Sleep Medicine 16 (2015) 310
Contents lists available at ScienceDirect
Sleep Medicine j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / s l e e p
Letter to the Editor Pain perception in narcolepsy with cataplexy patients To the Editor: Narcolepsy with cataplexy (NC) has an estimated prevalence of 0.047% [1], and it stems from a selective loss of hypocretin/orexinproducing neurons in the lateral hypothalamus. Recent studies have highlighted the role of hypocretin/orexin in central nociceptive processing [2,3], and it has been reported that chronic pain is more common and disabling in people with NC compared with healthy controls [4]. The present study hypothesized that hypocretin/ orexin deficiency in NC might lead to a dysregulation in the control of nociception. It also compared the pain perception of people with NC and healthy controls using standardized Quantitative Sensory Testing (QST) [5]. Thirteen participants with NC (mean age 32.8 years, 10 men, three women, disease duration 13.1 years) and 13 age-matched and gender-matched controls underwent QST. The QST test battery assessed the mechanical detection threshold, vibration detection threshold, cold detection threshold, cold pain threshold, warm detection threshold, heat pain threshold, mechanical pain threshold, and pressure pain threshold (PPT). Also, participants completed the Stanford Sleepiness Scale (SSS) for rating sleepiness immediately before and after QST, and the Epworth Sleepiness Scale (ESS) to assess overall daytime sleepiness. None of QST parameters differed significantly between people with narcolepsy and healthy controls. The ESS scores were significantly higher in people with narcolepsy than in healthy controls, but sleepiness immediately before and after testing did not differ between the two. The present data indicate that the increased pain reported in NC does not result from an altered perception of sensory or painful stimuli. These findings also suggest that sleep fragmentation in NC does not impair sleep to an extent that modifies pain perception. However, these results need to be verified in a larger group of people.
Conflict of interest Financial disclosure: Related to the research covered in this article, the authors have nothing to disclose.
http://dx.doi.org/10.1016/j.sleep.2014.09.018 1389-9457/© 2014 Elsevier B.V. All rights reserved.
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2014.09.018.
References [1] Ohayon MM, Priest RG, Zulley J, Smirne S, Paiva T. Prevalence of narcolepsy symptomatology and diagnosis in the European general population. Neurology 2002;58:1826–33. [2] Sadeghi S, Reisi Z, Azhdari-Zarmehri H, Haghparast A. Involvement of orexin-1 receptors in the ventral tegmental area and the nucleus accumbens in antinociception induced by lateral hypothalamus stimulation in rats. Pharmacol Biochem Behav 2013;105:193–8. [3] Date Y, Ueta Y, Yamashita H, Yamaguchi H, Matsukura S, Kangawa K, et al. Orexins, orexigenic hypothalamic peptides, interact with autonomic, neuroendocrine and neuroregulatory systems. Proc Natl Acad Sci U S A 1999;96:748– 53. [4] Dauvilliers Y, Bayard S, Shneerson JM, Plazzi G, Myers AJ, Garcia-Borreguero D. High pain frequency in narcolepsy with cataplexy. Sleep Med 2011;12:572– 7. [5] Rolke R, Baron R, Maier C, Tölle TR, Treede RD, Beyer A, et al. Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): standardized protocol and reference values. Pain 2006;123:231–43.
S. Spielberger Department of Neurology, Medical University Innsbruck, Innsbruck, Austria B. Högl * Department of Neurology, Medical University Innsbruck, Innsbruck, Austria * Address: Anichstr. 35, 6020, Innsbruck, Austria. Tel.: +0043 512 504 23890; fax: +0043 512 504 23842. E-mail address: [email protected] T. Mitterling Department of Neurology, Medical University Innsbruck, Innsbruck, Austria B. Frauscher Department of Neurology, Medical University Innsbruck, Innsbruck, Austria W.N. Löscher Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
Contents lists available at ScienceDirect
Sleep Medicine j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / s l e e p
Letter to the Editor Pain perception in narcolepsy with cataplexy patients To the Editor: Narcolepsy with cataplexy (NC) has an estimated prevalence of 0.047% [1], and it stems from a selective loss of hypocretin/orexinproducing neurons in the lateral hypothalamus. Recent studies have highlighted the role of hypocretin/orexin in central nociceptive processing [2,3], and it has been reported that chronic pain is more common and disabling in people with NC compared with healthy controls [4]. The present study hypothesized that hypocretin/ orexin deficiency in NC might lead to a dysregulation in the control of nociception. It also compared the pain perception of people with NC and healthy controls using standardized Quantitative Sensory Testing (QST) [5]. Thirteen participants with NC (mean age 32.8 years, 10 men, three women, disease duration 13.1 years) and 13 age-matched and gender-matched controls underwent QST. The QST test battery assessed the mechanical detection threshold, vibration detection threshold, cold detection threshold, cold pain threshold, warm detection threshold, heat pain threshold, mechanical pain threshold, and pressure pain threshold (PPT). Also, participants completed the Stanford Sleepiness Scale (SSS) for rating sleepiness immediately before and after QST, and the Epworth Sleepiness Scale (ESS) to assess overall daytime sleepiness. None of QST parameters differed significantly between people with narcolepsy and healthy controls. The ESS scores were significantly higher in people with narcolepsy than in healthy controls, but sleepiness immediately before and after testing did not differ between the two. The present data indicate that the increased pain reported in NC does not result from an altered perception of sensory or painful stimuli. These findings also suggest that sleep fragmentation in NC does not impair sleep to an extent that modifies pain perception. However, these results need to be verified in a larger group of people.
Conflict of interest Financial disclosure: Related to the research covered in this article, the authors have nothing to disclose.
http://dx.doi.org/10.1016/j.sleep.2014.09.018 1389-9457/© 2014 Elsevier B.V. All rights reserved.
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2014.09.018.
References [1] Ohayon MM, Priest RG, Zulley J, Smirne S, Paiva T. Prevalence of narcolepsy symptomatology and diagnosis in the European general population. Neurology 2002;58:1826–33. [2] Sadeghi S, Reisi Z, Azhdari-Zarmehri H, Haghparast A. Involvement of orexin-1 receptors in the ventral tegmental area and the nucleus accumbens in antinociception induced by lateral hypothalamus stimulation in rats. Pharmacol Biochem Behav 2013;105:193–8. [3] Date Y, Ueta Y, Yamashita H, Yamaguchi H, Matsukura S, Kangawa K, et al. Orexins, orexigenic hypothalamic peptides, interact with autonomic, neuroendocrine and neuroregulatory systems. Proc Natl Acad Sci U S A 1999;96:748– 53. [4] Dauvilliers Y, Bayard S, Shneerson JM, Plazzi G, Myers AJ, Garcia-Borreguero D. High pain frequency in narcolepsy with cataplexy. Sleep Med 2011;12:572– 7. [5] Rolke R, Baron R, Maier C, Tölle TR, Treede RD, Beyer A, et al. Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): standardized protocol and reference values. Pain 2006;123:231–43.
S. Spielberger Department of Neurology, Medical University Innsbruck, Innsbruck, Austria B. Högl * Department of Neurology, Medical University Innsbruck, Innsbruck, Austria * Address: Anichstr. 35, 6020, Innsbruck, Austria. Tel.: +0043 512 504 23890; fax: +0043 512 504 23842. E-mail address: [email protected] T. Mitterling Department of Neurology, Medical University Innsbruck, Innsbruck, Austria B. Frauscher Department of Neurology, Medical University Innsbruck, Innsbruck, Austria W.N. Löscher Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
