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Differences between Meningitis and Encephalitis
|1.||Definition||Inflammation of the thin membranes that surround the brain and spinal cord called the meninges (mostly of the pia mater and arachnoid mater).||Inflammation of the brain parenchyma.|
|2.||Causative Agent||Bacteria, Viruses and Fungi||Mostly Viruses|
|3.||Microorganisms involved||The most common are echovirus, poliovirus, and coxsackie.
Bacterial meningitis develops under the action of Streptococcus, Neisseria, Haemophilus, Listeria, and other bacteria.
|Viruses (herpes virus, rabies virus, arboreal viruses, cytomegalovirus, etc.);
Bacteria – often occurring as meningoencephalitis caused by meningococci, pneumococci,
Hemophilus, tuberculous bacteria, etc.)
Fungi or parasites such as leptospirosis, toxoplasmosis, trichinellosis, etc.
|4.||Other Causes||o Response to a brain tumor;
o Reaction after a chemotherapy;
o Poisoning with lead;
o Reaction after complex studies with a contrast medium;
o Parasites, fungal infections.
|o Complicated brain tumors;
o Multiple sclerosis;
o Lead poisoning;
o Reaction after application of various substances in the liquor;
o Cerebrovascular accidents, etc.
|5.||Incubation period||The symptoms of meningitis develop within a few hours to a couple of days.||The most common incubation period is 3-5 days.|
|6.||Symptoms||Headache is most common, along with vomiting or nausea, skin rash or discoloration of skin, high fever, stiff neck, confusion, double vision.||Headache, joint pain, irritability, fever, lethargy, seizures, behavioral changes.|
|7.||Complications||o Temporary or permanent loss of hearing or vision;
o Irreversible brain damage, affecting the cognitive abilities, movement abilities
|o Memory problems
o Personality and behavioral changes
o Speech problems
o Physical and motor difficulties
o Low mood
|8.||Rash||Skin discoloration or rash may be present||Absent|
|9.||Altered Mental Status||No focal deficits or AMS||Altered Mental Status|
|10.||Forms||Meningitis can be only of one form.||Primary and secondary encephalitis.
o Primary: the brain and spinal cord are directly affected.
o Secondary: the infection enters the brain after affecting another organ.
|11.||Types||o Tuberculous meningitis,
o Aseptic meningitis
o Syphilitic aseptic meningitis
o Cryptococcal meningitis
o Staphylococcal meningitis
o Gram negative meningitis
o Pneumococcal meningitis
o H.influenza meningitis Meningococcal meningitis.
|o Polyoencephalitis – localized in the gray matter of the brain/spinal cord;
o Leucoencephalitis – localized in the cerebral white brain matter;
o Panencephalomyelitis – localized in the gray and white matter of the brain/spinal cord;
o Perivenous encephalomyelitis.
|12.||Modes of Transmission
(Transmission possibility depends on the type of causative agent involved)
|Bacteria are present in discharges from the nose and mouth and cause transmission through droplets.||o Breathing in respiratory droplets from an infected person
o Skin contact
o Mosquito, tick, and other insect bites
o Tick of Horses
o Migratory Birds
o Contaminated food or drink
|13.||Risk group age||Those older than 60 and younger than 5 are at highest risk.||Occurs most frequently in infants younger than 1 year of age and in elderly patients older than the age of 65 with intermediate incidence in individuals between these age extremes.|
Followed by CBC with diﬀerential, C-reactive protein, and blood for Gram stain and culture.
|Clinical presentation and supported by spinal ﬂuid analysis and neuroimaging abnormalities, CSF, PCR.|
|15.||CSF findings||The cerebrospinal fluid (CSF) is abnormal.||The CSF findings are variable.|
|16.||Treatment||Ampicillin is usually prescribed along with an aminoglycoside or a cephalosporin (cefotaxime) medication.||Acyclovir, and is usually administered intravenously in the hospital for at least ten days.|
|17.||Vaccines||Vaccines of varying effectiveness exist against the following bacterial causes of meningitis:
o Streptococcus pneumoniae;
o Neisseria meningitides;
o Mycobacterium tuberculosis.
|Vaccines exist against some types of encephalitis:
o Tick-borne encephalitis vaccine;
o Japanese encephalitis vaccine.
- Infectious Diseases Society of America: www.idsociety.org.