What tests are conducted for encephalitis?

Written by Zhang Hui
Neurology
Updated on December 05, 2024
00:00
00:00

First, it is generally necessary to conduct an EEG test. This test is very convenient and non-invasive for patients. If significant slow waves are detected, encephalitis cannot be ruled out.

Secondly, an MRI of the brain should be performed. If the viral encephalitis is severe, abnormal signals can be observed in areas such as the frontal lobe, temporal lobe, and hippocampus on the MRI, which are of great diagnostic reference value.

Thirdly, lumbar puncture is also very important. It allows for a direct observation of the color of the cerebrospinal fluid, to monitor the pressure of the brain fluid, and to test the cerebrospinal fluid for cell count, protein, sugar, and chloride levels. These tests are very important for the diagnosis and differential diagnosis of encephalitis.

Other Voices

doctor image
home-news-image
Written by Zhang Hui
Neurology
1min 19sec home-news-image

Viral encephalitis and bacterial encephalitis differences

There are significant differences between viral encephalitis and bacterial encephalitis in clinical settings. Firstly, their clinical symptoms differ; the fever in viral encephalitis is generally lower than that in bacterial encephalitis, where there may be widespread chills and persistent high fever. From another perspective, laboratory tests also help differentiate the two. In viral encephalitis, a routine blood test shows no increase in white blood cells, mainly an increase in the proportion of lymphocytes. In contrast, bacterial encephalitis is characterized by a significant increase in white blood cells, which aids in distinguishing the two. Furthermore, an essential diagnostic tool is the lumbar puncture, through which cerebrospinal fluid can be tested. In viral encephalitis, the white blood cell count in the cerebrospinal fluid is slightly increased; in bacterial encephalitis, it is significantly increased. The cerebrospinal fluid in viral encephalitis has a slight increase in protein content with no significant change in chloride levels; however, in bacterial encephalitis, the protein content in the cerebrospinal fluid is notably higher, and there is a significant decrease in chloride levels.

doctor image
home-news-image
Written by Tang Li Li
Neurology
1min 46sec home-news-image

How is encephalitis caused?

Encephalitis generally falls into two categories: one is infectious inflammation caused by pathogenic infections, and the other is immune inflammation caused by abnormalities in immune mechanisms. Among these, the infectious type is the most common, including viral encephalitis, viral meningitis, tuberculous meningoencephalitis, purulent meningitis, and cryptococcal meningitis, which are associated with infections by viruses, bacteria, Mycobacterium tuberculosis, and Cryptococcus, respectively. Additionally, abnormalities in the immune system often cause autoimmune encephalitis, as well as multiple sclerosis and neuromyelitis optica when involving the brain, and acute disseminated encephalomyelitis, all of which are types of autoimmune encephalitis. The treatment approaches for these two types of encephalitis are different. For pathogen-induced cases, treatment primarily targets the pathogens: antiviral drugs for viral encephalitis, antibiotics for bacterial encephalitis, anti-tubercular therapy involving multiple drugs for Mycobacterium tuberculosis infection, and antifungal drugs, such as amphotericin B, for cryptococcal meningitis. For immune-mediated encephalitis, treatments generally involve immunosuppressants, high-dose corticosteroids, or intravenous immunoglobulins.

doctor image
home-news-image
Written by Zhang Hui
Neurology
1min 20sec home-news-image

How is encephalitis caused?

Encephalitis generally occurs when pathogens invade the central nervous system of the brain, resulting in corresponding clinical manifestations. Patients may exhibit symptoms such as headache, fever, nausea, vomiting, and even paralysis of limbs and cognitive impairments. Patients become confused, with reduced computational and comprehension abilities. Some may also exhibit psychiatric symptoms and even experience seizures and other manifestations of epilepsy. Encephalitis is caused by pathogens, commonly viruses. Viral infections that lead to what is known as viral encephalitis can spread through the bloodstream to the brain and cause illness. Additionally, bacterial infections can also cause encephalitis. There are mainly two routes for bacterial infections: one is through bloodstream transmission leading to inflammation of the nervous system, and the other can occur directly, for example, from inflammation of the mastoids, tonsils, or cavernous sinus, where bacteria directly invade the brain, leading to the respective clinical manifestations. Furthermore, tuberculosis can also infect and cause tuberculous encephalitis, meningitis, and similar conditions.

doctor image
home-news-image
Written by Zhang Hui
Neurology
1min 23sec home-news-image

How to relieve headache from encephalitis

Encephalitis is mainly divided into viral encephalitis, bacterial encephalitis, and tubercular meningitis, among others. Encephalitis usually causes patients to experience fever, headache, nausea, and vomiting. The cause of headaches includes the pain response due to inflammation stimulating the meninges. Moreover, these infections can cause an increase in intracranial pressure, leading to significant symptoms in patients such as headache, nausea, and vomiting. To alleviate headaches, it is important to actively treat the primary disease. This includes administering antiviral drugs for viral infections, and antibiotics for bacterial infections. If the headache is caused by increased intracranial pressure, it is crucial to actively administer dehydrating agents and drugs that lower intracranial pressure to reduce it, thereby relieving the headache. Additionally, the use of glucocorticoids can be combined to manage the treatment, suppress the inflammatory response, and alleviate pain. If the pain is significant, non-steroidal anti-inflammatory drugs may also be administered to relieve the pain. The treatment of pain in encephalitis is a comprehensive issue that requires addressing the pathogen, dehydration, reduction of intracranial pressure, and symptomatic treatment.

doctor image
home-news-image
Written by Zhang Hui
Neurology
59sec home-news-image

How is encephalitis transmitted?

The commonly mentioned encephalitis is mainly caused by viral infections. There are many types of viruses that can cause encephalitis, including the more severe herpes simplex virus, varicella-zoster virus, etc. There are also some enteroviruses, like Coxsackie virus, and some adenoviruses. Typically, the transmission of encephalitis can occur via the fecal-oral route, where some enteroviruses enter the digestive tract through this route, then from the cells of the digestive tract to the bloodstream, and from there to the brain. Additionally, some viruses are transmitted through blood contact. For instance, if a patient has blisters that rupture and release a large amount of virus, and another person's blood comes into contact with these fluids, transmission can occur via blood. Generally, encephalitis is primarily transmitted through fecal-oral routes and bloodborne transmission.