1- Restless legs syndrome (RLS),
A neurological condition characterized by throbbing, pulling, creeping, or other disturbing sensations in the legs and an intense, and sometimes compelling, urge to move them. Symptoms occur primarily at night when a person is at rest and can increase in severity during the course of the night. Moving the legs relieves the discomfort. The described sensations range in severity from a feeling of discomfort, to irritation, to actual pain.
The hallmark of RLS is that lying down and attempting to relax provokes the symptoms. Most people with RLS find it difficult to fall asleep and maintain sleep. This condition, if not managed properly, can lead to poor sleep pattern, with resultant exhaustion and daytime fatigue. Other situations that precipitate symptoms of RLS include periods of inactivity such as long car trips, sitting in a movie theater, long-distance flights, immobilization in a cast, or relaxation exercises. Many individuals also note a worsening of symptoms if their sleep is further reduced by events or activity.
RLS occurs in both males and females, with a higher predilection for women, in whom the incidence is two times more common than in men. The onset of symptoms can be at any age, and the symptoms typically become more frequent and last longer with age.
The cause of RLS is poorly understood in the majority of diagnosed cases, although a genetic component may play a role in cases of familial RLS. Some data also suggest that low levels of iron in the brain also may be responsible for RLS.
RLS has also been shown to be linked to the following factors or conditions:
• Chronic diseases such as kidney failure, diabetes, and peripheral neuropathy.
• Certain medications that may aggravate symptoms. These medications include antinausea drugs (prochlorperazine or metoclopramide), antipsychotic drugs (haloperidol or phenothiazine derivatives), antidepressants that increase serotonin, and some cold and allergy medications-that contain sedating antihistamines.
• Pregnancy, especially in the last trimester. In most cases, symptoms usually disappear within 4 weeks after delivery.
Alcohol and sleep deprivation precipitate or worsen symptoms in some individuals.
Diagnosis is made based upon the presence of four essential criteria:
• Symptoms that are worse at night and are absent or negligible in the morning;
• A strong and often overwhelming need or urge to move the affected limb(s), often associated with paresthesias or dysesthesias;
• Sensory symptoms that are triggered by rest, relaxation, or sleep; and
• Sensory symptoms that are relieved with movement and the relief persists as long as the movement continues.
2- sleep myoclonus:
Though a less likely possibility given your symptoms, but I will tackle it briefly. Sleep myoclonus occurs during sleep, usually in the stage just before deep sleep. This disorder rarely disturbs the individual to the extent waking and disrupting sleep.
Myoclonus is a brief twitching of the muscles, and can occur separately or in groups, as well as in a sequence or at random. Myoclonus is an important of possible underlying nervous system disorders including Parkinson’s disease, Alzheimer’s, multiple sclerosis and epilepsy. Myoclonus is caused by sudden jerks or contractions in the muscles, and also of the muscles uncontracting or relaxing after contraction. The most common form of myoclonus is hiccups, which are quick contractions affecting the diaphragm. Myoclonus, especially sleep myoclonus in particular, are not life threatening.
Sleep myoclonus primarily affects the fingers, toes, lips and eyes, and is often barely noticeable to an outside observer. It does not cause involuntary limb movement. Sleep myoclonus has been shown to be somewhat linked to certain stimuli, whereby contractions may be caused or increased by environmental factors such as light, sound or movement.
Myoclonus is a common occurrence, though it remains responsible for only about 5% of insomnia related cases. The presence of myoclonus may indicate one or more other sleeping disorders are present as well, including sleep apnea, narcolepsy and other movement disorders. It is most commonly found in adult males.
Myoclonus on its own will usually needs not be treated, but if suspicions of possible related conditions arise, further investigations may be then required.
Treatment for myoclonus is based on tranquilizers, which relax the muscles and inhibit contraction.