Psychiatric Presentations Heralding Hashimoto's Encephalopathy: A Systematic Review and Analysis of Cases Reported in Literature

Hashimoto encephalopathy: a literature review and case report with comprehensive neuropsychological evaluation

Objective: Hashimoto's encephalopathy (HE), a rare immune-mediated disorder, manifests as altered mental state, cognitive and psychological dysfunction, seizures, and myoclonus. Little is known, however, about the neuropsychological profiles of individuals with HE due to the sparse amount of research. This report overviews HE, summarizes findings from available published neuropsychological evaluations, and details neuropsychological examinations of a 57-year-old White woman with a confirmed HE diagnosis evidencing persistent neuropsychological impairment at two discrete timepoints. Method: An extensive literature search was conducted on PubMed and Google Scholar for studies including neuropsychological evaluations of HE cases. Our neuropsychological evaluation included chart review, diagnostic clinical interview, performance-based neurocognitive assessment, and measures of personality and psychopathology. Results: Our assessment revealed a largely subcortical pattern of neurocognitive impairment and impactful neuropsychiatric symptoms that, together, significantly impacted the patient's quality of life and functional status. The patient's performance improved during a six-month re-evaluation within the domains of cognition, psychological functioning, and functional independence. Conclusions: This article highlights the complexity and possible long-term sequela of HE. Complex medical history (including autoimmune disorders) and psychiatric presentation at onset may be factors related to longer-term cognitive dysfunction. Neuropsychology and psychology can serve important and unique roles in assessing long-term functioning and response to treatment in such cases.

Steroid responsive encephalopathy associated with autoimmune thyroiditis (SREAT) presenting as subacute psychosis: Case report and literature review

Clinicians should consider autoimmune thyroiditis in patients presenting with neuropsychiatric symptoms and promptly initiate appropriate investigations and treatment, such as corticosteroids, to improve clinical outcomes.

Myxedema Psychosis: Diagnostic Challenges and Management Strategies in Hypothyroidism-Induced Psychosis

Myxedema psychosis (MP), a rare psychiatric manifestation of hypothyroidism, presents significant diagnostic and therapeutic challenges. This case report details the presentation, diagnosis, and successful management of a 60-year-old woman with MP, who was initially admitted to the psychiatric department for new-onset psychosis following the cessation of hormone replacement therapy after a subtotal thyroidectomy performed 20 years prior. Despite the rarity of psychosis as an initial presentation of hypothyroidism, this case underscores the critical importance of considering endocrine disorders in the differential diagnosis of unexplained psychotic symptoms. The clinical findings included a polymorphic delusional system and auditory hallucinations, without significant abnormalities on magnetic resonance imaging. Elevated thyroid-stimulating hormone (TSH) levels confirmed hypothyroidism, leading to the diagnosis of MP. Treatment with l-thyroxine resulted in complete resolution of symptoms in three weeks, highlighting the efficacy of hormone replacement therapy. This case contributes to the limited literature on MP and echoes the need for awareness among clinicians to ensure timely and accurate diagnosis and treatment.

Association between free thyroxine levels and clinical phenotype in first-episode psychosis: a prospective observational study

Aim

To determine whether thyroid hormone levels are associated with a specific clinical phenotype in patients with first-episode psychosis (FEP).

Methods

Ninety-eight inpatients experiencing FEP and with less than 6 weeks of antipsychotic treatment were included in the study and were followed up for one year. Baseline psychiatric evaluation included assessment of prodromal symptoms, positive and negative symptoms, depressive symptoms, stressful life events and cycloid psychosis criteria. Thyroid function (thyroid-stimulating hormone (TSH) and free thyroxin (FT4)) was determined at admission. Partial correlation analysis was conducted to analyse the correlation between levels of TSH/FT4 and symptoms. Logistic regression was performed to explore the association between psychopathological symptoms, 12-month diagnoses and thyroid hormones while adjusting for covariates.

Results

Patients with prodromal symptomatology showed lower baseline FT4 levels (OR = 0.06; p = 0.018). The duration of untreated psychosis (DUP) was inversely associated with FT4 concentrations (r =  - 0.243; p = 0.039). FEP patients with sudden onset of psychotic symptoms (criteria B, cycloid psychosis) showed higher FT4 levels at admission (OR = 10.49; p = 0.040). Patients diagnosed with affective psychotic disorders (BD or MDD) at the 12-month follow-up showed higher FT4 levels at admission than patients diagnosed with nonaffective psychosis (schizophrenia, schizoaffective) (OR = 8.57; p = 0.042).

Conclusions

Our study suggests that higher free-thyroxine levels are associated with a specific clinical phenotype of FEP patients (fewer prodromal symptoms, shorter DUP duration and sudden onset of psychosis) and with affective psychosis diagnoses at the 12-month follow-up.

Autoantibody-associated psychiatric syndromes: a systematic literature review resulting in 145 cases

BACKGROUND

Autoimmune encephalitis (AE) is an important consideration during the diagnostic work-up of secondary mental disorders. Indeed, isolated psychiatric syndromes have been described in case reports of patients with underlying AE. Therefore, the authors performed a systematic literature review of published cases with AE that have predominant psychiatric/neurocognitive manifestations. The aim of this paper is to present the clinical characteristics of these patients.

METHODS

The authors conducted a systematic Medline search via Ovid, looking for case reports/series of AEs with antineuronal autoantibodies (Abs) against cell surface/intracellular antigens combined with predominant psychiatric/neurocognitive syndromes. The same was done for patients with Hashimoto encephalopathy/SREAT. Only patients with signs of immunological brain involvement or tumors in their diagnostic investigations or improvement under immunomodulatory drugs were included.

RESULTS

We identified 145 patients with AE mimicking predominant psychiatric/neurocognitive syndromes. Of these cases, 64% were female, and the mean age among all patients was 43.9 (±22.1) years. Most of the patients had Abs against neuronal cell surface antigens (55%), most frequently against the NMDA-receptor (N = 46). Amnestic/dementia-like (39%) and schizophreniform (34%) syndromes were the most frequently reported. Cerebrospinal fluid changes were found in 78%, electroencephalography abnormalities in 61%, and magnetic resonance imaging pathologies in 51% of the patients. Immunomodulatory treatment was performed in 87% of the cases, and 94% of the patients responded to treatment.

CONCLUSIONS

Our findings indicate that AEs can mimic predominant psychiatric and neurocognitive disorders, such as schizophreniform psychoses or neurodegenerative dementia, and that affected patients can be treated successfully with immunomodulatory drugs.

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.

Clinical manifestations and immunomodulatory treatment experiences in psychiatric patients with suspected autoimmune encephalitis: a case series of 91 patients from Germany

Autoimmune encephalitis (AE) can rarely manifest as a predominantly psychiatric syndrome without overt neurological symptoms. This study's aim was to characterize psychiatric patients with AE; therefore, anonymized data on patients with suspected AE with predominantly or isolated psychiatric syndromes were retrospectively collected. Patients with readily detectable neurological symptoms suggestive of AE (e.g., epileptic seizures) were excluded. Patients were classified as "probable psychiatric AE (pAE)," if well-characterized neuronal IgG autoantibodies were detected or "possible pAE" (e.g., with detection of nonclassical neuronal autoantibodies or compatible cerebrospinal fluid (CSF) changes). Of the 91 patients included, 21 (23%) fulfilled our criteria for probable (autoantibody-defined) pAE and 70 (77%) those for possible pAE. Among patients with probable pAE, 90% had anti-NMDA receptor (NMDA-R) autoantibodies. Overall, most patients suffered from paranoid-hallucinatory syndromes (53%). Patients with probable pAE suffered more often from disorientation (p < 0.001) and impaired memory (p = 0.001) than patients with possible pAE. Immunotherapies were performed in 69% of all cases, mostly with high-dose corticosteroids. Altogether, 93% of the patients with probable pAE and 80% of patients with possible pAE reportedly benefited from immunotherapies (p = 0.251). In summary, this explorative, cross-sectional evaluation confirms that autoantibody-associated AE syndromes can predominantly manifest as psychiatric syndromes, especially in anti-NMDA-R encephalitis. However, in three out of four patients, diagnosis of possible pAE was based on nonspecific findings (e.g., slight CSF pleocytosis), and well-characterized neuronal autoantibodies were absent. As such, the spectrum of psychiatric syndromes potentially responding to immunotherapies seems not to be limited to currently known autoantibody-associated AE. Further trials are needed.

Challenges in corticosteroid dose regulation in a patient with autoimmune thyroid disease and neuropsychiatric syndrome: A running commentary

In the following, we report a therapeutic challenge faced by reduction in corticosteroid therapeutic dosage in a patient diagnosed with Hashimoto's encephalopathy (HE), which is equivalent to corticosteroid-responsive encephalopathy related to autoimmune thyroiditis and often misdiagnosed as neuropsychiatric status. The patient developed psychiatric symptoms.

Autoantibody-associated psychiatric symptoms and syndromes in adults: A narrative review and proposed diagnostic approach

Background

Autoimmune-mediated encephalitis is a disease that often encompasses psychiatric symptoms as its first clinical manifestation’s predominant and isolated characteristic. Novel guidelines even distinguish autoimmune psychosis from autoimmune encephalitis. The aim of this review is thus to explore whether a wide range of psychiatric symptoms and syndromes are associated or correlate with autoantibodies.

Methods

We conducted a PubMed search to identify appropriate articles concerning serum and/or cerebrospinal fluid (CSF) autoantibodies associated with psychiatric symptoms and syndromes between 2000 and 2020. Relying on this data, we developed a diagnostic approach to optimize the detection of autoantibodies in psychiatric patients, potentially leading to the approval of an immunotherapy.

Results

We detected 10 major psychiatric symptoms and syndromes often reported to be associated with serum and/or CSF autoantibodies comprising altered consciousness, disorientation, memory impairment, obsessive-compulsive behavior, psychosis, catatonia, mood dysfunction, anxiety, behavioral abnormalities (autism, hyperkinetic), and sleeping dysfunction. The following psychiatric diagnoses were associated with serum and/or CSF autoantibodies: psychosis and schizophrenia spectrum disorders, mood disorders, minor and major neurocognitive impairment, obsessive-compulsive disorder, autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), anxiety disorders, eating disorders and addiction. By relying on these symptom clusters and diagnoses in terms of onset and their duration, we classified a subacute or subchronic psychiatric syndrome in patients that should be screened for autoantibodies. We propose further diagnostics entailing CSF analysis, electroencephalography and magnetic resonance imaging of the brain. Exploiting these technologies enables standardized and accurate diagnosis of autoantibody-associated psychiatric symptoms and syndromes to deliver early immunotherapy.

Conclusions

We have developed a clinical diagnostic pathway for classifying subgroups of psychiatric patients whose psychiatric symptoms indicate a suspected autoimmune origin.

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Autoantibodies are associated with a broad spectrum of psychiatric syndromes.

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More systematic studies are needed to elucidate the significance of autoantibodies.

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We developed a pathway to identify autoantibody-associated psychiatric syndromes.

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".

Myxedema Psychosis: Systematic Review and Pooled Analysis

BACKGROUND AND OBJECTIVE

The term myxedema psychosis (MP) was introduced to describe the occurrence of psychotic symptoms in patients with untreated hypothyroidism, but the optimal assessment and treatment of this condition are unclear. We aimed to synthesize data from the literature to characterize the clinical presentation and management of MP.

METHODS

We performed a systematic review according to the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines in PubMed (Medline), Embase, Google Scholar, and Cochrane databases, including observational studies, case series, and case reports published from 1/1/1980 to 31/12/2019 in the English language. Descriptive statistics along with univariate and multivariate analysis were used for data synthesis.

RESULTS

Out of 1583 articles screened, 71 case reports met our inclusion criteria providing data on 75 MP cases. The median age at diagnosis was 42 years [32-56]. About 53% had no prior hypothyroidism diagnosis. Delusions occurred in 91%, with a predominance of persecutory ideas (84%), while hallucinations occurred in 78%. Physical symptoms and signs of hypothyroidism were absent in 37% and 26%, respectively. If symptoms occurred, nonspecific fatigue was seen most frequently (63%). The median thyroid-stimulating hormone value was 93 mIU/L [60-139]. Thyroid peroxidase antibodies were found positive in 75% (23/33) of reported cases. Creatinine kinase was reported abnormal in seven cases. Cranial imaging (CT or MRI) and electroencephalogram were normal in 89%, 75%, and 73% of the cases reported. The majority of patients were treated orally with thyroxine in combination with short-term antipsychotics. More than 90% of them showed complete recovery. Univariate analysis revealed a trend towards a shorter duration of psychosis with IV thyroid hormone therapy (p= 0.0502), but the effect was not consistent in a multivariate analysis.

CONCLUSION

While we identified a substantial lack of published research on MP, our pooled analysis of case observations suggests that the condition presents a broad spectrum of psychiatric and physical symptoms lending support to the value of screening for thyroid dysfunction in patients with first-ever psychosis.

PROSPERO REGISTRATION NUMBER

CRD42020160310.

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.

Hashimoto’s Encephalopathy Revealed by Hypochondriacal Delusion: A Case Report Involving a Male Patient

Hashimoto’s encephalopathy (HE) is a rare autoimmune disorder. It associates encephalopathy with autoimmune thyroiditis, presenting abnormal elevations of thyroid antibodies. It is more common in females. It can present with various symptoms, including seizures, myoclonus, psychosis, hallucinations, and mood disturbances. Hypochondriacal delusion is an unusual clinical presentation of this disorder. The authors report a case of HE in a male patient whose clinical presentation was dominated by hypochondriacal delusion. The absence of response to antipsychotics, high serum antithyroid peroxidase antibodiesof about 199 UI/ml, the normality of magnetic resonance imaging, and improvement with corticosteroids confirmed the diagnosis. This neuroendocrine disorder is often misdiagnosed and it represents a diagnostic challenge for clinicians. It should be considered in patients presenting a refractory or an atypical neuropsychiatric disorder and having a family history of autoimmune disease.

Evaluation of Diagnostic Criteria for Hashimoto Encephalopathy Among Children and Adolescents

BACKGROUND

The recently proposed adult diagnostic criteria for the Hashimoto encephalopathy (HE) include a requirement of subclinical or mild thyroid disease. However, most reports indicate that most children treated for HE do not have evidence of thyroid disease. We aim to evaluate the impact of applying the current adult diagnostic criteria to pediatric patients.

METHODS

Pediatric patients with HE were evaluated at time of symptom onset and follow-up at least 1 year after initiation of immunomodulatory treatment for degree of impairment within the neuropsychiatric domains of cognition, language, psychiatric disturbance, seizure, movement disorder, sleep disruption, and overall functionality. We compared the response to treatment among patients stratified by the presence or absence of subclinical or mild thyroid disease using the Modified Rankin Scale, the Liverpool Outcome Score, and a novel multidomain scale designed for the population with pediatric autoimmune brain disorders.

RESULTS

Of 17 pediatric patients treated for HE, 6 met full adult diagnostic criteria, whereas 11 patients did not meet criteria solely owing to the absence of thyroid disease. Using our novel scale, the 6 patients meeting full criteria had statistically significant improvement from time of onset of disease to follow-up in the domain of cognition. The 11 patients who did not meet full criteria based on their absence of thyroid disease exhibited statistically significant improvement from time of onset of disease to follow-up in the domains of cognition, language, psychiatric disturbance, movement, and sleep.

CONCLUSIONS

Rigidly applying the current diagnostic criteria to pediatric patients with suspected HE may result in the failure to treat potential responders. We propose a set of diagnostic criteria for HE in children, which does not require thyroid disease but include abrupt onset cognitive regression with deficits in one or more other neuropsychiatric domains in the setting of antithyroid antibodies.

Hashimoto's Encephalopathy Mimicking Viral Encephalitis: A Case Report

Hashimoto's encephalopathy (HE) is a rare neuropsychiatric syndrome characterized by elevated levels of anti-thyroid antibodies. Diverse manifestations make timely diagnosis of HE difficult. Herein, we report a case of HE, in which the clinical symptoms and laboratory test results mimicked viral encephalitis. A 59-year-old male patient, who presented with a fever, headache, slow and unclear speech, sentence confusion, elevated levels of anti-thyroid antibodies in the serum, an increased white blood cell count, and positivity for anti-thyroid antibodies in the CSF, was finally diagnosed with HE and responded well to a small dose of methylprednisolone. This report helps bring the attention of clinicians to the fact that HE should be considered when cases of unexplained encephalopathy are encountered.

Medical comorbidities in patients with psychogenic non-epileptic seizures (functional seizures)

PURPOSE

We investigated medical comorbidities in patients with psychogenic non-epileptic seizures (PNES). We hypothesized that these patients commonly have significant medical comorbidities.

METHODS

In this retrospective study, all patients with PNES, who were diagnosed at Shiraz Comprehensive Epilepsy Center, Iran, from 2008 until 2019, were investigated. Age, gender, age at seizure onset, seizure semiology, and characteristics, known medical (organic) comorbidities reported by the patients and video-electroencephalography recordings of all patients were registered routinely.

RESULTS

During the study period, 272 patients with PNES-only had the inclusion criteria and were studied. Sixty-five patients (24%) reported having a medical (organic) comorbidity. The most commonly reported medical comorbidity was thyroid disorder. Age at onset (OR: 1.058; 95% CI: 1.026-1.090; p = 0.0001), duration of disease before the diagnosis (OR: 1.071; 95% CI: 1.025-1.119; p = 0.002), and sex (female) (OR: 1.97; 95% CI: 1.016-3.834; p = 0.04) were significantly associated with having medical comorbidities.

CONCLUSION

While we did not have a control group to provide the number and type of medical problems that are expected in the general population, and therefore our results should be interpreted with caution, we had some intriguing observations. About one quarter of patients with PNES reported having medical comorbidities. The exact nature of the relationship between medical illnesses and PNES is not clear; however, hypothetically they could have a complex relationship. This study provides valuable information on the frequency and nature of medical comorbidities in patients with PNES and opens new horizons for future research.

Autoimmune encephalitis as a differential diagnosis of schizophreniform psychosis: clinical symptomatology, pathophysiology, diagnostic approach, and therapeutic considerations

Primary schizophreniform psychoses are thought to be caused by complex gene-environment interactions. Secondary forms are based on a clearly identifiable organic cause, in terms of either an etiological or a relevant pathogenetic factor. The secondary or "symptomatic" forms of psychosis have reentered the focus stimulated by the discovery of autoantibody (Ab)-associated autoimmune encephalitides (AEs), such as anti-NMDA-R encephalitis, which can at least initially mimic variants of primary psychosis. These newly described secondary, immune-mediated schizophreniform psychoses typically present with the acute onset of polymorphic psychotic symptoms. Over the course of the disease, other neurological phenomena, such as epileptic seizures, movement disorders, or reduced levels of consciousness, usually arise. Typical clinical signs for AEs are the acute onset of paranoid hallucinatory symptoms, atypical polymorphic presentation, psychotic episodes in the context of previous AE, and additional neurological and medical symptoms such as catatonia, seizure, dyskinesia, and autonomic instability. Predominant psychotic courses of AEs have also been described casuistically. The term autoimmune psychosis (AP) was recently suggested for these patients. Paraclinical alterations that can be observed in patients with AE/AP are inflammatory cerebrospinal fluid (CSF) pathologies, focal or generalized electroencephalographic slowing or epileptic activity, and/or suspicious "encephalitic" imaging findings. The antibody analyses in these patients include the testing of the most frequently found Abs against cell surface antigens (NMDA-R, CASPR2, LGI1, AMPA-R, GABA_B-R), intracellular antigens (Hu, Ri, Yo, CV2/CRMP5, Ma2 [Ta], amphiphysin, GAD65), thyroid antigens (TG, TPO), and antinuclear Abs (ANA). Less frequent antineuronal Abs (e.g., against DPPX, GABA_A-R, glycine-R, IgLON5) can be investigated in the second step when first step screening is negative and/or some specific clinical factors prevail. Beyond, tissue-based assays on brain slices of rodents may detect previously unknown antineuronal Abs in some cases. The detection of clinical and/or paraclinical pathologies (e.g., pleocytosis in CSF) in combination with antineuronal Abs and the exclusion of alternative causes may lead to the diagnosis of AE/AP and enable more causal therapeutic immunomodulatory opportunities.

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].

[Autoantibody-associated schizophreniform psychoses: clinical symptomatology]

According to present concepts, primary psychotic disorders in the schizophrenia spectrum are probably caused by a complex interaction between multigenetic vulnerability and causally relevant environmental factors. In contrast, secondary psychotic disorders are the result of likely identifiable organic factors either in terms of a first causation (etiology) or a secondary cause (pathogenesis). In this context, autoantibody(ab)-associated autoimmune encephalitis (AE) plays an increasingly important role. Within the group of ab-associated AE with neuropsychiatric symptoms, anti-N-methyl-D-aspartate receptor encephalitis is the most prevalent one. Psychopathologically, polymorphic psychotic symptoms are often observed at onset of AE; however, over the course of this condition or even initially other neuropsychiatric phenomena are also common. The ill-defined entity of a steroid-responsive encephalopathy with thyroid antibodies (Hashimoto's encephalitis) is a heterogeneous syndrome that may also comprise isolated psychotic disorders presenting as classical schizophrenia.

Psychotic Symptoms of Hashimoto's Encephalopathy: A Diagnostic Challenge

Hashimoto’s encephalopathy (HE) is a rare and underdiagnosed neuropsychiatric illness. We present the case of a 17-year-old girl who was admitted to a tertiary-care psychiatric center with acute onset psychosis and fever. Her psychotic symptoms were characterized by persecutory and referential delusions, as well as tactile and visual hallucinations. Her acute behavioral disturbance warranted admission and treatment in a psychiatric setting (risperidone tablets, 3 mg/day). She had experienced an episode of fever with a unilateral visual acuity defect approximately 3 years before admission, which was resolved with treatment. Focused clinical examination revealed an enlarged thyroid, and baseline blood investigations, including thyroid function test results were normal. Abnormal laboratory investigations revealed elevated anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) levels (anti-TPO of 480 IU/mL; anti-TG of 287 IU/mL). Results of other investigations for infection, including cerebrospinal fluid examination, electroencephalography, and brain magnetic resonance imaging were normal. She was diagnosed with HE and was treated with intravenous corticosteroids (methylprednisolone up to 1 g/day; tapered and discontinued after a month). The patient achieved complete remission of psychotic symptoms and normalization of the anti-thyroid antibody titers. Currently, at the seventh month of follow-up, the patient is doing well. This case highlights the fact that in the absence of well-defined clinical diagnostic criteria, a high index of suspicion is required for early diagnosis of HE. Psychiatrists need to explore for organic etiologies when dealing with acute psychiatric symptoms in a younger age group.