Restless legs syndrome: An underdiagnosed sleep hinderance

General health
Restless legs syndrome: An underdiagnosed sleep hinderance

Restless legs syndrome - or irritable legs syndrome - is a common neurological sleep disorder, which is often associated with insomnia, excessive daytime sleepiness and, on some occasions, other underlying conditions.  

Characterised by an uncontrollable urge to move the legs in the evening or at night, thus disturbing sleep, restless legs syndrome is thought to affect up to 10% of people in the UK. Our sleep clinic has the expertise to diagnose and manage restless legs syndrome, as well as other comorbid conditions, for better quality sleep and improved wellbeing. 

It’s not just a nocturnal condition

Patients with restless legs syndrome often describe a feeling of tingling, aching or burning in the legs, which worsens in the evening and throughout the night. However, as patients with the condition often find it difficult to get to sleep or stay asleep, the effects of restless legs syndrome at night often seep into daytime activities.  

Dr Shruthi Konda, consultant respiratory physician at Royal Brompton Hospital, explains: “Restless legs syndrome can prevent patients from getting to sleep, or achieving a continuous period of restorative sleep, as they can report that they are awoken by their spontaneous leg movements, meaning they wake up feeling unrefreshed, fatigued and irritable.”  

“If restless leg movements happen during sleep, it is called periodic limb movements of sleep (PLMS). If the movements are frequent enough to cause sleep disturbance, it is called periodic limb movement disorder (PLMD).” 

Despite its common diagnosis, restless legs syndrome and PLMD remains underdiagnosed. “We often see patients who think they have insomnia, and while that may be true, they may not realise that restless legs syndrome is the cause of their chronic sleep disturbance,” says Dr Konda. 

Comorbidities are common

Sleep is a fundamental part of human functioning and chronic sleep disturbances can have adverse effects on overall wellbeing. In fact, psychiatric disorders, such as depression and anxiety, are common in patients with restless legs syndrome.

“Obstructive sleep apnoea (OSA) is another common comorbidity. Sometimes we investigate for OSA as a cause for fragmented sleep, and we find that the patient has restless leg syndrome and PLMD. They can sometimes be unaware of this,” explains Dr Konda. 

“That is why it is so important to perform a complete sleep study, which can help us identify underlying causes of sleep disturbances, so that we can treat each condition separately and effectively,” she adds. 

Restless legs syndrome is also common during the last trimester of pregnancy, often disappearing after birth. While is it unclear exactly why pregnancy can trigger restless legs syndrome, “underlying health issues often become more apparent during pregnancy because the body is in a hyperdynamic state,” says Dr Konda. “Iron deficiency, decreased iron availability, increased hormone levels and familial predisposition could play a role.’’ 

Sleep study for complete and accurate diagnosis

"To gain a full, personalised understanding of our patients’ sleep we perform a sleep study. We are one of a few centres that can provide a comprehensive service,” explains Dr Konda. We invite our patients to our sleep lab, where we can perform a respiratory polygraphy test with limb leads, which allows us to track leg movement. 

Additionally, we can provide a polysomnogram with video, which records brain waves, breathing, heart rate, eye and leg movements and blood oxygen levels. While this test is not required for a restless legs syndrome or PLMD diagnosis, it allows us to establish the frequency of movement during the night and can determine how that coincides with levels of wakefulness.  

“For example, we can determine that a patient moved their legs 40 times in one hour, and every time they moved, their electroencephalogram (EEG) showed that they went from asleep to awake,” says Dr Konda. 

Sleep disturbances are often multifactorial, and our tests can help uncover these factors, whether they be snoring, grinding their teeth, movement, outside noise or breathing interruptions.  

In addition to the sleep study, clinical evidence from the patient can be helpful in establishing a diagnosis. “We ask each patient to fill in an internationally-recognised questionnaire, which classifies symptoms from mild to severe,” explains Dr Konda. 

Clinical evidence from a bed partner can be helpful, too, as they often witness the patient’s movements during their sleep. “Bed partners often describe how the patient moves their toes or feet, bends their ankle or twitches and kicks the duvet– and this description can be helpful,” says Dr Konda. 

Restless legs syndrome treatment

Having made sure that we have eliminated all aggravating factors, the first method of treatment involves increasing iron levels. From green, leafy vegetables to iron supplements, we try to surpass normal levels and achieve a “super normal” level of iron, which can help to raise energy levels and reduce the frequency of leg movements. For some patients, this is enough to control the disease. 

If required, further treatment depends on the patient’s other comorbidities. We may prescribe dopamine agonists or gabapentinoids to help control the movements.  

When to refer to us 

It’s important to note that restless legs syndrome is not exclusive to sleep. Often, the uncontrollable leg movements begin before going to bed, such as while watching TV in the evening. Patients will often explain that it’s more comfortable to move their legs, and the crawling, itching or burning sensation goes away with movement. 

We are happy to see patients symptomatic of restless legs syndrome, or any patient who experiences chronic sleep disturbances, excessive daytime sleepiness, snoring or other sleep-related symptoms. 

Get in touch 

To find out more about our sleep clinic services, please contact our customer services team. Call +44 (0)20 3553 2615 or email privatepatients@rbht.nhs.uk.