Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

Benign Neonatal Sleep Myoclonus Clinical Presentation

  • Author: Marc P DiFazio, MD; Chief Editor: Ted Rosenkrantz, MD  more...
 
Updated: Jan 02, 2015
 

History

Although children are sometimes identified with abnormal movements within the first several hours of birth while still in the hospital, parents are often the first to witness the movements in children who were discharged early. These movements are often characterized as jerking of a limb during sleep. This may be repetitive and rhythmic and, thus, may prompt concerns regarding seizure. Unless the movements are previously videotaped or witnessed in the outpatient setting, patients are generally admitted for observation and workup, depending on the clinical concern for seizures.

Caretakers should be aware of the clinical characteristics of benign neonatal sleep myoclonus (BNSM), which are delineated in the International Classification of Sleep Disorders, revised: Diagnostic and Coding Manual (2nd and 3rd editions) (ICSD-2, ICSD-3), as follows[23, 24] :

  • Repetitive myoclonic jerks that involve the whole body, trunk, or limbs
  • Movements that occur in early infancy, typically from birth to age 6 months
  • Movements that occur only during sleep
  • Movements that stop abruptly and consistently when the child is aroused
  • A disorder that is not better explained by another sleep disorder, by a medical or neurologic disorder, or by medication use

An association with sleep is important because clinically evident seizures are often associated with eye opening. Gentle restraint has been reported to possibly worsen the manifestations. Provocative maneuvers include sound stimulus and, in one report, repetitive head-to-toe rocking of the infant.[21] In this report, increased rocking frequency seemed to be associated with increased clinical manifestations. Passive restraint of the child did not ameliorate the signs.

The most important maneuver is waking the child, which should entirely eliminate the symptoms. Movements are often superimposed on normal, purposeless movements of the infant and do not appear to occur in isolation, as is the case in the clonic movements of a seizure. One study reported an infant with benign neonatal sleep myoclonus who developed a pathologic form of myoclonus (ie, myoclonic-astatic epilepsy).[25] This association is likely incidental, and no clear evidence suggests that benign neonatal sleep myoclonus occurs in a continuum with other, more consequential forms of myoclonus.

Next

Physical

Physical examination findings of benign neonatal sleep myoclonus are normal, except for the movements themselves. Children are generally otherwise well; however, in one report, neurologic findings were reported.[11] These were described as mild and included hyperirritability and hypoxia. The authors believed these findings were incidental and not causative; long-term follow-up of these same children indicated only tonal abnormalities. Whether these children had presenting neurologic abnormalities and the degree to which their tone was abnormal is unclear.

Most other reports emphasize the normal aspects of the physical examination findings. In the author's experience, children have normal examination findings and no long-term residua. In fact, a paucity of neurologic findings is, in itself, an aspect of the diagnostic criteria. Additional neurologic findings should prompt more extensive diagnostic testing for possible causes of pathologic myoclonus in infants.

Previous
Next

Causes

The cause of benign neonatal sleep myoclonus is unknown. However, 2 reports indicate a probable genetic contribution, with several individuals affected within 2 pedigrees.[16, 17]

Previous
 
 
Contributor Information and Disclosures
Author

Marc P DiFazio, MD Associate Professor, Department of Neurology, Uniformed Services University of the Health Sciences; Director, Pediatric Subspecialty Services, Shady Grove Adventist Hospital for Children

Marc P DiFazio, MD is a member of the following medical societies: Alpha Omega Alpha, International Parkinson and Movement Disorder Society, American Academy of Cerebral Palsy and Developmental Medicine, American Academy of Neurology, Child Neurology Society

Disclosure: Nothing to disclose.

Coauthor(s)

Dalila W Lewis, MD Pediatric Neurology Fellow, Walter Reed Army Medical Center

Dalila W Lewis, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Neurology, American Academy of Pediatrics

Disclosure: Nothing to disclose.

Ayne Kimberly Iafolla, MD Corporate Medical Director, Pediatrix of Maryland; Medical Director of Neonatal Intensive Care Unit, Active Staff, Departments of Neonatology and Genetics, Southern Maryland Hospital; Active Staff, Department of Neonatology, Washington County Hospital, Western Maryland Health System, and Shady Grove Adventist Hospital; Associate Staff, Departments of Neonatology and Genetics, Washington Adventist Hospital

Ayne Kimberly Iafolla, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Medical Genetics and Genomics, American Medical Association, American Society for Parenteral and Enteral Nutrition, American Society of Human Genetics, Phi Beta Kappa, Sigma Xi

Disclosure: Nothing to disclose.

Specialty Editor Board

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Chief Editor

Ted Rosenkrantz, MD Professor, Departments of Pediatrics and Obstetrics/Gynecology, Division of Neonatal-Perinatal Medicine, University of Connecticut School of Medicine

Ted Rosenkrantz, MD is a member of the following medical societies: American Academy of Pediatrics, American Pediatric Society, Eastern Society for Pediatric Research, American Medical Association, Connecticut State Medical Society, Society for Pediatric Research

Disclosure: Nothing to disclose.

Additional Contributors

Scott S MacGilvray, MD Clinical Professor, Department of Pediatrics, Division of Neonatology, The Brody School of Medicine at East Carolina University

Scott S MacGilvray, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.

References
  1. Coulter DL, Allen RJ. Benign neonatal sleep myoclonus. Arch Neurol. 1982 Mar. 39(3):191-2. [Medline].

  2. Di Capua M, Fusco L, Ricci S, et al. Benign neonatal sleep myoclonus: clinical features and video-polygraphic recordings. Mov Disord. 1993 Apr. 8(2):191-4. [Medline].

  3. Caviness JN, Brown P. Myoclonus: current concepts and recent advances. Lancet Neurol. 2004 Oct. 3(10):598-607. [Medline].

  4. Maurer VO, Rizzi M, Bianchetti MG, Ramelli GP. Benign neonatal sleep myoclonus: a review of the literature. Pediatrics. 2010 Apr. 125(4):e919-24. [Medline].

  5. Welsh JP, Placantonakis DG, Warsetsky SI, et al. The serotonin hypothesis of myoclonus from the perspective of neuronal rhythmicity. Adv Neurol. 2002. 89:307-29. [Medline].

  6. Resnick TJ, Moshe SL, Perotta L, et al. Benign neonatal sleep myoclonus. Relationship to sleep states. Arch Neurol. 1986 Mar. 43(3):266-8. [Medline].

  7. Parmelee AH Jr. Sleep cycles in infants. Dev Med Child Neurol. 1969 Dec. 11(6):794-5. [Medline].

  8. Daoust-Roy J, Seshia SS. Benign neonatal sleep myoclonus. A differential diagnosis of neonatal seizures. Am J Dis Child. 1992 Oct. 146(10):1236-41. [Medline].

  9. Egger J, Grossmann G, Auchterlonie IA. Benign sleep myoclonus in infancy mistaken for epilepsy. BMJ. 2003 May 3. 326(7396):975-6. [Medline].

  10. Ramelli GP, Sozzo AB, Vella S, et al. Benign neonatal sleep myoclonus: an under-recognized, non-epileptic condition. Acta Paediatr. 2005 Jul. 94(7):962-3. [Medline].

  11. Paro-Panjan D, Neubauer D. Benign neonatal sleep myoclonus: experience from the study of 38 infants. Eur J Paediatr Neurol. 2008 Jan. 12(1):14-8. [Medline].

  12. Tinuper P, Bisulli F, Provini F, Montagna P, Lugaresi E. Nocturnal Frontal Lobe Epilepsy: new pathophysiological interpretations. Sleep Med. 2011 Dec. 12 Suppl 2:S39-42. [Medline].

  13. Prabhu AM, Pathak S, Khurana D, Legido A, Carvalho K, Valencia I. Nocturnal variant of benign myoclonic epilepsy of infancy: a case series. Epileptic Disord. 2014 Mar. 16(1):45-9. [Medline].

  14. Suzuki Y, Toshikawa H, Kimizu T, et al. Benign neonatal sleep myoclonus: Our experience of 15 Japanese cases. Brain Dev. 2015 Jan. 37(1):71-5. [Medline].

  15. Scher MS. Pathologic myoclonus of the newborn: electrographic and clinical correlations. Pediatr Neurol. 1985 Nov-Dec. 1(6):342-8. [Medline].

  16. Cohen R, Shuper A, Straussberg R. Familial benign neonatal sleep myoclonus. Pediatr Neurol. 2007 May. 36(5):334-7. [Medline].

  17. Vaccario ML, Valenti MA, Carullo A, et al. Benign neonatal sleep myoclonus: case report and follow-up of four members of an affected family. Clin Electroencephalogr. 2003 Jan. 34(1):15-7. [Medline].

  18. Turanli G, Senbil N, Altunbasak S, et al. Benign neonatal sleep myoclonus mimicking status epilepticus. J Child Neurol. 2004 Jan. 19(1):62-3. [Medline].

  19. Crossman AR, Sambrook MA, Jackson A. Experimental hemichorea/hemiballismus in the monkey. Studies on the intracerebral site of action in a drug-induced dyskinesia. Brain. 1984 Jun. 107 (Pt 2):579-96. [Medline].

  20. Sanchez RM, Jensen FE. Maturational aspects of epilepsy mechanisms and consequences for the immature brain. Epilepsia. 2001 May. 42(5):577-85. [Medline].

  21. Alfonso I, Papazian O, Aicardi J, et al. A simple maneuver to provoke benign neonatal sleep myoclonus. Pediatrics. 1995 Dec. 96(6):1161-3. [Medline].

  22. Ramelli GP, Sozzo AB, Vella S, et al. Benign neonatal sleep myoclonus: an under-recognized, non-epileptic condition. Acta Paediatr. 2005 Jul. 94(7):962-3. [Medline].

  23. American Academy of Sleep Medicine. American Academy of Sleep Medicine. International Classification of Sleep Disorders, revised: Diagnostic and Coding Manual. 2nd ed. Chicago, IL: 2001. 211-2.

  24. American Academy of Sleep Medicine. Sleep disorders. International Classification of Sleep Disorders – Third Edition (ICSD-3). Darien, Ill: American Academy of Sleep Medicine; February 2014. chapter 2.

  25. Nolte R. Neonatal sleep myoclonus followed by myoclonic-astatic epilepsy: a case report. Epilepsia. 1989 Nov-Dec. 30(6):844-50. [Medline].

  26. Symonds CP. Nocturnal myoclonus. J Neurol Neurosurg Psychiatry. 1953 Aug. 16(3):166-71. [Medline].

  27. Oswald I. Sudden bodily jerks on falling asleep. Brain. 1959 Mar. 82(1):92-103. [Medline].

  28. Sateia MJ. International classification of sleep disorders-third edition: highlights and modifications. Chest. 2014 Nov. 146(5):1387-94. [Medline].

 
Previous
Next
 
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.