Hashimoto's encephalopathy: A rare proteiform disorder

The use of intravenous immunoglobulin in the treatment of Hashimoto's encephalopathy: case based review

Background

Hashimoto's encephalopathy (HE) is a controversial immunological neuropsychiatric disease, with a poorly understood pathogenesis. It is characterized by symptoms of acute or subacute encephalopathy which usually occur in the presence of elevated levels of antithyroid antibodies. Even though it is also known as steroid responsive encephalopathy associated with autoimmune thyroiditis (SREAT), some cases appear to be steroid-resistant. This review examined whether treatment of Hashimoto's encephalopathy with intravenous immunoglobulin (IVIG) is associated with better clinical outcomes than the standard therapy. Additionally, we presented a case of a 59-year-old man who presented with severe neurological manifestations and was successfully treated with intravenous immunoglobulin.

Methods

The online databases PubMed and EMBASE were searched.

Results

A total of 1,365 articles were identified. After the deletion of 112 duplicates, 1,253 studies were screened by evaluating the title and abstract, focusing on Hashimoto's encephalopathy cases where IVIG were used. 846 studies were excluded because they were not relevant to the topic or included pediatric population. Therefore, 407 full-text articles were assessed for eligibility. The final analysis included 14 eligible articles after 393 were excluded (irrelevant texts, not written in English, full-text not available). In the majority of the selected case-reports, IVIG was associated with a good outcome, sometimes even with dramatic improvements in patient's status.

Conclusion

In last years, intravenous immunoglobulin therapy proved its utility in Hashimoto's encephalopathy's treatment, being a well tolerated therapy associated with remarkable improvement in patient's status. Further research is still needed in order to define the optimal treatment protocol for Hashimoto's encephalopathy and to establish if intravenous immunoglobulin can also be used as a first-line therapy, alone or in combination with steroids.

Effects of Excessive Iodine on the BDNF-TrkB Signaling Pathway and Related Genes in Offspring of EAT Rats

Excess iodine can cause autoimmune thyroiditis (AIT) in women, but it is unclear whether this has any implications for neurodevelopmental mechanisms in offspring. We studied the effects of experimental autoimmune thyroiditis (EAT) rats with different amounts of iodine intake on offspring brain development via the brain-derived neurotrophic factor (BDNF)-tropomycin receptor kinase B (TrkB) signaling pathway, because BDNF plays an important role in neurodevelopment. Rats in three thyroglobulin (Tg) immunized groups with varying iodine intakes (Tg (100 µg/L iodine), Tg + High-iodine I group (Tg + HI, 20 mg/L iodine), and Tg + High-iodine II group (Tg + HII, 200 mg/L iodine)) were injected with 800 µg Tg once every 2 weeks for 3 times. Rats in the control group (NI, 100 µg/L iodine) were immunized with saline. Arsenic-cerium catalytic spectrophotometry was used to measure urine iodine levels. The lymphocytic infiltration in the thyroids was observed by histopathological studies. Thyroid autoantibodies levels were measured using radioimmunoassay. The norepinephrine (NE) contents were measured by an enzyme-linked immunosorbent assay. The levels of the BDNF-TrkB signaling pathway and related genes were measured by quantitative real-time PCR and Western blot. Urinary iodine levels increased as iodine intake increased. Lymphocytes were significantly aggravated in Tg-immunized rats. Serum thyroglobulin antibody (TgAb) and thyroid peroxidase antibody (TPOAb) levels were clearly elevated in Tg-immunized rats. Tg-immune groups had significantly lower NE levels. The BDNF-TrkB signaling pathway and related gene mRNA and protein levels were found to be significantly lower in Tg-immune groups with higher iodine levels. Maternal AIT may reduce the levels of certain neurodevelopmental mechanisms in the offspring, such as the BDNF-TrkB signaling pathway and related factors, while excessive iodine consumption by the mother may exacerbate this effect.

Steroid responsive encephalopathy associated with autoimmune thyroiditis as a cause of acuteencephalopathy

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), known as Hashimoto's encephalopathy (HE), represents a heterogeneous group of neurological and neuropsychiatric symptoms associated with a presence of antithyroid antibodies in case of other causes of encephalopathy were excluded. Clinical symptoms most commonly includes acute onset of encephalopathy, behaviour changes and cognitive dysfunction, epileptic seizures as well as cerebellar and extrapyramidal symptoms. Corticoids provides rapid and sustained therapeutic benefit in most patients and only a few patients require other immunosuppressive therapy such as plasmapheresis, intravenous immunoglobulins, or others. We present the cases of two patients with acute onset of encephalopathy, status epilepticus based on SREAT, with rapid improvement after steroid treatment.

A Rare Case of Hashimoto’s Encephalopathy With Mosaic Turner Syndrome

Mosaicism in Turner syndrome (TS) is a 20%-30% occurrence, with 45, X plus at least another cell line. The haploinsufficiency of the X chromosome is usually responsible for the higher risk of autoimmunity in TS, exhibiting mainly as thyroiditis, type 1 diabetes, etc. Though Hashimoto’s thyroiditis is commonly seen in patients with TS, the concurrence of encephalopathy in these patients is significantly rare and has not been reported. We present a case of a young female with mosaic TS who presented with altered mental status. The initial workup was negative for stroke and pulmonary embolism and cerebrospinal fluid (CSF) analysis did not show any infectious etiology. Thyroid peroxidase (TPO) antibodies (Abs) and thyroglobulin Abs were elevated. As the patient’s mental status deteriorated, there was a concern for Hashimoto’s encephalopathy (HE), hence the patient was started on high-dose IV steroids. Within 24 hours, the patient responded to the IV steroids and an improvement in mentation was noted. HE is a rare immune-mediated disorder, characterized by impaired brain function. The onset of which can be rapid or slowly developing over the course of many years but responds effectively to steroids. Turner syndrome is associated with a high incidence of autoimmune disorders, thus in the setting of a negative workup for more obvious causes, HE should be a consideration when encountered in a clinical scenario.

Risk of Mental Illnesses in Patients With Hypopituitarism: A Nationwide Population-Based Cohort Study

OBJECTIVE

The associations of mental illnesses and hypopituitarism have been reported. But, pituitary disorders are rare. The epidemiological studies have rarely addressed these associations between pituitary disorder and mental illnesses. Until now, no cohort study has been conducted to investigate the association.

METHODS

We performed a nationwide, retrospective cohort study using the Taiwanese National Health Insurance Program dataset to analyze this relationship. In total, 1,194 patients diagnosed with hypopituitarism between 2000 and 2013 were identified. For the control group, 4,776 individuals without hypopituitarism and psychotic diseases were matched (1:4) according to age, sex, and index date. A Cox proportional hazards model was used to determine the adjusted hazard ratio (aHR).

RESULTS

Patients with hypopituitarism had a significantly higher risk of incident depression and anxiety disorders than those without hypopituitarism. The aHRs of depressive and anxiety disorders were 2.98 and 1.67, respectively, for the hypopituitarism cohort. Furthermore, the risk of both hypopituitarism-associated depressive and anxiety disorders was significantly high in female subjects and subjects aged ≥18 years. A statistically significant increase was not observed in the risk of bipolar disorders, dementia, or schizophrenia in the hypopituitarism group compared with the control group.

CONCLUSION

Although psychiatric morbidities were uncommon for the hypopituitarism cohort, the risk of developing depressive and anxiety disorders was significantly higher in those with hypopituitarism than in those without hypopituitarism.

Steroid-responsive encephalopathy associated with autoimmune thyroiditis presenting with a postpartum psychosis

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT) is a rare condition characterised by neuropsychiatric symptoms, presence of antithyroid antibodies and significant response to steroid therapy. Postpartum psychosis (PP), although having a low prevalence, is a psychiatrical emergency with potentially serious impact in the mother and children. PP has an atypical presentation when compared with affective or psychotic episodes unrelated to pregnancy. Autoimmune dysfunction is frequent in the postpartum period and is closely related to PP. We report a case of a primiparous woman in her 20s with PP who did not respond to initial treatment with antipsychotics. After reassessment, SREAT was considered in the differential diagnosis. Neuropsychiatric symptoms improved dramatically after 72 hours of treatment with high-dose steroids treatment and the patient was discharged after 16 days. In women with PP, an autoimmune cause must be ruled out before assuming a psychiatry aetiology.

Deliberate self-harm in a patient with hyperthyroidism with acute psychosis

A woman in her 30s with underlying Graves' disease, who recently completed radioactive iodine treatment, presented with 2 weeks of acutely altered behaviour associated with auditory hallucinations and religious preoccupations. Laboratory investigation demonstrated elevated free thyroxine levels and suppressed thyroid-stimulating hormone levels. Additionally, there was a presence of antithyroid peroxidase antibodies consistent with autoimmune thyroid disease. She responded to antipsychotics and achieved biochemical euthyroidism. Subsequently, antipsychotic was tapered off during outpatient follow-up at the patient's own request, with supplement thyroxine continuing. After 1 week, acute hallucinations and religious preoccupations re-emerged, driving her to inflict self-injuries by swallowing coins and nails and banging her head against the wall, sustaining laceration wounds. Furthermore, she hammered a roofing nail into the external genitalia, embedded in the symphysis pubis. After supplemental thyroxine was stopped and olanzapine was started, she achieved biochemical euthyroid followed by remission of psychosis within 1 week. This case illustrates the importance of elucidating organic causes of psychosis as they are easily and swiftly reversible.

Alexithymia, Emotional Distress, and Perceived Quality of Life in Patients With Hashimoto's Thyroiditis

Emotion-processing impairment represents a risk factor for the development of somatic illness, affecting negatively both health-related quality of life (HRQoL) and disease management in several chronic diseases. The present pilot study aims at (i) investigating the associations between alexithymia and depression, anxiety, and HRQoL in patients with Hashimoto's thyroiditis (HT); (ii) examining the association between these three psychological conditions together with HRQoL, and thyroid autoantibodies status as well as thyroid echotexture in patients with HT; and (iii) comparing the intensity of all these clinical psychological features in patients with HT versus controls. Twenty-one patients with serologically or ultrasonographically verified HT and 16 controls with non-toxic goiter or postsurgical hypothyroidism were recruited for this study. Serum thyrotropin (TSH) and free thyroxine, as well as thyroid autoantibodies (thyroglobulin antibodies and thyroid peroxidase antibodies), were assayed. Alexithymia, depression, anxiety, and HRQoL were assessed with Toronto Alexithymia Scale; Beck Depression Inventory, second edition; Hamilton Anxiety Rating Scale; and Health Survey Short-Form 36, respectively. A negative relationship between the difficulty to describe feelings and the cognitive component of depression was found (r = -0.46, p = 0.04). Besides, patients with seronegative HT had lower somatic anxiety than patients with HT who tested positive (r = -0.68, p = 0.01 and r = -0.59, p = 0.04, respectively). Besides, no statistically significant difference was found between patients with HT and controls with regard to somatic anxiety. The present study suggests the relevance of alexithymia in patients suffering from HT, which may be intertwined with a possible state of underreported depression that is mainly expressed through physical complaints. Promoting the capability to describe and communicate feelings could contribute to psychological elaboration and coping with the disease and, consequently, to the improvement of self-management and perceived HRQoL.

Clinical characteristics of paediatric Hashimoto's encephalopathy

BACKGROUND

Hashimoto's encephalopathy, also known as steroid responsive encephalopathy, is associated with thyroid antibodies (SREAT) and is a rare but serious form of encephalopathy. In this paper, we describe the signs, symptoms, outcome, and treatments as noted in the case reports reviewed.

METHODS

We searched PubMed, Embase, and the Cochrane library for articles in which cases of Hashimoto's encephalopathy were described. The case description had to include the diagnosis, age, sex, presenting symptoms, and diagnostic tests.

RESULTS

We retrieved 360 articles and 65 fulfilled the inclusion criteria. These articles gave reports of 100 cases, with a mean age of 10.9 (range 2.8-19), 78 of whom were female. Epilepsy (79) - including epileptic state [24] - behavioural problems [36], hallucinations [21], headache [21], and decline in school performance [19] were most often reported. Antithyroid peroxidase (aTPO) was reported elevated in all patients. Most children [70] recovered fully, however 16 had late sequelae, mostly epilepsy. Therapies used include steroids, intravenous gammaglobulines, and cytostatics.

CONCLUSIONS

Epilepsy, behavioural problems, decline in school performance, and hallucinations are frequent symptoms of Hashimoto's encephalopathy. Steroids are the basis of treatment, although other immunomodulatory drugs seem to be successful. About one in ten children will experience late sequelae. In any child with unexplained neurological, psychiatric, or psychological dysfunction, serum anti-thyroidperoxidase (aTPO) should be determined.

The association between systemic autoimmune disorders and epilepsy and its clinical implications

Systemic autoimmune disorders occur more frequently in patients with epilepsy than in the general population, suggesting shared disease mechanisms. The risk of epilepsy is elevated across the spectrum of systemic autoimmune disorders but is highest in systemic lupus erythematosus and type 1 diabetes mellitus. Vascular and metabolic factors are the most important mediators between systemic autoimmune disorders and epilepsy. Systemic immune dysfunction can also affect neuronal excitability, not only through innate immune activation and blood-brain barrier dysfunction in most epilepsies but also adaptive immunity in autoimmune encephalitis. The presence of systemic autoimmune disorders in subjects with acute seizures warrants evaluation for infectious, vascular, toxic and metabolic causes of acute symptomatic seizures, but clinical signs of autoimmune encephalitis should not be missed. Immunosuppressive medications may have antiseizure properties and trigger certain drug interactions with antiseizure treatments. A better understanding of mechanisms underlying the co-existence of epilepsy and systemic autoimmune disorders is needed to guide new antiseizure and anti-epileptogenic treatments. This review aims to summarize the epidemiological evidence for systemic autoimmune disorders as comorbidities of epilepsy, explore potential immune and non-immune mechanisms, and provide practical implications on diagnostic and therapeutic approach to epilepsy in those with comorbid systemic autoimmune disorders.

Hashimoto's Encephalopathy: A Rare Cause of Seizure-like Activity

Hashimoto’s encephalopathy is an uncommon disorder that may present with a wide variety of different neurological signs and symptoms that can include acute altered level of consciousness, psychosis, seizures, ataxia, dementia, myoclonus, and stupor. We present a case of a 60-year-old female patient who was admitted to the internal medicine floor for workup for seizures of unknown etiology. Investigations, including a complete blood count, basic metabolic panel, magnetic resonance imaging (MRI) of the brain, cerebrospinal fluid analysis, and NMDA (N-methyl-D-aspartate) receptor encephalitis screen, were all unremarkable. Thyroid-stimulating hormone levels and anti-thyroid peroxidase antibodies were found to be elevated, suggesting an underlying etiology of Hashimoto’s thyroiditis. Treatment with corticosteroids and levothyroxine can lead to resolution of symptoms. This case report is presented to suggest the importance of serological screening for anti-thyroid antibodies in the workup of all patients with unknown causes of encephalopathy along with providing a review of the literature.

Psychiatric autoimmune conditions in children and adolescents: Is catatonia a severity marker?

OBJECTIVES

Patients with autoimmune encephalitis (AE) are likely to exhibit an acute onset of severe psychiatric features, including psychosis and/or catatonia. Based on the high prevalence of catatonia in AE and our clinical experience, we hypothesized that catatonia might be a marker of severity requiring more aggressive treatment approaches.

METHODS

To reach a sufficient number of cases with brain-autoimmune conditions, we pooled two samples (N = 58): the first from the French National Network of Rare Psychiatric diseases and the second from the largest Italian neuro-pediatrics center for encephalopathies. Autoimmune conditions were diagnosed using a multidisciplinary approach and numerous paraclinical investigations. We retrospectively compared patients with and without catatonia for psychiatric and non-psychiatric clinical features, biological and imaging assessments, type of immunotherapy used and outcomes.

RESULTS

The sample included 25 patients (43%) with catatonia and 33 (57%) without catatonia. Forty-two patients (72.4%) had a definite AE (including 27 anti-NMDA receptor encephalitis) and 16 (27.6%) suspected autoimmune encephalitis. Patients with catatonia showed significantly more psychotic features [18 (72%) vs 9 (27.3%), p < 0.001)] and more movement disorders [25 (100%) vs 20 (60.6%), p < 0.001] than patients without catatonia. First line (corticoids, immunoglobulin and plasma exchanges) and second line (e.g., rituximab) therapies were more effective in patients with catatonia, with 24 (96%) vs 22 (66.7%) (p = 0.006) and 17 (68%) vs 9 (27.3%) (p = 0.002), respectively. However, those with catatonia received more combinations of first and second line treatments and had more relapses during outcomes.

CONCLUSION

Despite its exploratory design, the study supports the idea that autoimmune catatonia may be a marker of severity and morbidity in terms of initial presentation and relapses, requiring the need for early and aggressive treatment.

Association between acute disseminated encephalomyelitis and thyroid autoimmunity in children

BACKGROUND

Abnormal thyroid peroxidase antibody (TPOAb) levels are observed in various autoimmune diseases. However, the relationship between TPOAb and pediatric acute disseminated encephalomyelitis (PADEM) remains unclear. This study aimed to investigate the positive rate of TPOAb and thyroid dysfunction in children with acute disseminated encephalomyelitis (ADEM) and assess the relationship between TPOAb and clinical features of PADEM.

METHODS

This retrospective single-center case-control study was conducted from April 2017 to April 2019. We enrolled 23 children with ADEM and 23 age- and sex-matched healthy controls. Based on whether they were positive for TPOAb, the children with ADEM were allocated either to the TPOAb+ or TPOAb- group. The median follow-up time was 12 months (6-30 months). Observers were blinded to the patient groupings. We compared the clinical and imaging characteristics of the two groups.

RESULTS

Among the 23 patients with PADEM, 47.8% presented with abnormal TPOAb levels, while there were no TPOAb+ cases in the control group. Among the children with ADEM, there were significantly increased TPOAb positive rates and significantly decreased fT3 levels. TPOAb+ and TPOAb- subgroup analysis revealed significant differences in gait, fever, and total IgG. In the TPOAb+ group, there was a significant decrease in TPOAb levels at 2 weeks after ADEM onset. The follow-up of patients who were TPOAb+ at 3 months after onset showed a gradual decrease in their TPOAb levels back to normal. One patient who presented new nervous system symptoms after over 1 month also showed a simultaneous increase in TPOAb levels. There was a significant negative correlation between Glasgow Coma Scale (GCS) scores and TPOAb levels (p = 0.042, r = -0.892).

CONCLUSION

There was a negative correlation of TPOAb levels with GCS scores. Therefore, TPOAb levels could be used for the prognosis of patients with PADEM. We recommend determining thyroid function when assessing patients with PADEM during follow-up.

Attempted Suicide in a Woman With Steroid-responsive Encephalopathy Associated With Autoimmune Thyroiditis: A Case Report

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT) is a rare phenomenon that manifests with nonspecific psychiatric and neurological signs and symptoms, an elevated serum thyroid peroxidase antibody level, and a positive treatment response to corticosteroids. Current literature describes highly varied presentations of the disease, which makes its diagnosis a challenging endeavor. The psychiatric symptoms of SREAT, in particular, are very difficult to ascribe to the correct diagnosis, as there are few laboratory or imaging modalities available to workup these manifestations. As a result, authors have attempted to compose rough guidelines that would help clinicians more easily recognize SREAT, which is important given the wide accessibility and efficacy of the main treatment for this condition. We present the case of a young woman diagnosed with SREAT who presented after a suicide attempt. Although signs and symptoms of depression, psychosis, and mania have been well described as potential manifestations of the disorder, attempted suicide as a primary presentation of SREAT has not been well captured in the current literature. In fact, it appears that suicidal thoughts and attempts are not nearly as prevalent as would be expected given the high prevalence of psychiatric signs and symptoms in the disorder, but rather, they appear to be quite rare phenomena. In this case report, we identify other articles in the literature that address suicidal thoughts or attempts in association with SREAT. The patient described in our report is one of the only cases of a suicide attempt in the context of a primarily depressed state as a result of SREAT.

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 in association with retinitis pigmentosa - First reported case

Hashimoto's Encephalopathy (HE), also known as steroid responsive encephalopathy associated with autoimmune thyroiditis (SREAT), is a proteiform disorder known for its wide spectrum of presentations from subtle neuropsychiatric manifestations, movement disorders, seizures, stroke-like episodes to coma. Here, we report a case of HE which initially masqueraded as bipolar affective disorder (BPAD) and ultimately progressed to generalized tonic clonic seizures and coma. Although SREAT is characterized by exquisite responsive to steroid, in our case it was unresponsive to pulse methylprednisolone therapy. Rapid recovery was noted with intravenous immunoglobulin (IVIG) therapy. This case was also peculiar for its association with non-sydnromic retinitis pigmetosa (RP). To the best of our knowledge, this was the first reported case of HE which was associated with RP.

The role of protein disulphide-isomerase A3 as autoantigen in the pathogenesis of autoimmune thyroiditis and related brain damage in adult mice

Autoimmune thyroiditis (AIT)-related brain damage is one of most severe extrathyroidal manifestations of AIT, but the mechanism remains unclear. In this study, we confirmed that protein disulfide-isomerase A3 (PDIA3) is expressed in both thyroid and brain tissues of mouse, and found the significantly increased serum levels of anti-PDIA3 antibody (PDIA3Ab) in classical mouse models of thyroiditis. In addition, we investigated the PDIA3-specific autoimmune reaction in thyroid and brain tissues in a mouse model with high-serum PDIA3Ab induced by immunization with recombinant PDIA3 protein. PDIA3-immunized mice had elevated serum thyrotropin and impaired learning and memory. PDIA3-expressing cells had IgG deposition, and IgG colocalized with C3 in the thyroid and brain tissues of PDIA3-immunized mice, resulting in membrane attack complex formation. Our results suggest that PDIA3 protein may be a common autoantigen shared by the thyroid and brain tissues and involve in the thyroidal and intracerebral damage through activating complement system.

Hashimoto encephalopathy in the 21st century

Objective

To report the presenting syndromes and to determine whether pretreatment criteria of Hashimoto encephalopathy (HE) predict response to steroids.

Methods

We assessed symptoms and steroid responsiveness in 24 patients with pretreatment criteria of HE, including (1) subacute onset of cognitive impairment, psychiatric symptoms, or seizures; (2) euthyroid status or mild hypothyroidism; (3) serum thyroid peroxidase antibodies (TPOAb) >200 IU/mL; (4) absent neuronal antibodies in serum/CSF; and (5) no other etiologies. Additional studies included determination of TPOAb (>200 IU/mL) in 74 patients with criteria of possible autoimmune encephalitis (AE) without neuronal antibodies and 205 patients with different neuroimmunologic diseases, psychosis, or new-onset refractory status epilepticus (NORSE). Serum antibodies to the amino (ΝΗ2)-terminal of α-enolase (NH2-α-enolaseAb) were examined in the indicated 24 patients and 13 controls.

Results

The 24 patients (14 women) with suspected HE had a median age of 48 years (range 8–79 years). Four syndromes were identified: psychiatric (7, 29%), encephalopathy (7, 29%), NORSE-like (6, 25%), and limbic encephalitis (4, 17%). Only 6 of 19 (31.6%) patients completely responded to steroids. The frequency of TPOAb in the 74 patients with possible AE (6 of 74, 8.1%) was similar to that of the 205 controls (17 of 205, 8.2%; p = 0.84). NH2-α-enolaseAb were identified in 1 of 24 suspected HE cases and 1 of 13 controls.

Conclusion

Current pretreatment criteria of HE do not predict steroid responsiveness. The detection of TPOAb across all control groups reveals their poor disease-specificity. NH2-α-enolaseAb did not help in the diagnosis of HE. These findings imply a redefinition of HE that requires a systematic exclusion of antibody-mediated encephalitis.

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].

Hashimoto's Encephalopathy and Seizure Disorders

Hashimoto's encephalopathy (HE) is a rare, clinically heterogeneous condition associated with positive thyroid autoantibodies. It is increasingly recognized as an important and treatable cause of autoimmune encephalopathy. Thyroid-associated antibodies such as thyroperoxidase (TPO) antibody, thyroglobulin (TG) antibody, and thyrotropin receptor (TR) antibody were found in HE patients with seizure disorders. Although antithyroid antibodies are required for the diagnosis of HE, their role in the pathogenesis of HE remains uncertain. Instead of playing a key role in the pathophysiology processes of HE, it is suggested that thyroid-associated antibodies are hallmarks of HE. Seizure disorders were found in approximately two-thirds of HE patients, and common anticonvulsant therapy alone is usually ineffective. Some patients did not respond to any antiepileptic drugs. The use of immunotherapy can effectively control seizure disorders. Electroencephalography and imaging findings are not specific to HE patients and can also be seen in other causes of encephalopathies. However, the prognosis in the majority of patients with HE was usually good if it is diagnosed and treated correctly.

[Hashimoto thyroiditis, therapeutic options and extrathyroidal options - an up-to-date overview]

Hashimoto's thyroiditis is one of the most common organspecific autoimune diseases and the most frequent cause of hypothyroidism in areas with sufficient iodine supply. Excessively stimulated T cells CD4+ and their differentiated cells are known to play a key role in the pathogenesis. It is currently accepted that on the one hand genetic susceptibility, environmental factors, existential factors (gender difference) play an important role, on the other hand gut and intestinal microbiota seem to contribute to its development too. Diagnosis requires a detailed medical history, sonography, and blood analysis of thyroid function and thyroid antibodies. In case of an overt or subclinical hypothyroidism long-term or lifelong levothyroxine replacement may be needed, with a special focus on phases with an additional demand like during pregnancy. There are multifactorial reasons for poor response to therapy despite normal TSH levels in blood sampling like co-morbidities (other organspecific autoimmune diseases, psychiatric diseases), lack of vitamin and trace elements. Pharmacogenomic and pharmacokinetic factors may impact on levothyroxine bioavailability, also thyroid hormone resistance and transport- or conversion disorder due to insulin resistance or adrenal insufficiency for example. The relations between thyroid function, mental status and psychiatric disorders seem to be complex and the mechanisms underlying the interactions remain to be clarified. Continuing research in biochemical, genetic and neuroimaging fields are needed.

Relapsing encephalopathy with dancing eyes and jerky limbs

We report a case of relapsing-remitting opsoclonus-myoclonus-ataxia syndrome (OMAS) in a patient with Hashimoto's encephalopathy, diagnosed after comprehensive evaluation. OMAS as a manifestation of Hashimoto's encephalopathy has been reported once previously. It is hoped that recognition of this entity and early initiation of immunotherapy will improve clinical outcomes for patients.

An evolving redefinition of autoimmune encephalitis

Autoimmune encephalitis encompasses a wide variety of protean pathologic processes associated with the presence of antibodies against neuronal intracellular proteins, synaptic receptors, ion channels and/or neuronal surface proteins. This type of encephalitis can also involve children with complex patterns of seizures and unexpected behavioural changes, which jeopardize their prompt recognition and treatment. Many epidemiological studies have shown that numerous immune-based forms of encephalitis can be encountered, almost surpassing the rate of postinfectious encephalitides. However, the overall exact prevalence of autoimmune encephalopathies remains underestimated, and the definition of diagnostic algorithms results muddled. The spectrum of neuropsychiatric manifestations in the pediatric population with autoimmune encephalitis is less clear than in adults, but the integration of clinical, immunological, electrophysiological and neuroradiological data is essential for a general approach to patients. In this review we report the most relevant data about both immunologic and clinical characteristics of the main autoimmune encephalitides recognized so far, with the aim of assisting clinicians in the differential diagnosis and favouring an early effective treatment. Correlations between phenotype and autoantibodies involved in the neurological damage of autoimmune encephalitis are largely unknown in the first years of life, because of the relatively small number of pediatric patients adequately studied. Future multicenter collaborative studies are needed to improve the diagnostic approach and tailor personalized therapies in the long-term.

A causality algorithm to guide diagnosis and treatment of catatonia due to autoimmune conditions in children and adolescents

OBJECTIVES

Pediatric catatonia is a rare and life-threatening syndrome. Around 20% of juvenile catatonia is associated with organic condition (Consoli et al., 2012). Autoimmune conditions represent a diagnostic and therapeutic challenge since specific antibodies can be missed. To facilitate decision making, we recently formulated a causality assessment score (CAUS) using a stepwise approach and an immunosuppressive therapeutic challenge (Ferrafiat et al., 2016). Our objectives were to validate retrospectively CAUS and to define its threshold for an accurate distinction between organic catatonia and non-organic catatonia, and specifically between autoimmune catatonia and non-organic catatonia.

METHOD

To obtain a sufficient number of cases with organic catatonia, we pooled two samples (N=104) - one from a child psychiatry center, the other from neuro-pediatrics center - expert in catatonia and autoimmune conditions. Organic conditions were diagnosed using a multidisciplinary approach and numerous paraclinical investigations. Given the binary classification needs, we used receiver operating characteristic (ROC) analysis (Peacock and Peacock, 2010) to calculate the best classification threshold.

RESULTS

The cohort included 67 cases of non-organic catatonia and 37 cases of organic catatonia. ROC analysis showed that the CAUS performance in discriminating both organic catatonia vs. non-organic catatonia, and autoimmune catatonia vs. non-organic catatonia was excellent (Area Under the Curve=0.99). In both analyses, for a CAUS threshold≥5, accuracy equaled to 0.96.

CONCLUSION

Regarding juvenile catatonia, the use of the CAUS score algorithm combining a therapeutic challenge and a threshold≥5 may help to diagnose and treat autoimmune conditions even without formal identification of auto-antibodies.

A 15-Year-Old Boy With Refractory Status Epilepticus

In this case report, we discuss a 15-year-old previously healthy boy who presented with acute onset encephalopathy with refractory status epilepticus requiring pentobarbital-induced burst suppression for seizure control. We review the differential diagnosis and important diagnostic considerations for pediatric patients presenting with acute encephalopathy. We then review Hashimoto encephalopathy (SREAT) and discuss presentation, diagnosis, and treatment.

Hashimoto's encephalopathy presenting as pseudobulbar palsy

INTRODUCTION

Hashimoto's encephalopathy (HE) is an autoimmune condition with varied neurological and psychiatric features. HE is very unusual as a cause of pseudobulbar palsy (PSP).

CASE PRESENTATION

A 14-year-old male was admitted with right-sided weakness, dysphagia, speech disorder, and aggressiveness. Brain magnetic resonance imaging showed increased intensity in bilateral temporal, insular cortex, amygdala, and parahippocampal area on T2-weighted and fluid-attenuated inversion recovery images. Autoimmune encephalitis was considered as the patient had subacute onset of psychiatric and motor disturbances with normal findings for cerebrospinal fluid. N-methyl-D-aspartate receptor, anti-glutamate-type α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid 1 and 2, anti-contactin-associated protein-like 2, anti-gamma-aminobutyric acid receptor, anti-Leucine-rich, and glioma-inactivated 1 antibodies were negative but the anti-thyroperoxidase (antiTPO) level was greater than 998 IU/ML (n:0-9). Steroid therapy was initiated as pulse therapy and maintained with 2-mg/kg/day dose with the diagnosis of HE. He was symptom free for 6 months. In the follow-up period, he had two recurrences which responded to steroid therapy.

CONCLUSION

The common causes of PSP are demyelinating, vascular, and motor neuron diseases and congenital malformations of the opercular or insular cortex. However, there are no cases of PSP developing after any autoimmune encephalitis. This case highlights the importance of early detection of antiTPO antibodies with the findings of PSP due to autoimmune encephalitis.

Autoimmunity in 2016

The number of peer-reviewed articles published during the 2016 solar year and retrieved using the "autoimmunity" key word remained stable while gaining a minimal edge among the immunology articles. Nonetheless, the quality of the publications has been rising significantly and, importantly, acquisitions have become available through scientific journals dedicated to immunology or autoimmunity. Major discoveries have been made in the fields of systemic lupus erythematosus, rheumatoid arthritis, autoimmunity of the central nervous system, vasculitis, and seronegative spondyloarthrithritides. Selected examples include the role of IL17-related genes and long noncoding RNAs in systemic lupus erythematosus or the effects of anti-pentraxin 3 (PTX3) in the treatment of this paradigmatic autoimmune condition. In the case of rheumatoid arthritis, there have been reports of the role of induced regulatory T cells (iTregs) or fibrocytes and T cell interactions with exciting implications. The large number of studies dealing with neuroimmunology pointed to Th17 cells, CD56(bright) NK cells, and low-level TLR2 ligands as involved in multiple sclerosis, along with a high salt intake or the micriobiome-derived Lipid 654. Lastly, we focused on the rare vasculitides to which numerous studies were devoted and suggested that unsuspected cell populations, including monocytes, mucosal-associated invariant T cells, and innate lymphoid cells, may be crucial to ANCA-associated manifestations. This brief and arbitrary discussion of the findings published in 2016 is representative of a promising background for developments that will enormously impact the work of laboratory scientists and physicians at an exponential rate.

Abnormal brain functional connectivity leads to impaired mood and cognition in hyperthyroidism: a resting-state functional MRI study

Patients with hyperthyroidism frequently have neuropsychiatric complaints such as lack of concentration, poor memory, depression, anxiety, nervousness, and irritability, suggesting brain dysfunction. However, the underlying process of these symptoms remains unclear. Using resting-state functional magnetic resonance imaging (rs-fMRI), we depicted the altered graph theoretical metric degree centrality (DC) and seed-based resting-state functional connectivity (FC) in 33 hyperthyroid patients relative to 33 healthy controls. The peak points of significantly altered DC between the two groups were defined as the seed regions to calculate FC to the whole brain. Then, partial correlation analyses were performed between abnormal DC, FC and neuropsychological performances, as well as some clinical indexes. The decreased intrinsic functional connectivity in the posterior lobe of cerebellum (PLC) and medial frontal gyrus (MeFG), as well as the abnormal seed-based FC anchored in default mode network (DMN), attention network, visual network and cognitive network in this study, possibly constitutes the latent mechanism for emotional and cognitive changes in hyperthyroidism, including anxiety and impaired processing speed.

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.

Recent advances in understanding autoimmune thyroid disease: the tallest tree in the forest of polyautoimmunity

Autoimmune thyroid disease (AITD) is often observed together with other autoimmune diseases. The coexistence of two or more autoimmune diseases in the same patient is referred to as polyautoimmunity, and AITD is the autoimmune disease most frequently involved. The occurrence of polyautoimmunity has led to the hypothesis that the affected patients suffer from a generalized dysregulation of their immune system. The present review summarizes recent discoveries unravelling the immunological mechanisms involved in autoimmunity, ranging from natural autoimmunity to disease-specific autoimmunity. Furthermore, the clinical grounds for considering AITD in a setting of polyautoimmunity are explored. A better understanding of these may pave the way for designing new treatment modalities targeting the underlying immune dysregulation when AITD appears in the context of polyautoimmunity.

Autoantibody-Associated Movement Disorders in Children: Proven and Proposed

Movement disorders secondary to autoantibodies in children represent a rapidly expanding group of conditions. Once considered to be limited to poststreptococcal Sydenham's chorea or rare cases of childhood systemic lupus erythematosus, a variety of antibody-related movement abnormalities are now seen as part of noninfectious autoimmune encephalitis or within an expanding list of postinfectious disorders. In this article, several proposed autoantibody-mediated movement disorders in children are reviewed. In each one, there is a hypothesized antibody biomarker that is believed to be pathogenic and cause the clinical symptoms. As will be discussed, in some, such as anti-NMDA receptor encephalitis, the strength of supporting evidence is strong. In others, antibodies have been identified, but their role as the pathophysiological mechanism remains undetermined. Lastly, there are proposed disorders, such as PANDAS, that are controversial on both a clinical and autoimmune basis.

Prominent Bilateral Hand Tremor in Hashimoto's Encephalopathy: A Video Demonstration

BACKGROUND

Hashimoto's encephalopathy often presents with neuropsychiatric manifestations including seizures and movement disorders.

CASE REPORT

We describe a patient who presented with bilateral hand tremor and mild cognitive defects that fulfilled the criteria for a diagnosis of Hashimoto's encephalopathy. There was a rapid response to glucocorticoid therapy with relapse following treatment withdrawal.

DISCUSSION

Recently published clinical criteria for the diagnosis of Hashimoto's encephalopathy include seizures, myoclonus, hallucinations, or stroke-like episodes but do not include tremor. Our case had mild cognitive dysfunction and a coarse tremor as the predominant clinical features, which probably represent mild disease.