Encephalitis: A Review
Encephalitis is a neurological disorder caused by an inflammation of the brain, most commonly caused by a viral infection. It can cause a wide range of symptoms, from mild to severe, and in extreme cases can be fatal. This review will discuss the etiology, epidemiology, clinical presentation, diagnosis, and treatment of encephalitis.
Etiology
The most common cause of encephalitis is a viral infection; most commonly, herpes simplex virus (HSV) type 1 and 2, West Nile virus (WNV), varicella-zoster virus (VZV), and mumps virus (MV). Other causes of encephalitis include bacterial infections such as meningitis, and a rare but serious complication of measles or chickenpox known as post-infectious encephalitis. In some cases, encephalitis can be caused by autoimmune disorders, toxins, or drugs.
Epidemiology
Encephalitis is a rare disease, with an estimated incidence of 1 to 3 cases per 100,000 people. The highest rate of encephalitis is seen in children, particularly those younger than 5 years of age. The incidence of encephalitis is higher in developing countries, where access to medical care is limited.
Clinical Presentation
The clinical presentation of encephalitis can vary widely. Common symptoms include headache, fever, confusion, seizures, and loss of consciousness. Other more serious symptoms can include vision or hearing loss, difficulties with speech and movement, and personality changes.
Diagnosis
The diagnosis of encephalitis is based on a clinical assessment of symptoms, combined with laboratory tests such as blood tests, cerebrospinal fluid (CSF) analysis, and imaging tests such as MRI or CT scan.
Treatment
The treatment of encephalitis depends on the underlying cause. For viral encephalitis, treatment typically involves antiviral medications such as acyclovir or valacyclovir. For bacterial encephalitis, antibiotics are used. In some cases, corticosteroids may be used to reduce inflammation. In severe cases, supportive care such as mechanical ventilation or intravenous fluids may be necessary.
Conclusion
Encephalitis is a rare but serious neurological disorder that can cause a wide range of symptoms, from mild to severe. It is most commonly caused by a viral infection, but can also be caused by bacterial infections, autoimmune disorders, toxins, or drugs. Diagnosis is based on a clinical assessment of symptoms, combined with laboratory tests and imaging. Treatment depends on the underlying cause, but may include antiviral medications, antibiotics, corticosteroids, or supportive care.
References
Centers for Disease Control and Prevention. (n.d.). Encephalitis. Retrieved from https://www.cdc.gov/encephalitis/about/index.html
Kumar, H., & Gupta, N. (2020). Encephalitis: A Review. Cureus, 12(10), e11373. doi: 10.7759/cureus.11373
U.S. National Library of Medicine. (2020). Encephalitis. Retrieved from https://medlineplus.gov/ency/article/000664.htm