Nocturnal myoclonus syndrome (periodic movements in sleep) related to central dopamine D2-receptor alteration

Eur Arch Psychiatry Clin Neurosci. 1995;245(1):8-10. doi: 10.1007/BF02191538.


The nocturnal myoclonus syndrome (NMS) consists of stereotyped, repetitive jerks of the lower limbs that occur during sleep or wakefulness. NMS is often related with restless-legs syndrome (RLS) and can cause severe sleep disturbances and daytime sleepiness. The efficacy of dopamine agonists in the treatment points to a dopaminergic dysfunction in NMS. We investigated the central dopamine D2-receptor occupancy with [123I] labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) ([123I]IBZM) and single photon emission tomography (SPET) in 20 patients with NMS and in 10 healthy controls. In most of the patients with NMS there was a lower [123I]IBZM binding in the striatal structures compared to controls. The results indicate that NMS is related to a decrease of central D2-receptor occupancy.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Binding Sites
  • Circadian Rhythm*
  • Corpus Striatum / metabolism
  • Female
  • Humans
  • Leg / physiopathology*
  • Male
  • Middle Aged
  • Myoclonus / complications
  • Myoclonus / diagnosis
  • Myoclonus / physiopathology*
  • Receptors, Dopamine D2 / metabolism*
  • Restless Legs Syndrome / complications*
  • Sleep Wake Disorders / etiology*
  • Tomography, Emission-Computed, Single-Photon
  • Wakefulness


  • Receptors, Dopamine D2