Spontaneous recovery of memory functions in an untreated case of anti NMDAR encephalitis - a reason to maintain hope

Multicenter experience with Efgartigimod in the treatment of anti-NMDAR encephalitis compared with IVIG and SPA-IA during acute attacks

OBJECTIVES

The purpose of this study was to evaluate the efficacy of Efgartigimod (EFG) in anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis patients during acute attacks.

METHODS

A case-control study was designed to compare 26 anti-NMDAR encephalitis patients who were treated with EFG, and 15 patients with intravenous immunoglobulin (IVIG), and 23 patients with immunoadsorption with staphylococcal protein A column (SPA-IA) treatment.

RESULTS

At baseline, no significant differences in mRS scores were observed among the EFG, IVIG, and SPA-IA groups of anti-NMDAR encephalitis patients. When compared with the IVIG group, patients treated with EFG had significantly decreased serum IgG levels. Compared with the SPA-IA group, EFG-treated patients had lower CSF anti-NMDAR antibody titers at admission (p = 0.039) and higher post-treatment IgG levels (p = 0.002). When compared with the IVIG group, SPA-IA patients had higher CASE scores (p = 0.022) and baseline IgG levels (p = 0.023). All groups improved the symptoms of anti-NMDAR encephalitis patients after treatment during acute attacks, with significant decreases in mRS and CASE scores from admission to discharge (p < 0.01). In the EFG and SPA-IA groups, there was a significant reduction in anti-NMDAR antibody titers in both CSF and serum (p < 0.01), while no remarkable decrease was found in the IVIG group. Additionally, serum IgG levels significantly decreased in both the EFG and SPA-IA groups post treatment and during the 1-month follow-up. By the 3-month of follow-up, IgG levels in the blood of both groups remained below the baseline levels.

CONCLUSION

EFG could be an elegant alternative to both IVIG and SPA-IA therapies for anti-NMDAR encephalitis during acute attacks. It has a better effect on reducing antibody titers than IVIG and is comparable to SPA-IA therapy, and no serious adverse events were observed during infusion.

Case Report: Daratumumab in a Patient With Severe Refractory Anti-NMDA Receptor Encephalitis

Anti-NMDA receptor encephalitis is the most common type of antibody mediated autoimmune encephalitis (AIE). Patients often develop neuropsychiatric symptoms and seizures, women are affected about four times more than men, and in about 50% the disease is associated with a neoplasia, especially teratomas of the ovary. We describe the case of a 20-year-old woman suffering from a severe therapy refractory course of anti-NMDA receptor encephalitis. Treatment included glucocorticoids, plasma exchange, intravenous immunoglobulins, rituximab, and bortezomib without clinical improvement. Due to a therapy refractive course 28 weeks after disease onset, the patient received 10 cycles of daratumumab. Therapy escalation was performed with the anti-CD38 monoclonal antibody daratumumab as off label treatment, based on the therapy of refractory myeloma and led to an improvement of her clinical status. She spent about 200 days on the intensive care unit, followed by several weeks on the intermediate care unit with close follow ups every 4–6 weeks afterward. During follow-up, the patient was able to resume everyday and self-care activities, reflected by the modified Rankin scale (mRS) and Barthel index. Because this disease is potentially life threatening and can lead to irreversible brain atrophy, development of further therapy strategies are of great importance. Our case describes a successful treatment for therapy refractory anti-NMDA receptor encephalitis using the anti-CD38 antibody daratumumab.

A case of reversible anti-NMDA-receptor encephalitis: neuropsychological and neuroradiological features

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune encephalitis mainly affecting young women. We report a case of a mild paraneoplastic anti-NMDAR encephalitis in a 31-year-old female with an ovarian immature teratoma. The patient exhibited a severe short-term episodic memory impairment and psychiatric symptoms. A detailed diagnostic work-up including complete clinical and laboratory examinations, neuropsychological assessments, and neuroradiological investigations has been done at the onset and during follow-up. The amnestic syndrome and MRI medial-temporal abnormalities reversed after medical and surgical treatment. The present report indicates that the disease can be rapidly reversible if promptly diagnosed and treated. While the disease has already been described elsewhere, the course of neurospychological deficits in adults is not as much known. Usually, when the diagnosis of anti-NMDAR encephalitis is made, the severity of the disease makes the assessment of the neuropsycological profile particulary challenging. The present report is of interest because it describes the complete neuropsychological profile of a mild form of anti-NMDAR encephalitis.

Synaptic and Neuronal Autoantibody-Associated Psychiatric Syndromes: Controversies and Hypotheses

Autoimmune encephalitis (AE) mediated by antibodies against synaptic and neuronal surface targets frequently presents with a psychiatric syndrome. In these patients, removal of autoantibodies treats the disease and outcomes are closely linked to early intervention. The discovery of these autoantibodies in isolated psychiatric syndromes has raised the possibility that these patients may derive similar benefits from immunotherapy, a potentially transformational approach to the treatment of mental illness. Although open-label case series suggest impressive therapeutic outcomes, the pathological relevance of these autoantibodies outside of canonical presentations is debated. The advent of diagnostic criteria for AE attempts to facilitate its prompt identification but risks prematurely neglecting the potential scientific and clinical significance of isolated syndromes that do not satisfy these criteria. Here, we propose using a syndrome-level taxonomy that has occasional, but not necessary, overlap with AE: synaptic and neuronal autoantibody-associated psychiatric syndromes or "SNAps". This will prevent confusion with AE and act heuristically to promote active investigation into this rare example of psychopathology defined on a molecular level. We suggest that this concept would have application in other autoantibody-associated syndromes including seizure, cognitive, and movement disorders, in which similar issues arise. We review putative direct and indirect mechanisms and outline experimentally testable hypotheses that would help to determine prospectively in whom autoantibody detection is relevant, and as important, in whom it is not. We summarize a pragmatic approach to autoantibody testing and management in severe mental illness in order to promptly diagnose AE and advocate a research-orientated experimental medicine paradigm for SNAps, where there is greater equipoise. We conclude that SNAps remains a nascent area of clinical neuroscience with great potential and in ongoing need of psychiatry-led basic and clinical research.