Autoimmune dementia and encephalopathy

Overview of Paraneoplastic Autoantibody-Mediated Cognitive Impairment and Behavioral Changes: A Narrative Review

Cognitive dysfunction and behavioral change can be some of the manifestations of cancer, occurring as a part of paraneoplastic neurological syndrome, most commonly in small cell lung cancer. Paraneoplastic limbic encephalitis is the leading cause of cognitive disturbance and abnormal behavior in paraneoplastic syndromes, which is usually autoantibody-mediated. Autoantibodies are the main contributors to the development of cognitive dysfunction and behavioral change in cancer patients, with studies suggesting a higher liability for antibody-positive cancer patients to be affected. Anti-NMDAR and anti-AMPAR are antibodies targeted against surface antigens, manifesting predominantly as memory disturbance, abnormal behavior, psychiatric symptoms, and seizures. Other surface antigen-targeted antibodies include anti-GABA, anti-CASPR2, and anti-LGI1, which were shown to have cognitive function impairment and abnormal behavior as some of the main presentations, predominantly affecting memory. Cognitive deterioration and changes in behavior were also relatively common with some of the intracellular antigen-targeted antibodies, including anti-Hu, anti-SOX1, anti-PCA2, and anti-Zic2. Affected behavior and cognition, however, were reported less commonly in other paraneoplastic antibodies against intracellular antigens (anti-Yo, anti-GAD, anti-Ma2, anti-Ri, anti-CV2, and anti-KLHL11). Our article will provide a comprehensive review of the clinical manifestations of cognitive impairment and behavioral changes among cancer patients who develop paraneoplastic syndrome. Additionally, this review will discuss the role of specific paraneoplastic autoantibodies and the clinical spectrum linked to each separately.

Dementia in a patient with autoimmune disease and hypercoagulable state worsened by COVID-19 vaccination: A case report

Background

Systemic autoimmune disorders are associated with an increased risk of hypercoagulability. The hypercoagulable state in people with systemic autoimmune disorders has lately gained attention.

Presentation of case

We presented a 44-year-old male with a chief complaint of progressive difficulty concentrating, memory impairment, and weakness in all limbs. Seven months before admission to our Memory Clinic, the patient began to have infrequent short-term memory loss and sometimes got lost when he went for a drive. Three months later, he complained of feeling dizzy when in a crowd, being unable to watch television for a long time, and easily forgetting. Computed tomography (CT) scan showed brain infarction. After receiving the first dose of COVID-19 vaccine (Sinovac), the patient had difficulty communicating verbally and could only point at objects, as well as tetraparesis. These conditions severely intervened in his daily activities. The patient was then referred to an immunologist and diagnosed with autoimmune disease. In our Memory Clinic, his performances of attention, memory, language, visuospatial, and executive function were very poor. We diagnosed him with autoimmune dementia. The administration of methylprednisolone, mycophenolate mofetil, vitamin D3, donepezil, and memantine could improve his condition.

Discussion

Autoimmune disease can cause microvascular thrombosis and microembolism at the central nervous system level, which would cause vascular damage and cognitive impairment leading to brain infarction and dementia.

Conclusion

There seems to be a link between autoimmune disease, hypercoagulable state, and dementia, although the magnitude of this link and the underlying processes are not fully understood.

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Systemic autoimmune disorders are associated with an increased risk of hypercoagulability.

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Autoimmune diseases may develop cognitive impairment and vascular damage.

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Autoimmune disease can lead to brain infarction and dementia.

Rapidly Progressive Dementia

PURPOSE OF REVIEW

This article presents a practical approach to the evaluation of patients with rapidly progressive dementia.

RECENT FINDINGS

The approach presented in this article builds upon the standard dementia evaluation, leveraging widely available tests and emergent specific markers of disease to narrow the differential diagnosis and determine the cause(s) of rapid progressive decline. The discovery of treatment-responsive causes of rapidly progressive dementia underscores the need to determine the cause early in the symptomatic course when treatments are most likely to halt or reverse cognitive decline.

SUMMARY

A pragmatic and organized approach to patients with rapidly progressive dementia is essential to mitigate diagnostic and therapeutic challenges and optimize patient outcomes.

Retrospective Observational Study of Daytime Add-On Administration of Zopiclone to Difficult-to-Treat Psychiatric Inpatients With Unpredictable Aggressive Behavior, With or Without EEG Dysrhythmia

Managing violent behavior is a particularly challenging aspect of hospital psychiatric care. Available pharmacological interventions are often unsatisfactory. Aim: To assess the effectiveness and safety of daytime zopiclone add-on administration in violent and difficult-to-treat psychiatric inpatients. Methods: Chart review of inpatients treated with daytime zopiclone, between 2014 and 2018, with up to 12 weeks follow-up. Effectiveness was retrospectively assessed with the Clinical Global Impression rating scale (CGI) and the frequency and severity of aggressive incidents recorded with the Staff Observation Aggression Scale-Revised (SOAS-R). Results: Forty-five (30 male, 15 female) cases, 18-69 years age range, average (SD) baseline CGI-S score of 5.4 (1.0), and a variety of diagnoses. Sixty-nine percent showed CGI-S improvement of any degree. For patients with at least one aggressive incident within 7 days prior to initiation of zopiclone (N = 22), average (SD) SOAS-R-Severity LOCF to baseline change was -3.5 (2.7) P < 0.0001. Most patients reported no side effects; 24% reported one or more side effects, and 11% discontinued zopiclone due to sedation (4), insomnia (1) or slurred speech (1). No SAEs were recorded. Zopiclone maximum daily dose correlated with CGI-S baseline-to-LOCF change (rho = -0.5, P = 0.0003). The ROC AUC of zopiclone maximum daily dose and improvement on CGI-S was 0.84 (95% CI 0.70-0.93, P < 0.0001). The ROC AUC of zopiclone maximum daily dose and SOAS-R-N improvement was 0.80 (95% CI 0.58-0.92; P = 0.0008) and maximum Youden's index value was achieved at a dose of >30 mg. Conclusions: Zopiclone doses >30 mg daily achieved the best anti-aggressive effect.

Randomized Clinical Trial Examining the Impact of Lactobacillus rhamnosus GG Probiotic Supplementation on Cognitive Functioning in Middle-aged and Older Adults

PURPOSE

The gut microbiome has been linked to cognitive function and appears to worsen with aging. Probiotic supplementation has been found to improve the health of the gut microbiome. As such, it is possible that probiotic supplementation may protect the aging brain. The current study examined the cognitive benefits of probiotic supplementation (Lactobacillus rhamnosus GG) in healthy middle-aged and older adults.

MATERIALS AND METHODS

The study was a double-blind, placebo-controlled, randomized clinical trial. Two hundred community-dwelling adults aged 52-75 were enrolled (mean age=64.3, SD=5.52). A three-month intervention involved daily consumption of probiotic or placebo. Independent sample t-tests, chi-squared tests, and repeated measure ANOVAs compared groups and examined changes over time. Primary outcome was change in NIH Toolbox Total Cognition Score from baseline to follow-up.

RESULTS

A total of 145 participants were examined in primary analyses (probiotic=77, placebo=68) and excluded persons due to discontinuation, low adherence, missing data, or outlier values. Established criteria (ie ≥1 subtest t-scores ≤35; n=19, n=23) were used to operationally define cognitive impairment. Repeated measures ANOVAs revealed that persons with cognitive impairment who consumed probiotics exhibited a greater total cognition score improvement than persons with cognitive impairment in the placebo group and cognitively intact persons in probiotic or placebo groups.

CONCLUSION

Lactobacillus rhamnosus GG probiotic supplementation was associated with improved cognitive performance in middle-aged and older adults with cognitive impairment. Probiotic supplementation may be a novel method for protecting cognitive health in aging.

Cognitive impact of neuronal antibodies: encephalitis and beyond

Cognitive dysfunction is a common feature of autoimmune encephalitis. Pathogenic neuronal surface antibodies are thought to mediate distinct profiles of cognitive impairment in both the acute and chronic phases of encephalitis. In this review, we describe the cognitive impairment associated with each antibody-mediated syndrome and, using evidence from imaging and animal studies, examine how the nature of the impairment relates to the underlying neuroimmunological and receptor-based mechanisms. Neuronal surface antibodies, particularly serum NMDA receptor antibodies, are also found outside of encephalitis although the clinical significance of this has yet to be fully determined. We discuss evidence highlighting their prevalence, and association with cognitive outcomes, in a number of common disorders including cancer and schizophrenia. We consider mechanisms, including blood-brain barrier dysfunction, which could determine the impact of these antibodies outside encephalitis and account for much of the clinical heterogeneity observed.

Apheresis in Autoimmune Encephalitis and Autoimmune Dementia

Autoimmune encephalitis (AE) is a rapidly progressive inflammatory neurological disease. Underlying autoantibodies can bind to neuronal surfaces and synaptic proteins resulting in psychiatric symptoms, focal neurological signs, autonomic dysfunction and cognitive decline. Early and effective treatment is mandatory to reduce clinical symptoms and to achieve remission. Therapeutic apheresis, involving both plasma exchange (PE) and immunoadsorption (IA), can rapidly remove pathogenic antibodies from the circulation, thus representing an important first-line treatment in AE patients. We here review the most relevant studies regarding therapeutic apheresis in AE, summarizing the outcome for patients and the expanding clinical spectrum of treatment-responsive clinical conditions. For example, patients with slowly progressing cognitive impairment suggesting a neurodegenerative dementia can have underlying autoantibodies and improve with therapeutic apheresis. Findings are encouraging and have led to the first ongoing clinical studies assessing the therapeutic effect of IA in patients with anti-neuronal autoantibodies and the clinical presentation of dementia. Therapeutic apheresis is an established and well tolerated option for first-line therapy in AE and, potentially, other antibody-mediated central nervous system diseases.

Neuronal surface autoantibodies in dementia: a systematic review and meta-analysis

INTRODUCTION

Neuronal antibodies can cause encephalopathy syndromes often presenting with subacute cognitive impairment, sometimes resembling neurodegenerative dementias.

METHODS

We searched Medline and Embase for studies reporting associations between neuronal surface antibodies in all-cause dementia versus controls. Random-effects meta-analysis was used to pool adjusted estimates across studies.

RESULTS

Six studies were included, all reporting frequency of serum NMDAR antibodies in dementia with four also reporting frequency in atypical dementias. Both IgG [OR = 8.09 (1.51; 56.85), p = 0.036] and IgA/IgM NMDAR antibodies [OR = 42.48 (11.39; 158.52), p < 0.001] were associated with atypical dementia, but neither were associated with all-cause dementia.

DISCUSSION

In the first meta-analysis to explore this literature, serum IgG and IgA/IgM NMDAR antibodies were significantly more common in atypical dementias. However, methodological issues and small-sample sizes necessitate caution interpreting this result. Further studies measuring both serum and CSF antibodies are needed to investigate the role of neuronal antibodies in dementia, since evidence of pathogenicity in even a subset of patients could pave the way for novel treatment options.

Diagnosis and Management of Autoimmune Dementia

PURPOSE OF REVIEW

To describe the clinical, laboratory, and MRI features that characterize cognitive decline in the setting of central nervous system (CNS) autoimmunity, and provide an overview of current treatment modalities.

RECENT FINDINGS

The field of autoimmune neurology is rapidly expanding due to the increasing number of newly discovered autoantibodies directed against specific CNS targets. The clinical syndromes associated with these autoantibodies are heterogeneous but frequently share common, recognizable clinical, and MRI characteristics. While the detection of certain autoantibodies strongly suggest the presence of an underlying malignancy (onconeural autoantibodies), a large proportion of cases remain idiopathic. Cognitive decline and encephalopathy are common manifestations of CNS autoimmunity, and can mimic neurodegenerative disorders. Recent findings suggest that the frequency of autoimmune encephalitis in the population is higher than previously thought, and potentially rivals that of infectious encephalitis. Moreover, emerging clinical scenarios that may predispose to CNS autoimmunity are increasingly been recognized. These include autoimmune dementia/encephalitis post-herpes simplex virus encephalitis, post-transplant and in association with immune checkpoint inhibitor treatment of cancer. Early recognition of autoimmune cognitive impairment is important given the potential for reversibility and disability prevention with appropriate treatment. Autoimmune cognitive impairment is treatable and may arise in a number of different clinical settings, with important treatment implications. Several clinical and para-clinical clues may help to differentiate these disorders from dementia of other etiologies.

Behavioral, Psychiatric, and Cognitive Adverse Events in Older Persons Treated with Glucocorticoids

Background: Since the introduction of glucocorticoids (GCs) in the physician's pharmacological arsenal, it has been known that they are a cause of behavioral or psychiatric adverse events (BPAE), as well as of cognitive problems. To the best of our knowledge, the relationship between these adverse events and GCs in older persons has never been evaluated, except through case-reports or series with few cases. In this paper, a review of the literature regarding BPAEs and cognitive disorders in older people treated with CSs is undertaken. Methods: A comprehensive literature search for BPAEs was carried out on the three main bibliographic databases: EMBASE, MEDLINE and PsycINFO (NICE HDAS interface). Emtree terms were: Steroid, steroid therapy, mental disease, mania, delirium, agitation, depression, behavior change, dementia, major cognitive impairment, elderly. The search was restricted to all clinical studies and case reports with focus on the aged (65+ years) published in any language since 1998. Results: Data on the prevalence of the various BPAEs in older patients treated with GCs were very scarse, consisting mainly of case reports and of series with small numbers of patients. It was hence not possible to perform any statistical evaluation of the data (including meta-analysis). Amongst BPAEs, he possibility that delirium can be induced by GCs has been recently been questioned. Co-morbidities and polypharmacy were additional risk factors for BPAEs in older persons. Conclusions: Data on BPAEs in older persons treated with GCs, have several unmet needs that need to be further evaluated with appropriately designed studies.

Neuroimaging in Dementia

Although the diagnosis of dementia still is primarily based on clinical criteria, neuroimaging is playing an increasingly important role. This is in large part due to advances in techniques that can assist with discriminating between different syndromes. Magnetic resonance imaging remains at the core of differential diagnosis, with specific patterns of cortical and subcortical changes having diagnostic significance. Recent developments in molecular PET imaging techniques have opened the door for not only antemortem but early, even preclinical, diagnosis of underlying pathology. This is vital, as treatment trials are underway for pharmacological agents with specific molecular targets, and numerous failed trials suggest that earlier treatment is needed. This article provides an overview of classic neuroimaging findings as well as new and cutting-edge research techniques that assist with clinical diagnosis of a range of dementia syndromes, with an emphasis on studies using pathologically proven cases.