Encephalitis causes physical symptoms like fever, headaches and neck pain. It can also affect brain (cognitive) functioning, leading to confusion and behavior changes. In some cases, cognitive encephalitis symptoms linger long after physical symptoms go away.
Symptoms of encephalitis vary depending on the affected area of the brain, but often include headache, sensitivity to light, stiff neck, mental confusion and seizures. It's important to see a doctor promptly if you are experiencing symptoms, which may not seem troubling at the time.
Get immediate care if you are experiencing any of the more-severe symptoms associated with encephalitis. A severe headache, fever and change in consciousness require urgent care.
The mortality rate varies but can be up to 40% depending on a number of factors including the cause of the encephalitis, an individual's underlying health and the treatment given.
Severe disease often occurs including infection of the brain (encephalitis) or the membranes around the brain and spinal cord (meningitis). Initial symptoms can include fever, headache, vomiting, and weakness.
The severity of viral encephalitis depends on the particular virus and how quickly treatment was given. Generally, the acute phase of the illness lasts around one or 2 weeks, and the symptoms either disappear quickly or subside slowly over a period of time. In many cases, the person makes a full recovery.
Diagnosing encephalitis
Early diagnosis is vital, as symptoms can appear suddenly and escalate to brain damage, hearing and/or speech loss, blindness, or even death.
It's treated in hospital – usually in an intensive care unit (ICU), which is for people who are very ill and need extra care. How long someone with encephalitis needs to stay in hospital can range from a few days to several weeks or even months.
Encephalitis can damage the brain and cause long-term problems including: memory loss (amnesia) personality and behavioural changes. speech and language problems (aphasia)
Encephalitis is most often due to a virus, such as: herpes simplex viruses, which cause cold sores (this is the most common cause of encephalitis)
A scan of the brain can help show whether you have encephalitis or another problem such as a stroke, brain tumour or brain aneurysm (a swelling in an artery). The 2 main types of scan used are: a CT scan. an MRI scan.
Left untreated, autoimmune encephalitis can quickly become serious. It may lead to coma or permanent brain injury. In rare cases, it can be fatal.
Since 1 January 2021, 45 people have been infected with JEV in Australia. There were 7 deaths recorded in Australia during this period. There have been no new human cases identified in Australia since December 2022.
Transmission of Murray Valley encephalitis virus
People can be infected with Murray Valley encephalitis virus when they are bitten by a mosquito carrying the virus. It is not spread directly from person-to-person. Mosquitoes pick up the virus when feeding on water birds such as herons or egrets.
Avindra Nath, a neurologist at NIH. “Then, you may have a headache, along with fever, neck stiffness, and you can get sensitivity to light.” Other symptoms include nausea or vomiting, double vision, drowsiness, and confusion. More severe illnesses can cause speech, hearing, or vision problems.
Following encephalitis, some people may experience emotional and behavioural changes including low mood, increased anxiety, depression, mood swings, frustration, aggression, impulsivity, disinhibition, and/or poor emotional regulation.
At a later time, emotional or physical stress can reactivate the virus to cause an infection of the brain. It causes the most subacute (between acute and chronic) and chronic (lasting three or more months) encephalitis infections in humans.
Do people recover after Encephalitis? In many cases, people will make a good recovery from encephalitis, but nerve cells in the brain may be damaged. This can lead to long-term effects, which are sometimes severe.
Difficulty falling asleep or maintaining sleep, and decreased need for sleep, are the most prevalent sleep symptoms in patients with NMDAR encephalitis [4, 8].
All the patients included in this study with a confirmed diagnosis of encephalitis were admitted under the neuro-medicine service. The mean age was 29.77±12.45 years (Table 1), the mean duration of ICU stay was 5.45±2.62 days, and the mean length of hospital stay was 9.33±5.06 days (Table 3).
Diagnostics tests, which can help to confirm a diagnosis of encephalitis include laboratory tests which analyse cerebrospinal fluid, blood, urine and other body fluids and radiological tests (computed tomography - CT, magnetic resonance imaging - MRI, electroencephalogram - EEG).
COVID-19-associated encephalitis has been described as a neurological complication that can occur at all stages of a positive SARS-CoV-2 infection (2, 3) and considered a medical emergency requiring urgent care, with complications encompassing severe disability and death (3-6).
Encephalitis can cause a stroke by disrupting blood flow in the brain. An encephalitis-associated stroke can be ischemic (due to a lack of blood supply to an area of the brain) or hemorrhagic (due to bleeding in the brain).
Travelers abroad are most at risk for Japanese encephalitis and tick-borne encephalitis. Japanese encephalitis is mosquito-borne and occurs mainly in: China, Japan, and Korea. Eastern Russia.