Abstract
Background: One of the most common endocrine disease is hypothyroidism which is usually associated with mental retardation, lack of concentration, motor dysfunction, memory deficits, visual, and hearing impairment. These symptoms suggest the involvement of nervous system, where the processing efficiency and sensory motor association is affected, which can be assessed by reaction time.

Aims and Objective: The aim of the study was to compare the auditory reaction time in controls, newly diagnosed hypothyroid patients and in hypothyroid patients after attaining euthyroid status.

Materials and Methods: Auditory reaction time was recorded from 35 subjects from general population, who formed the control group and 35 newly diagnosed hypothyroid patients who were selected from OBG and Medicine department, RRMCH, Bangalore. These patients were followed up and reaction time recording was repeated after they attained euthyroid status.

Results: Statistically significant increase in ART values was observed in newly diagnosed hypothyroid patients compared to controls. The values were significantly reduced in hypothyroid patients after the treatment on attaining euthyroid status. There was no significant difference in both ART values between controls and hypothyroid patients after the treatment on attaining euthyroid status.

Conclusion: The present study showed a significantly prolonged auditory reaction time in hypothyroid patients which improved with treatment. We also demonstrated a positive correlation between ART and thyroid stimulating hormone levels. Hence, we conclude that auditory reaction time tests could be added to the routine thyroid dysfunction tests to know the early recognition of the neuronal involvement, prompt treatment, and assess prognosis of hypothyroid patients.

Key words: Auditory Reaction Time; Hypothyroidism; Thyroid Stimulating Hormone Levels