Understanding and managing acute encephalitis

Abstract

Encephalitis is an important cause of morbidity, mortality, and permanent neurologic sequelae globally. Causes are diverse and include viral and non-viral infections of the brain as well as autoimmune processes. In the West, the autoimmune encephalitides are now more common than any single infectious cause, but, in Asia, infectious causes are still more common. In 2006, the World Health Organization coined the term “acute encephalitis syndrome”, which simply means acute onset of fever with convulsions or altered consciousness or both. In 2013, the International Encephalitis Consortium set criteria for diagnosis of encephalitis on basis of clinical and laboratory features. The most important infectious cause in the West is herpes simplex virus, but globally Japanese encephalitis (JE) remains the single largest cause. Etiologic diagnosis is difficult because of the large number of agents that can cause encephalitis. Also, the responsible virus may be detectable only in the brain and is either absent or transiently found in blood or cerebrospinal fluid (CSF). Virological diagnosis is complex, expensive, and time-consuming. Different centres could make their own algorithms for investigation in accordance with the local etiologic scenarios. Magnetic resonance imaging (MRI) and electroencephalography are specific for few agents. Clinically, severity may vary widely. A severe case may manifest with fever, convulsions, coma, neurologic deficits, and death. Autoimmune encephalitis (AIE) includes two major categories: (i) classic paraneoplastic limbic encephalitis (LE) with autoantibodies against intracellular neuronal antigens (Eg: Hu and Ma2) and (ii) new-type AIE with autoantibodies to neuronal surface or synaptic antigens (Eg: anti-N-methyl-D-aspartate receptor). AIE has prominent psychiatric manifestations: psychosis, aggression, mutism, memory loss, euphoria, or fear. Seizures, cognitive decline, coma, and abnormal movements are common. Symptoms may fluctuate rapidly. Treatment is largely supportive. Specific treatment is available for herpesvirus group and non-viral infections. Various forms of immunotherapy are used for AIE.

Glutamate Chemical Exchange Saturation Transfer (GluCEST) Magnetic Resonance Imaging in Pre-clinical and Clinical Applications for Encephalitis

“…Encephalitis is serious inflammatory disease of the central nervous system (CNS) that is caused by many physiological or pathological factors (Kumar, 2020). According to its etiology, encephalitis can be divided into three types, namely, infectious encephalitis (e.g., bacterial, viral, fungal, and tuberculosis), autoimmune encephalitis, and unexplained encephalitis.…”

Anti-NMDAR encephalitis in a 19 year old female patient with ovarian teratoma: A case report

“…Etiologies include post infectious processes such as acute disseminated encephalomyelitis, and auto-immune encephalitis [ 1 ]. The latter is divided into two categories: the classic limbic paraneoplastic encephalitis (anti-Hu and anti Ma2) and the anti -N- methyl- d -aspartate receptor encephalitis [ 5 ]. The anti NMDAR encephalitis is characterized by the presence of antibodies against the GluN1 subunit of the NMDA receptor [ 6 ].…”

“…The anti NMDAR encephalitis is characterized by the presence of antibodies against the GluN1 subunit of the NMDA receptor [ 6 ]. It is mainly of abrupt onset, with psychiatric manifestations like aggression, psychosis and memory loss, associated to seizures, cognitive decline and coma [ 5 ].…”

“…Diagnosis of encephalitis and searching for the etiology remains complex, and more than 50 % of encephalitis remain of unknown etiology [ 5 ]. Diagnostic testing include lumbar puncture, brain MRI and EEG.…”

An atypical case of febrile infection-related epilepsy syndrome following acute encephalitis: impact of physiotherapy in regaining locomotor abilities in a patient with neuroregression

“…An infectious condition like 'acute encephalitis' can result in FIRES. Acute encephalitis syndrome means a sudden onset of fever with seizures or alteration of consciousness or both [ 4 ]. Neurologic sequelae can result due to acute encephalitis [ 5 ].…”