Amyotrophic lateral sclerosis.: Its relationship with thyroid function and phosphate-calcium metabolism

Introduction. Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disease involving motor neurons of the spinal cord, brain stem, and motor cortex. Previous studies reported the coexistence of motor neuron disease with thyroid dysfunction and primary hyperparathyroidism. These findings suggested an eventual role of the previously mentioned endocrine disorders and the development of ALS. Objective. Identify thyroid dysfunction and changes in mineral metabolism in patients affected by sporadic ALS. Patients and methods. We retrospectively analyzed data from 41 in-ward patients from June 1998, to June 2001. All of them were diagnosed with sporadic ALS. The following laboratory test were performed: thyrotropin (TSH), thyroxine (T-4), serum calcium, serum phosphate, parathyroid hormone (PTH) and ionic calcium concentrations. Results. None of the studied patients was found to be hyperthyroid. Two patients had elevated TSH and normal T4, these findings suggested subclinical hypothyroidism. Elevated PTH was found in one patient; another had primary hyperparathyroidism. Low serum calcium was found in three patients and elevated phosphate was found in another four. Conclusions. All these findings do not allow us to assert a pathogenic association between thyroid dysfunction or alteration of phosphate-calcium metabolism and ALS.