W23-L9: Viruses Affecting the Nervous System Flashcards
Neurotrophic virus
capable of replicating in nerve cells
Neuroinvasive virus
capable of entering or infecting the central nervous system
Neurovirulent virus
capable of causing disease within the nervous system
What is myelitis?
an infection of the spinal cord
What is Encephalomyelitis?
When both the brain and the spinal cord become inflamed
Primary viral encephalitis
direct viral infection of the spinal cord and brain. Can be focal or diffuse.
Secondary encephalitis
results from complications of a current viral infection where virus spreads to the brain, usually via the blood.
What is the main cause of viral meningitis?
Enterovirus
What is the main cause of viral encephalitis?
Herpes Simplex Virus type 1 and 2
What is Guillain-Barre syndrome?
Is an acute inflammatory demyelinating disease following infection with several viruses such as EBV
What is Reye’s syndrome?
Post-infection with influenza or chickenpox in children
Why are viruses protected from attack by cytotoxic T cells when within peripheral nerves?
nerve cells do not have class I molecules
Where does replication of viruses take place within nerves?
takes place in the body of nerve as this is where protein synthesis takes place
Can released progeny cross synaptic junctions?
Yes
Where does coronavirus and herpes simplex virus enter the brain?
Olfactory Bulb
Viruses that directly kill neurones cause?
Inflammatory
Features of the rabies virus?
Bullet shaped -ve stranded RNA virus with a helical capsid and an envelope
How invasive and virulent is the rabies virus?
Highly
What is part of the growth cycle of rabies virus?
Growth in nerve cells is an obligatory part of the life cycle of the virus
What is the pathogenesis of rabies?
- Aggression
* Thirst but muscle spasm and terror upon attempt to drink water
What is the treatment of rabies virus?
can vaccinate after infection as it takes a while to get to the brain
How invasive and virulent is the alpha herpesviruses virus?
Low neuroinvasiveness and high neurovirulence
How does herpes simplex type 1 enter the body?
Contact with infected saliva
What does Varicella zoster virus cause?
chicken pox (varicella) and shingles (zoster)
T/F Growth in nerve cells is NOT an obligatory part of the life cycle of Varicella zoster virus
True
What is poliovirus pathogenesis?
Poliovirus travels in the blood as free virus and can target the motor neuron cells in the anterior horn leading to paralysis
