Chapter 17: Infectious Diseases Affecting the Nervous System

central nervous system

brain and spinal cord; control center for the body; detects sensory info from the environment; interprets info; sends impulses to coordinate body’s control activities

neurons

cells that make up tissues of brain and spinal cord; receive and transmit signals to and from CNS to PNS

meninges

three layers of continuous membranes; protects the brain and spinal cord

cerebrospinal fluid

located between layers of meninges; provides nutrition to CNS and liquid cushion for brain and spinal cord; microbes can be found here during meningitis

peripheral nervous system

nerves that branch from the CNS; communication lines between the CNS and other parts of the body, and the external environment; consists of nerves and ganglia

nerves

bundles of axons that receive and transmit nerve signals

ganglion

where cell bodies of neurons aggregate

bony casings

protect the brain and spinal cord from traumatic injury

blood-brain barrier

cell layer that prevents solutes in blood from non-selectively crossing into CNS; regulates what can and cannot access brain cells; prohibits most microbes and antibiotics from entering the nervous system

immunologically privileged

the CNS is this; partial immune response when exposed to an immunological challenge; since the CNS is vital, temporary damage/inflammation from normal immune responses could be detrimental

circulating antibodies, phagocytic cells, complement

CSF has low levels of these

complement

proteins that help immune system destroy microbes

True

T/F: There is no normal biota of the PNS or CNS, microbes in these tissues indicates disease

bony structures, blood-brain barrier, microglial cells, and macrophages

List the main defenses of the brain

Meningitis

inflammation of the meninges

Encephalitis

inflammation of the brain

meningoencephalitis

inflammation of both the meninges and the encephalitis

the bloodstream and lymphatic system

Most common routes of CNS invasion are through these two places

meningitis

List the disease that matches the symptoms: triad of fever, headache, and stiff neck, followed by nausea and vomiting, may progress to convulsions and coma

meningococcal meningitis

List the disease that matches the description: begins as a throat infection, rash, and bacteremia; symptoms mostly from endotoxin; normal microbiota in nose and throat of 40% of people; common in sub-Saharan Africa; vaccine protects against 5/6 strains

pneumococcal meningitis 

List the disease that matches the description: most common in young children; high mortality

Haemophilus influenzae type b meningitis

List the disease that matches the description: normal throat microbiota; occurs mostly in children; prevented by the Hib vaccine

Cryptococcus neoformans meningitis

List the disease that matches the description: affects immunocompromised; spreads through blood to the CNS; mortality up to 30%; treatment with antifungals

Listeria monocytogenes meningitis

List the disease that matches the description: excreted in animal feces; wide distribution in soil and water; common food contaminant; psychrophile- foodborne illness; usually mild/symptomless; invades bloodstream and reaches CNS; more common in immunocompromised; can lead to stillbirth; manifests as meningitis after birth

meningitis 

List the disease this treatment matches: CSF samples taken by spinal tap or lumbar puncture; chemotherapy initiated before diagnosis; broad-spectrum antibiotics

Zika Virus

List the disease that matches the description: skin rash, conjunctivitis, and muscle/joint pain; small head, vision problems, involuntary movements, seizures, and irritability; no vaccine available

poliomyelitis

List the disease that matches the description: sore throat and nausea, virus moves to tonsils and lymph nodes; transient viremia; destroys motor nerve cells; results in paralysis; vaccine available

Primary amebic meningoencephalitis

List the disease that matches the description: destruction of brain and spinal tissue; results in hemorrhage and coma; death occurs within a week

Granulomatous amoebic meningoencephalitis

List the disease that matches the description: meningoencephalitis similar to Naegleria but a longer infection

Arbovirus

arthropod-borne virus

acute encephalitis

List the disease that matches the description: chills, headache, fever; can progress to mental confusion and coma; can cause polio-like paralysis and fatal encephalitis

prion

abnormally folded protein; difficult to destroy using standard methods; need to be autoclaved

subacute encephalitis

List the disease that matches the description: causes normal proteins (PrPc) in brain tissue to become abnormally foldes (PrPsc); leads to spongiform degeneration; brain becomes porous; chronic and fatal

rabies

List the disease that matches the description: muscle spasms of mouth and pharynx related to swallowing; hydrophobia; virus multiplies in skeletal muscles and travels through PNS to brain cells, causing encephalitis; can be treated with vaccine plus immune globulin; occurs due to animal bites

tetanus

List the disease that matches the description: grows in deep wounds with anaerobic conditions; infection causes no inflammation; release of a toxin can then enter the CNS via blood or peripheral nerves, blocking relaxation pathway in muscles, causing spasms; treatment with immune globulin

botulism

List the disease that matches the description: toxin produced is specific for the synaptic end of the nerve; blocks release of the neurotransmitter acetylcholine causing flaccid paralysis; nausea precedes neurological symptoms; difficulty swallowing, general weakness, blurred or double vision; death usually from respiratory or cardiac failure; infants lack intestinal microbiota to fight this off

Neisseria meningitidis, bacteria

List the etiological agent(s) for this disease: meningococcal meningitis

Streptococcus pneumoniae; bacteria

List the etiological agent(s) and classification of the agent for this disease: pneumococcal meningitis 

Haemophilus influenzae type b (Hib); bacteria

List the etiological agent(s) and classification of the agent for this disease: Haemophilus influenzae meningitis 

Cryptococcus neoformans; fungi

List the etiological agent(s) and classification of the agent for this disease: Crytococcus neoformans meningitis

Listeria monocytogenes; bacteria

List the etiological agent(s) and classification of the agent for this disease: Listeria monocytogenes meningitis 

Zika virus, virus

List the etiological agent(s) and classification of the agent for this disease: Zika virus

poliovirus, virus

List the etiological agent(s) and classification of the agent for this disease: Poliomyelitis

Naegleria fowleri, amoeba

List the etiological agent(s) and classification of the agent for this disease: Primary Amoebic Meningoencephalitis

Acanthamoeba, protozoa

List the etiological agent(s) and classification of the agent for this disease: Granulomatous Amoebic Meningoencephalitis

arbovirus, virus

List the etiological agent(s) and classification of the agent for this disease: West Nile Virus (acute encephalitis)

Herpes simplex 1 or 2, JC virus; virus

List the etiological agent(s) and classification of the agent for this disease: Acute Encephalitis

Toxmoplasma gondii; prion

List the etiological agent(s) and classification of the agent for this disease: Subacute Encephalitis 

rabies virus, virus

List the etiological agent(s) and classification of the agent for this disease: Rabies

Clostrisdium tetani, bacteria

List the etiological agent(s) and classification of the agent for this disease: tetanus

Clostrisdium botulinum; bacteria

List the etiological agent(s) and classification of the agent for this disease: Botulism

has a capsule, petechiae; droplet contact

List the mode of transmission and and any notable microbe or disease features of the following: meningococcal meningitis

has a capsule, most common form; droplet contact

List the mode of transmission and and any notable microbe or disease features of the following: : pneumococcal meningitis

has a capsule, prevented by Hib vaccine; droplet contact

List the mode of transmission and and any notable microbe or disease features of the following: : Haemophilus influenzae meningitis

has a capsule, more common in immunocompromised; vehicle (air, dust)

List the mode of transmission and and any notable microbe or disease features of the following: Crytococcus neoformans meningitis

manifests as meningitis; vehicle (food)

List the mode of transmission and and any notable microbe or disease features of the following: Listeria monocytogenes meningitis

microencephaly; vertical, vector-borne, sexual contact (blood transfusions)

List the mode of transmission and and any notable microbe or disease features of the following: Zika virus

nonenveloped virus, no cure; fecal-oral vehicle

List the mode of transmission and and any notable microbe or disease features of the following: Poliomyelitis

vehicle (exposure while swimming in water)

List the mode of transmission and and any notable microbe or disease features of the following: Primary Amoebic Meningoencephalitis

common in immunocompromised; direct contact

List the mode of transmission and and any notable microbe or disease features of the following: Granulomatous Amoebic Meningoencephalitis

vector (arthropod bites), vertical or reactivation of latent infection; ubiquitous

List the mode of transmission and and any notable microbe or disease features of the following: Acute encephalitis

long incubation period, fast progression; direct contact with infected tissue or interhited vehicle (meat, parenteral)

List the mode of transmission and and any notable microbe or disease features of the following: subacute encephalitis

postexposure prophylaxis; parenteral (bite trauma), droplet contact

List the mode of transmission and and any notable microbe or disease features of the following: rabies

endospore forming obligate anaerobe; tetanospasmin neurotoxin; parenteral, direct contact

List the mode of transmission and and any notable microbe or disease features of the following: tetanus

endospore forming, obligate anaerobe, botulium exotoxin; direct contact (wound), parenteral (injection)

List the mode of transmission and and any notable microbe or disease features of the following: botulism