Neuroinfectious Diseases Overview Flashcards
What causes neuroinfectious diseases
infectious agents, that are not necessarily living organisms
examples of nonliving agents that cause neuroinfectious diseases
viruses, prions, toxins
Treatments for neuroinfectious diseases
they are broad and diverse
- antimicrobials, anti-inflammatory, anticonvulsive medicines
what is the best treatment for neuroinfectious diseases
vaccines
Treatments for NID typically focus on what?
There are few NID cures, and most treatments focus on treating the symptoms
What are the drivers of poverty
NID
Why are there many NID that are neglected
- especially in low income countries, treatments can be too expensive or unavailable
- this creates a high medical burden
- also means most are absent from developed nations
Poverty trap cycle
low income leads to malnutrition which leads to sickness which leads to inability to work which leads to low income and so forth
NTD
Neglected tropical diseases
How do NTD affect the economy and the people?
- > 1.2 billion people affected by NTDs
- cost countries billions of dollars every year
Do NTDs only occur in tropical regions
no
What has been one reason as to why NTDs and IDs are no longer geographically restricted
Economic globalization
NTDs that are considered brain diseases (6)
1.chagas disease
2. human african trypanosomiasis
3. rabies
4. dengue and chikungunya
5. cysticercosis
6. schistosomiasis
Protozoa NTDs (3)
- chagas disease
- leishmaniasis
- human african trypanosomiasis
NTD Viruses (3)
- Rabies
- Dengue and Chikungunya
NTDs Bacteria (4)
- Buruli Ulcer
- Leprosy
- Trachoma
- Yaws
NTDs Helminth (8)
- Cysticercosis
- Guinea-worm
- Echinococcosis
- Foodborne trematodiases
- Lymphatic Filariasis
- Soil-transmitted helminthiases
- Schistosomiasis
- River Blindness
POVERTY is both the () and () of ID
Cause and Consequence
3 main nomenclature of CNS infections and the area they affect
- meninges -> meningitis
- brain parenchyma -> encephalitis
- spinal cord -> myelitis
what type of infection is an abscess or a cyst
a focal infection
3 broad ways that pathogens can enter the CNS
- travelling directly through a cellular monolayer
- through infected contiguous tissue
- through nerve endings
What are the three ways a pathogen can travel through a cellular monolayer to enter the CNS
- transcellular route: alien travels through the cell layer
- trojan horse (infected leukocytes): alien infects immune cell and piggy backs into the CNS with immune cell detecting it
- paracellular route: travels between the cells
What type of pathogens like to enter CNS by infecting contiguous tissue?
parasites and large pathogens, some bacteria as well
How do pathogens enter CNS by infecting contiguous cells?
pathogen lyses (or breaks open) the cell to gain access to its neighboring cell and continues the process with the next cell until it enters CNS
- aka forces its way in
What is lysis
the disintegration of a cell by rupture of the cell wall or membrane
Nerve hopping
another name for pathogens that enter CNS through nerve endings
What pathogens like to infect CNS through nerve endings
commonly seen in viruses
How do pathogens enter CNS through nerve endings
The pathogen will hijack secreted vesicles in synapses and make their way retrograde (into CNS)
Symptoms of Meningeal involvement in an infection (6)
- headache
- fever
- nausea
- vomiting
- neck pain (stiff neck)
- reflex impairment
How are all the meningeal involved symptoms related
all symptoms are related to the increase in intracranial pressure
CSF Analysis for Meningeal related infections
- high number of leukocytes, mainly polymorphonucleated cells
- high protein
- very low glucose
- high lactate
Symptoms indicated a parenchymal infection (6)
- headache
- fever
- impairment of senses (go blind, deaf)
- impairment of consciousness
- psychological changes
- focal neurologic deficits
How are all the parenchymal involved symptoms related
symptoms are related to what area of the brain is affected
CSF Analysis for Parenchymal related infection
- high number of leukocytes, mainly mononucleated cells
- high protein
- normal glucose
- normal to high lactate
How can the presence of a pathogen be confirmed for a suspected parenchymal infection
presence of pathogen can usually be seen on brain scan
Symptoms of Spinal Cord involvement in infection (5)
- back pain
- muscle pain
- partial paralysis
- lower limbs paralysis
- motor movement impairment
How are all the spinal cord involved symptoms related
symptoms are related to an interruption of communication bw CNS and PNS
CSF analysis of Spinal cord involved infection
- inflammatory markers
- immune cell population depends on pathogen
- normal glucose
- normal protein
What must be done to confirm spinal cord involvement in an infection
neuroimaging study
Spinal cord involvement is almost always in conjunction with what two things?
meningitis or encephalitis
What is the glasgow coma scale and how is it helpful
- scale that categorizes consciousness impairment into normal, somnolence, stupor, and coma
- helpful in clinical setting because it identifies possible causes associated with each category
What are pathogens restricted by
the way they cause infections
Most bacterial infections can only cause …?
meningitis
What does the route the pathogen uses to enter determine?
what area of the brain will be affected
How is pasmodium unique
it does not enter CNS and instead obstructs brain microvessels
CSF analysis for a viral encephalitis infection
- clear appearance
- high protein
- normal glucose
- high lactate
- high MNCs WBC count
- negative gram stain/microscopic visualization
CSF analysis for Bacterial meningitis infection
- turbid appearance
- high protein
- low glucose
- high lactate
- high PMNCs WBC count
- positive gram stain/microscopic visualization
CSF analysis for a fungal brain abscess infection
- clear appearance
- normal protein
- normal glucose
- normal lactate
- high MNCs WBC count
- negative gram stain/microscopic visualization
True Pathogen
infectious agent that causes disease in virtually any suspectable host
Opportunistic Pathogen
potentially infectious agents that rarely cause disease in individuals with healthy immune systems
epidemic
unexpected increase in number of disease cases in a specific geographical area
endemic
disease outbreak is endemic when it is consistently present but limited to a particular region
example of an endemic
malaria
