The Influence of Thyroid Hormones on Brain Structure and Function in Humans

Serum Metabolites as Mediator Between Autoimmune Hyperthyroidism and Epilepsy: A Mendelian Randomization Analysis

Epilepsy, a complex neurological condition, might intertwine with various immune system anomalies, including autoimmune hyperthyroidism. An overactive thyroid gland due to immune system misdirection could subtly influence epilepsy via mechanisms not fully understood. Our investigation leverages Mendelian randomization (MR) to dissect this association, aiming to illuminate the role of serum metabolites as a possible bridge connecting these conditions. A comprehensive MR analysis was conducted in three phases, using genetic variants from GWAS datasets. The first phase assessed the causal effect of autoimmune hyperthyroidism on epilepsy. The second phase examined the impact of 1400 serum metabolites on epilepsy. The final phase explored the mediation of these metabolites in the autoimmune hyperthyroidism-epilepsy pathway. The analysis employed inverse variance weighted (IVW) methods, along with sensitivity analyses including MR-Egger and weighted median approaches, to ensure robustness. Our Mendelian randomization analysis identifies a significant causal relationship from autoimmune hyperthyroidism to epilepsy. We observed that genetic predisposition towards autoimmune hyperthyroidism is associated with reduced risk of developing epilepsy (P = 0.037). Sensitivity analyses, such as culling analysis and funnel plot inspections, confirm the consistency and robustness of this finding. Further analysis revealed cAMP as a mediator in this causal pathway (P = 0.016), underscoring its role in the link between autoimmune hyperthyroidism and epilepsy. Conversely, no causal effect of epilepsy on the development of autoimmune hyperthyroidism was found, highlighting a unidirectional relationship. This study proposes that autoimmune hyperthyroidism may act as a protective factor against epilepsy, with this effect potentially mediated by serum metabolites, particularly cAMP. These findings provide novel insights into the interplay between autoimmune conditions, metabolic alterations, and neurological disorders, highlighting cAMP as a promising therapeutic target of epilepsy.

Hashimoto's Encephalopathy: Clinical Features, Therapeutic Strategies, and Rehabilitation Approaches

Hashimoto's encephalopathy (HE), also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), is an autoimmune disorder with heterogeneous presentation that poses diagnostic challenges. This review synthesizes the current literature to clarify the clinical, laboratory, and radiological features of SREAT/HE, including the diagnostic utility of thyroid peroxidase (TPO) antibodies, cerebrospinal fluid (CSF) abnormalities, and neuroimaging findings. Cognitive impairment and behavioral changes are common in HE, but specific manifestations vary widely, which can lead to misdiagnosis. While elevated TPO antibodies are frequently observed, a direct causal relationship with HE is unlikely, and their presence may indicate a general state of autoimmunity. Corticosteroids remain the cornerstone of treatment, although responses vary, and alternative immunosuppressive agents or intravenous immunoglobulin may be needed in some cases. Evidence regarding rehabilitation for people affected by HE is limited, but neurorehabilitation strategies adapted from other neurological conditions, including cognitive re-education (CR), physical therapy, and psychosocial support, may be beneficial. Further research is needed to elucidate the underlying mechanisms of SREAT, refine the diagnostic criteria, and develop more targeted and effective therapies, including rehabilitation strategies, for this debilitating neurological disorder.

Alterations in dynamic regional homogeneity within default mode network in patients with thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is a significant autoimmune eye disease known for causing exophthalmos and substantial optic nerve damage. Prior investigations have solely focused on static functional MRI (fMRI) scans of the brain in TAO patients, neglecting the assessment of temporal variations in local brain activity. This study aimed to characterize alterations in dynamic regional homogeneity (dReHo) in TAO patients and differentiate between TAO patients and healthy controls using support vector machine (SVM) classification. Thirty-two patients with TAO and 32 healthy controls underwent resting-state fMRI scans. We calculated dReHo using sliding-window methods to evaluate changes in regional brain activity and compared these findings between the two groups. Subsequently, we employed SVM, a machine learning algorithm, to investigate the potential use of dReHo maps as diagnostic markers for TAO. Compared to healthy controls, individuals with active TAO demonstrated significantly higher dReHo values in the right angular gyrus, left precuneus, right inferior parietal as well as the left superior parietal gyrus. The SVM model demonstrated an accuracy ranging from 65.62 to 68.75% in distinguishing between TAO patients and healthy controls based on dReHo variability in these identified brain regions, with an area under the curve of 0.70 to 0.76. TAO patients showed increased dReHo in default mode network-related brain regions. The accuracy of classifying TAO patients and healthy controls based on dReHo was notably high. These results offer new insights for investigating the pathogenesis and clinical diagnostic classification of individuals with TAO.

Essential New Complexity-Based Themes for Patient-Centered Diagnosis and Treatment of Dementia and Predementia in Older People: Multimorbidity and Multilevel Phenomenology

Dementia is a highly prevalent condition with devastating clinical and socioeconomic sequela. It is expected to triple in prevalence by 2050. No treatment is currently known to be effective. Symptomatic late-onset dementia and predementia (SLODP) affects 95% of patients with the syndrome. In contrast to trials of pharmacological prevention, no treatment is suggested to remediate or cure these symptomatic patients. SLODP but not young onset dementia is intensely associated with multimorbidity (MUM), including brain-perturbating conditions (BPCs). Recent studies showed that MUM/BPCs have a major role in the pathogenesis of SLODP. Fortunately, most MUM/BPCs are medically treatable, and thus, their treatment may modify and improve SLODP, relieving suffering and reducing its clinical and socioeconomic threats. Regrettably, the complex system features of SLODP impede the diagnosis and treatment of the potentially remediable conditions (PRCs) associated with them, mainly due to failure of pattern recognition and a flawed diagnostic workup. We suggest incorporating two SLODP-specific conceptual themes into the diagnostic workup: MUM/BPC and multilevel phenomenological themes. By doing so, we were able to improve the diagnostic accuracy of SLODP components and optimize detecting and favorably treating PRCs. These revolutionary concepts and their implications for remediability and other parameters are discussed in the paper.

Brain functional connectivity in hyperthyroid patients: systematic review

INTRODUCTION

Functional connectivity (FC) is the correlation between brain regions' activities, studied through neuroimaging techniques like fMRI. It helps researchers understand brain function, organization, and dysfunction. Hyperthyroidism, characterized by high serum levels of free thyroxin and suppressed thyroid stimulating hormone, can lead to mood disturbance, cognitive impairment, and psychiatric symptoms. Excessive thyroid hormone exposure can enhance neuronal death and decrease brain volume, affecting memory, attention, emotion, vision, and motor planning.

METHODS

We conducted thorough searches across Google Scholar, PubMed, Hinari, and Science Direct to locate pertinent articles containing original data investigating FC measures in individuals diagnosed with hyperthyroidism.

RESULTS

The systematic review identified 762 articles, excluding duplicates and non-matching titles and abstracts. Four full-text articles were included in this review. In conclusion, a strong bilateral hippocampal connection in hyperthyroid individuals suggests a possible neurobiological influence on brain networks that may affect cognitive and emotional processing.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42024516216.

Disrupted dynamic amplitude of low-frequency fluctuations in patients with active thyroid-associated ophthalmopathy

Purpose: Thyroid-associated ophthalmopathy (TAO) is an autoimmune disease that affects the orbit and is the most prevalent extra-thyroidal complication of Graves' disease. Previous neuroimaging studies have focused on abnormal static regional activity and functional connectivity in patients with TAO. However, the characteristics of local brain activity over time are poorly understood. This study aimed to investigate alterations in the dynamic amplitude of low-frequency fluctuation (dALFF) in patients with active TAO and to distinguish patients with TAO from healthy controls (HCs) using a support vector machine (SVM) classifier. Methods: A total of 21 patients with TAO and 21 HCs underwent resting-state functional magnetic resonance imaging scans. dALFFs were calculated in conjunction with sliding window approaches to assess dynamic regional brain activity and to compare the groups. Then, we used SVM, a machine learning algorithm, to determine whether dALFF maps may be used as diagnostic indicators for TAO. Results: Compared with HCs, patients with active TAO showed decreased dALFF in the right calcarine, lingual gyrus, superior parietal lobule, and precuneus. The SVM model showed an accuracy of 45.24%-47.62% and area under the curve of 0.35-0.44 in distinguishing TAO from HCs. No correlation was found between clinical variables and regional dALFF. Conclusion: Patients with active TAO showed altered dALFF in the visual cortex and the ventral and dorsal visual pathways, providing further details on the pathogenesis of TAO.

Reminiscence therapy care program as a potential nursing intervention to relieve anxiety, depression, and quality of life in older papillary thyroid carcinoma patients: A randomized, controlled study

Objective

Reminiscence therapy (RT) ameliorates psychological problems and quality of life in cancer patients. However, no study reports its effect on older papillary thyroid carcinoma (PTC) patients. This study intended to investigate the effect of the RT-care program (CP) on anxiety, depression, quality of life, and survival in older PTC patients.

Methods

Eighty-six postoperative older PTC patients were enrolled and randomly assigned to RT-CP group (N = 44) and usual (U)-CP group (N = 42) as a 1:1 ratio for a 6-month intervention. Hospital Anxiety and Depression Scale (HADS) and Quality of Life Questionnaire-Core 30 (QLQ-C30) scores were assessed at baseline, month (M)1, M2, M4, and M6.

Results

HADS and QLQ-C30 scores at baseline were not different between two groups. Additionally, HADS-anxiety score at M6 (p = 0.029), and HADS-depression score at M2 (p = 0.030), M4 (p = 0.029), M6 (p = 0.012) were reduced in RT-CP group versus U-CP group. Meanwhile, anxiety and depression rates from M1 to M6 were slightly decreased in RT-CP group versus U-CP group but did not reach statistical significance. Furthermore, depression severity at M6 was reduced in RT-CP group versus U-CP group (p = 0.049). Besides, QLQ-C30 global health status was increased at M2 (p = 0.023) and M6 (p = 0.033), QLQ-C30 function score was elevated at M2 (p = 0.040) and M4 (p = 0.035), while QLQ-C30 symptom score was decreased at M2 (p = 0.046) in RT-CP group versus U-CP group. Moreover, disease-free survival and overall survival were not different between two groups.

Conclusion

RT-CP may be a potential intervention for ameliorating anxiety, depression, and quality of life in older PTC patients.

Relationship between thyroid hormones and central nervous system metabolism in physiological and pathological conditions

Thyroid hormones (THs) play an important role in the regulation of energy metabolism. They also take part in processes associated with the central nervous system (CNS), including survival and differentiation of neurons and energy expenditure. It has been reported that a correlation exists between the functioning of the thyroid gland and the symptoms of CNS such as cognitive impairment, depression, and dementia. Literature data also indicate the influence of THs on the pathogenesis of CNS diseases, such as Alzheimer's disease, epilepsy, depression, and Parkinson's disease. This review describes the relationship between THs and metabolism in the CNS, the effect of THs on the pathological conditions of the CNS, and novel options for treating these conditions with TH derivatives.