Sleep Medicine xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Sleep Medicine journal homepage: www.elsevier.com/locate/sleep
Images in Sleep Medicine
Hypnic jerks: neurophysiological characterization of a new motor pattern Giovanna Calandra-Buonaura a,b, Maria Alessandria b, Rocco Liguori a,b, Elio Lugaresi b, Federica Provini a,b,⇑ a b
IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
a r t i c l e
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Article history: Received 16 December 2013 Received in revised form 22 January 2014 Accepted 24 January 2014 Available online xxxx Keywords: Hypnic jerks Sleep starts Sudden bodily jerks Myoclonus Insomnia Startle
1. Introduction to the case Hypnic jerks (HJs) are physiological, non-periodic, myoclonic bodily jerks, occurring mainly at sleep onset [1]. HJs occasionally reach abnormal proportions in frequency and degree (intensified HJs) impeding to fall or stay asleep [2]. In a recent video-polysomnographic (VPSG) study, four motor patterns of HJs have been recognized in 10 patients with intensified HJs and comorbid disorders: startle reflex, reticular reflex myoclonus, dystonic myoclonus and pyramidal myoclonus patterns [3]. We describe a further motor pattern of HJs, recorded through a nocturnal VPSG in a healthy 35-year-old man with a long history of sleep-onset insomnia due to involuntary jerks of the trunk and limbs accompanied by a sensation of ‘petrified head’. The patient was diagnosed with intensified HJs and received clonazepam with an improvement of jerks and insomnia. 2. Image analysis The study was approved by the institutional review board of the Department of BioMedical and NeuroMotor Sciences (University of ⇑ Corresponding author at: IRCCS Institute of Neurological Sciences of Bologna and Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Altura, 3, 40139 Bologna, Italy. Tel.: +39 051 4966829. E-mail address: [email protected] (F. Provini).
Bologna) and the patient gave his written consent to publish the manuscript and the figures. The patient slept for 280 min with reduced sleep efficiency (71%; normal value >85%), in absence of periodic limb movements or respiratory disturbances. During VPSG (Supplementary material 1), we recorded five spontaneous HJs and two evoked by an acoustic stimulus (Fig. 1A). HJs appeared without any periodic interval, independent of the patient’s body position. The jerks were characterized by a brief flexion of the head, trunk, and limbs (duration
Contents lists available at ScienceDirect
Sleep Medicine journal homepage: www.elsevier.com/locate/sleep
Images in Sleep Medicine
Hypnic jerks: neurophysiological characterization of a new motor pattern Giovanna Calandra-Buonaura a,b, Maria Alessandria b, Rocco Liguori a,b, Elio Lugaresi b, Federica Provini a,b,⇑ a b
IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
a r t i c l e
i n f o
Article history: Received 16 December 2013 Received in revised form 22 January 2014 Accepted 24 January 2014 Available online xxxx Keywords: Hypnic jerks Sleep starts Sudden bodily jerks Myoclonus Insomnia Startle
1. Introduction to the case Hypnic jerks (HJs) are physiological, non-periodic, myoclonic bodily jerks, occurring mainly at sleep onset [1]. HJs occasionally reach abnormal proportions in frequency and degree (intensified HJs) impeding to fall or stay asleep [2]. In a recent video-polysomnographic (VPSG) study, four motor patterns of HJs have been recognized in 10 patients with intensified HJs and comorbid disorders: startle reflex, reticular reflex myoclonus, dystonic myoclonus and pyramidal myoclonus patterns [3]. We describe a further motor pattern of HJs, recorded through a nocturnal VPSG in a healthy 35-year-old man with a long history of sleep-onset insomnia due to involuntary jerks of the trunk and limbs accompanied by a sensation of ‘petrified head’. The patient was diagnosed with intensified HJs and received clonazepam with an improvement of jerks and insomnia. 2. Image analysis The study was approved by the institutional review board of the Department of BioMedical and NeuroMotor Sciences (University of ⇑ Corresponding author at: IRCCS Institute of Neurological Sciences of Bologna and Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Altura, 3, 40139 Bologna, Italy. Tel.: +39 051 4966829. E-mail address: [email protected] (F. Provini).
Bologna) and the patient gave his written consent to publish the manuscript and the figures. The patient slept for 280 min with reduced sleep efficiency (71%; normal value >85%), in absence of periodic limb movements or respiratory disturbances. During VPSG (Supplementary material 1), we recorded five spontaneous HJs and two evoked by an acoustic stimulus (Fig. 1A). HJs appeared without any periodic interval, independent of the patient’s body position. The jerks were characterized by a brief flexion of the head, trunk, and limbs (duration
