eMedicine Specialties > Neurology > Seizures and Epilepsy

Epilepsy, Juvenile Myoclonic: Differential Diagnoses & Workup

Author: Jose E Cavazos, MD, PhD, Assistant Professor, Departments of Medicine (Neurology), Pharmacology, and Physiology, University of Texas Health Science Center at San Antonio
Coauthor(s): Frank Lum, MD, Instructor, Department of Neurology, University of Colorado Health Sciences Center; Mark Spitz, MD, Professor, Department of Neurology, University of Colorado Health Sciences Center
Contributor Information and Disclosures

Updated: Nov 29, 2007

Differential Diagnoses

Absence Seizures
Benign Childhood Epilepsy
Frontal Lobe Epilepsy
Tonic-Clonic Seizures

Other Problems to Be Considered

Epilepsy with generalized tonic-clonic seizures on awakening
Nocturnal generalized tonic-clonic seizures
Myoclonic absence epilepsy
Myoclonus
Partial seizures with secondary generalization
Progressive myoclonic epilepsies

Workup

Imaging Studies

  • Neuroimaging studies are typically normal in JME. Many clinicians believe that, in the presence of an adequate supportive history, EEG abnormalities, normal intelligence, and normal neurologic findings, neuroimaging studies are unnecessary. However, the clinical scenario might not be as clear as the classical description.
  • MRIs of the brain are usually unremarkable. This observation reflects the fact that JME is an idiopathic generalized epilepsy and not caused by conditions such as brain tumors or encephalitis.
  • Some patients with brain MRIs, particularly if the MRIs are high definition, or high Telsa studies, have shown minor abnormalities of cortical development.

Other Tests

  • Study of choice to confirm the clinical diagnosis is sleep-deprived EEG with activation procedures (ie, hyperventilation, photic stimulation). A normal study does not rule out epilepsy or JME. Typical EEG abnormalities are highly supportive of the clinical diagnosis (see Media file 1).
  • The typical interictal EEG abnormality consists of a generalized 4- to 6-Hz spike or polyspike and slow-wave discharges lasting 1-20 seconds (see Media file 1). Usually, 1-3 spikes precede each slow wave. When absence seizures are also present, 3-Hz spike-and-wave activity may be seen in addition to the polyspike-and-wave pattern.
  • The ictal EEG associated with myoclonic jerks typically reveals 10- to 16-Hz polyspike discharges. These may be preceded by spike and wave activity and are often followed by 1- to 3-Hz slow waves. The number of spikes is typically 5-20 and tends to be proportionately correlated with the clinical intensity of the seizure. These epileptic discharges may briefly persist, even after clinical activity has ceased.
  • Absence seizures of JME may be associated with ictal EEG patterns consisting of 3-Hz spike-and-wave activity. Sometimes, these are preceded by 4- to 6-Hz polyspike-and-wave discharges, which slow to 3 Hz as the patient loses consciousness.
  • Background activity of the EEG is normal in JME. Hyperventilation and photic stimulation often facilitate the appearance of epileptiform discharges. Photic stimulation frequently precipitates spike-and-wave patterns. This occurs in approximately 30% of patients with JME, compared with 18% of patients with childhood absence epilepsy, 13% of patients with epileptic seizures on awakening, and 7.5% of patients with juvenile absence epilepsy.
  • Ictal and interictal polyspike-and-wave discharges are not pathognomonic of JME; they may be seen in other primary generalized epilepsies as well as in myoclonic epilepsies of early childhood.
  • In addition to generalized epileptiform discharges, focal abnormalities may be found in 20-55% of patients with JME. These include focal slow waves, generalized discharges that evolve from a focal onset, and focal spikes or spike-and-wave discharges. Ignorance of these changes may lead to one's mistakenly ruling out the syndrome. The etiology of these focal abnormalities is unclear. A possible explanation is structural changes in the cerebral cortex secondary to recurrent seizures or head injury; another is fluctuation in the refractoriness of the cortex to the influence of a spike/wave generator.

More on Epilepsy, Juvenile Myoclonic

Overview: Epilepsy, Juvenile Myoclonic
Differential Diagnoses & Workup: Epilepsy, Juvenile Myoclonic
Treatment & Medication: Epilepsy, Juvenile Myoclonic
Follow-up: Epilepsy, Juvenile Myoclonic
Multimedia: Epilepsy, Juvenile Myoclonic
References
[ CLOSE WINDOW ]

References

  1. Herpin TH. Des asces incomplets de l'epilepsie. J Balliere et Fils. 1867.

  2. Rabot T. De la myoclonia epileptique. Paris, France: Medical thesis; 1899.

  3. Lundborg H. Die Progresive Myoklonusepilepsie (Unverricht's Myoklonie). Stockholm, Sweden: Almqvist & Wiksell; 1903.

  4. Janz D, Mathes A. Die Propulsiv Petit Mal Epilepsie. New York, NY: Garger; 1955.

  5. Janz D, Christian W. Impulsive petit mal. Deutsche Leitschrift f Nervenheilkunde. 1957;176:346-386.

  6. Lund M, Reintoft H, Simonsen N. Ein kontrolleret social og psychologisk Undersgelse af Patienter med Juvenil Myoklon Epilepsi. Ugeskr Laeg. 1975;137:2415-18.

  7. Delgado-Escueta AV. Advances in genetics of juvenile myoclonic epilepsies. Epilepsy Curr. May-Jun 2007;7(3):61-7. [Medline].

  8. Wallace R. Identification of a new JME gene implicates reduced apoptotic neuronal death as a mechanism of epileptogenesis. Epilepsy Curr. Jan-Feb 2005;5(1):11-3. [Medline].

  9. Suzuki T, Delgado-Escueta AV, Aguan K, et al. Mutations in EFHC1 cause juvenile myoclonic epilepsy. Nat Genet. Aug 2004;36(8):842-9. [Medline].

  10. Pal DK, Evgrafov OV, Tabares P, et al. BRD2 (RING3) is a probable major susceptibility gene for common juvenile myoclonic epilepsy. Am J Hum Genet. Aug 2003;73(2):261-70. [Medline].

  11. Sullivan JE, Dlugos DJ. Idiopathic Generalized Epilepsy. Curr Treat Options Neurol. May 2004;6(3):231-242. [Medline].

  12. Specchio LM, Gambardella A, Giallonardo AT, Michelucci R, Specchio N, Boero G, et al. Open label, long-term, pragmatic study on levetiracetam in the treatment of juvenile myoclonic epilepsy. Epilepsy Res. 2006;71(1):32-39. [Medline].

  13. Morris GL, Hammer AE, Kustra RP, Messenheimer JA. Lamotrigine for patients with juvenile myoclonic epilepsy following prior treatment with valproate: results of an open-label study. Epilepsy Behav. Aug 2004;5(4):509-12. [Medline].

  14. Prasad A, Kuzniecky RI, Knowlton RC, et al. Evolving antiepileptic drug treatment in juvenile myoclonic epilepsy. Arch Neurol. Aug 2003;60(8):1100-5. [Medline].

  15. Kothare SV, Valencia I, Khurana DS, et al. Efficacy and tolerability of zonisamide in juvenile myoclonic epilepsy. Epileptic Disord. Dec 2004;6(4):267-70. [Medline].

  16. Nicolson A, Appleton RE, Chadwick DW, Smith DF. The relationship between treatment with valproate, lamotrigine, and topiramate and the prognosis of the idiopathic generalised epilepsies. J Neurol Neurosurg Psychiatry. Jan 2004;75(1):75-9. [Medline].

  17. Aliberti V, Grunewald RA, Panayiotopoulos CP, Chroni E. Focal electroencephalographic abnormalities in juvenile myoclonic epilepsy. Epilepsia. Mar-Apr 1994;35(2):297-301. [Medline].

  18. Atakli D, Sozuer D, Atay T, et al. Misdiagnosis and treatment in juvenile myoclonic epilepsy. Seizure. Feb 1998;7(1):63-6. [Medline].

  19. Biton V, Montouris GD, Ritter F, et al. A randomized, placebo-controlled study of topiramate in primary generalizedtonic-clonic seizures. Topiramate YTC Study Group. Neurology. Apr 22 1999;52(7):1330-7. [Medline].

  20. Buchanan N. The use of lamotrigine in juvenile myoclonic epilepsy. Seizure. Jun 1996;5(2):149-51. [Medline].

  21. Canevini MP, Mai R, Di Marco C, et al. Juvenile myoclonic epilepsy of Janz: clinical observations in 60 patients. Seizure. Dec 1992;1(4):291-8. [Medline].

  22. Delgado-Escueta AV, Enrile-Bacsal F. Juvenile myoclonic epilepsy of Janz. Neurology. Mar 1984;34(3):285-94. [Medline].

  23. Delgado-Escueta AV, Greenberg DA, Treiman L, et al. Mapping the gene for juvenile myoclonic epilepsy. Epilepsia. 1989;30 Suppl 4:S8-18; discussion S24-7. [Medline].

  24. Delgado-Escueta AV, Serratosa JM, Liu A, et al. Progress in mapping human epilepsy genes. Epilepsia. 1994;35 Suppl 1:S29-40. [Medline].

  25. Dreifuss FE. Juvenile myoclonic epilepsy: characteristics of a primary generalized epilepsy. Epilepsia. 1989;30 Suppl 4:S1-7 discussion S24-7. [Medline].

  26. Durner M, Janz D, Zingsem J, Greenberg DA. Possible association of juvenile myoclonic epilepsy with HLA-DRw6. Epilepsia. Sep-Oct 1992;33(5):814-6. [Medline].

  27. Gram L, Alving J, Sagild JC, Dam M. Juvenile myoclonic epilepsy in unexpected age groups. Epilepsy Res. Mar-Apr 1988;2(2):137-40. [Medline].

  28. Grunewald RA, Panayiotopoulos CP. Juvenile myoclonic epilepsy. A review. Arch Neurol. Jun 1993;50(6):594-8. [Medline].

  29. International League Against Epilepsy. Proposal for classification of epilepsies and epileptic syndromes. Commission on Classification and Terminology of the International League Against Epilepsy. Epilepsia. May-Jun 1985;26(3):268-78. [Medline].

  30. Janz D. Epilepsy with impulsive petit mal (juvenile myoclonic epilepsy). Acta Neurol Scand. Nov 1985;72(5):449-59. [Medline].

  31. Janz D. Juvenile myoclonic epilepsy. Epilepsy with impulsive petit mal. Cleve Clin J Med. 1989;56 Suppl Pt 1:S23-33; discussion S40-2. [Medline].

  32. Janz D. The grand mal epilepsies and the sleeping-waking cycle. Epilepsia. Mar 1962;3:69-109. [Medline].

  33. Kleveland G, Engelsen BA. Juvenile myoclonic epilepsy: clinical characteristics, treatment and prognosis in a Norwegian population of patients. Seizure. Feb 1998;7(1):31-8. [Medline].

  34. Knott C, Panayiotopoulos CP. Carbamazepine in the treatment of generalised tonic clonic seizures in juvenile myoclonic epilepsy [letter]. J Neurol Neurosurg Psychiatry. Apr 1994;57(4):503. [Medline].

  35. Lancman ME, Asconape JJ, Penry JK. Clinical and EEG asymmetries in juvenile myoclonic epilepsy. Epilepsia. Mar-Apr 1994;35(2):302-6. [Medline].

  36. Meencke HJ, Janz D. Neuropathological findings in primary generalized epilepsy: a study of eight cases. Epilepsia. Feb 1984;25(1):8-21. [Medline].

  37. Meencke HJ, Janz D. The significance of microdysgenesia in primary generalized epilepsy: an answer to the considerations of Lyon and Gastaut. Epilepsia. Jul-Aug 1985;26(4):368-71. [Medline].

  38. Obeid T, Panayiotopoulos CP. Juvenile myoclonic epilepsy: a study in Saudi Arabia. Epilepsia. May-Jun 1988;29(3):280-2. [Medline].

  39. Oguni H, Mukahira K, Oguni M, et al. Video-polygraphic analysis of myoclonic seizures in juvenile myoclonic epilepsy. Epilepsia. Mar-Apr 1994;35(2):307-16. [Medline].

  40. Panayiotopoulos CP, Obeid T, Tahan AR. Juvenile myoclonic epilepsy: a 5-year prospective study. Epilepsia. Mar-Apr 1994;35(2):285-96. [Medline].

  41. Panayiotopoulos CP, Obeid T, Waheed G. Differentiation of typical absence seizures in epileptic syndromes. A video EEG study of 224 seizures in 20 patients. Brain. Aug 1989;112 ( Pt 4):1039-56. [Medline].

  42. Panayiotopoulos CP, Tahan R, Obeid T. Juvenile myoclonic epilepsy: factors of error involved in the diagnosis and treatment. Epilepsia. Sep-Oct 1991;32(5):672-6. [Medline].

  43. Pedersen SB, Petersen KA. Juvenile myoclonic epilepsy: clinical and EEG features. Acta Neurol Scand. Mar 1998;97(3):160-3. [Medline].

  44. Penry JK, Dean JC, Riela AR. Juvenile myoclonic epilepsy: long-term response to therapy. Epilepsia. 1989;30 Suppl 4:S19-23; discussion S24-7. [Medline].

  45. Shinnar S, Berg AT, Moshe SL, et al. Discontinuing antiepileptic drugs in children with epilepsy: a prospective study. Ann Neurol. May 1994;35(5):534-45. [Medline].

  46. Wirrell EC, Camfield CS, Camfield PR, et al. Long-term prognosis of typical childhood absence epilepsy: remission or progression to juvenile myoclonic epilepsy. Neurology. Oct 1996;47(4):912-8. [Medline].

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

JME, idiopathic generalized epileptic syndrome, myoclonic jerks, generalized tonic-clonic seizures, GTCSs, absence seizures

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

Jose E Cavazos, MD, PhD, Assistant Professor, Departments of Medicine (Neurology), Pharmacology, and Physiology, University of Texas Health Science Center at San Antonio
Jose E Cavazos, MD, PhD is a member of the following medical societies: American Academy of Neurology, American Clinical Neurophysiology Society, American Epilepsy Society, and Society for Neuroscience
Disclosure: Glaxo-SmithKline Honoraria Speaking and teaching; Ortho-McNeil Neurologics Honoraria Speaking and teaching; UCB Pharma Honoraria Speaking and teaching

Coauthor(s)

Frank Lum, MD, Instructor, Department of Neurology, University of Colorado Health Sciences Center
Disclosure: Nothing to disclose.

Mark Spitz, MD, Professor, Department of Neurology, University of Colorado Health Sciences Center
Mark Spitz, MD is a member of the following medical societies: American Academy of Neurology, American Clinical Neurophysiology Society, and American Epilepsy Society
Disclosure: Nothing to disclose.

Medical Editor

Ramon Diaz-Arrastia, MD, PhD, Assistant Professor, Department of Neurology, Comprehensive Epilepsy Center, University of Texas Southwestern
Ramon Diaz-Arrastia, MD, PhD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Neurology, New York Academy of Sciences, and Phi Beta Kappa
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Selim R Benbadis, MD, Professor, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida School of Medicine, Tampa General Hospital
Selim R Benbadis, MD is a member of the following medical societies: American Academy of Neurology, American Academy of Sleep Medicine, American Clinical Neurophysiology Society, American Epilepsy Society, and American Medical Association
Disclosure: Nothing to disclose.

CME Editor

Matthew J Baker, MD, Consulting Staff, Collier Neurologic Specialists, Naples Community Hospital
Matthew J Baker, MD is a member of the following medical societies: American Academy of Neurology
Disclosure: Nothing to disclose.

Chief Editor

Nicholas Y Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting Staff, Neurology Specialists and Consultants
Nicholas Y Lorenzo, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Neurology
Disclosure: Nothing to disclose.

 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.