The molecular fundamentals of neurorehabilitation and their modulation by thyroid hormones

Abstract

Neurological disorders affect a large population, often leading to different levels of disability and resulting in a decreased quality of life. Neurorehabilitation is the process of restoring the functions of the nervous system after injuries, diseases, or other impairments. The molecular basis of neurorehabilitation includes various aspects such as changes in gene expression, regulation of synaptic connections, nerve cell growth, and repair, among others. Typical objectives in rehabilitating the patient with neurologic disease are to minimize pain, reestablish normal neural pathways, prevent secondary complications, and ultimately improve quality of life. It is also essential not to worsen neurologic function or pain in patients with spinal instability. A decreased free triiodothyronine and thyroid stimulating hormone levels upon admission may predict an unfavorable outcome at the end of early rehabilitative treatment. Thus, thyroid hormone levels are not only important during acute treatment but also in prolonged critical illness. Thyroid hormones, specifically thyroxine and triiodothyronine, can influence these molecular processes through their receptors in nervous tissue. Thyroid hormones are essential for the normal functioning of the nervous system, including neurogenesis (the formation of new neurons) and synaptic plasticity (changes in the strength and structure of connections between neurons). Research has shown that thyroid hormones can affect the expression of genes related to the growth and survival of neurons, as well as synaptic plasticity processes, which may be relevant for rehabilitation after nervous system injuries. A deficiency of thyroid hormones such as in hypothyroidism can lead to disturbances in the development and functioning of the nervous system, which, in turn, can complicate the neurorehabilitation process. Thus, understanding the molecular basis of neurorehabilitation and the influence of thyroid hormones can help improve approaches to the rehabilitation of patients with various nervous system impairments.