1. Mike Parenteau

2. Etiology / Pathophysiology Encephalitis is an acute inflammation of the brain, commonly caused by a viral infection. Sometimes, encephalitis can result from a bacterial infection, such as bacterial meningitis, or it may be a complication of other infectious diseases like rabies (viral) or syphilis (bacterial) Encephalitis is an acute inflammation of the brain, commonly caused by a viral infection. Sometimes, encephalitis can result from a bacterial infection, such as bacterial meningitis, or it may be a complication of other infectious diseases like rabies (viral) or syphilis (bacterial)acutebrainviral infectionbacterialmeningitisrabiessyphilisacutebrainviral infectionbacterialmeningitisrabiessyphilis

4. Etiology / Pathophysiology Certain parasitic protozoal infestations, like by toxoplasma, can also cause encephalitis in people with compromised immune systems. Certain parasitic protozoal infestations, like by toxoplasma, can also cause encephalitis in people with compromised immune systems.parasiticprotozoaltoxoplasma immune systemsparasiticprotozoaltoxoplasma immune systems

5. Etiology / Pathophysiology Victims are usually exposed to viruses resulting in encephalitis by insect bites or food and drink. The most frequently encountered agents are herpes simplex viruses, arboviruses (carried by arthropods such as mosquitoes or ticks, see also tick- borne meningoencephalitis) and enteroviruses (coxsackievirus, poliovirus and echovirus). Victims are usually exposed to viruses resulting in encephalitis by insect bites or food and drink. The most frequently encountered agents are herpes simplex viruses, arboviruses (carried by arthropods such as mosquitoes or ticks, see also tick- borne meningoencephalitis) and enteroviruses (coxsackievirus, poliovirus and echovirus).herpes simplexarbovirusesarthropodsmosquitoestickstick- borne meningoencephalitis enterovirusescoxsackieviruspoliovirusechovirusherpes simplexarbovirusesarthropodsmosquitoestickstick- borne meningoencephalitis enterovirusescoxsackieviruspoliovirusechovirus

6. Etiology / Pathophysiology Some of the less frequent agents are measles, rabies, mumps, and varicella Some of the less frequent agents are measles, rabies, mumps, and varicella measlesrabiesmumpsvaricella measlesrabiesmumpsvaricella Numerically, the most important cause of encephalitis worldwide is probably Japanese encephalitis, as it causes up to 50 000 cases a year, with about 15 000 deaths. Numerically, the most important cause of encephalitis worldwide is probably Japanese encephalitis, as it causes up to 50 000 cases a year, with about 15 000 deaths.

8. Etiology / Pathophysiology The most widespread cause of encephalitis worldwide, however, is Herpes Simplex encephalitis. The herpes simplex virus causes inflammation on the temporal lobe of the brain, and if not treated, half to three quarters of the patients succumb. In very young children, however, the virus could affect any part of the brain, even sparing the temporal lobe. The most widespread cause of encephalitis worldwide, however, is Herpes Simplex encephalitis. The herpes simplex virus causes inflammation on the temporal lobe of the brain, and if not treated, half to three quarters of the patients succumb. In very young children, however, the virus could affect any part of the brain, even sparing the temporal lobe.

10. Encephalitis lethargica Encephalitis lethargica Encephalitis lethargica is an atypical form of encephalitis which caused an epidemic from 1917 to 1928. There have only been a small number of isolated cases since, though in recent years a few patients have shown very similar symptoms. The cause is now thought to be a bacterial agent or an autoimmune response following infection. As depicted in the book Awakenings Encephalitis lethargica is an atypical form of encephalitis which caused an epidemic from 1917 to 1928. There have only been a small number of isolated cases since, though in recent years a few patients have shown very similar symptoms. The cause is now thought to be a bacterial agent or an autoimmune response following infection. As depicted in the book Awakenings Encephalitis lethargicaepidemic 19171928 Awakenings Encephalitis lethargicaepidemic 19171928 Awakenings

12. Limbic System Encephalitis In a small number of cases, the pathogens responsible for encephalitis attack primarily the limbic system (a collection of structures at the base of the brain responsible for basic autonomic functions), often causing memory deficits similar to those observed in Alzheimer's disease or Creutzfeldt-Jakob disease (although limbic encephalitis does not cause the same cognitive deficits as these diseases In a small number of cases, the pathogens responsible for encephalitis attack primarily the limbic system (a collection of structures at the base of the brain responsible for basic autonomic functions), often causing memory deficits similar to those observed in Alzheimer's disease or Creutzfeldt-Jakob disease (although limbic encephalitis does not cause the same cognitive deficits as these diseases limbic system autonomicAlzheimer's diseaseCreutzfeldt-Jakob disease limbic system autonomicAlzheimer's diseaseCreutzfeldt-Jakob disease

13. Clinical Manifestations Patients with encephalitis suffer from Patients with encephalitis suffer from fever, headache, vomiting, confusion, drowsiness and photophobia fever, headache, vomiting, confusion, drowsiness and photophobia feverheadachevomitingconfusion drowsinessphotophobia feverheadachevomitingconfusion drowsinessphotophobia weakness, seizure, and less commonly, stiffness of the neck weakness, seizure, and less commonly, stiffness of the neck

14. The symptoms of encephalitis are caused by the brain's defense mechanisms activating to get rid of the infection, including swelling, small bleedings and cell death. The symptoms of encephalitis are caused by the brain's defense mechanisms activating to get rid of the infection, including swelling, small bleedings and cell death.

15. Assessment Neurologic examination usually reveal a drowsy or confused patients Neurologic examination usually reveal a drowsy or confused patients Stiff neck, due to the irritation of the meninges covering the brain, indicates that the patient has either meningitis or meningoencephalitis. Stiff neck, due to the irritation of the meninges covering the brain, indicates that the patient has either meningitis or meningoencephalitis.

16. Lumbar Puncture Examination of the cerebrospinal fluid obtained by a lumbar puncture procedure usually reveals increased amounts of protein and white blood cells with normal glucose, though in a significant percentage of patients, the cerebrospinal fluid may be normal. Examination of the cerebrospinal fluid obtained by a lumbar puncture procedure usually reveals increased amounts of protein and white blood cells with normal glucose, though in a significant percentage of patients, the cerebrospinal fluid may be normal.cerebrospinal fluidlumbar puncturecerebrospinal fluidlumbar puncture

19. Medical Management Symptomatic and Supportive Symptomatic and Supportive Diuretics and Corticosterids are used to control cerebral edema Diuretics and Corticosterids are used to control cerebral edema Acyclovir (Zovirax) and Vidarabine are used to treat encephalitis caused by herpes simplex virus. Acyclovir (Zovirax) and Vidarabine are used to treat encephalitis caused by herpes simplex virus.

20. Long Term Memory Impairment Memory Impairment Epilepsy Epilepsy Anosimia Anosimia Personality Changes Personality Changes Behavioral Abnormalities Behavioral Abnormalities Dysphasia Dysphasia