methimazole and Amyotrophic-Lateral-Sclerosis

ALS is commonly associated with a hypermetabolic state. In this study, we assess whether inhibition of this hypermetabolism via the induction of hypothyroidism can forestall disease onset and prolong life in the SOD1-G93A mouse. We treated a cohort of 16 SOD1-G93A mice with methimazole, a potent inhibitor of thyroid hormone synthesis and followed a second group of 23 untreated littermate control animals from approximately five weeks of age onward. Total thyroxine (T4) levels, weights, and rectal temperatures were obtained on a regular basis and animals were sacrificed when they were no longer able to feed themselves. Results revealed that T4 levels were effectively suppressed within two weeks of drug initiation. However, there was no significant difference between the two groups either in terms of clinical disease onset (120.1±9.3 days for treated animals and 116.7±6.3 days for untreated animals) or in terms of survival (131.4±11.7 days for treated animals and 134.0±10.0 days for untreated animals). A correlation analysis between mean T4 levels for each animal versus survival showed that, contrary to our hypothesis, higher T4 levels correlated with longer survival. In conclusion, these studies show that drug-induced hypothyroidism does not alter the disease course in the SOD1-G93A ALS mouse.

Topics: Amyotrophic Lateral Sclerosis; Animals; Antithyroid Agents; Case-Control Studies; Cohort Studies; Disease Models, Animal; Disease Progression; Disease-Free Survival; Hypothyroidism; Metabolism; Methimazole; Mice; Mice, Transgenic; Superoxide Dismutase; Thyroid Gland; Treatment Outcome

Four patients with clinical diagnosis of amyotrophic lateral sclerosis syndrome and laboratory results of hyperthyroidism were reported. There were 3 women aged 27, 59, 59 years and 1 man aged 50 years. All of them had symptoms and signs of dysarthria and dysphagia, fasciculations of the tongue, muscle weakness with generalized hyperreflexia. After treatment with antithyroid drugs, motor weakness and dysphagia improved.

Topics: Adult; Amyotrophic Lateral Sclerosis; Antithyroid Agents; Female; Humans; Hyperthyroidism; Male; Methimazole; Middle Aged; Treatment Outcome