Thyroid Dysfunction and Its Neurological Indicators: A Review of Pathophysiology and Clinical Management

Abstract

Thyroid hormones play a pivotal role in neurodevelopment, neuroplasticity, and the regulation of central and peripheral nervous system functions. Consequently, disturbances in thyroid function can manifest with a broad spectrum of neurological symptoms, ranging from subtle cognitive and mood changes to overt neuromuscular and neuropsychiatric disorders. This review provides an updated overview of the pathophysiological mechanisms linking thyroid dysfunction with neurological manifestations, alongside strategies for clinical recognition and management. Hypothyroidism is associated with cognitive slowing, depression, peripheral neuropathy, and, in severe cases, myxedema coma, while hyperthyroidism can present with tremors, anxiety, neuromuscular weakness, and, rarely, thyrotoxic crisis with encephalopathy. Autoimmune thyroid diseases, particularly Hashimoto’s thyroiditis and Graves’ disease, have been increasingly recognised as contributors to central nervous system autoimmunity, with conditions such as Hashimoto’s encephalopathy highlighting the interface between endocrine and neuroimmunological pathways. Diagnostic approaches require careful integration of neurological findings with biochemical evaluation of thyroid function, thyroid antibodies, and, when indicated, neuroimaging and electrophysiological studies. Management is guided by correction of thyroid hormone imbalance through levothyroxine in hypothyroidism or antithyroid medications, radioiodine, or surgery in hyperthyroidism, with adjunctive therapies targeting specific neurological symptoms. In cases of autoimmune encephalopathy, corticosteroids and immunomodulatory agents play critical roles. This review emphasises the importance of early recognition of thyroid-related neurological syndromes, given their reversibility with timely treatment. A multidisciplinary approach involving endocrinologists, neurologists, and psychiatrists is essential for optimal outcomes. Understanding the complex interplay between thyroid function and the nervous system not only improves patient care but also sheds light on broader neuroendocrine mechanisms relevant to clinical neuroscience.