Intoxication/Infection of the Nervous System Flashcards
What is the effect of tetanus toxin?
The exotoxin binds to interneurons of brain, brain stem, spinal cord, preventing release of inhibitory glycine and GABA leading to motor disinhibition.
What are the symptoms of tetanus poisoning?
– painful spasms in muscles near wound, or generalized,
including jaws, face, respiratory muscles
– generalized convulsive seizures
Where can you get C. tetani infection?
- Soil contaminated wounds
- Unsterile IV needles
What is the effect of botulism toxin?
Binds to presynaptic nerve terminals preventing ACh release
What are the symptoms of botulism poisoning?
Ptosis, diplopia, later dysphagia, facial, limb, and respiratory weakness may occur
What are the symptoms of lead poisoning in adults?
Peripheral neuropathy - wrist drop
What are the symptoms of lead poisoning in children?
Encephalopathy or abdominal pain
What are some lingering effects of CO poisoning that survivors may have?
Survivors may have amnesia and parkinsonism
What does a stroke in a young person raise suspicion of?
Drug Use - cocaine is most common
What is the early stage of alcohol withdrawal syndrome?
Hypersympathetic stage - tremulous, sweaty, tachycardic with limited seizures
What is the late stage of alcohol withdrawal syndrome?
Delirium tremens - 3-4 days after drinking stopped, with fluctuating motor and autonomic activity, confusion, hallucinations
What is the support for someone with alcohol withdrawal syndrome?
- Benzodiazepines for seizures and sedation
- Thiamine supplementation
Wernicke-Korsakoff Syndrome
Caused from chronic alcoholism
- Acute -> Wernicke encephalopathy (nystagmus, ophthalmoplegia, gait ataxia, confusion) correctible with thiamine supplementation
- Chronic -> Korsakoff psychosis (amnesia, confabulation)
Alcoholic Cerebellar Degeneration
Degeneration of the anterior-superior vermis that leads to gait ataxia and dysmetria of lower limbs
What is the more dangerous type of meningitis?
Acute bacterial meningitis is more severe, fulminant; may be fatal if not treated early and aggressively
What added with antibiotics can reduce neurological complications of meningitis?
Intravenous Dexamethasone
What is done when meningitis is suspected?
Lumbar Puncture
What is the profile of CSF in a bacterial meningitis?
Increased polymorphonuclear WBCs, decreased CSF glucose.
Who does chronic meningitis tend to affect?
- Elderly
- Immunocompromised
Encephalitis
Brain is the primary site of infection and inflammation - often viral
How does encephalitis present?
- Seizures
- Focal Neurological Deficits
- Impairment of Consciousness
Where does HSV encephalitis tend to affect?
Predilection for frontal and temporal lobes
What is used to treat HSV encephalitis?
Acyclovir
What are the signs of West Nile Virus?
Weakness from affecting peripheral nerves or anterior horn cells (similar to polio)
What does poliovirus tend to affect?
Anterior horn cells and brainstem motor nuclei
Progressive Multifocal Leukoencephalopathy
An opportunistic infection in immunodeficient patients that is caused by papovavirus infection of oligodendrocytes, leading to patchy demyelination in the CNS and focal deficits - UNTREATABLE
What are opportunistic infections that are common in AIDS?
- cerebral toxoplasmosis (protozoa)
- cryptococcal meningitis (fungus)
- cytomegalovirus (CMV) retinitis or encephalitis
What is AIDS vacuolar myelopathy similar to?
Similar to subacute combined degeneration from vitamin B-12 deficiency.
Abscess
Localized, encapsulated, usually bacterial, infection; meningitis if rupture into CSF
Creutzfeldt-Jakob Disease
Prion disease that is rapidly progressive, untreatable, fatal in weeks to months and presents with dementia with prominent myoclonus, often corticospinal, extrapyramidal, cerebellar or lower motor neuron signs
