Periodic Limb Movements
Periodic Limb Movement Disorder
Symptoms
Periodic limb movements (formerly called nocturnal myoclonus) are caused by repetitive cramping or jerking of the legs during sleep. Symptoms are pretty apparent, however some symptoms can be difficult to spot with the naked eye including twitching on less apparent areas of the body. Typically movements involve one or both limbs, movements also typically last 2 seconds and usually occur every 20-40 seconds. The movements often disrupt sleep even though you may not even remember.
Periodic limb movements are often associated with restless legs syndrome which is a condition involving sensations in the legs and sometimes arms while awake. 80% of people with restless legs syndrome have periodic limb movements.
Periodic limb movements are often associated with restless legs syndrome which is a condition involving sensations in the legs and sometimes arms while awake. 80% of people with restless legs syndrome have periodic limb movements.
Causes
Periodic limb disorder can be primary or secondary. Primary PLM’s have no known cause. Secondary plmd has many causes on the contrary including…
- Diabetes Mellitus
- Iron deficiency (first line test)
- Spinal cord trauma
- Sleep apnea
- Narcolepsy
- Medication including antidopaminergenic agents, dopaminergenic agents and antidepressants
- Withdrawal from sedative medications like benzodiazepines
Treatment
Unfortunately treatments do not cure the disorder but usually help relieve symptoms and reduce the amount of movements to improve our patients quality of sleep. Some limb movements are normal, but when you reach a certain level of movements they begin to affect the quality of your sleep. Medications are often a first line defense and can include…
- Benzodiazepines which can help supress muscle contractions.
- Dopaminergic agents that increase the levels of dopamine in the brain which is important in regulating muscle movements. Levodopa/carbidopa are two common examples.
- GABA agonists. These agents stop the release of certain neurotransmitters that stimulate muscle contractions. One of the more common agents is baclofen.