Case report
Pergolide-associated ‘sleep attacks’ in a patient with
restless legs syndrome
Claudio Bassetti
a,
*
, Sandra Clavadetscher
b
, Matthias Gugger
c
, Christian W. Hess
b
a
Neurologische Poliklinik, Universitatsspital, Frauenklinikstrasse 26, 8091 Zurich, Switzerland
b
Department of Neurology, University Hospital, Inselspital, Bern, Switzerland
c
Division of Pneumology, University Hospital, Inselspital, Bern, Switzerland
Received 14 February 2001; received in revised form 30 April 2001; accepted 2 May 2001
Abstract
The occurrence of irresistible sleep episodes (‘sleep attacks’) has been noted in patients with Parkinson’s syndrome treated with dopa-
agonists. This is the first report of ‘sleep attacks’ in a patient with restless legs syndrome in whom treatment with pergolide was reduced from
2 to less than 1 mg/day. ‘Sleep attacks’ were accompanied by a reduced mean sleep latency of 5 min and 20 s (without sleep onset REM
periods) on a multiple sleep latency test. ‘Sleep attacks’ disappeared when pergolide was tapered off and substituted with pramipexol. The
appearance of ‘sleep attacks’ as a ‘withdrawal’ effect of pergolide is consistent with a wakefulness-promoting action of postsynaptic
dopaminergic receptors at higher doses of dopamine agonists. q 2002 Published by Elsevier Science B.V.
Keywords: Sleep attacks; Pergolide; Restless legs syndrome
1. Introduction
Sedation and excessive daytime sleepiness, well known
side-effects of treatments with dopa-agonists, can be seen in
10–30% of patients. Over the past 2 years, several publica-
tions have drawn attention to the possible occurrence of
irresistible sleep episodes (‘sleep attacks’) in patients with
Parkinson’s syndrome treated with pramipexol, ropinirole,
pergolide, levodopa, and other dopaminergic drugs [1,2].
We report — to our best knowledge — the first observation
of a similar side-effect in a patient with restless legs
syndrome (RLS) treated with pergolide.
2. Case report
This 69-year-old man has been treated in our Sleep Clinic
since 1991 for severe idiopathic RLS, which appeared in the
early 1970s. Neurologic examination was always unremark-
able. A conventional polysomnography documented the
presence of dyskinesias while awake and a few periodic
limb movements during sleep (,5/h) while ruling out
significant sleep-disordered breathing (apnea–hypopnea-
index ¼ 7). In February 1998, the patient was being treated
with levodopa (1000 mg/day) and clomethiazol (300 mg/
day), and reported severe RLS symptoms. Treatment with
pergolide at a dose of 0.05 mg/day was started. Improve-
ment of RLS symptoms led to a discontinuation of levo-
dopa. Over the following months, the patient increased his
intake of pergolide (up to 2 mg/day) beyond the suggested
doses in order to maintain good control of his RLS symp-
toms. However, in February 1999, he reported a new
increase of the discomfort in his legs. While being treated
with pergolide at 2 mg/day and clomethiazol at 300 mg/day,
his RLS score (International Restless Legs Syndrome Study
Group, Neurology 2001;56(Suppl 3):A4) was 31 (.30: very
severe RLS) and his Epworth sleepiness score (ESS) was 8
(,10: normal). Codeine at a dose of 60 mg/day was started
and resulted in an improvement of the RLS symptoms (see
Fig. 1). In April 1999, with his RLS score at 22 (10–20:
moderate RLS) and his ESS at 7, the pergolide dosage was
reduced to 1.0 mg/day. He subsequently reported the onset
of previously unknown ‘sleep attacks’, describing episodes
— occurring about once daily, often before noon — of an
overwhelming sudden sleepiness which lead to voluntary
and involuntary naps lasting 10–15 min, and occasionally
up to 60 min. The episodes occurred, sometimes without
warning, at rest or during moderately intense motor activ-
ities, but never during such activities as eating, talking, or
walking. He experienced the naps as very deep, non-refresh-
ing sleep unaccompanied by dreams. His wife described his
Sleep Medicine 3 (2002) 275–277
1389-9457/02/$ - see front matter q 2002 Published by Elsevier Science B.V.
PII: S 1389-9457(01)00132-0
www.elsevier.com/locate/sleep
* Tel.: 141-1-255-5503; fax: 141-1-255-4507.
E-mail address: claudio.bassetti@nos.usz.ch (C. Bassetti).