In general, it is recommended that treatment be guided by a patients clinical status. Evolving Concepts in Autoimmune Encephalitis Novel Syndromes Associated with Neuronal Cell Surface Autoimmunity: Expanding beyond Autoimmune Encephalitis? Thus far, the discussion has centered on neuronal surface or synaptic-targeted antibodies associated with subacute autoimmune encephalitis syndromes. In the past few years, it has become evident that many of these encephalitides are autoimmune in origin, and represent specific clinical syndromes associated with antibodies that target neuronal surface antigens.2C4 It has been exhibited in vitro Rasagiline 13C3 mesylate racemic and in vivo that some of these cell surface-targeted antibodies are pathogenic and reversibly disrupt the structure and function of their target neuronal proteins.5C10 This in large part explains the responsiveness of patients symptoms to immunotherapy. These syndromes have a variable association with cancer and may be confused with the classic antibody associated paraneoplastic neurologic disorders (PNDs).11 However, in a classic PND of the central nervous system (CNS), the associated antibodies usually target intracellular neuronal proteins and are markers of paraneoplasia without being pathogenic. The neuronal damage in PNDs of the central nervous system (CNS) is usually T-cell mediated and mostly irreversible, resulting in the generally limited neurologic recovery of the patients, even with maximal treatment.12 As more autoimmune encephalitis (AE) with antibodies to neuronal cell surface antigens are identified, it can be difficult to keep track of newly described clinical associations and concepts that are still evolving. Because most of these syndromes are treatment responsive and if left undertreated can result in serious disability or death, it is important to promptly recognize and treat them. This review aims to provide a practical overview of the evaluation, diagnosis, and treatment of AE associated with antibodies against neuronal cell surface antigens. Diagnosis Recognizing Autoimmune Encephalitis Diagnosing AE involves familiarizing oneself with the various syndromes that have been described in detail elsewhere,4,5,9,13C22 and thus are only briefly summarized below and in ?Table 1, with an emphasis on defining features. Many AE share overlapping clinical features, and knowing their characteristic or unique indicators helps to differentiate them. However, there has been a growing tendency for some syndrome definitions to be used imprecisely. For instance, limbic encephalitis is usually a well-defined disorder characterized by subacute short-term memory loss, confusion, and mood/ behavioral changes, such as depressive disorder, irritability, and hallucinations, with or without seizures.23,24 In the literature, the term limbic encephalitis is frequently misused to describe any sort of autoimmune encephalopathy, which can misdirect the differential diagnosis.25 Some AE have been described in only a few patients, and it is possible that their full clinical spectra remain to be defined. In Rabbit Polyclonal to 14-3-3 gamma contrast, other disorders, such as anti-N-methyl-D-aspartate (NMDA) receptor encephalitis, have been comprehensively described, 26 and an atypical symptom could be unrelated or perhaps a part of an overlapping but impartial disorder, discussed further below. Table 1 Antineuronal antibody-associated autoimmune encephalitis syndromes
NMDAR (GluN1)Anti-NMDAR encephalitis: Psychiatric manifestations, insomnia, reduction of verbal output, seizures, amnesia, move- ment disorders, catatonia, autonomic instability, comaAge-dependent: ~10-45%, rare in children, ovarian teratomas, rarely carcinomas~50% Viral prodrome; EEG: delta brush pat- tern in ~30% of pa- tients; relapses 12% Rasagiline 13C3 mesylate racemic at 2 yearsAMPARLimbic encephalitis; may occur with pure psychiatric manifestations70% (Lung, breast, thymoma)Relapses commonGABABRLimbic encephalitis, prominent seizures50% (Lung, neuroendocrine)Status epilepticusLGI1Limbic encephalitis, focal faciobrachial seizures, REM sleep behavior Rasagiline 13C3 mesylate racemic disorder, myoclonus<10% (Lung, thymoma)~60% HyponatremiaCASPR2Encephalitis, Morvan syndrome, neuromyotonia0C40% (Thymoma)Encephalitis relapses commonmGluR5Limbic encephalitis, myoclonusHodgkin lymphoma; may occur without tumorVery few casesGlyRStiff-person, PERM, limbic encephalitis, cerebellar degeneration, or optic neuritisInfrequentWide clinical spectrumDPPXEncephalitis with CNS hyperexcitability: Confusion, psychiatric manifestations, tremor, myoclonus, nystagmus, hyper- ekplexia, PERM-like symptoms, ataxiaNoneDiarrhea Rasagiline 13C3 mesylate racemic commonGABAARRefractory seizures, status epilepticus, or.