Anti-thyroperoxidase antibodies from patients with Hashimoto's encephalopathy bind to cerebellar astrocytes

Brain alteration of autoimmune thyroid disease: Neuropsychiatric impact, neuroimaging insights, and neurobiological implications

Autoimmune thyroid disease (AITD) is the most common organ-specific autoimmune disease, characterized by thyroid function disorder and autoimmune imbalance. Previous studies have demonstrated the decreased quality of life and neuropsychiatric manifestations in AITD patients, including anxiety, depression, cognitive impairment and affective disorder. These problems also plague the euthyroid AITD patients. Advanced neuroimaging techniques were well carried out and employed as an explanatory instrument for the above intriguing phenomenon. In recent years, an increasing number of neuroimaging studies have reported that these neuropsychiatric manifestations are accompanied by significant structural and functional brain alterations in AITD patients, mainly involved in neurocognitive and emotional regions, despite the underlying neurobiological mechanism is still unclear. The existing studies suggest that the potential pathogenesis of the neuropsychiatric manifestations and brain alterations does not depend on a single factor, but may result from a combination of thyroid function dysfunction, metabolic disorders, dysregulated autoimmune and trans-synaptic degeneration.

Difficulties in the Diagnostics and Treatment of Hashimoto's Encephalopathy-A Systematic and Critical Review

Hashimoto's encephalopathy (HE) has been a poorly understood disease. It has been described in all age group, yet, there is no specific HE marker. Additionally, the treatment data in the available studies are frequently divergent and contradictory. Therefore, the aim of our systematic and critical review is to evaluate the diagnosis and treatment of HE in view of the latest findings. The databases browsed comprised PubMed, Scopus, and Google Scholar as well as Cochrane Library, and the search strategy included controlled vocabulary and keywords. A total of 2443 manuscripts were found, published since the beginning of HE research until February 2024. In order to determine validity of the data collected from studies, bias assessment was performed using RoB 2 tool. Ultimately, six studies were included in our study. HE should be considered in the differential diagnosis in patients with psychiatric and neurological symptoms. According to our findings, negative thyroid peroxidase antibodies (anti-TPOs) may represent a valuable parameter in ruling out HE. Nonetheless, this result cannot be used to confirm HE. Furthermore, the proposed anti NH2-terminal-α-enolase (anti-NAE) is non-specific for HE. The effectiveness of glucocorticoid therapy is 60.94%, although relapse occurs in 31.67% of patients following the treatment. Our review emphasizes the significance of conducting further large-scale research and the need to take into account the potential genetic factor.

Subclinical Hypothyroidism and Incident Depression in Adolescents and Young Adults: Results from a Nationwide Representative Prospective Study

Background: Although the relationship between subclinical hypothyroidism and major depressive disorder (MDD) has been studied in adults in cross-sectional and prospective population-based studies, this has not yet been done in adolescents. However, since thyroid function and MDD risk are subjected to maturational processes and ramifications of illness duration over the life span, these findings may not readily transfer to adolescents. Methods: The relationship between subclinical hypothyroidism and MDD was studied in a representative subsample of the nationwide KIGGS ("The German Health Interview and Examination Survey for Children and Adolescents") survey. A total of 4118 adolescents were examined over a median period of 6 years, and data were analyzed by a logistic regression approach accounting for important covariates related to thyroid function and/or MDD risk. The same approach was chosen to investigate the relationship between quartiles of thyrotropin (TSH) and free thyroxine (fT4) levels and incident MDD in euthyroid participants to broaden the focus on the relationship between thyroid hormone levels and MDD in a dose-response manner. Results: During the observation period, 121 cases of MDD were reported. There was no association between subclinical hypothyroidism and MDD when comparing 111 adolescents with subclinical hypothyroidism with 4007 euthyroid adolescents, representative of ∼106,000 and 3,610,000 adolescents from the general pediatric population, respectively. This also applied when studying the relationship between quartiles of TSH and fT4 levels and MDD in euthyroid participants. All results were confirmed by sensitivity analyses accounting for thyroid autoimmunity. Conclusions: Consistent with findings in adults, there is no association between subclinical hypothyroidism or quartiles of TSH and fT4 levels in the normal range and MDD in adolescents, despite potential age-related differences regarding thyroid function and MDD risk.

Hashimoto's encephalopathy with cerebellar ataxia as the main symptom: A case report and literature review

Hashimoto's encephalopathy (HE), also known as steroid responsive encephalopathy associated with autoimmune thyroiditis (SREAT), has a variety of clinical manifestations, with various neuropsychiatric characteristics, including tremors, transient aphasia, seizures, altered consciousness, myoclonus, cognitive impairment, and psychiatric manifestations. The hallmark presenting feature is a non-specific encephalopathy characterized by alteration of mental status and consciousness ranging from confusion to coma and impaired cognitive function, while those with cerebellar ataxia as the main manifestation is rare. We reported a case of Hashimoto's encephalopathy with cerebellar ataxia as the main manifestation, elevated anti-thyroid antibodies (anti-TPO/TG), and normal thyroid function. The symptoms of cerebellar ataxia improved after steroid treatment. Meanwhile, we reviewed the clinical features of 20 representative cases of HE with cerebellar ataxia as the core symptoms. In conclusion, based on our case findings and literature review, the diagnosis of HE should be suspected in cases of encephalopathy without an obvious cause, to quickly start an effective treatment.

Autoimmune Encephalopathy Associated With Anti-thyroid Antibodies: A Case Report

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), also known as Hashimoto encephalopathy (HE), is a rare condition. HE is characterized by abnormal brain function associated with elevated titers of anti-thyroid peroxidase (anti-TPO) and/or anti-thyroglobulin (anti-Tg) antibodies. We present a case of a 19-year-old female with rapidly progressing psychosis with mutism, catalepsy, echopraxia, and catatonia that developed over the course of three months. She was found to have high-level anti-thyroid antibodies raising suspicion of subclinical autoimmune thyroiditis and positive antinuclear antibodies. Imaging of the brain revealed generalized cerebral atrophy abnormal for her age. The patient was aggressively treated with corticosteroids and immunomodulators and her symptoms were greatly improved. This case emphasizes the significance of thyroid antibody measurement in patients presenting with psychiatric symptoms to evaluate patients for autoimmune encephalitis, since treatment with steroids and other immunosuppressive agents may be warranted.

Hashimoto's encephalopathy with psychiatric presentation

Hashimoto's encephalopathy is an uncommon neuropsychiatric syndrome with varied clinical presentations. It presents as an encephalopathy without central nervous system infection or tumor. Mostly observed ones are seizures, cognitive impairment, movement disorders, altered sensorium, and behavioral and psychotic symptoms. Treatment with steroids and immunosuppressants has led to excellent remission rates. Here, we report a case of a 55-year-old male who presented predominantly with psychiatric symptoms and rapidly progressing dementia. The patient was managed by intravenous steroids and low-dose oral risperidone. Prompt investigations and diagnoses helped in treating the condition. This case highlights that timely diagnosis can lead to an excellent prognosis in this condition.

Thyroid Function and Anti-thyroid Antibodies in Pediatric Anti-NMDAR Encephalitis

Objective: Recent studies found that changes of thyroid antibodies (ATAbs), thyroid hormone, and non-thyroidal illness syndrome (NTIS) characterized by thyroid hormone inactivation with low triiodothyronine and high reverse triiodothyronine followed by suppressed thyroid-stimulating hormone (TSH) in adult anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis were associated with disease severity. This study aimed to explore thyroid function and ATAbs in pediatric anti-NMDAR encephalitis and their clinical association. Methods: We retrospectively analyzed the clinical data of 51 pediatric cases with anti-NMDAR encephalitis hospitalized in Guangzhou Women and Children's Medical Center from August 2016 to 2019. Results: A percentage of 52.9% of patients belonged to the ATAb (+) group, with 26 cases both positive for anti-thyroid peroxidase antibodies (TPOAb) and anti-thyroglobulin antibodies (TGAb), and one patient only positive for TPOAb. A percentage of 62.7% of patients had at least one abnormality in terms of FT₃, free thyroxin (FT₄), or TSH levels. Meanwhile, 45.1% of patients were diagnosed with NTIS. Among 25 cases retested for thyroid function 2 months after the initial test, the respectively decreased FT₃ and FT₄ in 13 and 11 cases on admission returned to normal or closer normal than before; TPOAb in eight cases and TGAb in 12 cases were changed from positivity to negativity. Compared with onset, the level of TPOAb and TGAb at relapse remained stable or significantly decreased, respectively. Compared with the ATAb (-) group, the ATAb (+) group had an older onset age, a higher ratio of movement disorders, elevated rate of sleep disorders, increased anti-nuclear antibody positivity rate, and higher ratio of more than one course of intravenous immunoglobulin treatment. There were no significant differences between the NTIS and non-NTIS groups in clinical characteristics. Conclusion: Anti-thyroid antibody positivity, abnormality of FT₃, FT₄, or TSH levels and NTIS are frequent in pediatric anti-NMDAR encephalitis. Thyroid antibody and thyroid hormone abnormalities could be improved through the course of treatment of anti-NMDAR encephalitis. Cases with ATAbs (+) are at older onset ages and more likely to be treated by intravenous immunoglobulin therapy more than once. Unlike adult anti-NMDAR encephalitis, NTIS might not be associated with the clinical characteristics of anti-NMDAR encephalitis in pediatric patients.

An observational study on the association of anti-thyroid autoantibodies with clinical, EEG, MRI, FDG-PET, cerebrospinal fluid and anti-neuronal antibody findings in 530 patients with schizophreniform and affective disorders

INTRODUCTION

Although the link between autoimmune thyroiditis and mental illnesses is well established, the precise underlying pathophysiology and the influence of anti-thyroid antibodies on diagnostic findings require further research.

PATIENTS AND METHODS

A total of 530 patients with schizophreniform and affective syndromes were screened for anti-thyroid antibodies against thyroid peroxidase (TPO), thyroglobulin (TG), and thyroid-stimulating hormone receptor (TSH-R). The patient group analyzed here is a patient subgroup of a previously published cohort (Endres et al., 2020, Translational Psychiatry). The anti-thyroid antibody positive (N = 91) and negative (N = 439) patients were compared in terms of various clinical parameters, routine cerebrospinal fluid (CSF) findings, and the number of positive anti-neuronal antibodies in serum and/or CSF, as well as electroencephalography (EEG), magnetic resonance imaging (MRI), and ^[18 F]fluorodeoxyglucose positron emission tomography (FDG-PET) findings.

RESULTS

Anti-TPO antibodies were increased in 17%, anti-TG antibodies in 15%, and anti-TSH-R antibodies in 2% of all patients. In CSF, higher protein concentrations (p = 0.018) and albumin quotients (p = 0.008) were found in the anti-thyroid antibody positive patient group. Also, there were more patients with elevated age-corrected albumin quotients in this group (p = 0.031). FDG-PET hypometabolism was significantly more frequent and the number of positive anti-neuronal intracellular antibodies was significantly higher in patients with anti-thyroid antibodies (p = 0.048, N = 29 and p = 0.032, N = 497 respectively). In addition, there was a trend for higher white blood cell (WBC) counts in all patients with anti-thyroid antibodies (p = 0.090). In the patient subgroup with anti-TPO antibodies this difference was statistically significant (p = 0.027). No relevant differences were found in the other CSF routine parameters, the number of anti-neuronal antibodies against cell surface antigens in serum and/or CSF, EEG and MRI findings.

DISCUSSION

The present study provides evidence of impaired blood CSF barrier (BCSFB) function in patients with anti-TPO and anti-TG antibodies. An influence of anti-TG antibodies on BCSFB structures has been shown in previous laboratory studies, which reported that the antibodies bind to vascular smooth muscle cells. Due to BCSFB breakdown anti-thyroid antibodies might lead to increased autoimmune susceptibility. The alterations in the FDG-PET, WBC count, and anti-neuronal antibody findings against intracellular structures indicate that it could be useful to extend diagnostic investigations in patients with anti-thyroid antibodies. Further studies should investigate whether anti-thyroid antibodies can also act as "drivers of disease".

Association of thyroid peroxidase antibodies with anti-neuronal surface antibodies in health, depression and schizophrenia - Complementary linkage with somatic symptoms of major depression

Hashimoto's thyroiditis has been associated with major depression (MD) and schizophrenia (Sz) in epidemiological studies. However, diagnostically relevant antibodies (Abs) against thyroid peroxidase (TPO) and thyroglobulin (Tg) do not act directly on neurons. We hypothesized that an increased prevalence of anti-brain-Abs in thyroid-Ab-carriers could be linked with MD and Sz even without clinically manifest Hashimoto's thyroiditis. Serum samples from 638 acutely-ill patients with MD, Sz or matched controls were systematically screened for TPO- and Tg-Abs, other endocrine-Abs and a spectrum of specific anti-brain-Abs (directed against neuronal cell surface, synaptic, other neuronal or glial proteins). Analyses were based on indirect immunofluorescence in biochip mosaics of frozen tissue sections and transfected HEK293 cells expressing respective recombinant target antigens. Psychopathology was assessed on admission and after 6 weeks treatment by HAMD-21 (in MD) or PANSS (in Sz). Seroprevalence of TPO- and/or Tg-Abs was comparable in ill and healthy individuals (MD ~10%, Sz ~7%, controls ~9%) but thyroid-Abs were associated with neuronal cell surface/synaptic-Abs (p = 0.005), particularly in schizophrenia. Thyroid Ab-positive MD patients showed higher HAMD-21 scores (particularly somatic symptoms) at baseline (p = 0.026) and better reduction of symptoms after 6 weeks (p = 0.049) than thyroid-Ab-negative patients. This was unrelated to antidepressant drug dosage, thyroid hormonal-, inflammation- and anti-brain-Ab-status. No link with PANSS scores was observed in Sz. In conclusion, the co-occurrence of thyroid-Abs and neuronal surface/synaptic-Abs may be associated with Sz. Future cerebrospinal fluid research may be promising to clarify if thyroid-Ab-associated neuronal-Abs reach the brain in Sz patients. Thyroid-Ab-related differences regarding disease-severity and -course in MD are currently unexplained, but may be caused by un-identified anti-brain-Abs or a direct action of TPO-Abs on astrocytes.

Hashimoto's Encephalopathy: A Case Report and Literature Review of an Encephalopathy With Many Names

We present the case of a male patient, initially treated for myxedema coma secondary to Hashimoto’s thyroiditis, who was discharged on levothyroxine and a low-dose steroid taper but was re-admitted for the treatment of status epilepticus. During the second admission, the patient developed encephalopathy and cognitive dysfunction. Thyroid peroxidase (TPO) antibodies (Abs) were elevated and the patient was treated with high-dose steroids with clinical improvement. The patient was determined to have Hashimoto’s encephalopathy (HE) due to the clinical picture as well as the response to high-dose glucocorticoid therapy. Cerebrospinal fluid (CSF) analysis demonstrated elevated protein, immunoglobulin G (IgG) index, and IgG synthesis rate; however, albumin index was elevated, indicating a disrupted blood-brain barrier. We suggest that HE be considered in the differential diagnosis for patients presenting with seizures, coma, stroke-like symptoms, behavior changes, and unexplained encephalopathy. After ruling out more common pathologies, HE should be considered by testing for anti-TPO Abs.

Anti-Thyroid Peroxidase and Anti-Thyroglobulin Autoantibodies in the Cerebrospinal Fluid of Patients with Unipolar Depression

INTRODUCTION

The risk of developing depression is increased in patients with autoimmune thyroiditis. Autoimmune Hashimoto thyroiditis is diagnosed using the serum markers anti-thyroid peroxidase (TPO) and anti-thyroglobulin (TG) antibodies. In rare cases, patients with autoimmune thyroiditis can also suffer from the heterogeneous and ill-defined syndrome of Hashimoto encephalopathy. Biomarkers for Hashimoto encephalopathy or for any brain involvement of autoimmune thyroiditis are currently lacking. The aim of the present descriptive study was therefore to determine whether a subgroup of seropositive patients shows intrathecal anti-thyroid antibody synthesis in the cerebrospinal fluid (CSF).

PARTICIPANTS AND METHODS

Paired serum and CSF samples from 100 patients with unipolar depression were examined for anti-TPO and anti-TG antibodies using enzyme-linked immunosorbent assays. Antibody-specific indices (ASIs) were calculated for seropositive samples. These ASIs allow the differentiation between the brain-derived fraction of antibodies and antibodies which are passively diffused from the serum. ASIs >1.4 were assessed as positive for brain-derived antibodies. Additionally, for explorative evaluations, a stricter ASI limit of >2 was applied.

RESULTS

Anti-TPO antibodies were increased in the serum of 16 patients (16%); increased anti-TPO ASIs (>1.4) were detected in 11 of these patients (69%). Anti-TG antibodies in the serum were detected in three patients (3%), with two of them (67%) showing increased ASIs (>1.4). Overall, the authors found increased anti-thyroid antibodies in 17 of 100 patients (17%), with 13 out of 17 patients showing increased ASIs (76%; range 1.4-4.1). Choosing ASI levels of >2 led to positive findings in six out of 16 patients (38%) with anti-TPO antibodies in their serum but no increase in ASIs in three patients (0%) who were seropositive for anti-TG antibodies. The patients with elevated ASIs (N = 13) were younger than the ASI-negative patients (N = 87; p = 0.009); no differences were noted in the frequency of CSF, electroencephalography, and/or magnetic resonance imaging alterations.

DISCUSSION

A subgroup of seropositive patients showed intrathecal synthesis of anti-TPO and, more rarely, of anti-TG antibodies, which might be an indication of central autoimmunity in a subgroup of patients with unipolar depression. The confirmation of elevated ASIs as a biomarker for Hashimoto encephalopathy must await further studies. The relevance of the findings is limited by the study's retrospective and uncontrolled design.

Anti-Thyroid Peroxidase/Anti-Thyroglobulin Antibody-Related Neurologic Disorder Responsive to Steroids Presenting with Pure Acute Onset Chorea

Background:

Pure acute onset chorea without encephalopathy has rarely been reported in anti-thyroid peroxidase (anti-TPO)/anti-thyroglobulin (anti-TG) antibody-related neurologic disorders responsive to steroids (ATANDS).

Case report:

We report a 16-year-old female who presented with acute chorea without encephalopathy. Anti-TPO antibodies were found to be strongly positive (>1200 IU/ml) along with anti-thyroglobulin and anti-thyroid stimulating hormone receptor antibodies. After pulse intravenous methylprednisolone therapy (1 g/day for five consecutive days), all the movements seized, and she was discharged with oral prednisolone 30 mg/day with gradual tapering over next three months. After one year of follow-up, she is stable, drug-free, and never had any other problems.

Discussion:

Anti-thyroid antibodies testing should be included in routine/conventional panel that is done for elucidating causes of chorea as ATANDS can be easily missed and is treatable with widely available, relatively low-cost drugs like steroids with a promising outcome.

Hashimoto`s Encephalopathy Presenting with Progressive Cerebellar Ataxia

Hashimoto`s encephalopathy is a rare neurological syndrome occurring in patients with autoimmune thyroid disease. The diagnosis of Hashimoto`s encephalopathy is based on the clinical picture with the presence of serum anti-thyroid antibodies regardless of the thyroid disorder. Acquired cerebellar ataxia associated with Hashimoto`s disease is a rare occurrence. In this article, we present a case who had progressive non-familial autoimmune pancerebellar disease in association with an increased level of thyroid peroxidase and thyroglobulin antibodies. The patient was managed aggressively with both intravenous immunoglobulins and plasma exchange, which stopped the progression of the disease and allowed for slow improvement. Early diagnosis of Hashimoto`s encephalopathy with autoimmune cerebellar ataxia and intervention with immunomodulatory therapy are of paramount importance. Close monitoring after steroid therapy is important since some patients with this rare disease might be resistant to steroid therapy and require aggressive immunomodulatory therapy.

No Effect of Thyroid Dysfunction and Autoimmunity on Health-Related Quality of Life and Mental Health in Children and Adolescents: Results From a Nationwide Cross-Sectional Study

Background: In adults, a significant impact of thyroid dysfunction and autoimmunity on health-related quality of life (HRQoL) and mental health is described. However, studies in children and adolescents are sparse, underpowered, and findings are ambiguous. Methods: Data from 759 German children and adolescents affected by thyroid disease [subclinical hypothyroidism: 331; subclinical hyperthyroidism: 276; overt hypothyroidism: 20; overt hyperthyroidism: 28; Hashimoto's thyroiditis (HT): 68; thyroid-peroxidase antibody (TPO)-AB positivity without apparent thyroid dysfunction: 61] and 7,293 healthy controls from a nationwide cross-sectional study ("The German Health Interview and Examination Survey for Children and Adolescents") were available. Self-assessed HRQoL (KINDL-R) and mental health (SDQ) were compared for each subgroup with healthy controls by analysis of covariance considering questionnaire-specific confounding factors. Thyroid parameters (TSH, fT4, fT3, TPO-AB levels, thyroid volume as well as urinary iodine excretion) were correlated with KINDL-R and SDQ scores employing multiple regression, likewise accounting for confounding factors. Results: The subsample of participants affected by overt hypothyroidism evidenced impaired mental health in comparison to healthy controls, but SDQ scores were within the normal range of normative data. Moreover, in no other subgroup, HRQoL or mental health were affected by thyroid disorders. Also, there was neither a significant relationship between any single biochemical parameter of thyroid function and HRQoL or mental health, nor did the combined thyroid parameters account for a significant proportion of variance in either outcome measure. Importantly, the present study was sufficiently powered to identify even small effects in children and adolescents affected by HT, subclinical hypothyroidism, and hyperthyroidism. Conclusions: In contrast to findings in adults, and especially in HT, there was no significant impairment of HRQoL or mental health in children and adolescents from the general pediatric population affected by thyroid disease. Moreover, mechanisms proposed to explain impaired mental health in thyroid dysfunction in adults do not pertain to children and adolescents in the present study.

Climacteric symptoms are related to thyroid status in euthyroid menopausal women

BACKGROUND

Climacteric symptoms are a variety of disturbing complaints occurring during menopausal transition, many of which may be influenced by hormonal abnormalities other than related to sex steroids.

AIM OF THE STUDY

In this study, we investigated the association between the intensity of climacteric symptoms measured with the Kupperman index and a thyroid status.

MATERIAL AND METHODS

We evaluated by measuring serum thyrotropin (TSH), and free thyroxine (fT4) 202 euthyroid women admitted to the Department of Gynecological Endocrinology, Poznan University of Medical Sciences because of climacteric symptoms. Patients were both in perimenopause (n = 74) and postmenopause (n = 128), with no history of thyroid disorders.

RESULTS

Results presented as the mean value and standard deviation were as follows: age 54.2 ± 4.9 years, BMI 26.8 ± 4.6 kg/m², Kupperman index 26 ± 13.1 points, TSH 2.4 ± 2.6 mU/l, fT4 1.2 ± 0.37 ng/dl. We observed a negative correlation between fT4 and the time since the last menses (R = - 0.38; p = 0.02) as well as between serum TSH concentration and sweating (R = - 0.18; p = 0.03), general weakness (R = - 0.17; p = 0.03), and palpitation (R = - 0.18; p = 0.02) and a positive correlation between fT4 and nervousness (R = 0.34; p = 0.007) and palpitations (R = 0.25; p = 0.04). In the perimenopausal subgroup, there was a positive correlation between fT4 and general weakness (R = 0.42; p = 0.03), palpitations (R = 0.50; p = 0.009), and paresthesia (R = 0.46; p = 0.01). In the postmenopausal subgroup, there was a negative correlation between TSH and sweating (R = - 0.21; p = 0.03).

CONCLUSIONS

Menopausal symptoms are related to thyroid status in euthyroid menopausal women.

Rapid cycling bipolar disorder is associated with antithyroid antibodies, instead of thyroid dysfunction

BACKGROUND

Conclusions regarding the association between antithyroid antibodies or thyroid dysfunction and rapid cycling bipolar disorder (RCBD) have been conflicting. Previous studies suggest that the impact of antithyroid antibodies on mental wellbeing seems to be independent of thyroid function. Here, we investigated their independent association with RCBD in a large, well-defined population of bipolar disorder (BD).

METHODS

Fast serum levels of free thyroxine (FT4), free triiodothyronine (FT3), thyroid Stimulating Hormone (TSH), TPO-abs and Tg-abs were simultaneously measured in 352 patients with BD. Clinical features of BD were collected through semi-structural interview conducted by trained interviewers with background of psychiatric education.

RESULTS

Neither hypothyroidism nor hyperthyroidism was significantly associated with RCBD. Both TPO-abs and Tg-abs were significantly related to RCBD, even after controlling for gender, age, marriage status, education, antidepressants treatment, comorbidity of thyroid diseases, and thyroid function (serum levels of FT3, FT4 and TSH). Although TPO-abs and Tg-abs were highly correlated with each other, binary logistic regression with forward LR selected TPO-abs, instead of Tg-abs, to be associated with RCBD. TPO-abs was significantly, independently of Tg-abs, associated with hyperthyroidism, while Tg-abs was marginally significantly related to hypothyroidism at the presence of TPO-abs.

CONCLUSION

TPO-abs might be treated as a biomarker of RCBD. Further exploring the underlying mechanism might help understand the nature of RCBD and find out new treatment target for it.

Thyroid gland and brain: Enigma of Hashimoto's encephalopathy

The versatile clinical manifestations of the Hashimoto's chronic autoimmune thyroiditis often include psycho-neurological disorders. Although hypothyroidism disturbs significantly the ontogenesis and functions of central nervous system, causing in severe cases of myxedema profound impairment of cognitive abilities and even psychosis, the behavioral, motor and other psychoneurological disorders accompany euthyroid and slightly hypothyroid cases and periods of Hashimoto's disease as well, thus constituting the picture of so called "Hashimoto's encephalopathy". The entity, although discussed and explored for more than 50 years since its initial descriptions, remains an enigma of thyroidology and psychiatry, because its etiology and pathogenesis are obscure. The paper describes the development of current views on the role of thyroid in ontogeny and functions of brain, as well as classical and newest ideas on the etiology and pathogenesis of Hashimot's encephalopathy. The synopsis of the world case reports and research literature on this disorder is added with authors' own results obtained by study of 17 cases of Hashimoto's thyroiditis with schizophrenia-like clinical manifestations. The relation of the disease to adjuvant-like etiological factors is discussed. Three major mechanistic concepts of Hashimoto's encephalopathy are detailed, namely cerebral vasculitis theory, hormone dysregulation theory and concept, explaining the disease via direct action of the autoantibodies against various thyroid (thyroperoxidase, thyroglobulin, and TSH-receptor) and several extrathyroid antigens (alpha-enolase and other enzymes, gangliosides and MOG-protein, onconeuronal antigens) - all of them expressed in the brain. The article demonstrates that all above mentioned concepts intermingle and prone to unification, suggesting the unified scheme of pathogenesis for the Hashimoto's encephalopathy. The clinical manifestations, criteria, forms, course, treatment and prognosis of Hashimoto's encephalopathy and its comorbidity to other diseases - are also discussed in brief. The relation between Hashimoto's encephalopathy and non-vasculitis autoimmune encephalomyelitides of paraneoplastic and non-paraneoplastic origin is emphasized [1 figure, bibliography - 200 references].

Management of Autoimmune Encephalitis: An Observational Monocentric Study of 38 Patients

Over the last years the clinical picture of autoimmune encephalitis has gained importance in neurology. The broad field of symptoms and syndromes poses a great challenge in diagnosis for clinicians. Early diagnosis and the initiation of the appropriate treatment is the most relevant step in the management of the patients. Over the last years advances in neuroimmunology have elucidated pathophysiological basis and improved treatment concepts. In this monocentric study we compare demographics, diagnostics, treatment options and outcomes with knowledge from literature. We present 38 patients suffering from autoimmune encephalitis. Antibodies were detected against NMDAR and LGI1 in seven patients, against GAD in 6 patients) one patient had coexisting antibodies against GABA_A and GABA_B), against CASPR2, IGLON5, YO, Glycine in 3 patients, against Ma-2 in 2 patients, against CV2 and AMPAR in 1 patient; two patients were diagnosed with hashimoto encephalitis with antibodies against TPO/TG. First, we compare baseline data of patients who were consecutively diagnosed with autoimmune encephalitis from a retrospective view. Further, we discuss when to stop immunosuppressive therapy since how long treatment should be performed after clinical stabilization or an acute relapse is still a matter of debate. Our experiences are comparable with data from literature. However, in contrary to other experts in the field we stop treatment and monitor patients very closely after tumor removal and after rehabilitation from first attack.

Hashimoto's thyroiditis induces neuroinflammation and emotional alterations in euthyroid mice

Background

Although studies have reported an increased risk for mood disorders in Hashimoto’s thyroiditis (HT) patients even in the euthyroid state, the mechanisms involved remain unclear. Neuroinflammation may play a key role in the etiology of mood disorders in humans and behavioral disturbances in rodents. Therefore, this study established a euthyroid HT model in mice and investigated whether HT itself was capable of triggering neuroinflammation accompanied by emotional alterations.

Methods

Experimental HT was induced by immunizing NOD mice with thyroglobulin and adjuvant twice. Four weeks after the last challenge, mice were tested for anxiety-like behavior in the open field and elevated plus maze tests and depression-like behavior in the forced swimming and tail suspension tests. Then, animals were sacrificed for thyroid-related parameter measure as well as detection of cellular and molecular events associated with neuroinflammation. The changes in components of central serotonin signaling were also investigated.

Results

HT mice showed intrathyroidal monocyte infiltration and rising serum thyroid autoantibody levels accompanied by normal thyroid function, which defines euthyroid HT in humans. These mice displayed more anxiety- and depressive-like behaviors than controls. HT mice further showed microglia and astrocyte activation in the frontal cortex detected by immunohistochemistry, real-time RT-PCR, and transmission electron microscopy (TEM). These observations were also accompanied by enhanced gene expression of proinflammatory cytokines IL-1β and TNF-α in the frontal cortex. Despite this inflammatory response, no signs of neuronal apoptosis were visible by the TUNEL staining and TEM in the frontal cortex of HT mice. Additionally, IDO1 and SERT, key serotonin-system-related genes activated by proinflammatory cytokines, were upregulated in HT mice, accompanied by reduced frontal cortex serotonin levels.

Conclusions

Our results are the first to suggest that HT induces neuroinflammation and alters related serotonin signaling in the euthyroid state, which may underlie the deleterious effects of HT itself on emotional function.

Hashimoto encephalopathy in pediatric patients: Homogeneity in clinical presentation and heterogeneity in antibody titers

OBJECTIVE

Hashimoto encephalopathy is an autoimmune encephalopathy characterized by elevated antithyroid antibodies and a favorable response to corticosteroid. This study delineated the clinical characteristics of pediatric Hashimoto encephalopathy and the significance of low antithyroid antibody titers in diagnosis and treatment.

SUBJECTS AND METHODS

Clinical manifestations, antibody titers, and treatment responses were retrospectively reviewed in six consecutive children diagnosed with Hashimoto encephalopathy between August 2008 and July 2016.

RESULTS

Age at diagnosis was 10-17years. Presenting symptoms were seizures, altered consciousness, behavioral changes, psychosis, tremor, and dystonia. Thyroid function was normal in five patients, and one had hypothyroidism prior to the encephalopathy. Antithyroid antibody titer was increased at presentation in five patients and one week later in the other. Antibody levels were extremely varied (anti-thyroglobulin, 20.5-2318.0U/ml; anti-thyroid peroxidase, 12.5-2231.0U/ml; reference range, <60U/ml) and <180U/ml in two patients. Electroencephalogram was abnormal in five patients. Brain magnetic resonance imaging was unremarkable. Four patients responded to high-dose corticosteroid and one improved with additional intravenous immunoglobulin. The remaining patient did not respond to both treatments and normalized after plasmapheresis. Autoantibody titers decreased with treatment response in the acute stage. Two patients with low antibody titers showed similar clinical presentations and responses.

CONCLUSIONS

The clinical presentations and treatment responses in Hashimoto encephalopathy were similar, irrespective of antithyroid antibody titer. Because the initial antithyroid antibody titers can be normal or mildly-elevated, follow-up testing of antithyroid antibodies is required in patients who are clinically suspect for Hashimoto encephalopathy.

The association between anti-thyroid antibodies and quality of life in patients with thyroid disorders: a systematic review protocol

REVIEW QUESTION

The objective of this systematic literature review is to identify the association between anti-thyroid antibodies and quality of life in patients with thyroid disorders.

Detection of Thyroid Abnormalities in Aquaporin-4 Antibody-Seropositive Optic Neuritis Patients

OBJECTIVE

This study retrospectively analyzed the frequency of anti-thyroid antibodies (ATAs) and thyroid disease in patients with optic neuritis (ON).

METHODS

Tests of serum thyroglobulin (TG) and thyroid peroxidase (TPO) antibodies and thyroid function were performed in 97 ON patients. Blood also was drawn to test for AQP4-Ab using cell-based and enzyme-linked immunosorbent assays. Comparisons of the frequencies of ATAs, thyroid diseases and thyroid function were performed based on AQP4-Ab status.

RESULTS

Seropositive AQP4-Ab was found in 47/97 (48.5%) patients. ATA was considered positive in 34/97 (35.1%) patients. The prevalence of ATA was two times higher (P = 0.019) in the AQP4-Ab+ group compared to the AQP4-Ab- group. AQP4-Ab+ ON patients exhibited lower FT3 (P = 0.006) and FT4 (P = 0.025) levels and a higher prevalence of definite Hashimoto thyroiditis (HT) (P = 0.005). Among AQP4-Ab+ patients, those with HT had a worse visual outcome than non-HT patients.

CONCLUSION

A high prevalence of ATAs and HT was found in AQP4-Ab+ ON patients, and AQP4-Ab+ patients with HT exhibited worse visual outcomes than non-HT patients.

Is thyroid autoimmunity itself associated with psychological well-being in euthyroid Hashimoto's thyroiditis?

Recent studies imply that euthyroid Hashimoto's thyroiditis (HT) might be related with impaired HRQoL, depression and anxiety. Ninety three patients with euthyroid HT and 31 age- and gender-matched euthyroid control subjects were enrolled into this study. SF-36 questionnaire, Beck Depression Inventory and Beck Anxiety Inventory tests were used for evaluating HRQoL, depression and anxiety. Beck Depression Inventory scores were higher in patients with HT compared to control subjects (7.5 (4.0-14.75) vs. 5.0 (2.25-9.0), p=0.008). Beck Anxiety Questionnaire scores were also higher in patients with HT than controls (9.50 (5.0-17.0) vs. 5.0 (2.0-11.75), p=0.021). In SF-36 questionnaire; physical functioning (26.0 (20.0-28.0) vs. 29.0 (26.0-30.0), p=0.038), general health (16.4 (13.4-20.4) vs. 19.4 (16.3-21.2), p=0.026) and mental health (20.5 (16.0-23.0) vs. 23.0 (21.0-25.0), p=0.001) scores were lower in patients with HT than control subjects. There were no significant differences between patients with HT under levothyroxine replacement therapy compared to those without therapy in terms of depression and anxiety scores and components of SF-36 questionnaire. Beck Depression Inventory scores were positively correlated with TSH (r=0.250, p=0.01). In SF-36, role physical (r=0.192, p<0.05) and vitality (r=0.181, p<0.05) were positively correlated with fT4. Role emotional was negatively correlated with TSH (r=-0.185, p<0.05) and anti-TPO (r=-0.234, p<0.05). Mental health was negatively correlated with anti-TPO (r=-0.287, p<0.01). HRQoL is impaired and depression and anxiety scores are high in patients with euthyroid HT independent of levothyroxine replacement. Therefore, our results indicate that thyroid autoimmunity itself may have an impact on psychological well-being in euthyroid patients with HT.

Hashimoto encephalopathy: literature review

Hashimoto encephalopathy (HE) presents as an encephalopathy without central nervous system infection or tumor. HE is associated with autoimmune thyroiditis and is thus considered to be an autoimmune disorder. The prevalence of HE is low, but death and status epilepticus have been reported. HE manifests with a wide range of symptoms that include behavioral changes and confusion. Elevated thyroid antibodies are present in the majority of cases and are required for the diagnosis of HE. Normal brain MRI findings are found in the majority of patients diagnosed with HE. The most consistent CSF abnormality noted in HE patients is the presence of elevated protein. Most HE patients respond well to steroid therapy. Clinical improvements are also observed with IV immunoglobulin and plasmapheresis. In conclusion, it is now generally accepted that the diagnosis of HE must include encephalopathy characterized by cognitive impairment associated with psychiatric features, such as hallucinations, delusions, and paranoia. Autoimmune encephalitis and prion disease should be considered in the differential diagnosis due to the similarity of the clinical features of these conditions to those of HE.

Evolution, immunity and the emergence of brain superautoantigens

While some autoimmune disorders remain extremely rare, others largely predominate the epidemiology of human autoimmunity. Notably, these include psoriasis, diabetes, vitiligo, thyroiditis, rheumatoid arthritis and multiple sclerosis. Thus, despite the quasi-infinite number of "self" antigens that could theoretically trigger autoimmune responses, only a limited set of antigens, referred here as superautoantigens, induce pathogenic adaptive responses. Several lines of evidence reviewed in this paper indicate that, irrespective of the targeted organ (e.g. thyroid, pancreas, joints, brain or skin), a significant proportion of superautoantigens are highly expressed in the synaptic compartment of the central nervous system (CNS). Such an observation applies notably for GAD65, AchR, ribonucleoproteins, heat shock proteins, collagen IV, laminin, tyrosine hydroxylase and the acetylcholinesterase domain of thyroglobulin. It is also argued that cognitive alterations have been described in a number of autoimmune disorders, including psoriasis, rheumatoid arthritis, lupus, Crohn's disease and autoimmune thyroiditis. Finally, the present paper points out that a great majority of the "incidental" autoimmune conditions notably triggered by neoplasms, vaccinations or microbial infections are targeting the synaptic or myelin compartments. On this basis, the concept of an immunological homunculus, proposed by Irun Cohen more than 25 years ago, is extended here in a model where physiological autoimmunity against brain superautoantigens confers both: i) a crucial evolutionary-determined advantage via cognition-promoting autoimmunity; and ii) a major evolutionary-determined vulnerability, leading to the emergence of autoimmune disorders in Homo sapiens. Moreover, in this theoretical framework, the so called co-development/co-evolution model, both the development (at the scale of an individual) and evolution (at the scale of species) of the antibody and T-cell repertoires are coupled to those of the neural repertoires (i.e. the distinct neuronal populations and synaptic circuits supporting cognitive and sensorimotor functions). Clinical implications and future experimental insights are also presented and discussed.

Hashimoto's encephalitis associated with AMPAR2 antibodies: a case report

BACKGROUND

Hashimoto's encephalitis (HE) is a rare neurological complication of Hashimoto's thyroiditis (HT), while limbic encephalitis (LE) is an autoimmune inflammatory disorder frequently associated with anti-neuronal antibodies. The glutamate receptor α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPAR) is important for synaptic transmission, memory, and learning. The etiology of HE remains unclear. We present a case of HE with antibodies to AMPAR2 both in the serum and cerebrospinal fluid.

CASE PRESENTATION

The patient presented with progressive memory loss and subsequently went into a coma. Magnetic resonance imaging revealed temporal lobe and hippocampal lesions, while the electrocardiogram showed paroxysmal delta waves. Elevated serum levels of antibodies against thyroid globulin, thyroid peroxidase, and thyroid stimulating receptor were also noted. Ultrasonography showed enlargement of the thyroid gland. Therefore, the diagnosis was established as HE. Both the CSF and serum samples of the patient tested positive for antibodies to the cell-surface antigen AMPAR2. Intravenous injection of immunoglobulin followed by dexamethasone treatment resulted in recovery from the coma. Follow-up examination three months later showed some improvement of memory. To our knowledge, this is the first report on the detection of AMPAR2 antibodies in HE.

CONCLUSIONS

Our findings suggest that antibodies to AMPAR2 may be involved in the pathogenesis of HE. Elevated levels of thyroid antibodies possibly cause immune dysfunction, leading to the production of anti-AMPAR2 antibodies that are detrimental to the neurons. We believe that encephalitis patients with thyroid abnormalities should undergo screening for anti-neuronal antibodies, and early immune therapy may improve prognosis.

Steroid-Responsive Chronic Schizophreniform Syndrome in the Context of Mildly Increased Antithyroid Peroxidase Antibodies

BACKGROUND

Schizophreniform syndromes can be divided into primary forms from polygenic causes or secondary forms due to immunological, epileptiform, monogenic, or degenerative causes. Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT) is a secondary immunological form associated with increased thyroid antibodies, such as antithyroid peroxidase antibodies and shows a good response to corticosteroids.

CASE PRESENTATION

We present the case of a 41-year-old woman suffering from a schizophreniform syndrome. Starting at the age of 35, she developed psychotic exacerbations with formal thought disorder, acoustic hallucinations, cenesthopathic experiences, and loss of ego boundaries. At the same time, she began to suffer from chronic sexual delusions and olfactory hallucinations, which did not respond to neuroleptic medication. Her levels of antithyroid peroxidase antibodies were slightly increased, and the blood-brain barrier was disturbed. An electroencephalogram (EEG) showed intermittent generalized slowing, and cerebral magnetic resonance imaging (cMRI) depicted mild temporolateral atrophy. High-dose corticosteroid treatment led to convincing improvement of attentional performance and the disappearance of delusions and olfactory hallucinations.

CONCLUSION

SREAT can mimic typical symptoms of schizophreniform syndromes. The increased titer of antithyroid peroxidase antibodies in combination with the EEG slowing, blood-brain barrier dysfunction, and the cMRI alterations were the basis for suspecting an immunological cause in our patient. Chronic delusions, olfactory hallucinations, and cognitive deficits were successfully treated with corticosteroids. The occurrence of secondary immunological forms of schizophreniform syndromes demonstrates the need for innovative immunosuppressive treatment options.

Plasmapheresis Responsive Rapid Onset Dementia with Predominantly Frontal Dysfunction in the Context of Hashimoto's Encephalopathy

BACKGROUND

Hashimoto's encephalopathy (HE) is a rare immunological neuropsychiatric disorder characterized by increased antithyroid antibodies and mixed neurological and psychiatric symptoms. HE has been previously discussed as a differential diagnosis for rapid progressive dementia. However, most of these patients suffered from additional neurological symptoms, like ataxia or seizures.

CASE PRESENTATION

Here, we present the case of a 59-year-old female patient suffering rapid onset dementia with salient frontal executive dysfunction. She developed rapid onset symptoms, including apathy, verbal depletion up to a stuporous state, severe working memory deficits, evidence of primitive reflexes, disturbed Luria's three-step test, and micturition disorder. Analysis of her cerebrospinal fluid was normal. The serum analyses showed increased antithyroid (antithyroid peroxidase and antithyroglobulin) antibodies. In the cerebral magnetic resonance imaging, supratentorial deep and peripheral white matter lesions were found; the electroencephalography showed intermittent slowing, and the [¹⁸F]fluorodeoxyglucose positron emission tomography (FDG-PET) depicted medial and superior dorsolateral frontal hypometabolism. Several different psychopharmacological therapeutic approaches with various neuroleptics, antidepressants, and high doses of lorazepam were unsuccessful. Due to the organic alterations, including increased antithyroid antibodies, HE was suspected. Against expectations, treatment with high-dose corticosteroids proved to be ineffective and was associated with worsening symptoms. However, escalated treatment with plasmapheresis over 5 days led to significant improvement in all reported symptoms and in psychometric testing. The neuropsychological improvement was stable over a 6-month follow-up period, and the FDG-PET normalized.

CONCLUSION

This case report reveals that (1) HE can mimic rapid onset dementia with predominantly frontal dysfunction; (2) this syndrome can be successfully treated in the context of HE; and (3) plasmapheresis can be effective in such a disease constellation. The detection of the immunological causes of rapid onset dementia and other psychiatric syndromes is important because it opens opportunities for new, innovative immunosuppressive treatment options.

Delirious Mania Associated with Autoimmune Gastrothyroidal Syndrome of a Mid-Life Female: The Role of Hashimoto Encephalopathy and a 3-Year Follow-Up including Serum Autoantibody Levels

We report the case study of a 57-year-old Caucasian female with steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), commonly termed Hashimoto encephalopathy (HE). This presentation includes one of the longest lasting follow-up studies of HE considering the neuropsychiatric symptoms (here delirium, mania, and EEG-slowing) and their relation to serum autoantibody levels. Antithyroid-peroxidase autoantibodies, the hallmark of autoimmune thyroiditis, were found in the serum and also in the cerebrospinal fluid. Diagnostic analyses found no evidence of limbic encephalopathies characterized by serum antibodies against intracellular, synaptic, or further cell surface antigenic targets, neoplasm, and connective tissue or vasculitis diseases. A potential contribution of bipolar disorder and metabolic encephalopathies due to severe hypothyroidism, glucocorticoid treatment, accelerated thyroid hormone replacement therapy, or vitamin B deficiency is critically discussed. Another special feature of this case report is the linkage of HE to an autoimmune polyendocrine syndrome (type 3B) affecting the gastroduodenum in addition to the thyroid gland.

Hashimoto Encephalopathy Presenting With Stroke-Like Episodes in an Adolescent Female: A Case Report and Literature Review

BACKGROUND

Hashimoto encephalopathy is a rare form of encephalopathy thought to be of autoimmune etiology. Cognitive changes and seizures are the most commonly reported presenting manifestation. Stroke-like episodes have also been documented in these individuals. We describe a rare adolescent with Hashimoto encephalopathy who presented with stroke-like symptoms.

PATIENT DESCRIPTION

A previously well 15-year-old girl experienced sudden-onset language disturbance and right hemiparesis. Her symptoms resolved, but weeks later, she began experiencing refractory seizures, episodes of status epilepticus, and cognitive decline. An extensive evaluation was unremarkable, but thyroid peroxidase antibodies were elevated, and a diagnosis of Hashimoto encephalitis was made. Steroid therapy was initiated, and her symptoms resolved with return to baseline cognitive function.

CONCLUSION

Hashimoto encephalopathy is a highly treatable condition that may be considered in the differential diagnosis of children and adolescents presenting with stroke-like symptoms.

Bipolar disorder and antithyroid antibodies: review and case series

Mood disorders and circulating thyroid antibodies are very prevalent in the population and their concomitant occurrence may be due to chance. However, thyroid antibodies have been repeatedly hypothesized to play a role in specific forms of mood disorders. Potentially related forms include treatment-refractory cases, severe or atypical depression, and depression at specific phases of a woman’s life (early gestation, postpartum depression, perimenopausal). With regard to bipolar disorder, studies of specific subgroups (rapid cycling, mixed, or depressive bipolar) have reported associations with thyroid antibodies. Offspring of bipolar subjects were found more vulnerable to develop thyroid antibodies independently from the vulnerability to develop psychiatric disorders. A twin study suggested thyroid antibodies among possible endophenotypes for bipolar disorder. Severe encephalopathies have been reported in association with Hashimoto’s thyroiditis. Cases with pure psychiatric presentation are being reported, the antithyroid antibodies being probably markers of some other autoimmune disorders affecting the brain. Vasculitis resulting in abnormalities in cortical perfusion is one of the possible mechanisms.

Thyroid Autoantibodies in the Cerebrospinal Fluid of Subjects with and without Thyroid Disease: Implications for Hashimoto's Encephalopathy

Introduction. Plasma antithyroid peroxidase (anti-TPO) and anti-thyroglobulin antibodies (anti-Tg) are widely used in the diagnosis of autoimmune thyroiditis. No research has compared anti-TPO and anti-Tg both in plasma and cerebrospinal fluid (CSF) of healthy individuals vis-à-vis patients with thyroid disease. Methods. We measured anti-TPO and anti-Tg antibodies in plasma and CSF in nine subjects (mean age ± SD: 73 ± 6 years) with hypothyroidism and nine subjects (mean age ± SD: 73 ± 8 years) without thyroid disease. Results. The concentration of anti-TPO autoantibodies in CSF was very low compared to plasma in both subjects with thyroid and without thyroid disease (P = 0.007). CSF anti-Tg autoantibodies titers were very low compared to the plasma in subjects with thyroid disease (P = 0.004), whereas, in subjects without thyroid disease, this difference did not reach statistical significance (P = 0.063). Conclusions. Thyroid autoantibodies levels were low in plasma and CSF; we did not observe any transfer of thyroid autoantibodies from the peripheral blood to the CSF. Therefore, regarding Hashimoto's encephalopathy, where elevated antithyroid autoantibodies are often measured in blood, it is more likely that thyroiditis and encephalopathy represent nonspecific, but distinct, events of an aggressive immune system.

Free thyroxine levels are associated with cognitive abilities in subjects with early psychosis

INTRODUCTION

Subjects with a psychotic disorder show mild to moderate cognitive impairment, which is an important determinant of functional outcome. The underlying biological process of cognitive impairment in psychosis is unclear. We aimed to explore whether hypothalamic-pituitary-thyroid axis hormones or thyroid autoimmunity modulate cognitive functioning in subjects with early psychosis.

METHODS

We studied 70 patients with a psychotic disorder (<3years of illness) and a control group of 37 healthy subjects (HS). Plasma levels of thyroid-stimulating hormone (TSH), free thyroxine (FT4) and thyroid-peroxidase (TPO-Abs) and thyroglobulin antibodies (TG-Abs) were determined. Cognitive assessment was performed with the MATRICS Cognitive Consensus Cognitive Battery. We also explored the relationship between thyroid variables and cognition in three subgroups of psychotic patients: psychosis not otherwise specified, affective psychosis (bipolar disorder or schizoaffective disorder) and non-affective psychosis (schizophrenia or schizophreniphorm disorder).

RESULTS

In patients with early psychosis, higher FT4 levels (but not TSH or thyroid antibodies) were associated with better cognitive performance in attention/vigilance and overall cognition. The relationship between FT4 levels and the attention/vigilance domain remained significant in a multivariate analysis after adjusting for education level, age, gender, substance use, and benzodiazepine and antipsychotic treatments. We did not find a significant association between FT4 and cognitive performance in HS. In the exploratory analysis by psychotic subtypes, subjects with affective psychosis had increased FT4 levels and better cognitive profile than those with non-affective psychosis.

CONCLUSIONS

Our study suggests that FT4 levels are associated with cognitive abilities (attention/vigilance and overall cognition) in individuals with early psychosis.

Down Syndrome Disintegrative Disorder: New-Onset Autistic Regression, Dementia, and Insomnia in Older Children and Adolescents With Down Syndrome

Over a 10-year period in a Down syndrome Clinic, 11 children and adolescents were encountered with a history of new-onset (8) or worsening (3) autistic characteristics. Ten of the 11 (91%) had cognitive decline to a dementia-like state and 9 of the 11 (82%) new-onset insomnia. The mean age at which symptoms developed was 11.4 years (standard deviation = 3.6 years; range 5-14 years), an older age than usual for autistic regression in Down syndrome. Ten of 11 cases (91%) had elevated ("positive") thyroperoxidase antibody titers compared to only 5 of 21 (23%) age-matched control subjects with Down syndrome (P < .001). At follow-up at a mean age of 20.7 years (standard deviation = 3.9 years), 8 of the 11 (73%) were at least somewhat better. Down syndrome disintegrative disorder seems an appropriate name for this newly recognized clinical association, which may be due to autoimmunity.

Hashimoto's encephalopathy: a brief review

Hashimoto's encephalopathy (HE) is a syndrome of altered mental status, hallucinations, delusional thinking, and often, epileptic seizures. It is diagnosed by the clinical syndrome, the presence of elevated titers of antithyroid antibodies, the lack of another diagnosis based on clinical evaluation, and the response to corticosteroid and other immunosuppressant treatment. This review discusses the symptoms, pathophysiology, and treatment of HE. The disorder is important to recognize because aggressive treatment may bring about a favorable clinical outcome. The disorder has a relatively benign prognosis, compared with many of the entities for which it can be mistaken.

Altered mental status: what is the diagnosis?

We report a patient presenting with a 2-day history of altered mental status and lethargy. She had recently started taking prednisone for suspected 'autoimmune arthritis'. Clinical deterioration in hospital characterised by increasing confusion, alternating hyperarousal and somnolence, auditory hallucinations and eventual unresponsiveness led to an intensive care unit transfer. Initial laboratory and radiological testing did not reveal a cause for her symptoms. The only abnormality detected was antithyroid peroxidase antibody levels elevated to >900 IU/mL with patient demonstrating marked clinical improvement within 24 h of receiving high-dose steroids and plasmapheresis. Hashimoto's encephalitis is an underdiagnosed reversible neuropsychiatric disorder with unknown pathogenesis. Recent studies indicate that autoimmune encephalopathy and specifically Hashimoto's encephalitis is under-reported. Our case demonstrates the importance of maintaining a wide differential for altered mental status, especially after negative initial diagnostic work-up of more common aetiologies. Although steroids are an effective treatment for Hashimoto's encephalitis, the addition of early plasmapheresis may be indicated in patients with severe presentation and those who develop disease while taking steroids.

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT): case report of reversible coma and status epilepticus in an adolescent patient and review of the literature

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), also termed Hashimoto's encephalopathy (HE), is a rare immune-mediated disorder and is also affecting children and adolescents. It is characterized by altered mental status, seizures, and cognitive dysfunction. Therapeutic options include steroid treatment and prognosis range from complete recovery, a relapsing course to long-term cognitive sequelae. We describe a previously healthy 13-year-old girl presenting to the emergency room with coma and refractory status epilepticus. Generalized tonic-clonic seizures persisted after pre-hospital infusion of antiepileptic medication. She was found to have highly elevated levels of thyroid-stimulating hormone and anti-thyroid peroxidase antibodies not only in blood but also in cerebrospinal fluid while showing negative results for traumatic, infectious, metabolic, toxic, neoplastic, or other known specific autoimmune diseases. Cranial neuroimaging revealed no abnormality. A diagnosis of SREAT was established, and the patient improved rapidly on corticosteroids and levothyroxine therapy. However, 3 months after the discontinuation of steroid treatment, the girl relapsed. The current literature regarding SREAT is reviewed and summarized.

CONCLUSION

In children with SREAT, early diagnosis and treatment with corticosteroids is crucial and can lead to rapid clinical improvement. Clinicians should be aware of this uncommon but treatable condition, especially in female adolescents with unexplained seizures or an encephalopathic state.

Cognitive and affective dysfunctions in autoimmune thyroiditis

Hashimoto's thyroiditis (HT) is the most frequent cause of hypothyroidism in areas with sufficient iodine intake. While the impact of thyroid function on mood and cognition is well known, only in the recent years, an increasing number of studies report on the association of HT with cognitive and affective disturbances also in the euthyroid state. Recent imaging studies have shown that these impairments are accompanied by altered brain perfusion, in particular, in the frontal lobe and a reduced gray matter density in the left inferior gyrus frontalis. Brain function abnormalities in euthyroid patients with HT may be subtle and only detected by specific testing or even severe as it is the case in the rare neuropsychiatric disorder Hashimoto's encephalopathy (HE). The good response to glucocorticoids in patients with HE indicates an autoimmune origin. In line with this, the cognitive deficits and the high psycho-social burden in euthyroid HT patients without apparent signs of encephalopathy appear to be associated with anti-thyroid peroxidase auto-antibody (TPO Abs) levels. Though in vitro studies showing binding of TPO Abs to human cerebellar astrocytes point to a potential direct role of TPO Abs in the pathogenesis of brain abnormalities in HT patients, TPO Abs may function only as a marker of an autoimmune disorder of the central nervous system. In line with this, anti-central nervous system auto-antibodies (CNS Abs) which are markedly increased in patients with HT disturb myelinogenesis in vitro and, therefore, may impair myelin sheath integrity. In addition, in HT patients, production of monocyte- and T-lymphocyte-derived cytokines is also markedly increased which may negatively affect multiple neurotransmitters and, consequently, diverse brain neurocircuits.

Thyroid disease and the nervous system

Thyroid disorders are common in the general population and in hospitalized patients. Thyroid disease may present first with neurological complications or else may occur concurrently in patients suffering other neurological disorders, particularly those with an autoimmune etiology. For this reason neurologists will commonly encounter patients with thyroid disease. This chapter provides an overview of the neurological complications and associations of disorders of the thyroid gland. Particular emphasis is placed on conditions such as thyrotoxic periodic paralysis and myxedema coma in which the underlying thyroid disorder may be occult leading to a first, often emergency, presentation to a neurologist. Information about clinical features, diagnosis, pathogenesis, therapy, and prognosis is provided. Emphasis is placed on those aspects most likely to be relevant to the practicing neurologist and the interested reader is directed to references to good, recent review articles for further information.

Elevated titers of anti-thyroperoxidase antibodies in patients with multiple system atrophy: a pilot study

OBJECTIVES

Multiple system atrophy (MSA) is a neurodegenerative disease characterized by progressive neuronal loss and alpha-synuclein deposition in oligodendroglial cells in the central nervous system. The cause of MSA remains essentially unknown. A cerebellar syndrome was associated with autoimmune thyroid disease in some cases, apparently not related to MSA and was partially responsive to immunomodulatory therapy.

PATIENTS AND METHODS

28 euthyroid patients who fulfilled the diagnostic criteria for probable MSA, 11 with MSA-cerebellar type (MSA-C), 17 with MSA-parkinsonian type (MSA-P), 28 patients with Parkinson's disease (PD) and 26 normal euthyroid controls were tested the for serum levels of anti-thyroperoxidase antibodies (anti-TPO) and anti-thyroglobulin (Anti-TG) antibodies (Ab).

RESULTS

The laboratory results were statistically similar in all three groups, but 3 MSA-C patients had highly elevated anti-TPO Ab titers.

CONCLUSION

We identified the presence of elevated anti-TPO levels in a small subgroup of MSA-C patients but neither in MSA-P or PD patients nor in healthy controls. These findings may suggest an autoimmune etiology in some cases of MSA-C.

Adult-onset temporal lobe epilepsy, cognitive decline, multi-antiepileptic drug hypersensitivity, and Hashimoto's encephalopathy: Two case studies

Hashimoto's encephalopathy is defined by the coexistence of encephalopathy and antithyroid antibodies. We report two cases of adult-onset temporal lobe epilepsy with subacute cognitive decline, high titers of antithyroid antibodies, multi-antiepileptic drug hypersensitivity, and good response to immunomodulatory treatment. The relevance of multidrug hypersensitivity in the setting of adult-onset epilepsy and the importance of searching for autoimmune causes for epilepsy are discussed.

Diagnostic and therapeutic aspects of Hashimoto's encephalopathy

OBJECTIVE

To share our experience on clinical presentation and management of patients diagnosed with Hashimoto's Encephalopathy (HE) at Vanderbilt Medical Center between 1999 and 2012.

BACKGROUND

HE is a rare disorder characterized by encephalopathy and central nervous system (CNS) dysfunction, elevated antithyroid antibodies, the absence of infection or structural abnormalities in the CNS, and a response to treatment with steroids. The relationship between thyroid antibodies and encephalopathy has remained unresolved.

DESIGN/METHODS

Retrospective chart review.

RESULTS

We identified 13 patients who met the criteria for the diagnosis of HE. The median age was 49 years (range, 2-66) and all except one were women. Encephalopathy in the form of altered mental status, stroke-like symptoms or seizures, with prompt resolution of symptoms upon receiving steroids, was the commonest presentation, seen in 7 patients. The second commonest presentation was subacute progressive decrease in cognitive function, which reversed within days to weeks after steroid therapy, seen in 4 patients. Electroencephalogram (EEG) was available in 12 patients and was abnormal in 8, showing nonspecific cerebral dysfunction in all 8 and epileptiform activity in 3. Treatment consisted of steroids in the acute phase for 12 of 13 patients with rapid improvement in symptoms. Maintenance therapy was rituximab in 7 patients, intravenous immunoglobulin (IVIg) in 7, azathioprine in 4, mycophenolate mofetil in 3, and methotrexate in 1 (some patients received sequential therapy with different agents). There was complete or near complete resolution of symptoms in 12 of the 13 patients.

CONCLUSIONS

We present a cohort of patients in whom CNS dysfunction was associated with elevated antithyroid antibodies and reversal of disease followed immunomodulatory therapies.

Hashimoto's encephalopathy: identification and long-term outcome in children

OBJECTIVE

To identify the clinical findings of Hashimoto's encephalopathy (HE) in children and assess their neurological outcome.

METHODS

In this retrospective observational study of 42 children with encephalitis dominated by acute neuro-behavioral features, eight met the diagnostic criteria of HE. Their biological, EEG and brain MRI characteristics were compared to those of the other 34 children. Their clinical outcome was also compared to that of 14 children with Hashimoto's thyroiditis (HT).

RESULTS

All eight HE children were girls and had high levels of anti-thyroid peroxidase (TPO) antibodies at onset (4043.3 ± 2969.8 IU/mL, inclusion criteria: TPO > 60 IU/mL) despite normal T4 and TSH levels in six of them. All HE children had abnormal EEG and brain MRI was abnormal in four of them. Relapses were observed in five children with a second relapse, despite steroid therapy, occurring sooner after the previous episode (median 18 days (range 17-188) vs 213 days (range 14-518)). Immunosuppressive therapy was started in all five children and two developed sequelae by the last follow-up visit (after 4 ± 1.3 years). Mean anti-TPO antibody titers were significantly higher in HE children than in those with Hashimoto's thyroiditis (HT) (4043.3 ± 2969.8 IU/mL vs 1980.9 ± 3449.9 IU/mL, p = 0.03). Four HE children subsequently developed hypothyroidism whereas only one HT patient presented encephalitis.

CONCLUSION

HE is characterized by suggestive clinical symptoms with high levels of anti-TPO antibodies and, in most cases, normal T4 and TSH titers. Despite steroid treatment, relapses and sequelae are frequent. HE may evolve toward HT, but the reverse appears to be rare.