A severe and sometimes deadly inflammation of the brain that can be caused by a number of different viruses.

An acute inflammatory process affecting the brain parenchyma.

An inflammatory process affecting the brain parenchyma. Causes include viral infections and less frequently bacterial infections, toxins, and immune-mediated processes.

Encephalitis is inflammation (swelling) of the brain. It can happen when an infection or medical condition that affects the brain activates your immune system. The inflammation can cause a wide range of symptoms. In extreme cases, it can lead to brain damage, stroke, or even death. There are different types of encephalitis, based on what the cause is. The two main types are infectious encephalitis and autoimmune encephalitis. Infectious encephalitis is usually caused by a virus. In fact, viruses are the most common cause of encephalitis. Some of the different viruses that cause it include: Herpes viruses, including herpes simplex (HSV), the Epstein-Barr virus (which causes infectious mononucleosis) and the varicella-zoster virus (which causes chickenpox).; Viruses you can get if you are bitten by an infected tick, such as tick-borne encephalitis (TBE virus) and Powassan virus.; Viruses you can get if you are bitten by an infected mosquito, such as eastern equine encephalitis virus, West Nile virus, and La Crosse virus.; Enteroviruses, which are a common group of viruses that mostly cause mild illness or respiratory infection. These infections usually happen in the summer and fall. Bacteria, fungi, and parasites can also cause infectious encephalitis. But this is not common. Autoimmune encephalitis happens when your immune system mistakenly attacks healthy brain cells. It can be triggered by conditions such as certain cancers, benign tumors, and infections. Sometimes the cause is not known. Anyone can get encephalitis, but you are more likely to get it if you: Have a weakened immune system, for example from having HIV or taking certain medicines. These could include medicines taken after an organ transplant, certain chemotherapy medicines, and specialized treatments for certain autoimmune diseases.; Are a young child or older adult.; Live in areas where there are ticks and mosquitoes that carry viruses that can cause encephalitis. The symptoms of encephalitis can vary a lot, depending on how severe it is. Many people do not have any symptoms. Others may have mild flu-like symptoms such as fever, fatigue, headache, or body aches. If encephalitis becomes more serious, it can cause: Severe headache; Stiff neck; Vomiting; Seizures; Behavior changes; Drowsiness; Muscle weakness; Partial paralysis in your arms and legs; Coma. Encephalitis can be dangerous in infants. Their symptoms may include: Fever; Lethargy (weakness or drowsiness); Poor feeding; Vomiting; Body stiffness; Unusual irritability or crying; A full or bulging fontanel (the soft spot on the top of the head). If you or your child is having symptoms of encephalitis, it's important to get medical care right away. To find out if you have encephalitis, your health care provider: Will do a physical exam; Will take your medical history, which includes asking about your symptoms; May do a neurologic exam; May order imaging tests, such as a brain...

Inflammation of the BRAIN due to infection, autoimmune processes, toxins, and other conditions. Viral infections (see ENCEPHALITIS, VIRAL) are a relatively frequent cause of this condition.

Encephalitis is inflammation of the parenchyma of the brain, resulting from direct viral invasion. Acute disseminated encephalomyelitis is brain and spinal cord inflammation caused by a hypersensitivity reaction to a virus or another foreign protein. Both disorders are usually triggered by viruses. Symptoms include fever, headache, and...

Encephalitis, an inflammation of the brain parenchyma, presents as diffuse and/or focal neuropsychological dysfunction. Although it primarily involves the brain, the meninges are frequently involved (meningoencephalitis).

Encephalitis (en-sef-uh-LIE-tis) is inflammation of the brain. There are several causes, but the most common is a viral infection.

Encephalitis is defined as inflammation of the brain parenchyma associated with neurologic dysfunction such as altered state of consciousness, seizures, personality changes, cranial nerve palsies, speech problems, and motor and sensory deficits. It is the result of direct inflammation of the brain tissue, as opposed to the inflammation...

Encephalitis, from Greek enkephalos ("brain") and itis ("inflammation"), inflammation of the brain. Inflammation affecting the brain may also involve adjoining structures; encephalomyelitis is inflammation of the brain and spinal cord, and meningoencephalitis is inflammation of the brain and...