Oxidative stress can:

a) play a fundamental role in the development of primary hypothyroidism

b) In which case, neurones are likely to be adversely affected for the same reason that thyrocytes are (Imbalance between the rate of generation of “cellular exhaust” [= Reactive Oxygen Species=ROS] on the one hand and on the other hand, the capacity of the Antioxidant System to quench the ROS (Such imbalance in favour of potentially toxic ROS-> “Oxidative Stress”).

Here is a paper which lends support to this proposal:
http://www.dc1.netfunda.com/~biomedre/journal/pdf/650.pdf

Biomedical Research 2012; 23 (2): 286-288


Oxidative stress status in hypothyroid patients.?
Bhawna Bhimte, B.K. Agrawal, V.K. Sharma and Sarika Singh Chauhan

Department of Medical Biochemistry, Gandhi Medical College, Bhopal (M.P.), India Department of Medicine, Gandhi Medical College, Bhopal 462001. (M.P.), India

Abstract

Thyroid hormone controls various metabolic functions. Hypothyroidism is a clinical condi- tion with reduced thyroid activity. Study intended to appraise the oxidative stress in various degree of Hypothyroidism. Recently detected hypothyroid patients were grouped according to the TSH level into three categories as Group I: TSH level 6-20uIU/dl, Group II TSH level 21-40uIU/dl: & Group III TSH level above 40uIU/dl. Oxidative stress has been assessed by detecting Total antioxidant capacity (TAC) of hypothyroid patients, compared to euthyroid control. Total Antioxidant Capacity was reported to be reduced at baseline in all three groups of hypothyroid patients. After six weeks of thyroxin replacement therapy TAC level has been found to be increased. The reduction of Total Antioxidant Capacity in hypothyroid patients reflects increase oxidative stress in hypothyroidism. Oxidative stress has been associated with early aging and precipitating factor of many anomalous metabolic reactions. Consequently antioxidant therapy should also be included with thyroid replacement therapy.