Enkefalitis

Enkefalitis, also known as encephalitis, is inflammation of the brain tissue. It is a serious condition that can result from infections, autoimmune processes, or other causes, and it requires prompt evaluation and treatment.

Causes and types: Viral infections are the most common cause in many regions, with herpes simplex virus type 1 (HSV-1) being a classic example. Other viruses include enteroviruses, West Nile virus, varicella-zoster virus, and influenza. Autoimmune encephalitis is immune-mediated, often involving antibodies against neuronal receptors or synaptic proteins (for example, NMDAR, LGI1, CASPR2). Less common etiologies include bacterial, fungal, parasitic infections, prion diseases, and paraneoplastic syndromes.

Clinical features: Symptoms typically include fever, headache, confusion or altered mental status, seizures, and behavioral or personality changes. Focal neurological deficits, speech or movement problems, and, in severe cases, coma may occur. The presentation can be acute or subacute, and outcomes vary based on cause and treatment timing.

Diagnosis: Diagnosis combines clinical suspicion with imaging and laboratory studies. Magnetic resonance imaging often reveals focal brain abnormalities; HSV encephalitis frequently affects the temporal lobes. Cerebrospinal fluid analysis may show pleocytosis and elevated protein with normal glucose. PCR testing of CSF for viral DNA/RNA (notably HSV-1) is central. Autoantibody panels, EEG, and, rarely, brain biopsy may be used to identify autoimmune or atypical causes.

Treatment and prognosis: If HSV encephalitis is suspected, empirical intravenous acyclovir is started promptly. Bacterial meningitis is considered and treated if needed. Supportive care, seizure management, and measures to control intracranial pressure are important. Autoimmune encephalitis often requires immunotherapy. Early treatment improves outcomes, but prognosis remains variable and depends on the underlying cause and patient factors.