Autoimmune Encephalitis-Misdiagnosis, Misconceptions, and How to Avoid Them

Encephalitis associated with anti-mGluR5 antibodies

A 30-year-old woman had 5 days of visual hallucinations, nystagmus, memory impairment and mutism. On examination, she was disorientated with reduced attention span, gaze-evoked nystagmus, paratonia and abnormal frontal reflexes. Cerebrospinal fluid (CSF) showed 80 cells, protein 0.41 g/L and glucose 3.2 mmol/L (plasma glucose 5.0 mmol/L). MR scan of the brain showed involvement of limbic and extra-limbic regions and brainstem. Commercial cell-based assays were negative, but tissue-based assays showed neuropil staining, and cell-based assays for anti-metabotropic glutamate receptor 5 (mGluR5) antibodies were positive in serum and CSF. Six months later, she was diagnosed with Hodgkin's lymphoma. This case emphasises the broader clinical spectrum of anti-mGluR5 encephalitis, challenging its initial characterisation as Ophelia syndrome. It underscores the significance of interpreting commercial cell-based assays and advocates for tissue-based assay testing followed by cell-based assay testing in serum and CSF for diagnosing rare autoimmune encephalitis.

Reversible dementia and insomnia in ABGA related encephalitis

BACKGROUND

ABGAs are historically associated with Encephalitis Lethargica (EL). Typically ABGAs are also found in children resulting in a variety of neuropsychiatric and extrapyramidal disorders, rare cases are reported in adults with atypical movement disorders. No description of basal ganglia reversible lesions related to ABGAs are reported and these antibodies are not included in the list of autoimmune encephalitis.

METHODS AND RESULTS

A 55 years old female presented sub-acute onset of an anxious-depressive disorder and obsessive-compulsive behavior associated with intractable insomnia affecting sleep onset and sleep maintenance. Brain-MRI showed diffuse hyperintensities on FLAIR sequences in the basal ganglia. A therapy with IV-immunoglobulin was started and the clinical condition improved dramatically and insomnia and psychiatric symptoms resolved completely.

CONCLUSION

Our case highlights the importance of making a fast diagnosis. When caught early ABGAs-related encephalitis is susceptible of a good outcome and response to treatment. Reversible insomnia and dementia in our case expand ABGA clinical presentation in adults and favors the hypothesis of an immune pathogenesis for Encephalitis Lethargica, especially in the hyperkinetic form as previously suggested, as in our case.

Misdiagnosis Diagnosis of Pneumocystis Pneumonia as Chemical Pneumonitis

Background

Auxiliaries, a mixed chemicals, for printing and dyeing characterized by their diverse range and complex chemical compositions are commonly utilized in the textile industry. These chemicals can lead to environmental contamination and pose health risks to humans.

Case Description

A 29-year-old man who worked in a printing and dyeing factory in Suzhou, China, reported having tightness in his chest and coughing. Despite seeking medical treatment at several hospitals, the initial diagnosis remained elusive. High-resolution chest CT scans showed multifocal lesions in both lungs. The patient had no significant medical history, and the respiratory symptoms only surfaced after exposure to dyeing auxiliaries. Physicians initially suspected chemical pneumonitis due to occupational exposure. However, a subsequent evaluation at a hospital specializing in occupational diseases led to a diagnosis of AIDS and pneumocystis pneumonia.

Conclusion

This case underscores the importance of comprehensive clinical diagnosis to avoid biases and reduce the incidence of misdiagnosis.

Genetic causes of infection induced encephalitis

INTRODUCTION

Patients with encephalitis following a viral infection are often thought to have a para infectious, inflammatory, or autoimmune cause for their presentation. These diagnoses usually result in treatments with immunosuppressant therapies which can have side effects. However, there is an increasing body of evidence demonstrating that patients can have a direct genetic cause mediating viral infection triggered encephalitis, where inflammation is a secondary response. These patients may benefit not from immunosuppressive therapies, but from protection from infection through dedicated immunisation programs and early antiviral therapies at times of infection.

METHODS

A small case series of paediatric neurology patients (n = 2) from a single institution with infection induced encephalitis and an underlying genetic cause, is presented. Patients with a confirmed genetic cause of infection induced encephalitis were identified and consented by their treating neurologist for inclusion in this case series. Ethics approval was gained for this case series and review of the surrounding literature.

CONCLUSION

A case of both DBR1 and NUP214 genetic changes resulting in infection induced encephalitis is presented. This case series raises awareness of this rare group of disorders and provides clues to their identification. Features to prompt clinician consideration of such genetic conditions are also highlighted. Although rare, identification of these patients is important due to implications on treatment, prognosis, and family planning.

Case report: Successful treatment of an anti-D2R and DPPX antibody-associated autoimmune encephalitis patient with high-dose methylprednisolone and intravenous immunoglobulin

Background

Autoimmune encephalitis is a neurological condition caused by abnormal immune responses, manifesting as cognitive impairments, behavioral abnormalities, and seizures. Its diagnosis depends on the detecting neuronal surface antibodies in serum or cerebrospinal fluid. Despite recent advances in understanding, clinical recognition remains challenging, especially with rare antibodies such as anti-dopamine D2 receptor (D2R) and anti-dipeptidyl-peptidase-like protein 6 (DPPX) antibodies. Delayed diagnosis can lead to severe complications. This case presentation emphasizes the diagnostic intricacies and effective treatment of the anti-D2R and DPPX antibody-associated autoimmune encephalitis.

Case description

The patient presented with a 3-day history of fatigue and limb soreness followed by a 3-h episode of confusion and limb convulsions. Upon admission to our facility, the initial diagnosis included status epilepticus, aspiration pneumonia, metabolic acidosis, respiratory alkalosis, and suspected encephalitis. Despite receiving antiepileptic, anti-infection, and antivirus therapy, the patient's condition deteriorated. Both computed tomography (CT) scan and magnetic resonance imaging (MRI) of the brain showed no significant abnormalities. No pathogen was identified in the cerebrospinal fluid (CSF). However, further CSF and serum examination revealed positive results of anti-D2R and anti-DPPX antibodies, confirming a diagnosis of anti-D2R and DPPX antibody-associated autoimmune encephalitis. The patient underwent a comprehensive treatment regimen, including high-dose methylprednisolone pulse therapy combined with intravenous immunoglobulin (IVIG), antiviral and anti-infection treatments, and antiepileptic medications. Significant clinical improvement was observed, and by the 18th day of admission, the patient was stable and coherent.

Conclusions

The current patient represents the first reported case of double-positive autoimmune encephalitis for anti-D2R and DPPX antibodies, with epilepsy as a prominent feature. High-dose methylprednisolone pulse therapy combined with IVIG has shown significant safety and efficacy in treating anti-D2R and DPPX antibody-positive autoimmune encephalitis-associated epilepsy.

Do vaccines cause epilepsy? Review of cases in the National Vaccine Injury Compensation Program

OBJECTIVE

The National Childhood Vaccine Injury Act of 1986 created the National Vaccine Injury Compensation Program (VICP), a no-fault alternative to the traditional tort system. Since 1988, the total compensation paid exceeds $5 billion. Although epilepsy is one of the leading reasons for filing a claim, there has been no review of the process and validity of the legal outcomes given current medical information. The objectives were to review the evolution of the VICP program in regard to vaccine-related epilepsy and assess the rationale behind decisions made by the court.

METHODS

Publicly available cases involving epilepsy claims in the VICP were searched through Westlaw and the US Court of Federal Claims websites. All published reports were reviewed for petitioner's theories supporting vaccine-induced epilepsy, respondent's counterarguments, the final decision regarding compensation, and the rationale underlying these decisions. The primary goal was to determine which factors went into decisions regarding whether vaccines caused epilepsy.

RESULTS

Since the first epilepsy case in 1989, there have been many changes in the program, including the removal of residual seizure disorder as a vaccine-related injury, publication of the Althen prongs, release of the acellular form of pertussis, and recognition that in genetic conditions the underlying genetic abnormality rather than the immunization causes epilepsy. We identified 532 unique cases with epilepsy: 105 with infantile spasms and 427 with epilepsy without infantile spasms. The petitioners' experts often espoused outdated, erroneous causation theories that lacked an acceptable medical or scientific foundation and were frequently criticized by the court.

SIGNIFICANCE

Despite the lack of epidemiological or mechanistic evidence indicating that childhood vaccines covered by the VICP result in or aggravate epilepsy, these cases continue to be adjudicated. After 35 years of intense litigation, it is time to reconsider whether epilepsy should continue to be a compensable vaccine-induced injury.

Special Issue: Immune-Mediated Neurological Disorders

For a long time, the immune system has been considered responsible for only a minority of neurological conditions involving the central and peripheral nervous system (CNS, PNS), respectively, namely multiple sclerosis and myasthenia gravis (with myastheniform syndromes) [...].

Mimics of Autoimmune Encephalitis: Validation of the 2016 Clinical Autoimmune Encephalitis Criteria

BACKGROUND AND OBJECTIVES

The clinical criteria for autoimmune encephalitis (AE) were proposed by Graus et al. in 2016. In this study, the AE criteria were validated in the real world, and common AE mimics were described. In addition, criteria for probable anti-LGI1 encephalitis were proposed and validated.

METHODS

In this retrospective cohort study, patients referred to our national referral center with suspicion of AE and specific neuroinflammatory disorders with similar clinical presentations were included from July 2016 to December 2019. Exclusion criteria were pure cerebellar or peripheral nerve system disorders. All patients were evaluated according to the AE criteria.

RESULTS

In total, 239 patients were included (56% female; median age 42 years, range 1-85). AE was diagnosed in 104 patients (44%) and AE mimics in 109 patients (46%). The most common AE mimics and misdiagnoses were neuroinflammatory CNS disorders (26%), psychiatric disorders (19%), epilepsy with a noninflammatory cause (13%), CNS infections (7%), neurodegenerative diseases (7%), and CNS neoplasms (6%). Common confounding factors were mesiotemporal lesions on brain MRI (17%) and false-positive antibodies in serum (12%). Additional mesiotemporal features (involvement extralimbic structures, enhancement, diffusion restriction) were observed more frequently in AE mimics compared with AE (61% vs 24%; p = 0.005). AE criteria showed the following sensitivity and specificity: possible AE, 83% (95% CI 74-89) and 27% (95% CI 20-36); definite autoimmune limbic encephalitis (LE), 10% (95% CI 5-17) and 98% (95% CI 94-100); and probable anti-NMDAR encephalitis, 50% (95% CI 26-74) and 96% (95% CI 92-98), respectively. Specificity of the criteria for probable seronegative AE was 99% (95% CI 96-100). The newly proposed criteria for probable anti-LGI1 encephalitis showed a sensitivity of 66% (95% CI 47-81) and specificity of 96% (95% CI 93-98).

DISCUSSION

AE mimics occur frequently. Common pitfalls in AE misdiagnosis are mesiotemporal lesions (predominantly with atypical features) and false-positive serum antibodies. As expected, the specificity of the criteria for possible AE is low because these criteria represent the minimal requirements for entry in the diagnostic algorithm for AE. Criteria for probable AE (-LGI1, -NMDAR, seronegative) and definite autoimmune LE are applicable for decisions on immunotherapy in early disease stage, as specificity is high.

Long-term outcomes and health-related quality of life in patients with autoimmune encephalitis: An observational study

Autoimmune encephalitis (AE) subacutely causes severe and multiple symptoms; however, most patients achieve neurologically favorable outcomes. Despite the substantial recovery in motor function, persistent impairments in mental/social aspects lasting for several years have been recognized, and its potential effect on health-related quality of life (HRQOL) has been argued. To urgently evaluate the long-term effects of AE on patients' HRQOL, we investigated patient-oriented long-term outcomes and assessed the HRQOL of patients with AE. Data of patients who were diagnosed with probable/definite AE, defined by Graus AE criteria 2016, and treated at our hospital between January 2011 and October 2020 were retrospectively retrieved. Their long-term (≥2 years) outcomes, which included various sequelae and handicaps in social activities such as returning to previous work/school life through structured interview forms, were evaluated, and the HRQOL was assessed using Neuro-QOL battery. We identified 32 patients who met the Graus AE criteria 2016 and eventually enrolled 21 patients in the study. The median interval between disease onset and survey period was 63 (25-156) months, and 43% of the patients had persistent neuropsychiatric symptoms, including memory disorders, personality changes, and seizures. No more than 71% returned to their previous work/school life. Although most of the patients had global QOL within normal limits, 48% had social QOL under normal limits. Patients with sequelae were significantly less likely to return to previous work/school and had worse global/social quality of life than patients without sequelae. In conclusion, nearly half of patients with AE had social QOL under normal limits 5 years after onset. The difficulty in returning to work/school and a worse HRQOL were notable in patients with sequelae.

Paraneoplastic Neurological Syndromes of the Central Nervous System: Pathophysiology, Diagnosis, and Treatment

Paraneoplastic neurological syndromes (PNS) include any symptomatic and non-metastatic neurological manifestations associated with a neoplasm. PNS associated with antibodies against intracellular antigens, known as "high-risk" antibodies, show frequent association with underlying cancer. PNS associated with antibodies against neural surface antigens, known as "intermediate- or low-risk" antibodies, are less frequently associated with cancer. In this narrative review, we will focus on PNS of the central nervous system (CNS). Clinicians should have a high index of suspicion with acute/subacute encephalopathies to achieve a prompt diagnosis and treatment. PNS of the CNS exhibit a range of overlapping "high-risk" clinical syndromes, including but not limited to latent and overt rapidly progressive cerebellar syndrome, opsoclonus-myoclonus-ataxia syndrome, paraneoplastic (and limbic) encephalitis/encephalomyelitis, and stiff-person spectrum disorders. Some of these phenotypes may also arise from recent anti-cancer treatments, namely immune-checkpoint inhibitors and CAR T-cell therapies, as a consequence of boosting of the immune system against cancer cells. Here, we highlight the clinical features of PNS of the CNS, their associated tumors and antibodies, and the diagnostic and therapeutic strategies. The potential and the advance of this review consists on a broad description on how the field of PNS of the CNS is constantly expanding with newly discovered antibodies and syndromes. Standardized diagnostic criteria and disease biomarkers are fundamental to quickly recognize PNS to allow prompt treatment initiation, thus improving the long-term outcome of these conditions.