If your sleep is disrupted and you discover your legs or arms are twitching during sleep – or your partner tells you as much – then you may be suffering from restless legs syndrome or periodic limb movements in sleep. Both can be disorienting, with uncontrollable urges to move, and pain relief is often temporary. Thankfully, there are other treatment options, including ketamine.
People, regardless of age, can get RLS. The symptoms may start in childhood or adulthood, but the risk of developing the illness increases markedly with age. RLS is more widespread in women than men, and up to 10 percent of people in the United States have RLS.
Many people experience periodic limb movements in sleep (PLMS). This is seen in nearly 80% of people with restless legs syndrome (RLS). Thirty 30% of people older than 65 can have the condition but are asymptomatic. PLMS is widespread in patients with REM and behavior disorder narcolepsy, and may also show in patients experiencing obstructive sleep apnea and during positive airway pressure therapy initiation.
How RLS & PLMS Are the Same or Different
The most significant difference between the two conditions, especially when PLMS becomes period limb movement disorder (PLMD), is that most people aren’t aware of any random leg movement during sleep. Leg jerks are mostly reported by a partner awakened by the motion.
Symptoms of PLMS/D may also include:
- Frequently waking from sleep
- Non-restorative sleep
- Fatigue during daylight hours
- Daytime sleepiness
PLMD is often connected with restless legs syndrome, but it isn’t the same condition. It’s characterized by people having rhythmic and monotonous limb movement happening about every 20-40 seconds. And even though it’s a physical illness, it’s considered a sleep disorder because its symptoms disturb sleep and sleep function.
With restless legs syndrome, people may experience one or more of the following symptoms:
- A strong, sometimes irresistible, desire to move the legs.
- Uncomfortable feelings in their legs. People have described these sensations as creeping, creepy-crawly, gnawing, itching, painful pulling, or tugging.
- Symptoms that begin or get worse while resting. The longer someone rests, the greater the risk the symptoms will happen and the more intense they could be.
- RLS symptoms are most painful in the evening when someone is lying down.
- Temporary relief when the person moves their legs. The relief may be complete or limited but normally begins very soon after activity starts, including something as simple as walking. The relief will continue if the motion continues.
- RLS can cause difficulty in falling or staying asleep, which can be one of the chief complaints of the syndrome.
Another differentiator between the two is genetics. While restless legs syndrome can be passed down from parent to biological child, that doesn’t seem to be the case with PLMS/D.
- Low levels of iron (iron deficiency)
- Uremia (a condition associated with worsening kidney function)
- Parkinson’s disease
- Side effects of certain medications like antidepressants, including tricyclic antidepressants and SSRIs (selective serotonin reuptake inhibitors), dopamine-receptor antagonists (anti-nausea drugs), lithium, and select anticonvulsants
- It could also be caused by narcolepsy (another sleep disorder with an overpowering urge to sleep during non-sleep hours) and eating while sleeping (sleep-related eating disorder)
- Attention deficit hyperactivity disorder, William’s syndrome, and other neurodevelopmental and genetic disorders
- Spinal cord injuries or tumors
Diagnosis & Treatment
The diagnosis of RLS is primarily clinical, and sleep studies aren’t needed. For diagnosis, symptoms must include the desire to move, irregular leg feeling worsens during evening hours and when resting, and pain is only reduced with movement such as stretching the legs or walking. This is the prime differentiator between RLS and other neurological illnesses, like those related to peripheral nerve damage. Your healthcare provider may use the International RLS Scale to rank RLS severity.
Diagnosing periodic leg movements in sleep is like RLS, but if your healthcare provider makes a positive conclusion, you can expect to undergo a full clinical examination with a recording of personal and family medical history, and will be required to undergo an overnight polysomnogram which records sleep and bioelectrical signals coming from your body while you’re sleeping.
Both conditions are treatable with non-drug options, including diet and lifestyle changes, regular exercise, physical and psychotherapy, and, in some cases, prescription pain relievers or perhaps ketamine therapy. It’s essential to ask your healthcare provider which treatment offers the best outcomes for your particular condition.