Intoxications and Infections of the Nervous System Flashcards
Tetanus (demented monkeys)
- prevent release of inhibitory GABA
- prolonged painful muscle spasms
- localized vs generalized (diffuse mu spasms and generalized convulsive seizures from cortical disinhibition)
painful muscle spasms of tetanus
- clenching lockjaw (trismus)
- grimacing smile (risus sardonicus)
- arching back (opisthotonus)
Botulism (robots)
- improperly canned or contaminated food or in wound infections
- prevent release of ACh from LMN and parasympathetic nerves=paralysis of skeletal muscle, bowel, bladder, and salivary glands
Guanidine
oral drug helps facilitate ACh release from motor nerve endings
Environmental toxins
- lead poisoning: adults-peripheral neuropathy + focal neuropathy (wrist drop); kids-encephalopathy and abdo pain
- organic solvent/glues and adhesives: peripheral neuropathy +/or encephalopathy
- CO-HA, v, blurry vision…coma, sz, cardiopulm arrest. survivors: memory and cognition deficits, parkinsonism
what should a stroke syndrome in a young, otherwise healthy, pt make you think of?
drug induced vasoconstriction or HTN leading to ischemic infarction or brain hemorrhage. **cocaine
Alcohol withdrawal
- hypersympathetic stage-tremulousness, sweating, tachy, jitters
- 12hr-3d after last drink: cluster of generalized tonic-clonic seizures (d/t diffuse toxic effect on the brain)
- 3-4d after last drink: DTs
what provides sedation and seizure control for DTs
benzos
Wernicke-Korsakoff syndrome
- B1 (thiamine) deficiency in pts with malnutrition or malabsorption
- acute phase: W’s encephalopathy=nystagmus, ophthalmoplegia, gait ataxia, and confusion (resolve in hours to days of thiamine administration)
Korsakoff’s psychosis
- 2/2 persistent, severe, or recurrent thiamine deficiency
- chronic memory deficit or amnestic syndrome leading to confabulation
pathology of Korsakoff
-tiny petechial hemorrhages and gliosis around 3rd and 4th ventricles and connecting aqueduct, involving mammilary bodies, fornix, and dorsomedial thalamus
alcoholic cerebellar degeneration
-involves anterior-superior vermis=ataxic gait and dysmetria of the lower limbs
central pontine myelinolysis
- 2/2 overly rapid correction of severe hyponatremia
- get demyelination of the corticospinal and corticobulbar tracts in the pons
where can meningitis come from
-can directly spread form an infection in an area near (ex otitis or sinusitis) or f/m infectious organisms spread through the bloodstream from a remote infection (PNA)
acute meningitis
- fever, HA, stiff neck, malaise, lethargy, n/v
- acute bacterial meningitis can be fatal!!
what causes neck stiffness/nuchal rigidity?
- meningeal irritation or inflammation
- can cause signs of Kernig or Brudsinski
what is initial Abx coverage for meningitis
ceftriaxone and vancomycin (add Ampicillin to cover for Listeria)
role of iv dexamethasone (0.15mg/kg)
- reduces neuro complications
- lowers mortality
- give just before/with initial abx
When substantial amt of purulent exudate or pus develops from bacterial meningitis what can it cause
hydrocephalus by obstructing CSF pathways
meningoencephalitis
when pus accumulates over the cortical subarachnoid space and leads to inflammation and edema of the cortex itself…can also get infraction of underlying brain or SC when local superficial blood vessels become inflamed and thrombose