UpToDate
Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Clinical features and diagnosis of infantile spasms

Author
Daniel G Glaze, MD
Section Editor
Douglas R Nordli, Jr, MD
Deputy Editor
April F Eichler, MD, MPH

INTRODUCTION

Infantile spasms (IS) is an age-specific epileptic disorder of infancy and early childhood. Children with IS typically exhibit epileptic spasms along with the electroencephalographic pattern known as hypsarrhythmia. Infantile spasms were described first by West in 1841 [1]. The triad of spasms, arrest of psychomotor development, and hypsarrhythmia is known as West syndrome.

IS as used in this topic is not considered to be interchangeable with the term “epileptic spasms.” Epileptic spasms refers not only to the seizures seen in IS but also late-onset spasms and periodic spasms.

The clinical features and diagnosis of IS are reviewed here. The etiology and pathogenesis, and management and prognosis are discussed separately. (See "Etiology and pathogenesis of infantile spasms" and "Management and prognosis of infantile spasms".)

CLINICAL FEATURES

IS is characterized by epileptic spasms with onset in infancy or early childhood that are usually associated with the electroencephalographic (EEG) pattern of hypsarrhythmia, and also developmental regression [2].

Age of onset — The majority (90 percent) of affected children present at less than one year of age, with a range from one day to 4.5 years of age (figure 1) [2-4]. The peak incidence of onset (50 to 77 percent) is between three and seven months; onset after 18 months is rare. The true age of onset may be uncertain because IS may be initially mistaken for other conditions, such as hyperirritability, exaggerated startle responses, and/or colic [5]. (See 'Differential diagnosis' below.)

                

Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Nov 2016. | This topic last updated: Sun Jul 24 00:00:00 GMT+00:00 2016.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
References
Top
  1. West, WJ. On a peculiar form of infantile convulsions. Lancet 1841; 1:724.
  2. Pellock JM, Hrachovy R, Shinnar S, et al. Infantile spasms: a U.S. consensus report. Epilepsia 2010; 51:2175.
  3. Trevathan E, Murphy CC, Yeargin-Allsopp M. The descriptive epidemiology of infantile spasms among Atlanta children. Epilepsia 1999; 40:748.
  4. Vigevano F, Fusco L, Cusmai R, et al. The idiopathic form of West syndrome. Epilepsia 1993; 34:743.
  5. Lúthvígsson P, Olafsson E, Sigurthardóttir S, Hauser WA. Epidemiologic features of infantile spasms in Iceland. Epilepsia 1994; 35:802.
  6. Kellaway P, Hrachovy RA, Frost JD Jr, Zion T. Precise characterization and quantification of infantile spasms. Ann Neurol 1979; 6:214.
  7. Kellaway P, Frost JD Jr, Hrachovy RA. Infantile spasms. In: Antiepileptic Drug Therapy in Pediatrics, Morselli PL, Pippenger CE, Penry JK (Eds), Raven Press, New York 1983.
  8. Hrachovy RA, Frost JD Jr. Infantile epileptic encephalopathy with hypsarrhythmia (infantile spasms/West syndrome). J Clin Neurophysiol 2003; 20:408.
  9. Ramgopal S, Shah A, Zarowski M, et al. Diurnal and sleep/wake patterns of epileptic spasms in different age groups. Epilepsia 2012; 53:1170.
  10. Glaze DG, Zion TE. Infantile spasms. Curr Probl Pediatr 1985; 15:1.
  11. Koo B, Hwang PA, Logan WJ. Infantile spasms: outcome and prognostic factors of cryptogenic and symptomatic groups. Neurology 1993; 43:2322.
  12. Wong M, Trevathan E. Infantile spasms. Pediatr Neurol 2001; 24:89.
  13. Lacy JR, Penry JK.. Infantile spasms, Raven Press, New York 1976.
  14. Hrachovy RA, Glaze DG, Frost JD Jr. A retrospective study of spontaneous remission and long-term outcome in patients with infantile spasms. Epilepsia 1991; 32:212.
  15. Maydell BV, Berenson F, Rothner AD, et al. Benign myoclonus of early infancy: an imitator of West's syndrome. J Child Neurol 2001; 16:109.
  16. Lombroso CT, Fejerman N. Benign myoclonus of early infancy. Ann Neurol 1977; 1:138.
  17. Coulter DL, Allen RJ. Benign neonatal sleep myoclonus. Arch Neurol 1982; 39:191.
  18. Vigevano F, Lispi ML. Tonic reflex seizures of early infancy: an age-related non-epileptic paroxysmal disorder. Epileptic Disord 2001; 3:133.
  19. Wilmshurst JM, Gaillard WD, Vinayan KP, et al. Summary of recommendations for the management of infantile seizures: Task Force Report for the ILAE Commission of Pediatrics. Epilepsia 2015; 56:1185.
  20. Gaily E, Liukkonen E, Paetau R, et al. Infantile spasms: diagnosis and assessment of treatment response by video-EEG. Dev Med Child Neurol 2001; 43:658.
  21. Gibbs, FA, Gibbs, EL. Atlas of Electroencephalography, Addison-Wesley, Reading, MA 1952.
  22. Philippi H, Wohlrab G, Bettendorf U, et al. Electroencephalographic evolution of hypsarrhythmia: toward an early treatment option. Epilepsia 2008; 49:1859.
  23. Hrachovy RA, Frost JD Jr, Kellaway P. Hypsarrhythmia: variations on the theme. Epilepsia 1984; 25:317.
  24. Donat JF, Lo WD. Asymmetric hypsarrhythmia and infantile spasms in west syndrome. J Child Neurol 1994; 9:290.
  25. Drury I, Beydoun A, Garofalo EA, Henry TR. Asymmetric hypsarrhythmia: clinical electroencephalographic and radiological findings. Epilepsia 1995; 36:41.
  26. Wirrell EC, Shellhaas RA, Joshi C, et al. How should children with West syndrome be efficiently and accurately investigated? Results from the National Infantile Spasms Consortium. Epilepsia 2015; 56:617.
  27. Haginoya K, Kon K, Takayanagi M, et al. Heterogeneity of ictal SPECT findings in nine cases of West syndrome. Epilepsia 1998; 39 Suppl 5:26.
  28. van Bogaert P, Chiron C, Adamsbaum C, et al. Value of magnetic resonance imaging in West syndrome of unknown etiology. Epilepsia 1993; 34:701.
  29. Aydinli N, Calişkan M, Ozmen M, Tonguç E. Neuroradiologic aspects of West syndrome. Pediatr Neurol 1998; 19:211.
  30. Gaillard WD, Chiron C, Cross JH, et al. Guidelines for imaging infants and children with recent-onset epilepsy. Epilepsia 2009; 50:2147.
  31. Saltik S, Kocer N, Dervent A. Informative value of magnetic resonance imaging and EEG in the prognosis of infantile spasms. Epilepsia 2002; 43:246.
  32. Chugani HT, Conti JR. Etiologic classification of infantile spasms in 140 cases: role of positron emission tomography. J Child Neurol 1996; 11:44.
  33. Dimassi S, Labalme A, Ville D, et al. Whole-exome sequencing improves the diagnosis yield in sporadic infantile spasm syndrome. Clin Genet 2016; 89:198.
  34. Michaud JL, Lachance M, Hamdan FF, et al. The genetic landscape of infantile spasms. Hum Mol Genet 2014; 23:4846.