Diagnostic tools for immune causes of encephalitis.
Clin Microbiol Infect. 2018 Dec 21;:
Authors: Lascano AM, Vargas MI, Lalive PH
BACKGROUND: Autoimmune encephalitis (AE) refers to a central nervous system (CNS) antibody-mediated entity characterized by a rapid onset behavioral and cognitive decline associated with epileptic and dysautonomic features. Interestingly, it is sought to be as common as its infectious disease counterpart and can share some clinical, radiological and laboratory findings.
OBJECTIVE: To describe the main clinical features of AE caused by antibodies targeting cell-surface neuronal agents and the diagnostic means to identify them. Paraneoplastic syndromes, triggered by intracellular antibodies, will not be tackled in this review.
CONTENT: According to a recent population-based study, autoimmunity seems to be the second cause of encephalitis after infectious agents. Its diagnosis lies upon "classic" clinical features, which are dominated by neuropsychiatric symptoms and epileptic seizures. Cerebral spinal fluid (CSF) and serum autoantibody testing can confirm AE. Complementary examination with magnetic resonance imaging (MRI) and electroencephalogram (EEG) may be helpful for excluding other causes and managing seizures. In addition, exclusion of infectious and other origins must be considered.
IMPLICATIONS: AE misdiagnosis can lead to a delay in treatment onset and, thus, clinical worsening. In this sense, identifying the causative agent is of utmost importance. However, the absence of CSF or serum antibody detection does not exclude the diagnosis of AE. Despite extensive testing, many encephalitis cases remain of unknown origin. It is obvious that some auto-antibodies have not yet been identified in AE. Since radiological and biological exams are rarely contributive, early symptom recognition might help to hasten the diagnostic process.
PMID: 30583056 [PubMed - as supplied by publisher]