Intoxications and infections of the NS

Question 1

how does tetanospasmin (the tetanus toxin) affect the nervous system

Answer 1

binds to cortical, brain stem, and spinal interneurons, preventing the release of the inhibitory neurotransmitters glycine and GABA

Question 2

what symptoms does tetanus cause

Answer 2

Severe, prolonged, painful muscle spasms (may be localized or diffuse), if the toxin enters the blood stream there are generalized convulsive seizures. Trismus or lockjaw, grimacing smile (risus sardonicus) and arching back (opisthotonus)

Question 3

how is tetanus treated

Answer 3

ICU care with mechanical ventilation, sedation, pharmacological neuromuscular blockade and anticonvulsants. human tetanus immune globulin may neutralize any remaining tetanospasmin

Question 4

where do patients commonly get botulism from

Answer 4

improperly canned or contaminated food (destroyed with proper cooking)

Question 5

how does the botulism toxin affect the nervous system

Answer 5

the exotoxin binds to presynaptic nerve terminals and prevents the release of ACh from LMNs and parasympathetic nerves. Resulting in paralysis of skeletal muscle, bowel, bladder and salivary glands. Severity depends on how much toxin in consumed

Question 6

what are the symptoms seen with botulism toxin

Answer 6

ptosis, diplopia, and pupillary paralysis, followed by dysphagia, facial and limb weakness, and possibly respiratory paralysis

Question 7

what antitoxin is available for botulism toxin

Answer 7

guanidine to help facilitate ACh release

Question 8

what is the prognosis for botulism toxin

Answer 8

gradual spontaneous recovery after days to weeks given good supportive care

Question 9

how does lead poisoning present in adults

Answer 9

peripheral neuropathy often with prominent focal neuropathies like wrist drop

Question 10

how does lead poisoning present in children

Answer 10

encephalopathy and abdominal pain

Question 11

how is lead poisoning treated

Answer 11

chelating agents

Question 12

what does organic solvent exposures cause

Answer 12

peripheral neuropathy or encephalitis

Question 13

what are some environmental exposures to consider when a patient presents with peripheral neuropathies

Answer 13

lead poisoning, organic solvents, carbon monoxide

Question 14

what are early symptoms of CO poisoning

Answer 14

headache, vomiting, and blurry vision that can progress to coma, seixures and cardiopulmonary arrest

Question 15

how do you treat CO poisoning

Answer 15

100% oxygen or a hyperbaric chamber

Question 16

what may happen after a CO poisoning (lasting effects)

Answer 16

memory or cognition deficits and a few may get parkinsonism symptoms after a few weeks (basil ganglion is very sensitive to CO)

Question 17

what should be a consideration when stroke symptoms are seen in a young, otherwise healthy patient

Answer 17

drug induced vasoconstiction or hypertension leading to ischemic infarction or brain hemorrhage – cocaine is the most common culprit

Question 18

what are symptoms of an alcohol withdrawal syndrome

Answer 18

initially hypersympathic stage - tremulousness, sweating, tachycardia and jitteriness, cluster of generalized tonic-clonic seizures

Question 19

what kind of seizure should raise suspicion for a focal brain lesion in a patient undergoing alcohol withdrawal

Answer 19

any aura or partial seizure since seizures due to withdrawal should be generalized and diffuse

Question 20

when are delirium tremors seen in an alcoholic patient

Answer 20

3-4 days after alcohol cessation

Question 21

what are delirium tremors

Answer 21

fluctuating motor and autonomic activity, confusion, and hallucinaitons - must be treated or may become fatal

Question 22

what drug may be given to a patient undergoing alcohol withdrawal for seizure control

Answer 22

benzodiazepines - provide sedation and seizure control

Question 23

what causes Wernicke-Korsakoff syndrome

Answer 23

Thiamine (B1) deficiency - common in alcoholic

Question 24

what does Wernicke’s encephalopathy refer to

Answer 24

acute phase of the Wernicke-Korsakoff syndrome consisting of nystagmus, ophthalmoplegia, gait ataxia, and confusion - resolves with thiamine administration

Question 25

what causes Korsakoff's psychosis

Answer 25

persistant, severe, or recurrent thiamine deficiency

Question 26

how does Korsakoff's psychosis present

Answer 26

chronic memory deficit or amnestic syndrome with frequent confabulation (story telling- to fill in memory gaps)

Question 27

what is seen pathologically in Korsakoff's psychosis

Answer 27

petechial hemorrhages and gliosis in the vicinity of the third and fourth ventricles and connecting aqueduct - involving the mammillary bodies, fornix and dorsomedial thalamus

Question 28

what structure does Alcoholic Cerebellar degeneration affect

Answer 28

anterior-superior vermis

Question 29

what symptoms does Alcoholic Cerebellar degneration

Answer 29

ataxic gait and dysmetria of the lower limbs

Question 30

who gets central pontine myelinolysis

Answer 30

occurs in alcoholics and patients who undergo an overly rapid correction of severe hyponatremia (low to high the pons will die)

Question 31

what is central pontine myelinolysis

Answer 31

demyelination of the corticospinal and corticobulbar tracts in the pons

Question 32

how can menengitis spread

Answer 32

either from the blood stream or directly from an otitis or sinusitis

Question 33

what are symptoms of acute menengitis

Answer 33

fever, headache, stiff neck, malaise, lethargy, nausea, and vomiting = medical emergency

Question 34

what are the signs seen in meningitis due to nuchal rigidity

Answer 34

Kernig or Brudzinski

Question 35

what kind of meningitis is associated with a petechial rash

Answer 35

N. meningitidis - meningococcal

Question 36

what is common initial antibiotics used for meningitis

Answer 36

newer cephalosporin such as ceftriaxone plus vancomycin for any pneumococci resistant to pcn + ampicillin for elderly or neonates to cover listeria

Question 37

what can be given with antibiotics to reduce neurological complications

Answer 37

IV dexamethasone (reduces complications of deafness and cognitive deficits and lowers mortality)

Question 38

what are complications of bacterial meningitis

Answer 38

hydrocephalus due to pus obstructing the CSF pathways. inflammation and edema of the cortex itself, or infarction of the brain due to inflammation of superficial blood vessels

Question 39

what are common causes of meningitis in a neonate

Answer 39

Group B strep E. coli listeria

Question 40

what are common causes of meningitis in children

Answer 40

N. meningitidis | S. pneumo

Question 41

what are common causes of meningitis in adults

Answer 41

S. pneumo N. meningitis E. coli

Question 42

when should a lumbar puncture be postponed

Answer 42

if the patient has elevated ICP (unconscous state, papilledema) or an intracranial mass with edema

Question 43

what is the typical CSF profile for bacterial meningitis

Answer 43

Predominantly PMN WBS, low CSF glucose and high protein

Question 44

what is the typical CSF profile for viral meningitis

Answer 44

lymphocytes, normal protein, normal glucose

Question 45

what is the typical CSF profile for fungal meningitis

Answer 45

lymphocytes, high protein, low glucose

Question 46

who is at risk for chronic meningitis

Answer 46

the elderly, malnourished or immunocompromised

Question 47

what is encephalitis

Answer 47

when the brain (not the subarchnoid space) is the primary site of infection and inflammation

Question 48

what is the usual cause of encephalitis

Answer 48

viruses

Question 49

what is the onset and symptoms associated with encephalitis

Answer 49

symptoms evolve over hours to days and involve fever and headache, seizures, focal neurological deficits, behavioral changes and impairment of consciousness

Question 50

what happens pathologically in encephalitis

Answer 50

patchy demyelination, edema and tiny, petechial hemorrhages

Question 51

what can be seen microscopically in encephalitis

Answer 51

neuronal destruction by microglia, perivascular lymphocytes and viral inclusions within neurons or glia

Question 52

what does the CSF show in encephalitis

Answer 52

it looks similar to viral meningitis with lymphocytes and normal or slightly decreased glucose

Question 53

what should you look for in a patient with encephalitis

Answer 53

antibody titres to suspected viruses and HSV-1 via PCR

Question 54

what is the treatment for encephalitis

Answer 54

acyclovir if due to herpes virus. treat the increased ICP, anticonvulsants and sedatives

Question 55

where does HSV-1 usually infect

Answer 55

frontal and medial temporal lobes - often bilaterally and symmetrically

Question 56

what signs and symptoms are indicative of herpes simplex encephalitis

Answer 56

aphasia, behavioral changes, and memory deficits

Question 57

what treatment is important when there is suspicion for herpes simplex encephalitis

Answer 57

Acyclovoir (decreases mortality from > 40% to 20%)

Question 58

what is unique to west nile encephalitis

Answer 58

causes significant weakness by affecting peripheral nerves or anterior horn cells

Question 59

what areas does polio affect

Answer 59

viral invasion and destruction of anterior horn cells and brain stem motor nuclei

Question 60

what does the varicella-zoster virus cause

Answer 60

shingles

Question 61

how does shingles present

Answer 61

eruption of a vesicular rash with severe neuralgic pain on one or two adjacent dermatomes or on the torso or limbs

Question 62

what treatment can be given for shingles

Answer 62

acyclovoir

Question 63

what is destroyed by the HIV-1 virus

Answer 63

T4 helper cells

Question 64

what kind of brain tumor is most commonly associated with AIDS patents

Answer 64

Primary cerebral lymphoma

Question 65

what opportunistic infections of the CNS are most often associated with AIDS patients

Answer 65

cerebral toxoplamosis, cryptococcal meningitis and CMV retinitis or encephalitis, PML

Question 66

in addition to bacterial infections causing abscesses in the immunocompromised what else do you need to consider

Answer 66

fungal and parasitic

Question 67

what symptoms are seen with abscess

Answer 67

headache and fever the patient may be severely ill from a systemic infection. a cerebral abscess may cause seizures and focal neurological signs dependent on its location or it could cause brain edema with mass effect and increased ICP

Question 68

what results when a brain abscess ruptures

Answer 68

it can produces meningitis

Question 69

how do prions cause disease

Answer 69

they are misfolded proteins that induce other proteins to convert into a misfolded state as well

Question 70

what is unique about how prions cause disease

Answer 70

they don't have nucleic acid and they don't invoke an inflammatory response

Question 71

what is the most common prion disease

Answer 71

Creutzfeldt-Jakob dementia (CJD)

Question 72

what is Creutzfeldt-Jakob dementia

Answer 72

a very rapidly progressive dementia with cerebellar, corticospinal, lower motor neuron, or extrapyramidal signs and symptoms

Question 73

what is the prognosis of Creutzfeldt-Jakob dementia

Answer 73

it progressives to death within weeks to months and has no cure

Question 74

what is seen on biopsy of someone with Creutzfeldt-Jakob dementia

Answer 74

spongiform changes which are cytoplasmic vacuoles in neurons and astrocytes and neuronal loss without inflammation.

Question 75

what may be detected on an EEG of someone with Creutzfeldt-Jakob dementia

Answer 75

periodic sharp wave discharges

Question 76

what is the variant of Creutzfeldt-Jakob dementia that causes a slower progressing disease with more psychiatric and behavioral symptoms

Answer 76

Mad Cow disease