WED is more common or symptoms are more severe in iron deficient patients, and symptoms ameliorate when iron treatment is administered. These facts imply that iron plays a central role in WED pathophysiology. These clinical and therapeutic observations may also be explained in terms of the IMBTH/DA as the main cause of WED. Lack of iron will impair the balance between TH and DA in two ways: (1) by decreasing DA synthesis and (2) by diminishing TH metabolism. Many MRI and ultrasound observations have documented decreased brain iron in the substantia nigra. More importantly, the levels of ferritin (which is a measure of iron deposits) are low in some WED patients, and when these patients are treated with iron to increase their ferritin levels, they experience an improvement of their WED symptoms. As it is improbable that the WED symptoms are generated inside the brain, it becomes unimportant to know if the brain iron is scarce or not. As iron is a cofactor for THy, iron scarcity may cause impaired synthesis of DA by low activity of the THy. For WED patients who do not have iron deficiency, the cause of the tuberoinfundibular DA hypo production is unknown.
Last date updated on April, 2021