Autoantibody-Mediated Encephalitis

Abstract

A cute or subacute disorders of wakefulness (quantitative impairment of consciousness, ICD-10 R40.-) and qualitative impairment of consciousness (confusion, impaired orientation, amnesia syndromes; ICD-10 R41.-) are frequently occurring causes of hospitalization. In a large neurological emergency department, quantitative disorders of consciousness were the cardinal symptom in every fifth patient seen (reduced vigilance 9%, epileptic seizures 11%) (1). Around 20 to 30% of all hospital inpatients, 50% of elderly patients, and up to 70% of intensive care patients suffer from delirium, i.e., acute deterioration of alertness, organized cognition, memory, attentiveness, and perception (2, e1-e3). Particularly with delirium syndromes the causes are unclear and the treatment principally comprises supportive measures, e.g., management of systemic infections or electrolyte shifts (3). Recently an additional differential diagnosis has been described, namely a group of previously unknown immune-mediated forms of encephalitis with Summary Background: Acute and subacute disturbances of wakefulness and cognitive function are common neurological manifestations in the hospital and in outpatient care. An important element of the differential diagnosis was described only a few years ago: autoimmune encephalitis, a condition whose diagnosis and treatment pose an interdisciplinary challenge. Methods: This review is based on pertinent publications from the years 2005-2017 that were retrieved by a selective search in PubMed, and on the authors' personal experience and case reports. Results: The incidence of autoimmune encephalitis in Germany is estimated at 8-15 cases per million persons per year. In some patients with psychotic manifestations or impaired consciousness of acute or subacute onset, an autoimmune pathogenesis can be demonstrated by the laboratory detection of autoantibodies against neuronal target antigens (e.g., glutamate receptors). Testing of this type should be performed in patients with inflammatory changes in the cerebrospinal fluid or on magnetic resonance imaging (MRI), or those who have had an otherwise unexplained first epileptic seizure or status epilepticus. The cumulative sensitivity of testing for all potentially causative antineuronal antibodies in patients with clinically defined autoimmune encephalitis is estimated at 60-80 %. Figures on cumulative specificity are currently unavailable. Conclusion: The detection of antineuronal antibodies in patients with the corresponding appropriate symptoms implies the diagnosis of autoimmune encephalitis. Observational studies have shown that rapidly initiated immunosuppressive treatment improves these patients' outcomes. Further studies are needed to determine the positive predictive value of antineuronal antibody detection and to develop further treatment options under randomized and controlled conditions.

Single‐center study of autoimmune encephalitis‐related autoantibody testing in Hungary

“…However, in some anti‐LGI1 antibody‐positive patients, autoantibodies can be found only in serum or only in CSF (Table ) (Dalmau & Graus, ). It has been reported previously that detection of the characteristic autoantibodies in clinically suspected AIE could serve as confirmatory diagnosis, and in case of anti‐NMDAR encephalitis, testing of CSF can be used to monitor disease activity, and autoantibody levels often correlate with patient outcome and relapse rates (Lee & Lee, ; Wandinger, Leypoldt, & Junker, ). The highest sensitivity and specificity of the tests can be achieved by testing both serum and CSF.…”

Autoimmune Enzephalitiden – diagnostischer und therapeutischer Entscheidungsbaum aus psychiatrischer, neurologischer und ethisch-juristischer Sicht

“…Für Unsicherheit sorgen immer wieder Antikörpertiter isoliert nur im Serum, da diese auch beiBlutspenderngefundenwerden [4]. In solchen Fällen wird ein Bestätigungstest auf Hirnschnitten oder lebenden Neuronen empfohlen [8,25].…”

“…Als Therapien der ersten Wahl kommen Steroide, intravenöse Immunglobuline oder die therapeutische Apherese (Plasmapherese oder Immunadsorption) frage. Der frühe Beginn einer Immuntherapie ist mit einem besseren Outcome assoziiert, weshalb etliche Autoren bereits nach 10 bis 14 Tagen eine Eskalation der Immuntherapie empfehlen [24,25]. Bei der NMDAR-Enzephalitis und den meisten anderen neuen antikörpervermittelten Enzephalitiden wird Rituximab empfohlen (2 × 1000 mg im Abstand von 14 Tagen, ggf.…”

“…Da diese nicht so leicht zu finden sind, wäre es sinnvoll, den Richtern einige Adressen von AIE-Experten zur Verfügung zu stellen. Des Weiteren sollten Ärzte den Richtern die wichtigsten Leitlinien, Konsenspapiere und Übersichtsarbeiten zur Verfügung stellen [7,8,16,17,21,25].…”

Diagnostische Kriterien und Diagnose der Demenz vom Alzheimer-Typ

“…Es liegen verschiedene mehr oder weniger validierte visuelle Skalen vor, die kürzlich evaluiert wurden [14]. Wir verwenden in unserer Memory-Clinic die "Scheltens-Skala" [15] in Zusammenhang mit einem systematischen Vorgehen in Anlehnung an einen publizierten Algorithmus [16] (es muss erwähnt werden, dass dieser nicht für cCT validiert ist.). Man erreicht eine Interraterreliabilität von 0,72-0,84 und eine Intraraterreliabilität von 0,83-0,94 [14].…”