Hashimoto encephalopathy, also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis, has been defined by subacute onset encephalopathy, with elevated thyroid antibodies, and immunotherapy responsiveness, in the absence of specific neural autoantibodies. We aimed to retrospectively review cases referred with suspected Hashimoto encephalopathy over a 13 year period, and to determine the clinical utility of thyroid antibodies in the course of evaluation of those patients. One hundred and forty-four patients (all thyroid antibody positive) were included; 72% were women. Median age of symptom onset was 44.5 years (range, 10-87). After Mayo Clinic evaluation, 39 patients (27%) were diagnosed with an autoimmune CNS disorder (autoimmune encephalopathy [36], dementia [2] or epilepsy [1]). Three of those 39 patients had neural-IgGs detected (high glutamic acid decarboxylase-65, AMPA-receptor and neural-restricted unclassified antibody), and 36 were seronegative. Diagnoses among the remaining 105 patients (73%) were functional neurological disorder (n = 20), neurodegenerative disorder (n = 18), subjective cognitive complaints (n = 14), chronic pain syndrome (n = 12), primary psychiatric (n = 11), sleep disorder (n = 10), genetic/developmental (n = 8), non-autoimmune seizure disorders (n = 2), and other (n = 10). More patients with autoimmune CNS disorders presented with subacute symptom onset (p < 0.001), seizures (p = 0.008), stroke-like episodes (p = 0.007), aphasia (p = 0.04) and ataxia (p = 0.02), and had a prior autoimmune history (p = 0.04). Abnormal brain MRI (p = 0.003), abnormal EEG (p = 0.007), CSF inflammatory findings (p = 0.002) were also more frequent in the autoimmune CNS patients. Patients with an alternative diagnosis had more depressive symptoms (p = 0.008), anxiety (p = 0.003), and chronic pain (p = 0.002). Thyoperoxidase antibody titer was not different between the groups (median 312.7 vs 259.4 IU/mL, p = 0.44, normal range <9 IU/mL). None of the non-autoimmune group and all but three of the CNS autoimmune group (two with insidious dementia presentation, one with seizures only) fulfilled the autoimmune encephalopathy criteria proposed by Graus et al (sensitivity 92%, specificity 100%). Among patients who received an immunotherapy trial at our institution and had objective post-treatment evaluations, the 16 responders with autoimmune CNS disorders more frequently had inflammatory CSF, compared to 12 non-responders, all eventually given an alternative diagnosis (p = 0.02). Seventy-three percent of patients referred with suspected Hashimoto encephalopathy had an alternative non-immune mediated diagnosis, and more than half had no evidence of a primary neurological disorder. Thyroid antibody prevalence is high in the general population, and does not support a diagnosis of autoimmune encephalopathy in the absence of objective neurological and CNS-specific immunological abnormalities. Thyroid antibody testing is of little value in the contemporary evaluation and diagnosis of autoimmune encephalopathies.

Background: Treatment decisions in patients with multiple sclerosis (MS) during the coronavirus disease 2019 (COVID-19) pandemic are challenging. It is not known whether and how various disease modifying therapies, especially immunosuppressive drugs, affect COVID-19 risk and disease course. Methods: Case report Results: We report a fingolimod-treated MS patient who developed severe COVID-19 but recovered after treatment with tocilizumab. Conclusion: This report suggests that a brief course of tocilizumab for the treatment of severe COVID-19 may be effective while not aggravating pre-existing MS.

In stroke secondary to cardiac myxoma, mechanical thrombectomy might represent a safe and effective treatment option. The authors suggest the use of histological examination of the clot for diagnosis as its composition may explain the differences in treatment outcome.

ObjectivesTo report the expanded neurological presentations and oncological associations of tripartite motif-containing protein 46 (TRIM46)-IgG seropositive patients.MethodsArchived sera/cerebrospinal fluid (CSF) were evaluated by tissue-based immunofluorescence assay to identify patients with identical axon initial segment (AIS)-specific staining pattern. Phage immunoprecipitation sequencing (PhIP-Seq) was used to identify the putative autoantigen.ResultsIgG in serum (17) and/or CSF (16) from 25 patients yielded unique AIS-specific staining on murine central nervous system (CNS) tissue. An autoantibody specific for TRIM46 was identified by PhIP-Seq, and autoantigen specificity was confirmed by transfected COS7 cell-based assay. Clinical information was available for 22 TRIM46-IgG seropositive patients. Fifteen were female (68%). Median age was 67 years (range 25–87). Fifteen (68%) patients presented with subacute cerebellar syndrome (six isolated; nine with CNS accompaniments: encephalopathy (three), brainstem signs (two), myelopathy (two), parkinsonism (one)). Other phenotypes included limbic encephalitis (three), encephalopathy with/without seizures (two), myelopathy (two). Eighteen (82%) had cancer: neuroendocrine carcinomas (9; pancreatic (3), small-cell lung (4), oesophagus (1), endometrium (1)), adenocarcinomas (6; lung (2), ovarian (2), endometrial (1), breast (1)), sarcoma (2) and gastrointestinal tumour (1). Neurological symptoms in three followed immune checkpoint inhibitor (ICI) administration.ConclusionsThis study supports TRIM46-IgG being a biomarker of paraneoplastic CNS disorders and expands the neurological phenotypes, oncological and ICI-related adverse event associations.

Paraneoplastic neurological syndromes are more commonly seen with malignancies such as small cell lung cancer, thymoma, gynecological malignancies, and breast cancer as well as seminoma. With the introduction of immune checkpoint inhibitor (ICI) cancer immunotherapy we see an increase of autoimmune neurological complications in patients with malignancies not traditionally associated with paraneoplastic neurological syndromes, such as melanoma and renal cell carcinoma. Immune checkpoint inhibitors enhance antitumor immune responses resulting often in immune-related adverse effects that can affect any organ, including the central and peripheral nervous system, neuromuscular junction and muscle. Neurological complications are rare; neuromuscular complications are more common than central nervous system ones but multifocal neurological presentations are often encountered. The vast majority of neurological complications appear within 3 months of ICI initiation, but have been described even after ICI cessation. Neural autoantibody testing reveals autoantibodies in approximately half of the patients with CNS complications. Early suspicion and diagnosis is critical to avoid worsening and improve outcomes. Therapeutic strategies depend on the severity of the symptoms and initially typically involve discontinuation of ICI and high dose steroids. Further immunosuppression might be necessary. Outcomes are dependent on patient's characteristics and clinical presentations.