Restless Leg Syndrome Flashcards
What is restless leg syndrome? 5
It is a sensorimotor disorder that results in an urge to move due to unpleasant sensations that is relieved by movement. It is exacerbated by inactivity and is worse in the evening. These symptoms cannot be accounted for by any alternative diagnosis
What criteria support a RLS diagnosis? 3
1) positive family history of RLS 2) positive response to dopaminergic treatment 3) Presence of periodic limb movements
What can complicate an RLS diagnosis? 3
1) People have various descriptions of what they are feeling? E.g. being stung by 20 mosquitoes, my leg is like a candy cane slowly being eaten from the inside out. 2) Various phenotypes 3) Many conditions mimic RLS.
What are the two RLS phenotypes ? 2
Primary and idiopathic/secondary RLS
Describe the phenotype of RLS. 3
1) Can have an early or late onset 2) can be familial or sporadic, however 60-65% of RLS cases indicate a positive family history 3) the 2:1 female preponderance
What causes secondaryRLS?3
Usually a condition that results in iron deficiency e.g.: 1) Iron deficient anemia 2) Pregnancy 3) Renal failure
What is a periodic limb movement? 2
Involuntary repetitive leg movement and with primarily extension of the big toe and dorsiflexion of the ankle
What does a babinski imply and what is the importance in RLS? 5
RLS patients often present with PLM, characterized by extension of the big toe and dorsiflexion of the ankle, this is similar to the Babinski sign found in patients with UMN lesions. This suggests that the spinal cord is isolated from inhibitory control resulting in spinal hyperexcitability.
What are the PLM criteria? 4
1) EMG amplitude that increases by 8uv above baseline. 2) Each individual burst last for between 0.5 to 10 seconds. 3) Each EMG must be separated by at least 5 but not more than 90 seconds. 4) There must be at least 4 EMG burst.
How many PLM/H are required for it to be considered pathological?
5
What are consequences of PLMs? 2
Cortical arousal and autonomic arousal —> tachycardia and increased BP.
What other sleep disorders are PLMs associated with? 5
1) Sleep apnea 2) Rapid eye movement sleep behavior disorder 3) Insomnia 4) hypersomina 5) narcolepsy
What non-sleep related disorders are associated with PLMs?
1) Congestive HF 2) Spinal cord injury 3) End stage renal failure 4) Hypertension
Can healthy people experience PLMS?
Yes, between 30- 50% of people over the age of 60 have a PLM index of more than 5/h
What is the clinical significance of RLS and PLM?
1) Delays in sleep onset, sleep disruption and decreased sleep efficiency 2) CVD risk 3) Excessive daytime sleepiness 4) Depression and pain
What can sleep deprivation result in? 8
1) decreased survival 2) increased pain 3) Impaired memory and concentration 4) Poor focus and attention 5) Slower reaction times 6) Greater utilization of healthcare 7) More frequent MVA and work place errors 8) Heightened inflammation and risk of disease
What are the four main theories regarding the pathophysiology of RLS?
1) Genetic abnormalities 2) Disorders of iron metabolism 3) Dopaminergic dysfunction 4) Central opiate system dysfunction
Describe the possible aetiology of RLS? 5
1) insufficient brain iron 2) impaired dopaminergic brain function 3) Spinal hyperexcitabilty 4) Spontaneous sensations and movements 5) RLS and PLMs
What genetic factors are implicated in RLS? 2
1) MEIS1 has been identified as the strongest genetic risk factor for developing RLS. It is important in the embryonic development of the limbs, heart and eye development.