Viruses in the Brain

Hagop, Charlene, and Mollie

Meningitis•The inflammation and infection of the fluid around the brain and the

Meninges (the protective membranes covering the brain)

•Can be caused by either a virus or bacteria

•Bacterial Meningitis is more life threatening than Viral Meningitis

Causes/Diagnosis•Three types of bacteria:

-Haemophilus influenzae (Hib), Neisseria meningitidis, Streptococcus pneumoniae

•Can be spread through fluids from the nose or throat, but not through air

•Diagnosed by studying spinal fluid and noticing growing bacteria

Meningitis in the brain

Symptoms

• Early symptoms include:– Fever, headache, stiff neck– nausea, confusion (more severe)

•If the Disease isn’t treated:-Can result in seizures, coma or death

Treatment/Vaccines

• Bacterial meningitis can be treated with different antibiotics depending on the type of bacteria infecting the brain

• Vaccines for the different types of bacteria are available– Hib vaccine most popular

and affectiveHib Bacteria

BibliographyImageshttp://www.google.com/imgres?imgurl=http://cdn.sheknows.com/articles/hib-bacteria.jpg&imgrefurl=http://www.sheknows.com/health-and-wellness/

articles/811197/hib-vaccine&usg=__G7eQ57iottTnrLzzCrwa26SbDGc=&h=399&w=600&sz=156&hl=en&start=1&zoom=1&um=1&itbs=1&tbnid=nwG4daAFjg0IfM:&tbnh=90&tbnw=135&prev=/images%3Fq%3Dhib%2Bbacteria%26um%3D1%26hl%3Den%26safe%3Dactive%26sa%3DN%26rls%3Dcom.microsoft:en-us%26tbs%3Disch:1

http://ecx.images-amazon.com/images/I/51ZINkgIrbL._SL500_AA300_.jpghttp://www.aurorahealthcare.org/healthgate/images/si2230.jpg

TextBacterial Meningitis Factshttp://www.dhpe.org/infect/Bacmeningitis.htmlMeningitishttp://kidshealth.org/parent/infections/lung/meningitis.htmlMeningitis in Adultshttp://www.webmd.com/brain/meningitis-in-adults

Characteristics of Encephalitis• Encephalitis is a viral disease characterized by the

infection and inflammation of the brain• The virus can be dormant in the body for long

periods of time, but may be reactivated by factors such as stress and be carried through the bloodstream to the brain.

Symptoms• Usually flu-like symptoms appear such as fever,

fatigue, soreness, vomiting, headache, sensitivity to light, etc.

• When a person has severe encephalitis, symptoms include seizures, memory loss, unbalanced reasoning, and even paralysis.

How is Encephalitis diagnosed– CT Scans or MRI– EEG patterns may inform about the electrical

activity of the brain– Spinal Tap, which gathers fluid from space

around spinal cord and analyses the liquid.

Cure for Encephalitis?• Encephalitis cannot be treated with antibiotics

since it is a viral illness.• Severe cases depend on the age of the patient

and the strength of the immune system (People with cancer or AIDS).

How Encephalitis affects the brain

• Swelling of the brain may occur as more fluid and unwanted substances enter it.

• In turn, glia force themselves to suck up the fluid to protect the neurons.

• White blood cells get activated as soon as chemicals from dead neurons get leaked.

• As glia cleans up the mess, scar tissue forms and the brain changes structure.

Normal Brain vs Infected Brain

Bibliography

• http://www.webmd.com/a-to-z-guides/encephalitis

• http://healthguide.howstuffworks.com/viral-encephalitis-in-depth.htm

• http://www.encephalitis.info/Info/Recovery/Impact/EffectsOnBrain.aspx

HIV’s effect on the brain

HIV: Characteristics• HIV (human immunodeficiency

virus) infects cells in immune system and central nervous system.

• HIV infects T helper lymphocytes. (CRUCIAL to the immune system.)

• In its later stages, HIV may affect the brain.

• AIDS Dementia Complex: characterized by abnormalities in cognition, motor performance, and behavior.

• Warning:*Causes not well understood!*

How does HIV infect the brain?• The virus most likely crosses the blood brain

barrier using infected immune cells.• Once in the brain, HIV does not directly

infect neurons, but instead affects supporting cells that can release immune factors that harm neurons.

• In up to 20% of people with HIV, the virus manages to escape from the bloodstream and cross into the brain, resulting in HIV-related dementia and other cognitive disorders.

Diagnosing HIV-related Dementia• Mental status

examination• Neuropsychological

testing• Brain scans: MRI or CT

scans• Lumbar puncture to

evaluate the cerebrospinal fluid

• No single test alone can confirm the diagnosis.

Symptoms:• Cortical thinning in the parietal

and frontal lobes• Reduced blood flow to the brain• Thus, HIV-related dementia may

result in the following symptoms:impaired cognitiondecline in memorylack of coordinationunpredictable behavior

Treatment?• Still working on it.• New anti-viral drugs are being tested in

clinical trials.• Lots of research is being done!

Sources:http://www.sciencedaily.com/releases/2010/01/100122102441.htm

http://www.hivandhepatitis.com/recent/2008/090508_c.html

http://www.sciencemag.org/cgi/content/abstract/239/4840/586

http://www.medicalnewstoday.com/articles/26390.php

http://emedicine.medscape.com/article/292225-overview