Encephalitis – Symptoms, Causes, Diagnosis & Treatment

 

Introduction:

*Encephalitis* is a serious medical condition characterized by *inflammation of the brain* tissue, usually due to viral infections. It can lead to seizures, altered consciousness, neurological deficits, and in severe cases, coma or death. Early diagnosis and treatment are crucial for better outcomes.

Pathophysiology:

Encephalitis is caused by:

- *Direct viral invasion* of brain tissue (*e.g., HSV, West Nile virus*)

- *Post-infectious autoimmune response* damaging neurons

The inflammation leads to:

- *Brain swelling*

- *Disrupted neural transmission*

- *Increased intracranial pressure (ICP)*

- *Neuronal death*

Types of Encephalitis:

1. *Viral Encephalitis* – Most common (e.g., HSV-1, Japanese encephalitis, West Nile virus)

2. *Autoimmune Encephalitis* – Antibodies attack brain tissue (e.g., anti-NMDA receptor encephalitis)

3. *Post-infectious Encephalitis* – After measles, mumps, or chickenpox

4. *Parasitic, bacterial or fungal encephalitis* – Rare

Symptoms and Signs:

- High-grade *fever*

- *Headache*

- *Seizures*

- *Altered mental status* (confusion, hallucinations)

- *Neck stiffness*

- *Photophobia*

- *Lethargy or coma*

- *Focal neurological deficits* (e.g., weakness, aphasia)

Diagnosis:

1. *Clinical examination*

2. *MRI Brain* – Inflammation, edema

3. *EEG* – Abnormal brain activity

4. *Lumbar Puncture (CSF analysis)*

   - ↑ Lymphocytes

   - ↑ Protein

   - Normal or ↓ glucose

5. *PCR test* – Detect viral DNA (especially HSV)

6. *Serology & Antibody tests* – For autoimmune types

Treatment:

*1. Antiviral Therapy*

*Acyclovir (Zovirax)*  

- *Use:* First-line for suspected *HSV encephalitis*  

- *Dose:* 10 mg/kg IV every 8 hours for 14–21 days  

- *Side Effects:* Nephrotoxicity (monitor renal function), nausea, crystalluria

*2. Supportive Care*

- IV fluids  

- Antipyretics (Paracetamol)  

- Seizure control (e.g., *Levetiracetam 500–1000 mg BID*)  

- Oxygen and ventilation if required

*3. Autoimmune Encephalitis*

- *Steroids* (e.g., methylprednisolone 1g/day IV for 5 days)  

- *IVIG or Plasma Exchange*  

- *Immunosuppressants* (e.g., Rituximab, Cyclophosphamide)

Prognosis:

- *Early antiviral treatment* can significantly reduce mortality in HSV encephalitis.

- Delayed treatment may lead to *permanent neurological damage*.

Prevention:

- *Vaccination* (e.g., Japanese Encephalitis, Measles)  

- *Insect control* (for mosquito-borne types)  

- *Prompt treatment of infections* to avoid complications

Conclusion:

Encephalitis is a potentially life-threatening condition requiring urgent medical attention. Whether viral or autoimmune, early *diagnosis*, *hospital care*, and *targeted treatment* are key to improving survival and minimizing complications. Public awareness and preventive measures can also play a vital role in reducing the incidence of encephalitis.