CHENNAI: Restless Legs Syndrome (RLS) is a sensorimotor disorder characterised by an uncontrollable and irresistible urge to move the legs with abnormal sensation, which usually leads to partial or complete resolution of the abnormal sensation after moving the legs. The diagnosis is purely clinical and hence this is a problem, especially among children. The exact prevalence of RLS in children is unknown, however some studies report it to be around 6 per cent. When it comes to the pathophysiology of RLS, the central dopaminergic systems are involved as there is complete relief of symptoms with dopaminergic drugs.
Causes of RLS
There can be various causes of RLS. As some of the cases had a family history, there is a genetic predisposition which can be the causative factor. This is called the primary RLS which is inherited and some evidence indicates that there could be an autosomal dominant inheritance.
There are secondary causes for RLS which are the most common. Anaemia is a well-known causative factor associated, as there will be a deficiency of ferritin associated with these symptoms. Other causes such as uremia, peripheral neuropathy, Vit B12 deficiency, caffeine or alcohol consumption, smoking, sleep deprivation, narcoleptic or antidepressant use can be seen in adolescents.
Children having this disorder will show symptoms such as aggression, hyperactivity, inattention, and daytime somnolence because of difficulty in maintaining sleep or inability to sleep. The consequences of RLS in children can include poor performance in school, unsatisfactory social development, and abnormal social interactions which may overlap with various diseases like Attention Deficit Hyperactivity Disorder (ADHD).
Children can get restless, fidgety, and overactive and they may walk abnormally, run or kick continuously. Sometimes, children may describe it as pain or ache. Partial or complete resolution of symptoms by
movement is an important feature. Some of the differential diagnoses or mimics of the disease in children are positional discomfort, sore leg muscles, ligament sprain/tendon strain, positional ischemia (numbness), motor tics arthralgia or growing pains.
To conclude, the diagnosis of RLS in children, unlike adults is challenging. This is because the child will not be able to give a proper description of the symptoms. There are some diseases which mimic RLS and have to be recognised as well. If not recognised and treated at the right time, it may lead to poor scholastic performance, poor social interaction and behavioural changes.
— The author is senior consultant, neurologist and epileptologist, stroke specialist, BGS Gleneagles Global Hospital, Bengaluru
Diagnostic criteria for RLS in children are similar as in adults
An urge to move the legs, usually accompanied or caused by uncomfortable and unpleasant sensations in the legs
The urge to move or unpleasant sensations beginning or worsening during periods of rest or inactivity such as lying or sitting
The urge to move or the unpleasant sensations are worse or only occur in the evening or night
The urge to move or unpleasant sensations are partially or totally relieved by movement, such as walking or stretching, at least as long as the activity continues