Understanding Encephalitis: Causes, Symptoms and Diagnosis

Encephalitis is a serious, life-threatening condition caused by brain swelling. It is usually brought on by viral infections, insect bites, or autoimmune reactions that affect the brain. According to WHO (the World Health Organisation), Japanese encephalitis, primarily spread by mosquitoes, is widespread in 24 Southeast Asian countries, with its primary vector spread across India.  

Without proper intervention and treatment, the disease can lead to long-term complications or even become fatal. It is vital for individuals to understand the signs and symptoms of encephalitis. This article examines what encephalitis is, its causes, symptoms, and diagnosis. 

What is Encephalitis?

Encephalitis refers to inflammation of the brain caused by viral, bacterial, fungal, or autoimmune diseases. It results in the swelling of specific active brain tissues, which is characterized by various physical and cognitive symptoms. Some of these may be fever, headaches, fatigue, or even severe ones, such as seizures and memory loss. 

What Causes Encephalitis?  

Encephalitis occurs either due to infections or autoimmune diseases. Based on these factors, it’s categorised into: 

1. Infectious Encephalitis

When a brain swelling arises through viral infection, bacterial infection, or fungal infection, it’s termed infectious encephalitis.  

– Viral encephalitis: Viral encephalitis, the most common type, often occurs after certain infections or diseases.  

– Arboviral encephalitis: Arboviral encephalitis is caused by arboviruses carried by insects like mosquitoes, fleas, and ticks.  

– Bacterial or Fungal encephalitis: This is the least common type. It is caused by bacteria or fungi.  

2. Autoimmune Encephalitis

When the immune system attacks the brain, resulting in the latter’s inflammation, it is termed autoimmune encephalitis. For example, when individuals experience brain dysfunction as a result of liver dysfunction, it is known as hepatic encephalitis.

 What are the Risk Factors of Encephalitis? 

Various factors pose the risk of encephalitis:

– Age: Infants and older adults  

– Locality: People living in areas surrounded by mosquitoes and ticks 

– Season: Summers or fall when insects are active. 

– Immunity: People with weaker immune systems. 

– Vaccination: MMR (mumps, measles, rubella) vaccine resulted in encephalitis, rare though. 

What are the Symptoms of Encephalitis?

The symptoms of encephalitis depend on the severity of the condition. For example, in the case of Japanese encephalitis, signs and symptoms are headaches, fever, confusion, and mental delirium. EEE symptoms include chills and fever, which appear only after 4-10 days of being infected by the mosquito. Some general signs of encephalitis to watch for include:   

– Fever 

– Headaches 

– Excessive fatigue 

– Muscle or joint pain 

– Stiffness in the neck 

– Confusions and hallucinations 

– Weakness in muscles 

– Problems in speaking or hearing 

– Irregular body movements 

– Seizures 

– Difficulty in moving some parts of the face or body 

– Memory loss 

– Changes in personality, like getting increased irritability  

– Speaking difficulties  

– Loss of movement in some body parts  

– Trouble in walking 

– Sleep problems  

– Changes in vision 

– Seizures 

– Bladder and bowel movements  

Unlike adults, infants and young children suffering from encephalitis may experience symptoms including: 

– Poor feeding 

– Bulging soft spot on the scalp (called a bulging fontanel) 

– Constant crying 

– General irritability 

– Stiffness in the body 

– Nausea and vomiting 

How is Encephalitis Diagnosed? 

When someone experiences symptoms related to encephalitis, such as fever and headaches, or even severe ones like confusion and hallucinations, diagnostic procedures are required to determine the underlying cause. Various medical tests help in the diagnosis of encephalitis, including:

1. Blood tests: Blood samples are examined to tests for infection in the patient’s blood. These are rarely used alone, and are typically used along with other tests to diagnose encephalitis.

2. Imaging tests: Imaging tests like Computerised Tomography (CT) scans and Magnetic Resonance Imaging (MRIs) detect can rule out other causes for symptoms. They can also highlight which part of the brain has been affected by the virus.

3. Electroencephalogram (EEG): In this test, electrodes are attached to the individual’s scalp to record the brain’s electrical activity. Specific patterns may signal encephalitis.

4. Urine and stool tests: Samples of urine and stools are examined to test for any possible organisms or antibodies causing the infection.

5. Lumbar puncture (Spinal tap): A needle is inserted into the individual’s lower back to draw a small amount of protective fluid passing between the brain and spinal column. Samples are tested to check for infection.

6. Biopsy: A biopsy of the affected brain tissue may aid in examining infections. However, this test is rarely performed. 

Timely diagnosis of encephalitis is crucial for successful treatment. Individuals experiencing any symptoms should contact a healthcare professional immediately.  For more information regarding encephalitis tests, visit the Dr Lal PathLabs website.  

FAQs

1. What are the main causes of encephalitis?

Encephalitis occurs either due to infections or autoimmune diseases. 

2. What are the symptoms of encephalitis?

The signs of encephalitis may include fever, headache, and excessive fatigue if caused by infection. In the case of autoimmune encephalitis, memory loss, seizures, and other symptoms also appear. 

3. Can viral encephalitis be prevented?

Practicing personal hygiene and maintaining clean surroundings considerably reduces the risk of contracting viral encephalitis.