Wherever there is infection there will be inflammation and inflammation includes fluid build-up at the site. The central nervous system is enclosed in bone (skull and spinal vertebrae) so any fluid build-up will put dangerous pressure on the brain or spinal cord.
Correct Answer: Inflammation
All of the organisms listed can cause infection of the central nervous system.
Correct Answer: All of the choices
The middle ear, the sinuses and the mastoid areas of the skull are frequently involved in CNS infections, since they are in close proximity to the central nervous system. Tuberculosis infections rarely travel to the CNS, but on rare occasions can cause chronic meningitis.
Correct Answer: Tuberculosis
Antibiotics are only effective against bacterial infections and therefore have no effect on viral meningitis. If bacterial meningitis is suspected, antibiotics should be started immediately because bacterial meningitis is a severe infection that is usually fatal if not treated and delay can cause irreversible brain damage and/or septicaemia.
Correct Answer: Antibiotics
The pathogen for botulism is Clostridium botulinum, which enters the body through the gastrointestinal route. This damage is done by the exotoxin secreted by C. botulinum, which is a powerful neurotoxin.
Correct Answer: An exotoxin
The pathology of tetanus results from the presence of a toxin rather than the pathogenic organism. Antibiotics have no effect on the toxins that have already been produced, so if the antibiotics are given early they could kill the organisms before the toxin is produced but antibiotics would have no effect after the toxin is produced.
Correct Answer: Effective only if given early in the infection
Infant botulism occurs between the ages of three weeks and eight months and is the most commonly diagnosed form of botulism. The organism is introduced either on weaning or through dietary supplements, particularly honey. It multiplies in the infant’s colon, and the botulinum toxin is then absorbed into the blood. The symptoms of infant botulism include constipation, poor muscle tone, lethargy, and feeding problems. In severe cases, vision problems and paralysis can also occur.
Correct Answer: Constipation
The rabies virus is found in the saliva of animals and is transmitted to humans by bites.
Correct Answer: The saliva of an infected animal
Rabies exists in two forms, urban and sylvatic, with the urban form being associated with unimmunized dogs and cats, and the sylvatic form being seen in wild animals. Infection in humans is incidental and does not contribute to maintenance or transmission of the infection.
Correct Answer: Unimmunized dogs and cats
Polio is a peripheral nervous system disease which rules out astrocytes, lymphocytes, and neutrophils as possible answers.
Correct Answer: Motor neurons
A prion is a protein coded for by a normal gene. This protein is designated PrPC and can be converted into the infectious form called PrPSC.
Correct Answer: Bacteria
Subacute sclerosing panencephalitis is a rare chronic measles infection that occurs in children and produces progressive neurological disease. It is characterized by the insidious onset of personality change, progressive intellectual deterioration, and dysfunction of the autonomic nervous system.
Correct Answer: Subacute sclerosing panencephalitis
Cryptococcosis is caused by Cryptococcus neoformans, which is a fungus that exists as an encapsulated form of yeast.
Correct Answer: Fungal infection of the CNS
Naegleria (and Acanthamoeba) infections affect children and young adults and are acquired by swimming in fresh water.
Correct Answer: Swimming
Many viruses have an affinity for the CNS.
Correct Answer: False
There are two types of viral CNS infection: acute and persistent.
Rabies is an acute and fatal viral CNS infection, first reported more than 3000 years ago. The most common viral causes of acute CNS infections are enteroviruses, herpes simplex virus, HIV, Epstein–Barr virus, and several arthropod-borne viruses.
Correct Answer: True
A variety of progressive neurological diseases in both humans and other animals are caused either by viruses. These are persistent viral infections with a long period between infection and the onset of disease and a prolonged period of illness. Measles virus, rubella virus, and enterovirus can all cause persistent infections.
Prions become infectious when they come into contact with an infectious form of the protein — there is no nucleic acid involvement.
Brain swelling can result from the toxic substances produced by bacteria and from neutrophil invasion, both of which result in oxygen and nutrient deficiencies. This produces another kind of swelling, the kind known as cytotoxic edema.
Enterovirus infections usually affect newborns and young children.
Overt infections occur through complications of pneumonia, pharyngitis, skin abscesses, or infectious endocarditis.
Viral meningitis is also known as aseptic meningitis.