The medical condition encephalitis causes inflammation of the brain, and can be caused by an infection, an autoimmune disease, or cancer. It is more common in older adults and young children, but it can affect anyone. As encephalitis can result in serious consequences, such as brain damage, seizures, comas, or death, it is crucial to recognize the signs and symptoms and seek medical attention promptly.
Infections with viruses are the most common cause of encephalitis. Herpes simplex virus (HSV), Epstein-Barr virus (EBV), enteroviruses, mumps viruses, measles viruses, rabies viruses, and arboviruses are among the many types of viruses that can infect the brain. West Nile virus, Japanese encephalitis virus, and Eastern equine encephalitis virus are among the arboviruses that are transmitted by mosquitoes, ticks, and other insects.
This can be caused by a previous infection or a genetic predisposition to encephalitis. It occurs when the body's own immune system mistakenly attacks brain tissue, causing inflammation. Hashimoto's encephalopathy, anti-NMDA receptor encephalitis, and anti-LGI1 encephalitis are some examples of autoimmune encephalitis.
The most common cause of encephalitis is bacterial infection, including meningococcal meningitis, syphilis, tuberculosis, and Lyme disease. Occasionally, encephalitis is caused by parasitic infections, such as toxoplasmosis or cysticercosis, as well as fungal infections, such as cryptococcal meningitis or histoplasmosis. Finally, some types of cancers may cause encephalitis by spreading to the brain or triggering an immune response.
The symptoms of encephalitis vary depending on the cause, severity, and location of the inflammation. However, some common symptoms include:
Fever
Headache
Nausea and vomiting
Stiff neck
Confusion
Agitation
Hallucinations
Seizures
Loss of sensation or movement
Muscle weakness
Problems with speech or hearing
Loss of consciousness
In infants and young children, the symptoms may also include:
Bulging fontanelles (soft spots on the skull)
Poor feeding
Irritability
Restlessness
It is possible for encephalitis symptoms to develop gradually over days or weeks or suddenly within hours. Some people may experience mild symptoms that are similar to influenza, while others may have severe symptoms that require immediate medical attention.
A patient's medical history, physical examination, and laboratory tests are used to diagnose encephalitis. Symptoms, exposure to potential sources of infection or triggers of autoimmune disease, travel history, and vaccination status will be asked for by the doctor. Additionally, the doctor will look for symptoms of neurological impairment, such as altered mental status, focal deficits, or abnormal reflexes.
The laboratory tests that are used to diagnose encephalitis include:
Blood tests: To look for signs of infection or inflammation in the blood.
Cerebrospinal fluid (CSF) analysis: To examine the fluid that surrounds the brain and spinal cord for evidence of infection or inflammation.
Brain imaging: To visualize the structure and function of the brain using computed tomography (CT) scan or magnetic resonance imaging (MRI) scan.
Electroencephalogram (EEG): To measure the electrical activity of the brain and detect any abnormal patterns.
Brain biopsy: To obtain a sample of brain tissue for microscopic examination and identification of the cause of inflammation.
Encephalitis is treated by reducing inflammation in the brain, preventing complications such as seizures and brain damage, and supporting the patient's vital functions.
The treatment options for encephalitis include:
Antiviral drugs: To treat viral infections that cause encephalitis, such as acyclovir for HSV or ganciclovir for EBV.
Antibiotics: To treat bacterial infections that cause encephalitis, such as penicillin for syphilis or rifampin for tuberculosis.
Antifungal drugs: To treat fungal infections that cause encephalitis, such as amphotericin B for cryptococcosis or itraconazole for histoplasmosis.
Antiparasitic drugs: To treat parasitic infections that cause encephalitis, such as pyrimethamine for toxoplasmosis or albendazole for cysticercosis.
Corticosteroids: To reduce the inflammation and swelling in the brain caused by autoimmune or neoplastic encephalitis.
Immunotherapy: To modulate the immune system and suppress the autoimmune response that causes encephalitis, such as intravenous immunoglobulin (IVIG) or plasmapheresis.
Chemotherapy: To treat cancer that causes encephalitis, such as methotrexate or cyclophosphamide.
Anticonvulsants: To prevent or control seizures that may occur as a complication of encephalitis, such as phenytoin or levetiracetam.
Analgesics: To relieve pain and discomfort caused by encephalitis, such as ibuprofen or acetaminophen.
Fluids and electrolytes: To maintain hydration and balance of minerals in the body, especially if the patient has nausea, vomiting, or diarrhea.
Oxygen therapy: To provide adequate oxygen to the brain and other organs, especially if the patient has breathing difficulties or low blood oxygen levels.
Mechanical ventilation: To assist the patient’s breathing if they are unable to breathe on their own due to severe encephalitis or coma.
Some forms of encephalitis can be prevented by taking certain measures, such as:
Getting vaccinated against diseases that can cause encephalitis, such as measles, mumps, rubella, chickenpox, influenza, and Japanese encephalitis.
Avoiding contact with people who have infections that can cause encephalitis, such as herpes simplex, mononucleosis, or meningitis.
Practicing good hygiene and washing hands frequently to prevent the spread of germs that can cause encephalitis.
Using insect repellents and wearing protective clothing when outdoors in areas where there are mosquitoes, ticks, or other insects that can transmit viruses that can cause encephalitis.
Avoiding exposure to animals that may carry rabies virus, such as bats, raccoons, skunks, or dogs. If bitten by a suspected rabid animal, seek medical attention immediately and receive rabies post-exposure prophylaxis.
Seeking medical attention promptly if experiencing any symptoms of encephalitis or suspecting a possible cause of encephalitis.
If you are aware of the causes, symptoms, diagnosis, treatment, and prevention of encephalitis, you can protect yourself and your loved ones from this potentially life-threatening condition.
