Acute dopamine-agonist treatment in restless legs syndrome: effects on sleep architecture and NREM sleep instability.
OBJECTIVE
To analyze cyclic alternating pattern (CAP) in restless legs syndrome (RLS) and the eventual changes induced by the acute administration of pramipexole.


METHODS
Sleep clinic in a scientific research institute.


METHODS
Placebo or pramipexole 0.25 mg.


METHODS
Thirty-four patients were included: 19 patients received 0.25 mg of pramipexole and 15 were given placebo. The control group included 13 normal subjects. Nocturnal polysomnography was carried out in all subjects, and a second night was recorded after pramipexole or placebo was administered to patients with RLS. Sleep stages, CAP, and leg movement activity were scored following standard criteria.


RESULTS
At baseline, rapid eye movement sleep latency was significantly longer in patients with RLS than in normal control subjects, and the periodic leg movement during sleep index (PLMS) was also significantly higher. On the contrary, many CAP parameters appeared to be significantly different, with a general increase in CAP rate in patients with RLS. Acute administration of pramipexole induced moderate changes in sleep architecture (increased number of stage shifts/h, sleep efficiency, and percentage of stage 2 sleep; decreased wakefulness after sleep onset; and a lower PLMS index. No effects of treatment on CAP were observed.


CONCLUSIONS
Patients with RLS show significant abnormalities in sleep microstructure, represented by an excessive sleep instability/discontinuity. Acute pramipexole administration seems to exert no action on these abnormalities; the moderate effects seen on sleep architecture might be interpreted as the beneficial consequence of the removal of presleep RLS symptoms and PLMS.
Ferri
Raffaele
R
Sleep Research Centre, Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy. rferri@oasi.en.it
Manconi
Mauro
M
Aricò
Debora
D
Sagrada
Carolina
C
Zucconi
Marco
M
Bruni
Oliviero
O
Oldani
Alessandro
A
Ferini-Strambi
Luigi
L
D052160:Benzothiazoles / Q000627:therapeutic use*; D018491:Dopamine Agonists / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000187:drug effects / Q000379:methods / Q000706:statistics & numerical data; D000077487:Pramipexole; D011446:Prospective Studies; D012148:Restless Legs Syndrome / Q000188:drug therapy*; D016037:Single-Blind Method; D012890:Sleep / Q000187:drug effects*; D012894:Sleep Stages / Q000187:drug effects
D052160:Benzothiazoles; D018491:Dopamine Agonists; D000077487:Pramipexole