Cognitive function in Hashimoto’s thyroiditis under levothyroxine treatment

Abstract

ObJEcTIVE: Although overt hypothyroidism has been documented as exerting detrimental effects on cognition and behavior, it remains controversial whether subclinical hypothyroidism or euthyroid patients with Hashimoto's thyroiditis (HT) under levothyroxine (LT4) treatment may experience any noticeable decline in cognitive function. PATIENTS: Two otherwise healthy, highly-functioning, first-degree relatives with a diagnosis of HT, under LT4 treatment for two years, were prospectively recruited into a clinical research study setting and followed for a year. MEASUrEMENTS: Thyroid functions tests and a detailed battery of tests assessing global cognitive status, attention, verbal and working memory, visuoperceptual skills, executive functions and mood were performed at baseline and at one year after recruitment. rESULTS: Overall, patients' performance on the neuropsychological battery was good and, in the majority of cognitive functions, their performance could be characterized as exceptional. No noticeable changes in any of the studied parameters were detected. cONcLUSIONS: The present case study failed to detect any noticeable changes in the cognitive and emotional function of two women with HT under LT4 treatment. The course of cognitive function of the two HT patients, evaluated by a detailed battery of tests, tends to confirm the benign nature of HT.Key words: Hashimoto's thyroiditis, Neuropsychology, LT4 treatment HORMONES 2014, 13(3):430-433 Address for correspondence: Vaitsa Giannouli, School of Medicine, Aristotle University of Thessaloniki, Greece, E-mail: giannouliv@hotmail.com Received: 30-11-2013, Accepted: 16-01-2014 Letter to the editor Chronic autoimmune (Hashimoto's) thyroiditis (HT) is the most common thyroid disorder in iodine-sufficient areas. HT is marked by the presence of complement-fixing autoantibodies to thyroid peroxidase (TPOabs) which tend to correlate with progressive thyroidal damage 1 and may lead to subclinical and overt hypothyroidism. Thyroid hormone deficiency (overt hypothyroidism) has profound and multi-systemic detrimental effects from which brain and behavior are not spared. The latter may relate to global cognitive, behavioral and emotional changes, including depression. 2 This is not the case for subclinical hypothyroidism and euthyroid HT, whether under levothyroxine (LT4) treatment or not, the effect of which on cognitive performance is somewhat controversial. Whereas it has been suggested that "a state of brain hypothyroidism in the context of systemic

A 2-Year Preliminary Longitudinal Study of Neuropsychological Functioning in Hashimoto’s Thyroiditis Under Levothyroxine Treatment: Only Trail Making Test Is Making a Difference

“…The present study did not detect any baseline visual and verbal memory deficits in middle-aged euthyroid women with HT who are under chronic LT4 treatment and no statistically significant differences were found at one and two years retesting. This is in line with previous results from a case study of a 62-year-old woman (Giannouli, Toulis & Syrmos, 2014), but not in line with results from a research in euthyroid patients with primary hypothyroidism on adequate thyroxine (T4) treatment, which supports that neurocognitive functioning as well as psychological well-being may not be completely restored in patients with hypothyroidism, despite T4 treatment (Wekking et al, 2005). In this study, although a slightly better cognitive performance for healthy women is reported, it does not reach statistical significance.…”

“…Some researchers claim poor performance on various domains of neurocognitive functioning (attention and verbal memory tests) as well as lower levels of well-being in euthyroid HT patients compared with those of the general population (Τoudou Daouda et al, 2016), thus supporting that neurocognitive functioning and psychological well-being may not be completely restored in patients with hypothyroidism despite T4 treatment (Wekking et al, 2005). In addition, even slightly higher levels of free T3 and thyroglobulin antibodies levels within the normal range are claimed to associate with slower cognitive performance and more errors on neuropsychological tests of executive function (Grigorova & Shewin, 2012), while other studies find no such detrimental influences on cognition when baseline measures are of neurocognitive functioning is normal (Giannouli, Toulis, & Syrmos, 2014).…”

“…Nevertheless, cognitive performance in subclinical hypothyroidism and euthyroid HT, whether under levothyroxine (LT4) treatment or not, still remains a vastly unexplored topic, while emotional factors that directly influence performance during neuropsychological assessment, such as stress and depression, are disregarded (Giannouli, Toulis, & Syrmos, 2014).…”

Health-Related Quality of Life in Levothyroxine-Treated Hypothyroid Women and Women without Hypothyroidism: A Case–Control Study

“…For example, the persistency of tiredness complaints, cognitive dysfunction, sexual disorders, mood disorders, working memory disorders, and motor learning disorders in properly treated patients have been reported [11,[19][20][21][22]. On the contrary, several authors found no more neuropsychological problems in treated hypothyroid patients than in controls [23][24][25]. Similarly, Engum et al reported no unusual anxiety or depression disorders in patients with thyroid disorders treated with levothyroxine [26].…”

Interactive Effects of Methionine and Lead Intake on Cognitive Function among Chinese Adults

“…According to the seventh Chinese national census of 2020, the number of individuals aged 60 years and above was 264 million, accounting for 18.7% of the population [ 3 ]. In addition to aging, socioeconomic factors (e.g., education, income), lifestyle factors (including smoking and physical activity), and chronic conditions (e.g., traumatic brain injury, thyroid function, COPD) have been found to be associated with cognition [ 4 , 5 , 6 , 7 , 8 , 9 ]. As most types of cognitive impairment are incurable, investigations of potentially modifiable lifestyle and environmental risk factors to prevent cognitive decline are urgently needed.…”