What Are the Classifications of Seizures?

Patient Presentation
A an 8 month-old female was referred for evaluation and treatment of episodes of sudden, jerking of her body such that she seems to collapse in half like a jack-knife. These occur multiple times a day and last for 5-30 seconds and are occurring more frequently.
Three weeks ago she began having episodes of sudden crying episodes and over time her mother noticed that when she picked up the child, the baby would seem to twitch. The baby is described as more tired lately but has been drinking formula normally. She has been otherwise well.
The past medical history revealed a full-term infant with normal pre- and perinatal history. She has received her regular well child care, but has been noted to be slow in her development.
She smiled at 12 weeks, rolled over at 5-6 months, sits with support and makes vowel sounds. She has not lost developmental milestones.
The family history noted family members with epilepsy and learning problems.
The review of systems was normal including no fever, rashes, cough or upper respiratory tract infections.
The pertinent physical exam showed a child who was afebrile with normal vital signs. She was 25-50% for weight and height. Head circumference was 10-25% and all were tracking normally. Her skin showed a small capillary hemangioma on her leg.
Neurologically she appears sleepy and is somewhat difficult to arouse. Her cranial nerves III-XII are normal. Her deep tendon reflexes are normal with upward going toes bilaterally. She has normal tone and strength. Symmetric tonic neck reflex and palmar grasp primitive reflexes are elicited.
During observed episodes she has flexion of the trunk and extremities that occurs suddenly and appears to cluster in frequency. The episodes last 10-30 seconds. The rest of the examination is normal.
The work-up included an electroencephalogram (EEG) which showed hypsarrhythmia.
The diagnosis of infantile spasms was made and adrenocorticotropic hormone was begun with great improvement of the seizures. Further evaluation, including evaluation for tuberous sclerosis, did not reveal an obvious cause for the infantile spams.

Discussion
West syndrome includes infantile spams, hypsarrhythmia on EEG and mental retardation. It usually occurs in infants < 12 months with a peak at 4-6 months. Hypsarrhythmia is a chaotic EEG abnormality that has random, high-voltage slow waves and spikes that arise from multiple foci and spread to all cortical areas.
It was first described in 1841 by Dr. W. J. West where he describes the seizures of his own son, James Edwin West, who showed the first symptoms at the age of about four months and lived until ~ age 20.
West described the seizures "…cause a complete heaving of the head forward towards his knees, and then immediately relaxing into the upright position…these bowings and relaxings would be repeated alternately at intervals of a few seconds, and repeated from ten to twenty or more times at each attack, which attack would not continue more than two or three minutes; he sometimes has two, three or more attacks in the day."
Dr. West did not know what caused the seizures but hypothesized that "… it depended on some irritaiton of the nervous system from teething…." He tried treating his son with leeches, cold application to his head, calomel purgatives, lancing of his gums, opium, syrup of poppies and castor oil. He also sought consultation with preeminant physicians who knew of a total of 6 other cases and referred to them as "salaam convulsions." They also believed they were related to teething.

Infantile spasms are classifed by suspected etiology:

  • Idiopathic – patient has normal development before the spasms occur and no obvious or suspected cause is identified

  • Cryptogenic – no cause is identifed but a cause is suspected
  • Symptomatic – almost any problem which causes brain damage can be associated with infantile spasms. Tuberous sclerosis is the most common identified cause of infantile spasms (10-30% of prenatal cases), therefore evaluation for tuberous sclerosis is indicated.

Infantile spasms are also commonly associated with Lennox-Gastalt syndromewhich is a syndrome characterized by multiple types of seizures, mental retardation or regression, and abnormal EEG with generalized slow spike-and-wave discharges. It is very difficult to treat.

Learning Point
Classification by the International League Against Epilepsy include:

  • Partial seizures or seizures with a focal onset
    • Simple partial seizures (consciousness unimpaired)
      • with motor signs

      • with somatosensory or special sensory symptoms
      • with autonomic symptoms or signs
      • with psychic signs
    • Complex partial seizures (consciousness impaired)

      • beginning as a simple partial seizure

        • with automatisms

        • without automatisms
      • impaired consciousness at the beginning of the seizure

        • with automatisms

        • without automatisms
    • Partial seizure which evolve into secondarily generalized seizure (e.g. Jacksonian march)
  • Generalized seizures
    • Absence seizures – briefly unaware without postictal impairment
    • Myoclonic seizures – brief repetitive symetric muscle contractions or loss of tone – which includes infantile spasms
    • Clonic seizures – rhymic jerking with flexor spasms of muscles
    • Tonic seizures – sustained muscle contraction
    • Tonic-clonic seizures
    • Atonic seizures – sudden loss of muscle tone
  • Unclassified seizures

Initial treatment for partial seizures or generalized tonic-clonic seizures usually is carbamazepine or valproic acid.
Initial treament for absence seizures is often ethosuxamide and for infantile spasms is adenocorticotropic hormone.

Questions for Further Discussion
1. What are the normal neurological primitive reflexes and at what age should they disappear by?
2. What is the long term outcome of patients with infantile spasms or Lennox-Gastalt syndrome?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at MEDLINEplus for this topic: Epilepsy
and at Pediatric Common Questions, Quick Answers for these topics: Epileptic Seizure and Febrile Seizure.

To view current news articles on this topic check Google News.

Robertson J, Shilkofski N. The Harriet Lane Handbook. 17th. Edit. Mosby Publications: St. Louis. 2005:515.

Glauser TA, Morita DA. Lennox-Gastaut Syndrome. eMedicine.
Available from the Internet at http://www.emedicine.com/neuro/topic186.htm (rev.1/30/2002, cited 11/17/2005).

Glauser TA, Morita DA. Infantile Spasms (West Syndrome). eMedicine.
Available from the Internet at http://www.emedicine.com/neuro/topic171.htm (rev. 6/21/2002, cited 11/17/2002).

Who Named It? William James West. Available from the Internet at http://www.whonamedit.com/doctor.cfm/2676.html (cited 11/17/2005).

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effecively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

    Author
    Donna M. D’Alessandro, MD
    Associate Professor of Pediatrics, Children’s Hospital of Iowa