From the Research
Yes, delayed relaxation in deep tendon reflexes is consistent with hypothyroidism, as it is a classic neurological manifestation of this condition, often referred to as "hung reflexes" or Woltman's sign 1. When testing deep tendon reflexes in a hypothyroid patient, the reflex hammer strike produces a normal contraction, but the relaxation phase is noticeably slowed. This phenomenon occurs because thyroid hormone deficiency affects muscle contraction and relaxation cycles at the cellular level.
Key Points to Consider
- The severity of the delayed relaxation often correlates with the degree of hypothyroidism, and this finding typically improves with appropriate thyroid hormone replacement therapy, such as levothyroxine 2.
- While this sign is not present in all hypothyroid patients and is not specific only to hypothyroidism, its presence should prompt consideration of thyroid function testing, particularly in patients with other symptoms of hypothyroidism such as fatigue, cold intolerance, weight gain, or dry skin.
- The diagnosis of hypothyroidism relies on blood levels of thyroid-stimulating hormone and free thyroxine, and symptom relief and normalized thyroid-stimulating hormone levels are achieved with levothyroxine replacement therapy 3.
- It is essential to consider the impact of patient weight, residual thyroid function, age, comorbidities, and quality of life when adjusting levothyroxine dosage to maintain euthyroidism and avoid risks from overtreatment or undertreatment 4.
Clinical Implications
- The presence of delayed relaxation in deep tendon reflexes should prompt consideration of thyroid function testing, particularly in patients with other symptoms of hypothyroidism.
- Appropriate thyroid hormone replacement therapy, such as levothyroxine, can improve this finding and alleviate other symptoms of hypothyroidism.
- Regular assessment of thyroid-stimulating hormone levels and symptom relief is necessary to ensure effective management of hypothyroidism.