enkefaliitti

Enkefaliitti is the Finnish term for encephalitis, an inflammation of the brain parenchyma that can arise from infections, autoimmune processes, or other etiologies. It is a medical emergency because brain inflammation can progress rapidly and cause lasting neurologic damage or death.

Most cases are infectious, with viruses as the leading causes. Herpes simplex virus type 1 (HSV-1) is a major cause of sporadic encephalitis worldwide. Other viral causes include enteroviruses, arboviruses, varicella-zoster virus, and influenza. Autoimmune encephalitis, such as anti-NMDA receptor encephalitis, is increasingly recognized and may follow an infection or occur independently. Less common causes include post-infectious immune responses or paraneoplastic syndromes.

Clinical features are variable but commonly include fever, headache, confusion or altered consciousness, personality or memory changes, seizures, and focal neurological deficits. Symptoms can progress over hours to days, and some patients develop coma. In children and older adults, presentations may differ, underscoring the need for prompt assessment in any acute encephalitic syndrome.

Diagnosis relies on a combination of clinical suspicion, neuroimaging, and laboratory tests. Magnetic resonance imaging (MRI) often reveals inflammatory changes; computed tomography (CT) may be used initially. Lumbar puncture with cerebrospinal fluid (CSF) analysis typically shows lymphocytic pleocytosis and elevated protein; polymerase chain reaction (PCR) testing can detect viral DNA or RNA. EEG and broad infectious and autoimmune testing may be performed.

Treatment requires urgent management. For suspected HSV encephalitis, intravenous acyclovir is started promptly and continued until HSV is excluded. Autoimmune encephalitis is treated with immunotherapy (steroids, IVIG, plasmapheresis) and management of seizures and other complications. Prognosis varies; timely diagnosis and treatment improve outcomes, but many patients experience residual cognitive or neurological deficits.