The impact of Graves' disease and its treatment on handwriting characteristics

Handwriting characteristics in patients with overt autoimmune hypothyroidism: a prospective case-control study

PURPOSE

Previous studies have demonstrated handwriting changes in patients with overt hyperthyroidism due to Graves' disease. The aim of the present study was to investigate handwriting features in patients affected by overt autoimmune hypothyroidism.

METHODS

Thirty subjects - 24 females and 6 males, mean and median age of 50.15 ± 16.8 years and 52.5 years, respectively - with overt hypothyroidism (OH) related to Hashimoto's thyroiditis (Group 1), and 30 age- and sex-matched euthyroid individuals (Group 2) were recruited to write a "standard text". Group 1 patients repeated the text once the euthyroid state was reached on L-T4 substitution therapy. Group 2 subjects wrote the text again 1 to 4 weeks thereafter. The letters underwent a detailed analysis by a handwriting expert, through inspection, a stereoscopic microscope and a magnifying glass. Furthermore, the time that both Groups took to go through with the text was clocked.

RESULTS

None of the handwriting variables differed significantly within each Group and between the two Groups. Hypothyroid patients took significantly more time to go through with the text compared to the time taken once they became euthyroid (3.29 ± 1.66 vs 2.63 ± 1.55 minutes, respectively) and the time taken by the control group (p < 0.01). Of note, three Group 1 patients missed to copy some words or even whole sentences on the paper while they were overtly hypothyroid.

CONCLUSIONS

The present study demonstrates that handwriting speed is able to disclose the impact of thyroid hormone deficiency on the central nervous system's functions. In particular, the longer time taken to go through with the text and the sentences missed by some hypothyroid patients, are the counterpart of psychomotor slowdown, impaired attention and memory loss peculiar to OH.

Effects of hyperthyroidism on hand grip strength and function

Hyperthyroidism is a pathologic condition in which the body is exposed to excessive amounts of circulating thyroid hormones. Skeletal muscle is one of the major target organs of thyroid hormones. We evaluated hand grip strength and function in patients with overt hyperthyroidism. Fifty-one patients newly diagnosed with hyperthyroidism and 44 healthy controls participated in this study. Age, height, weight, and dominant hand of all participants were recorded. The diagnosis of hyperthyroidism was confirmed by clinical examination and laboratory tests. Hand grip strength was tested at the dominant hand with a Jamar hand dynamometer. The grooved pegboard test (PGT) was used to evaluate hand dexterity. The Duruöz Hand Index (DHI) was used to assess hand function. No significant differences were found in terms of clinical and demographic findings between the patients with hyperthyroidism and healthy controls (p > 0.05). Significant differences were found between the patients with hyperthyroidism and healthy controls regarding PGT and DHI scores (p < 0.05). Hyperthyroidism seemed to affect hand dexterity and function more than hand grip strength and seemed to be associated with reduced physical function more than muscle strength. This may also indicate that patients with hyperthyroidism should be evaluated by multidisplinary modalities.