People suffering from RLS will often experience episodes with severe unrest in their legs and an irresistible urge to move them. Moreover, the muscles in the legs can feel uncomfortably tight and tingling, and some people experience muscle aches simultaneously. These symptoms frequently occur shortly after you have allowed the legs to rest – i.e. when you have gone to bed in the evening. The unrest disappears again, when the legs are moved. RLS will affect about 1 in 10 people throughout their life.
Cause and treatment of restless legs
Currently, there is no treatment that can cure restless legs, but usually the condition will be examined to understand the cause of it. Afterwards, the doctor will focus on treating the cause in the hope that it relieves the symptoms of restless legs. The disease may have developed as a side effect to a different drug against an entirely different disease, which is why quitting the drug may be enough to cure the patient of the condition.
In other cases, the disease is caused by a disturbance in the brain which involves the neurotransmitter (a signalling substance for nerves) dopamine. Dopaminergic medication can be considered in these cases. Moreover, it is recommended to massage your legs, to do stretching exercises before going to bed and to avoid coffee, alcohol and smoking in the evening.
Iron deficiency and restless legs
Can a lack of iron cause restless legs? A group of researchers asked themselves this question and afterwards decided to investigate it. They discovered that people, suffering from iron deficiency, are more prone to developing restless legs syndrome. Studies have shown that a lack of iron in certain brain cells can cause restless legs. Therefore, it is important to avoid this deficit.
You might be thinking; Why does iron deficiency lead to these symptoms? To answer this question, we need to know a little bit about a specific area in the brain. This area is called ‘substantia nigra’ and is located in the midbrain. The cells in this area control the production of an enzyme (a catalyst) called ‘tyrosine-hydroxylase’ (TH). The cells in the substantia nigra can activate or deactivate TH. When TH is activated, it can increase the production of the neurotransmitter ‘dopamine’. Dopamine is a signalling substance, which some nerve cells release to signal other cells – i.e. a message from the central nervous system in the body with instructions about usual tasks which the body must perform.
Dopamine is necessary to control, regulate and coordinate muscle movements. If this brain area is damaged, the level of dopamine will drop, and this results in muscle spasms and uncontrollable movements. This can be seen in patients with Parkinson’s disease. People, suffering from restless legs, usually have very high levels of active TH.
In theory, this should result in an overproduction of dopamine, but this only happens if there is enough iron in the cells. You can only have a proper regulation of dopamine if you have active TH as well as enough iron in the substantia nigra. The researchers believe that the substantia nigra receives signals about the need for more dopamine, causing the cells to activate TH. The active TH, however, is not fully functional without enough iron. The amount of active TH increases without the dopamine production doing so as well. As mentioned, a lack of dopamine can lead to discomfort in the legs. Therefore, iron deficiency can be the cause of restless legs. Moreover, research has shown that the level of dopamine in the substantia nigra drops in the evening. This may explain why many patients, suffering from restless legs, often experience more severe symptoms in the evening.
Pregnant women, who are in their last trimester, also frequently experience restless legs, and it is during this stage of the pregnancy, where several of the women are also in iron deficit. This corresponds with the data that suggests that iron deficiency causes restless legs. The above mentioned can also explain why many patients with restless legs experience relief of their symptoms when they are given dopaminergic medicine. The dopaminergic drugs are also used to treat Parkinson’s disease as they can relieve the tremors, which are common in this patient group. A dopaminergic drug replaces dopamine in the brain and can temporarily improve the nerve signals that are being sent from the central nervous system to the body.
Can you measure iron deficiency in the brain?
The doctor can take a blood sample and measure how much iron is in the blood, but this value does not provide any indication of iron deficiency in the brain. Many doctors have actually measured normal values of iron in the blood of patients with restless legs despite their level of iron in the substantia nigra being low. Instead of a blood sample, doctors can conduct a lumbar puncture and extract spinal fluid. In this fluid, doctors can measure the amount of a protein called ‘ferritin’ which stores iron. The amount of ferritin in the spinal fluid is therefore an indication of iron in the brain, and this value is usually low in patients with restless legs. Another way of measuring iron in the midbrain is with an MR scan.
Iron supplement
If you suffer from restless legs, it may be a good idea to have your iron levels measured to establish whether you suffer from iron deficiency. You can buy iron supplements in several supermarkets and pharmacies. A little tip is that iron is easier absorbed if you take it with vitamin C. You can do this by taking a pill with vitamin C and one with iron simultaneously or by drinking a glass of juice. Contrary, the ingestion of calcium (dairy products) or manganese can reduce the absorption of iron.
