Encephalitis is an inflammation of the brain caused, most often, by a viral infection. The specific viruses that cause encephalitis vary. Exposure to viruses that cause encephalitis occur mostly through insect bites. The virus enters through the blood stream and spreads to the brain, causing inflammation of the nerve cells (encephalitis) or the surrounding membranes (meningitis). Encephalitis is different from meningitis, but these two brain infections often occur together. Although the vast majority of individuals with encephalitis recover after a long period of time, inflammation may cause irreparable damage to the brain, bleeding within the brain, and even death. An estimated 10,000 - 20,000 cases of encephalitis are reported annually in the United States.

• Ninety percent of people with encephalitis have flu-like symptoms, such as fever, sore throat, cough, and malaise.
• If meningitis accompanies encephalitis, an individual may experience headache, stiff neck, intolerance to light, and vomiting.
• A change in the level of consciousness, ranging from mild confusion to coma, develops in most people with encephalitis, often including disorientation and delusion with possible hallucinations, agitation, and personality changes.
• Seizures occur in up to 50% of individuals with encephalitis.
• Other signs and symptoms of encephalitis depend on which area of the brain is most affected. These may include an impaired ability to use or comprehend words or coordinate voluntary muscle movements, muscle weakness or partial paralysis on one side of the body, uncontrollable tremors or involuntary movements, and an inability to regulate body temperature.

Arboviruses, or viruses carried by insects, are among the most common causes of viral encephalitis. Some of the major arboviruses include:

• Eastern equine encephalitis -- transmitted by mosquito, primarily affecting individuals along the eastern seaboard of the United States. One-third of infected individuals die of the condition, and many others suffer permanent brain damage.

• European and Far Eastern (Russian) encephalitis -- transmitted by ticks. Although vaccine against this type of encephalitis is available in Europe, there is speculation that it may cause serious side effects.

• Japanese encephalitis -- transmitted by mosquito and is widespread in Asia. Between 10 - 30% of infected individuals, primarily children, die of the condition.

• La Crosse encephalitis -- transmitted by mosquito, and primarily affecting children under 16 years of age in the upper Midwestern United States. About 1% of infected individuals die of the condition.

• St. Louis encephalitis -- transmitted by mosquito. Individuals in rural Midwestern and southern United States are primarily affected, with 7% of infected children and 30% of infected elderly dying of the condition.

• Venezuelan equine encephalitis -- transmitted by mosquito and primarily affects individuals in Central and South America. Fatalities rare in humans but common in horses, with epidemics in people occasionally occur after an outbreak in horses.

• West Nile encephalitis -- transmitted by mosquito, primarily affecting individuals in Africa and the Middle East, but outbreaks have also been recorded in the United States (New York City area and parts of New England). Infections are most common in children and the elderly, and as many as 10% of infected individuals die of the condition.

• Western equine encephalitis -- transmitted by mosquito, primarily affecting individuals in western United States and Canada. It usually causes a mild infection in people, except in children under 1 year of age, who often suffer permanent complications. Almost % of infected individuals die of the condition.

Other viruses that commonly cause viral encephalitis include:

• Herpes simplex virus type 1 (HSV1)
• Measles
• Enteroviruses (viruses that typically occur in the gastrointestinal tract)
• Mumps

Less common causes include:

• Cytomegalovirus
• Epstein-Barr virus (EBV)
• Human immunodeficiency virus (HIV)
• Varicella-zoster virus (VZV)
• Rabies virus

Not all cases of encephalitis are caused by viruses. Some nonviral causes of encephalitis include:

• Bacterial infection
• Fungal infection
• Parasitic infection
• Noninfectious causes, such as allergic reactions or toxins

The following factors may increase your risk of becoming infected with viral encephalitis:

• Very young or very old age
• Exposure to mosquitoes or ticks
• Compromised immune system
• Not being immunized against measles, mumps, and rubella
• Traveling to areas where viral encephalitis is prevalent
• Handling potentially infected animals

Encephalitis is a serious condition, so diagnosis and initial treatment usually take place in a hospital setting. After performing a physical exam, a doctor may take the following steps to diagnose the condition:

• Blood test -- detects viruses in the blood
• Spinal tap -- detects viruses in the cerebrospinal fluid
• MRI and CT scan -- determines whether bleeding is present in the brain
• Electroencephalogram (EEG) -- detects abnormal brain waves

The most effective way to prevent encephalitis is to avoid contracting viruses that lead to encephalitis:

• Take protective measures when working or playing outside, such as using insect repellant and wearing long pants and long sleeves. Some insect repellants are very toxic, so check with your health care provider about some alternatives.
• Immunize against viruses that lead to encephalitis with vaccines such as the measles, mumps, rubella (MMR), and rabies.
• Maintain a balanced diet to keep the immune system healthy.
• An infectious disease specialist may recommend a particular Japanese encephalitis vaccine for those traveling to Asia during the summer, but serious allergic reactions have been reported with its use.

Viral encephalitis is a serious medical condition. Because encephalitis can cause severe complications, treatment usually occurs in the hospital and sometimes requires intensive care. Generally, there are no specific medications to treat the viruses causing encephalitis. HSV1, VZV, and EBV are exceptions to this rule, however, as acyclovir is an excellent treatment. Often, people with symptoms of encephalitis are treated with this medication until the virus causing the condition is identified. Behavioral techniques, such as those used to treat people with traumatic brain injury, have been recently explored in the treatment of those recovering from viral encephalitis. Although complementary and alternative therapies have not been extensively studied for the treatment of encephalitis, some studies indicate that scalp acupuncture, combined with proper medication, may aid the healing process. Careful observation and supportive care, including rest, proper nutrition, and fluids are a mainstay of treatment for encephalitis and allow the body to fight the infection.

Always tell your health care provider about the herbs and supplements you are using or considering using, as some supplements may interfere with conventional treatments.

Medications

Medications used to treat viral encephalitis include:

• Acyclovir -- treats encephalitis caused by HSV, VZV, and EBV
• Ganciclovir or foscarnet -- treats encephalitis caused by cytomegalovirus and HSV1
• Anticonvulsant medications -- prevent and treat seizures associated with encephalitis

Nutrition and Dietary Supplements

Following these nutritional tips may help improve general health and well-being:

• Try to eliminate potential food allergens, including dairy, wheat (gluten), corn, preservatives, and food additives. Your health care provider may want to test for food sensitivities.
• Eat antioxidant foods, including fruits (such as blueberries, cherries, and tomatoes), and vegetables (such as squash and bell peppers).
• Avoid refined foods, such as white breads, pastas, and especially sugar.
• Eat fewer red meats and more lean meats, cold-water fish, tofu (soy, if no allergy), or beans for protein.
• Use healthy oils in foods, such as olive oil or vegetable oil.
• Reduce or eliminate trans-fatty acids, found in commercially baked goods such as cookies, crackers, cakes, French fries, onion rings, donuts, processed foods, and margarine.
• Avoid coffee and other stimulants, alcohol, and tobacco.
• Drink 6 - 8 glasses of filtered water daily.
• Exercise at least 30 minutes daily, 5 days a week.

You may address deficiencies with the following supplements:

• A multivitamin daily, containing the antioxidant vitamins A, C, E, the B-complex vitamins, and trace minerals, such as magnesium, calcium, zinc and selenium.
• Omega-3 fatty acids, such as fish oil, one to two capsules or one to three tablespoonfuls oil, one to three times daily, to help decrease inflammation and help with immunity. Cold-water fish, such as salmon or halibut, are good sources but not substitutes for supplementation.
• Vitamin C, 500 - 1000 mg one to three times daily, as an antioxidant and for immune support.
• Coenzyme Q10, 100 - 200 mg at bedtime, for antioxidant, immune, and muscular support.
• Acetyl-L-carnitine, 500 mg daily, for antioxidant and antiviral activity.
• Probiotic supplement (containing Lactobacillus acidophilus), 5 - 10 billion CFUs (colony forming units) a day, for maintenance of gastrointestinal and immune health. You should refrigerate your probiotic supplements for best results.
• L-glutamine, 500 - 1000 mg three times daily, for support of gastrointestinal health and immunity.
• Resveratrol (from red wine), 50 - 200 mg daily, for antioxidant and antiviral effects.
• L-theanine, 200 mg one to three times daily, for nervous system support.
• Melatonin, 2 - 5 mg 1 hour before bedtime, for sleep and immune protection. Ask your health care provider about potential drug interactions with the use of melatonin.

Herbs

Herbs are generally a safe way to strengthen and tone the body's systems. As with any therapy, you should work with your health care provider to get your problem diagnosed before starting any treatment. You may use herbs as dried extracts (capsules, powders, teas), glycerites (glycerine extracts), or tinctures (alcohol extracts). Unless otherwise indicated, you should make teas with 1 tsp. herb per cup of hot water. Steep covered 5 - 10 minutes for leaf or flowers, and 10 - 20 minutes for roots. Drink 2 - 4 cups per day.

• Green tea ( Camellia sinensis) standardized extract, 250 - 500 mg daily, for antioxidant, anti-inflammatory, and immune effects. Use caffeine-free products. You may also prepare teas from the leaf of this herb.
• Milk thistle (Silybum marianum) seed standardized extract, 80 - 160 mg two to three times daily, for detoxification support and antiviral effects.
• Cat's claw (Uncaria tomentosa) standardized extract, 20 mg three times a day, for inflammation and antiviral activity.
• Garlic (Allium sativum), standardized extract, 400 mg two to three times daily, for antibacterial or antifungal and immune activity.
• Astragalus (Astragalus membranaceus) standardized extract, 250 – 500 mg four times daily for immune support and antiviral activity.
• Maitake mushroom (Grifola frondosa) standardized extract (D-fraction), 600 mg twice daily, for immune and antiviral effects. You may also take a tincture of this mushroom extract, 30 - 60 drops two to three times a day.
• Phyllanthus (Phyllanthus amarus) standardized extract, 200 mg two to four times daily for antiviral effects.
• Elderberry (Sambucus nigra), one to two teaspoonfuls of standardized liquid extract two to four times daily, for immune support and antiviral activity.

Acupuncture

A study of a small number of people with complications from encephalitis suggests that acupuncture delivered to the scalp may lessen the severity of the complications and reduce the symptoms of the condition. Some researchers believe that scalp acupuncture is effective for people with encephalitis because all meridians converge at the head, and the method can stimulate and regulate qi (energy) throughout the entire body. More research is necessary.

Massage and Physical Therapy

Behavioral and Physical Training

Behavioral and physical training techniques recently have been explored in the treatment of individuals recovering from encephalitis. In one case, a woman experiencing poor short-term memory and decreased muscle coordination as a result of viral encephalitis began to improve significantly after participating in a behavioral rehabilitation training program. As a result of the program, she gained a high level of independence and was able to return home from the hospital with only minimal assistance from a caregiver. More studies are needed.

Pregnancy

The most common cause of encephalitis in newborns is vaginal delivery by a mother who is infected with herpes simplex virus 2 (HSV2). This infection in newborns is often severe and fatal. For this reason, cesarean section may be advised for pregnant women with a history of HSV2, even if there is no sign of an active infection.

Prognosis and Complications

Full recovery from encephalitis can take weeks or months, during which time many individuals experience complications ranging from fatigue and difficulty concentrating to tremors and personality changes. The most severe problems associated with encephalitis result from the destruction of nerve cells in the brain that do not regenerate. The severity of complications depends on the condition of the immune system (whether it is healthy or weak) and the infection causing the encephalitis. For example, 80% of those infected with Eastern equine encephalitis, St. Louis encephalitis, and Japanese encephalitis have permanent neurologic impairments (such as memory, speech, vision, hearing, muscle control, and sensation) and a very low survival rate. Those infected with EBV or Venezuelan equine encephalitis rarely experience any serious complications. The long-term outlook for those with HSV encephalitis depends primarily on how quickly the condition is treated.

Between 80 - 95% of people infected with viral encephalitis will survive the condition, but 20% will experience debilitating side effects or complications, such as memory loss or severe personality changes. The survival rate for those with HSV encephalitis increases dramatically from 30 - 70% when the condition is detected early and treated with antiviral medications.

Abe T, Kojima K, Shoji H, et al. Japanese encephalitis. J Magn Reson Imaging. 1998;8(4):755-761.

Adams RD, Victor M, Ropper AH. Principles of Neurology. 6th ed. New York, NY: McGraw-Hill; 1997:749-755.

Arribas JR, Storch GA, Clifford DB, Tselis AC. Cytomegalovirus encephalitis. Ann Intern Med. 1996;125(7):577-587.

Bale JF Jr. Viral encephalitis. Med Clin North Am. 1993;77(1):25-42.

Barak V, Halperin T, Kalickman I. The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines. Eur Cytokine Netw. 2001;12(2):290-6.

Bhat KPL, Kosmeder JW 2nd, Pezzuto JM. Biological effects of resveratrol. Antioxid Redox Signal. 2001;3(6):1041-64.

Ben-Nathan D, Maestroni GJ, Lustig S, Conti A. Protective effects of melatonin in mice infected with encephalitis viruses. Arch Virol. 1995;140(2):223-230.

Bonilla E, Valero-Fuenmayor N, Pons H, Chacin-Bonilla L. Melatonin protects mice infected with Venezuelan equine encephalomyelitis virus. Cell Mol Life Sci. 1997;53(5):430-434.

Cabrera C, Artacho R, Gimenez R. Beneficial effects of green tea--a review. J Am Coll Nutr. 2006;25(2):79-99.

Clancy RL, Gleeson M, Cox A, et al. Reversal in fatigued athletes of a defect in interferon gamma secretion after administration of Lactobacillus acidophilus. Br J Sports Med. 2006;40(4):351-4.

Clifton ER. Herpes simplex encephalitis: an overview. J Miss State Med Assoc. 1991;32(12):437-440.

Eo SK, Kim YS, Lee CK, Han SS. Antiviral activities of various water and methanol soluble substances isolated from Ganoderma lucidum. J Ethnopharmacol. 1999;68(1-3):129-36.

Evansa RW: Diagnostic Testing in Neurology. Philadelphia, Pa: W.B. Saunders Company; 1999:187-188.

Fauci AS, Braunwald E, Isselbacher KJ, et al, eds. Harrison's Principles of Internal Medicine. 14th ed. Vol 1. New York, NY: McGraw-Hill; 1998:1136-1139, 2442-2445.

Feign RD, Cherry JD. Textbook of Pediatric Infectious Diseases. 3rd ed. Vol 1. Philadelphia, Pa: W.B. Saunders Company; 1992:445-452.

Gaby AR. The role of coenzyme Q10 in clinical medicine: Part 1. Alt Med Rev. 1996; 1(1):11-17.

Gorbach SL, Bartlett JG, Blacklow NR: Infectious Diseases. 2nd ed. Philadelphia, Pa: W.B. Saunders Company; 1998:1408-1414.

Gresikova M, Kaluzova M. Biology of tick-borne encephalitis virus. Acta Virol. 1997;41(2):115-124.

Irani MT, Singh AR, Udwadia AD, Merchant RH. Neonatal herpes simplex virus-2 encephalitis. Indian Pediatr. 1995;32(4):476-480.

Johnson RT. Acute encephalitis. Clin Infect Dis. 1996;23(2):219-224.

Kajimura K, Takagi Y, Ueba N, et al. Protective effects of Astragali radix by intraperitoneal injection against Japanese encephalitis virus infection in mice. Biol Pharm Bull. 1996;19(6):855-859.

Katzmann S, Mix C. Improving functional independence in a patient with encephalitis through behavior modification shaping techniques. Am J Occup Ther. 1994;48(3):259-262.

Kimura K, Ozeki M, Juneja LR, Ohira H. l-Theanine reduces psychological and physiological stress responses. Biol Psychol. 2006 Aug 21.

LaValle JB, Krinsky DL, Hawkins EB, et al. Natural Therapeutics Pocket Guide. Hudson, OH:LexiComp; 2000: 452-454.

Levitz RE. Herpes simplex encephalitis: a review. Heart Lung. 1998;27(3):209-212.

Liang D. Treatment of the sequelae of viral encephalitis by needling Sishencong (Extra). J Chinese Med. 1996;50:26.

Liu J, Lin H, McIntosh H. Genus Phyllanthus for chronic hepatitis B virus infection: a systematic review. J Viral Hepat. 2001;8(5):358-66.

Luft BJ, Remington JS. Toxoplasmic encephalitis in AIDS. Clin Infect Dis. 1992;15(2):211-222.

Mayer KE, Myers RP, Lee SS. Silymarin treatment of viral hepatitis: a systematic review. J Viral Hepat. 2005;12(6):559-67.

Mrak RE, Young L. Rabies encephalitis in humans: pathology, pathogenesis, and pathophysiology. J Neuropathol Exp Neurol. 1994;53(1):1-10.

O'Meara M, Ouvrier R. Viral encephalitis in children. Curr Opin Pediatr. 1996;8(1):11-15.

Patrick L. Nutrients and HIV: part three - N-acetylcysteine, alpha-lipoic acid, L-glutamine, and L-carnitine. Altern Med Rev. 2000;5(4):290-305.

Pointer JE, Mulligan-Smith DA. Genital infections. In: Rosen P, Barkin R, eds. Emergency Medicine: Concepts and Clinical Management. 4th ed. St. Louis, Mo: Mosby-Year Book; 1998.

Roos KL.Encephalitis. Neurol Clin. 1999;17(4):813-833.

Rosen P, et al. Emergency Medicine: Concepts and Clinical Practice. 4th ed. Vol 3. St. Louis, Mo: Mosby; 1998:2198-2209.

Rotsein OD. Oxidants and antioxidant therapy. Crit Care Clin. 2001;17(1):239-47.

Rubeiz H, Roos RP. Viral meningitis and encephalitis. Semin Neurol. 1992;12(3):165-177.

Rust RS, Thompson WH, Matthews CG, Beaty BJ, Chun RW. La Crosse and other forms of California encephalitis. J Child Neurol. 1999;14(1):1-14.

Samuels MA, Feske S. Office Practice of Neurology. New York, NY: Churchill Livingstone; 1996:401-408.

Simopoulos AP. Omega-3 fatty acids in inflammation and autoimmune diseases. J Am Coll Nutr. 2002;21(6):495-505.

Skoldenberg B. Herpes simplex encephalitis. Scand J Infect Dis Suppl. 1996;100:8-13.

Sparling PF. Introduction to sexually transmitted diseases and common syndromes. In: Cecil RI, Plum F, Bennett JC, eds. Cecil Textbook of Medicine. 20th ed. Philadelphia, Pa: W.B. Saunders Co; 1996.

Toltzis P. Viral encephalitis. Adv Pediatr Infect Dis. 1991;6:111-136.

Wang HK. The therapeutic potential of flavonoids. Expert Opin Investig Drugs. 2000;9(9):2103-19.

Whitley RJ, Kimberlin DW. Viral encephalitis. Pediatr Rev. 1999;20(6):192-198.

Williams JE. Review of antiviral and immunomodulating properties of plants of the Peruvian rainforest with a particular emphasis on Una de Gato and Sangre de Grado. Altern Med Rev. 2001;6(6):567-79.

Yoon JH, Baek SJ. Molecular targets of dietary polyphenols with anti-inflammatory properties. Yonsei Med J. 2005;46(5):585-96.

Zupanc ML, Handler EG, Levine RL, et al. Rasmussen encephalitis: epilepsia partialis continua secondary to chronic encephalitis. Pediatr Neurol. 1990;6(6):397-401.