Periodic Limb Movement Syndrome, Restless Legs Syndrome,
Seizures, Sleep Apnea and Other Causes Of
Abnormal Body Movements During Sleep



Understanding the symptoms of sleep disorders.

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Analyzing the problem.
-Sleepwalking, screaming, arousals with panic & frantic, agitated behaviors.
-Abnormal body movements during sleep.
-Eating during sleep.
-Inappropriate sexual activity during sleep ("sleep sex") .
-Biting of the tongue or inside of the cheek during sleep.
-Bruxism (toothgrinding; toothclenching).
-Night sweats (sleep-related hyperhidrosis).
-Headaches related to sleep.
-Enuresis (bed wetting) and frequent urination at night (nocturia).
-Abnormal heart rhythms during sleep.
-Choking, shortness of breath and chest pains occurring during sleep.
-Sleep paralysis.




Body jerks occurring only in drowsiness--when first falling asleep:

-In most cases are “sleep starts” or “hypnic jerks”-- a harmless phenomenon experienced by nearly everyone on occasion when first dozing off, sometimes with a sensation of falling.  Can be aggravated by stress, fatigue and caffeine.  While they usually require no treatment, they rarely can occur repeatedly to the point of making it difficult to fall asleep.

-Occasionally can be due to epileptic seizures  or a type of non-epileptic movement disorder called myoclonus (which involves abrupt, shock-like muscle contractions due to various non-epileptic causes) when these occur primarily in drowsiness and light sleep.  In such cases, the resulting body jerks may occur repeatedly, and they may appear virtually identical each time that they happen.

-Periodic limb movement syndrome (PLMS) usually occurs throughout a good part of sleep-- particularly stage 2 sleep, but it may be noticed by the patient only when drowsy (see below).

-Breathing problems such as sleep apnea may arouse drowsy patients with an abrupt start--they may jerk awake because they had stopped breathing while dozing off.  Look for: snoring, restless sleep, arousals with snores/ gasps/ shortness of breath/ chest discomfort/ headache/ dry throat, worsening with weight gain, nasal congestion and after consumption of alcohol, or such daytime complaints as sleepiness, irritability, trouble concentrating and memory problems.  At the same time, realize that some people with sleep apnea have none of these symptoms. 

-Rhythmic movement disorders before sleep onset are common in infants and toddlers.  May involve repetitive headbanging, headrolling, body rocking, and body rolling--sometimes with humming or chanting. While affected youngsters are usually quite normal and outgrow it by age four, occurrence in late childhood is sometimes associated with retardation and other problems. It rarely is mimicked by seizure activity.  While usually benign, injuries have followed violent headbanging.

Body jerks and abnormal movements occurring once fully asleep:

-Periodic limb movement syndrome (PLMS) and Restless Legs Syndrome [RLS]

PLMS is extremely common, particularly in older individuals. It involves jerks usually beginning in the feet and ankle: the toes fan out and move upward, with “cocking up” of the ankle (dorsiflexion). In some cases, the knees and hips may flex abruptly and occasionally, the arms will also jerk.

PLMS most often occurs primarily in non-REM sleep--particularly stages 1 and 2--and has an unusual periodicity--with a jerk occurring at nearly predictable intervals of roughly 15-40 seconds. It is not a form of seizure.  

Most patients with restless legs syndrome (RLS--defined by a restless, “antsy” uncomfortable sensation in the legs, that compels people to get up and walk about to get relief--and which tend to occur particularly when they try to go to bed) have PLMS.  However, the majority of people with PLMS don’t suffer from RLS.

Both PLMS and RLS can “run in families”.  Sometimes, underlying causes can be found.  Some cases may be due to iron deficiency, deficiencies of certain vitamins like folic acid, kidney failure, and damage to the nerves in the legs. 

Certain medications--particularly antidepressants--can make these problems much worse, and excessive exercise and even small amounts of caffeine may aggravate them.

Many people with PLMS do not experience awakenings as a consequence, feel their sleep is good, and require no treatment--although the repeated jerking (or even kicking!) of their legs can be a problem for their bedpartners.    

Treatment of PLMS and RLS may be required, however, in cases in which severe sleep fragmentation and insomnia complaints result. Medications include:                       

-drugs acting on dopamine receptors in the brain that are used to treat Parkinson’s disease such as L-DOPA containing preparations [Sinemet®], ropinirole [Requip®] and pramipexole [Mirapex®] and a similar agent, cabergoline [Dostinex®] which is used in the United States to treat prolactin-secreting pituitary tumors.

Sinemet®, Requip® and Mirapex® can markedly decrease the actual leg jerks and RLS symptoms-- at least initially.  Unfortunately, in many cases, they may lose their effectiveness and ultimately may cause worsening of symptoms: with occurrence of more intense restless legs symptoms earlier in the day and with spread into the arms. This phenomenon, called augmentation, may be less likely to occur with Dostinex.

-narcotic medications like codeine, oxycodone [Percodan®] and methadone

-anti-epileptic drugs like gabapentin [Neurontin®] and clonazepam [Klonopin®]

-Many other drugs also have been tried--some with anecdotal reports of success, but generally without much scientific proof that they would help most people.

-Some of these treatments do not suppress the leg jerks, but instead may help people sleep through them better. 

The limitations and possible side effects of current drug treatments for PLMS and RLS render it all the more important to identify and avoid any factors that are making them worse.

-Sleep apnea.

Sleep apnea can cause jerking, thrashing, flinging of the arms, sitting up, jumping up onto one’s feet or even falling out of bed-- as a consequence of violent struggling to overcome throat collapse and smothering.  Snoring is usually present.  Other possible clues (not present in all cases) include: night sweats, headaches/ dry throat on awakening, arousals with shortness of breath, gasps or snorts, daytime sleepiness, irritability or memory difficulties, occurrence in obese individuals, and worsening with nasal congestion and after alcohol consumption. 

-Sleep-related seizures.

Sleep-related epileptic seizures can involve repetitive twitches and jerks that are usually rhythmic and which may involve either one or both sides of the body and/or face.  If observers are available-- ask them to turn on bedroom lights immediately during onset of the episodes and look for the following:

-Does the jerking start on one side?  If so, always on the same side?  Is there head turning or drawing of the face to that side?
-Are the eyes open?  If so, do they turn to one side (which side?), or roll up?  Do the pupils look large or dilated?
-Any sign of breathing difficulty?  Any cyanosis (lips or face appear bluish)?  Or, does the face look pale?
-Any rigid stiffening or posturing?  Clenching of the teeth?  Biting of the tongue?  Loss of urine?          -Difficulty awakening thereafter?  Lethargy and confusion following these episodes?

Sleep-related seizures are rather common and in most cases, quite readily treated.  Often, no underlying cause is found.  However, they may “run in families” or result from various medical and neurological disorders-- including sleep-related abnormal heart rhythms or breathing disorders with resulting lack of oxygen: particularly if no seizural symptoms have ever been experienced during wakefulness. 

-Nocturnal paroxysmal dystonia.

A r elatively uncommon syndrome of repeated body stiffening, eye opening and sometimes violent posturing in sleep.  Attacks may occur almost nightly and may respond to certain anti-seizure medications.  Many cases appear to represent a form of epilepsy. 


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Columbus, Ohio, Central Ohio, hospitalssleep, wake, insomnia, sleepiness 

Accredited by the American Academy of Sleep Medicine.

Robert W. Clark, M.D., Medical Director
1430 South High Street, Columbus OH 43207

Tel: [614] 443-7800
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