracranial pressure and treatment with anticonvulsants and sedatives

22

Herpes simplex encephalitis
Location in brain it affects
Symptoms
Treatment

non epidemic, nonseasonal, high mortality when not treated

-inferior frontal and medial temporal lobes, often bilaterally and asymmetrically

Symptoms:
1. aphasia
2. behavioral changes
3. memory deficits

Treatment: acyclovir
-treated on suspicion


23

West nile virus causing encephalitis
Location of CNS and pns
Symptoms

fever, headache, rash, significant weakness by affecting:
1. peripheral nerves(similar to Guillain barre syndrome)
2. anterior horn cells (similar to polio)

24

Polio

viral invasion and destruction of anterior horn cells and brain stem motor nuclei
-lower motor neuron sign asymmetrical
-post polio atrophy-gradual metabolic failure or burnout of lower motor neurons which collaterally sprouted to control the denervated fibers in polio-weakened muscles

25

Zoster or shingles

-chickenpox lays dormant in dorsal root ganglia
eruption of a vesicular rash with severe neuralgic pain along one or adjacent dermatomes on the torso or limbs
treatment: acyclovir

26

late AIDS

1. chronic, painful neuropathy
2. cognitive changes
3. HIV dementia
4. myelopathy similar to combined degeneration from B12

-direct viral invasion or indirect damage from cell lysis and inflammation or complications related to immuno deficient state

27

Primary cerebral lymphoma-

rare immune system tumor arising within the brain

28

Opportunistic infections in HIV

cerebral toxoplasmosis
cryptococcal meningitis
CMV retinitis or encephalitis

**Progressive multifocal leukoencephalopathy

29

What is PML?

JV virus
infect oligodendrocytes
patchy or spotty demyelination of CNS white matter occurs from destruction of the oligodendrocytes

no cure

30

abcess

localized, encapsulated infection within or outside the brain or spinal cord
-usually bacterial but may be fungal or parasitic in immunocompromised patients

symptoms: fever and headache and may be ill from serious systemic infection
-seizures and focal neurological signs depend on its location
-may create brain edema with mass effect and increased intracranial pressure
-->rupture-->meningitis

31

prion

infectious proteins
-->spongiform encephalopathies in human animals
-progressive aggregation of prions in neurons destroys them in the absence of any inflammation

32

Creutzfeldt Jakob dementia

often sporadic rather than transmitted
-rapidly progressive dementia with cerebellar, cortico spinal, lower motor neuron or extrapyramidal signs and symptoms

-myoclonus

-no cure
-cytoplasmic vacuoles in neurons and astrocytes and neuronal loss without inflammation


mad cow-->human-->variant of CJD-slower progression and more psych and behavioral symptoms