SleepInfo.org

A Patient & Physician

Education Website

Home Sleep Apnea Insomnia Narcolepsy Insufficient Sleep Sleep Studies Board Review Contact Us

ICSD-2 Classification

VI. Sleep Related Movement Disorders

• Restless Legs Syndrome

• Periodic Limb Movement Disorder

• Sleep Related Leg Cramps

• Sleep Related Bruxism

• Sleep Related Rhythmic Movement Disorder

• Sleep Related Movement Disorder, Unspecified

• Sleep Related Movement Disorder Due to Drug or Substance

• Sleep Related Movement Disorder Due to Medical Condition

Restless Legs Syndrome

• Diagnostic Criteria

– Urge to move legs with an uncomfortable/unpleasant sensation

– Worse when rest / inactive

– Partially or completely relieved by movement

– Worse or only occur in the evening

• PSG: 80-90% have PLMS, often associated with arousals

– PLMW > 15/hr of wakefulness during nocturnal PSG supports dx

• SIT: 1 hr PSG (without resp), sitting in bed with legs outstretched

– PLMW > 40/hr in evening prior to bed supports RLS

• 5-10% European population, > 40 typical, 1.5-2 times more in women

• Secondary causes: iron deficiency, pregnancy, ESRD, peripheral neuropathy, meds (antihistamines, dopamine antagonists, antidepressants except buproprion)

• 50% familial pattern

• Iron dysregulaton in the brain, particularly substantia nigra, with associated dopamine deficiency

• Early onset RLS:

– Onset before age 45

– Tends to have intermittent sxs, gradually progressive course and only develops daily sxs between age 45-60

• Late onset RLS:

– Stable sxs at onset or reaches stable pattern within 5 yrs

Periodic Limb Movement Disorder

• Diagnostic Criteria

– PSG demonstrates repetitive, stereotyped limb movements:

• 0.5 – 5 sec

• Amplitude >= 25% of toe dorsiflexion during biocals

• Four or more in a row

• Interval 5-90 sec (typically 20-30 sec)

– PLMS index > 5 peds, > 15 adults (but should be interpreted in relation to sxs)

– Clinical sleep disturbance or daytime fatigue

– Not explained by another disorder

• In particular PLMs after apnea should not be counted

• Arousal may precede, coincide with, or follow the PLM

• Often complain of initiation or maintenance insomnia

• Unrefreshing sleep

• PTAF or esophageal manometry should be used to detect subtle respiratory events to exclude SRBD as the cause of PLMs

– In the setting of SRBD, PLMD can be dx when the PLMS and sleep disturbance persist despite adequate control with CPAP

• Sustained response to dopaminergic therapy support the dx of PLMD

• PLMS are commonly seen; PLMD is rare

– PLMS increase to 34% people > 60 yrs

• PLMS commonly associated with:

– RLS 80-90%

– RBD 70%

– Narcolepsy 45-65%

• Precipitating factors: SSRIs, TCAs, lithium, dopamine antagonists, iron deficiency

Sleep Related Leg Cramps

• Diagnostic Criteria

– Painful sensation in leg associated with muscle tightness

– Only occur during the sleep period

– Pain relieved by stretching

Sleep Related Bruxism

• Diagnostic Criteria

– Tooth grinding sounds or tooth clenching during sleep

– One or more:

• Abnormal wear of teeth

• Jaw muscle pain, fatigue or jaw lock on awakening

• Masseter muscle hypertrophy upon voluntary forceful clenching

• Can be primary or secondary to psychoactive meds, recreational drugs, in kids cerebral palsy and mental retardation, personality types (highly motivated or maintain high vigilance)

• PSG not required for dx, but requires EMG (ideally on masseter) and audio recording (see ICSD for details)

Reference:

The International Classification of Sleep Disorders, Second Edition. The American Academy of Sleep Medicine Press, 2005. Can be purchased at the AASM store online!