Clinical characteristics and outcome of patients with autoimmune encephalitis: clues for paraneoplastic aetiology

Abstract

Background and purpose Autoimmune encephalitis (AE) represents a complex syndrome with diverse clinical manifestations and therapeutic outcomes. The aim of this study was to report the clinical characteristics and the long‐term outcome of patients with paraneoplastic and idiopathic AE. Methods All patients with subacute encephalopathy admitted to the Neurology Department of our Institution from January 2012 to May 2019 were consecutively enrolled. Patients’ serum and cerebrospinal fluid were tested for neural‐specific autoantibodies by indirect immunofluorescence assays on mouse brain, rat neurons, cell‐based assays and immunoblots. Outcome was assessed by the modified Rankin Scale score. Results From 107 adult patients with subacute encephalopathy, 50 patients were finally diagnosed with AE. Neural antibodies (Abs) were detected in 45/50 patients (90%). Leucine‐rich glioma‐inactivated protein 1 immunoglobulin G was the most frequent (6/50, 12%) Ab specific to neural surface antigens detected in adults with AE. Paraneoplastic encephalitis was diagnosed in 16/50 patients (32%). The presence of bilateral temporal lobe lesions on magnetic resonance imaging and cerebrospinal fluid restricted oligoclonal bands was associated with a higher probability to detect cancer at the time of AE diagnosis. All patients with Abs to neural surface antigens had a good outcome at last follow‐up. Severe disability at AE onset and the lack of long‐term immunosuppression predicted a poor outcome. Conclusions Leucine‐rich glioma‐inactivated protein 1 immunoglobulin G was the most frequent Ab detected. Patients with bilateral temporal lobe lesions and oligoclonal bands have a higher probability to harbour an occult tumour. In these patients, a strict surveillance and monitoring for cancer detection is recommended.

Isolated Memory Loss in Anti-NMDAR Encephalitis

“…Early diagnosis and the prompt initiation of appropriate immunotherapy are critical for patients' outcome. 5 Of interest, PET imaging showed hypometabolism of the right temporal lobe and the cerebellar hemispheres. The patient did not have any signs or symptoms of cerebellar dysfunction, but the PET imaging findings suggest a possible cerebellar involvement.…”

Clinical features and outcome of patients with autoimmune cerebellar ataxia evaluated with the Scale for the Assessment and Rating of Ataxia

“…Despite the extensive autoantibody testing performed, IgG binding to unclassified neural antigens was detected in one third of the cases, suggesting that in patients with suspected PCS or idiopathic ACA with negative results on first‐line neural antibody testing, IFA on mouse or rat brain may significantly improve the diagnosis, as has been recently shown in autoimmune encephalitis [15,22]. Importantly, this finding justified immunotherapy administration, with a trend toward a good response in six of seven patients, all presenting with idiopathic ACA (data not shown).…”

“…Serum and/or CSF was first evaluated for the presence of neural autoantibodies by an indirect immunofluorescence assay (IFA) on a composite substrate of frozen sections of mouse brain, kidney, and stomach (serum 1:100, CSF 1:2 dilution), using previously described techniques [15]. Samples with a specific intracellular pattern at IFA were then tested for intracellular antigens (Hu, Yo, Ri, CRMP5, amphiphysin, Ma2, Tr) by blots.…”

Neural autoantibodies and autoimmune encephalitis – the conjunction of both counts

“…Nevertheless, human curiosity will keep looking for unusual manifestations and antibody correlations, and such studies may inform us about broader conditions. One has the greatest prognostic and therapeutic success by identifying appropriate clinical syndromes [8] in conjunction with specific corresponding antibodies as in the recent study by Iorio et al [7]. (e-mail: christian.bien@gmx.de)…”

“…In this issue, a group of neurologists and laboratory researchers have studied 107 consecutive patients with an appropriate clinical presentation, subacute complex encephalopathy, for serum and cerebrospinal fluid autoantibodies by sensibly chosen and appropriately interpreted antibody tests [7]. Among 107 adults, 50 fulfilled the criteria of autoimmune encephalitis [8].…”