Who is susceptible to restless legs syndrome?
The most common conditions associated with RLS include systemic iron deficiency, renal failure, neuropathy, spinal cord lesions, pregnancy, multiple sclerosis, and possibly Parkinson disease (PD) and essential tremor.
Rare associated disorders: certain hereditary ataxias, fragile X-associated tremor ataxia syndrome, fibromyalgia, rheumatism, migraine, and diabetes.
What are the clinical manifestations of restless legs syndrome?
The hallmark symptom is the usually unpleasant or uncomfortable urge to move the legs (and occasionally the arms). Symptoms appear at rest, are most prominent at night, and may be temporarily relieved by activity. This sensation is usually felt deep in the legs, often between the knees and ankles. Patients may have difficulty articulating this feeling, and subjective descriptions may be varied and suggestible.
Words commonly used by patients to describe symptoms include: "need to move", "squirming", "tingling", "restlessness", "spasms", "crawling", "pulling", "electric shock", "nervousness", "discomfort", "pain", and "itching". It is usually deep rather than superficial. The sensation of the patient is unpleasant, but not necessarily painful. Almost all patients report temporary improvement in symptoms with walking and other exercises or movements. Methods include rubbing, pressing, stretching, and soaking in hot or cold water.
Common consequences of restless legs syndrome include sleep-onset insomnia, nocturnal awakenings, depression, and anxiety. Severe patients often have arm symptoms, usually after years of isolated leg involvement. A rare clinical variant involving perineal and lower abdominal discomfort has been reported, called bladder disturbance syndrome and genital restless syndrome.
What medications make restless legs syndrome worse?
Antihistamines, such as diphenhydramine, chlorpheniramine, and hydroxyzine.
Dopamine receptor antagonists, such as prochlorperazine, chlorpromazine, metoclopramide.
Certain antidepressants, such as mirtazapine, may also include tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), and serotonin-norepinephrine reuptake inhibitors (SNRIs).
Periodic limb movements during sleep
PLMS is defined as repetitive, highly stereotyped limb movements that occur periodically during sleep. Specifically, polysomnography shows repetitive movements lasting 0.5-10 seconds, typically spaced 20-40 seconds apart (range 5-90 seconds).
PLMS can occur in both legs at the same time or alternately, or in one leg. Leg movements typically last 1.5 to 2.5 seconds and vary in intensity and anatomical distribution, from slight extension of the big toe to marked triple flexion of the entire leg. The frequency of seizures ranges from an average of 1 every 20 seconds to 1 every 40 seconds.
Exercise is most pronounced during N1 and N2 phases of sleep, when polysomnography is often accompanied by K complexes and increased pulse and blood pressure. PLMS may cause arousal, but is usually not associated with insomnia. Dopaminergic drugs reduce leg movement and associated blood pressure spikes, but do not necessarily reduce K-complex waves and arousal, which tend to precede PLMS.