Viral Encephalitis: Understanding Its Diverse Symptoms and Progression

Viral encephalitis is an inflammation of the brain caused by a viral infection directly affecting brain tissue. This condition presents a wide range of clinical symptoms, varying in severity and progression depending on the affected individual's age and immune response.

Common Early Symptoms Across All Age Groups

One of the key characteristics of viral encephalitis is that it can affect individuals of any age group. Interestingly, more than half of the diagnosed cases involve adults over the age of 20. The illness can occur throughout the year and often begins with flu-like symptoms, including headache, fever, muscle pain, fatigue, and abdominal discomfort. These initial signs may appear mild, making early diagnosis particularly challenging.

Progressive Neurological and Behavioral Changes

In most cases, the disease follows an acute course. Early indicators may include a history of oral herpes lesions and a high fever exceeding 38.5°C. This phase is often marked by headaches, subtle changes in personality, and altered consciousness. Some patients experience generalized or focal motor seizures as the first neurological symptom.

As the disease progresses, more pronounced mental and behavioral symptoms typically emerge. Patients may show signs of inattention, slowed reactions, reduced speech, emotional blunting, and a lack of facial expression. In advanced stages, individuals may become unresponsive, sit motionless for extended periods, neglect personal hygiene, or require assistance with basic daily activities. Conversely, some patients may exhibit increased activity, unusual behaviors, impulsiveness, or significant cognitive impairments.

Severe Neurological Complications

Neurological deficits are common in more severe cases. These may include hemiplegia (paralysis on one side of the body), hemianopia (loss of half the visual field), aphasia (language difficulties), ophthalmoplegia (eye muscle weakness), ataxia (loss of coordination), and movement disorders. A significant number of patients develop altered levels of consciousness, with approximately one-third experiencing epileptic seizures.

In the most critical cases, widespread brain tissue necrosis and cerebral edema (brain swelling) can occur. These complications may lead to increased intracranial pressure and potentially life-threatening brain herniation. Without timely intervention, the condition can be fatal. For those who survive, the typical disease course lasts between one to two months, although recovery may extend beyond this timeframe depending on the severity of neurological damage.