Case Study

A 15 year old female with weekly staring spells beginning at 8 years of age defied medical diagnosis until 11 years old when a convulsion was noted. Head deviation to the right was described during the convulsion. An MRI brain and routine EEG were normal. She was diagnosed with “partial complex seizures”. Phenytoin use lead to somnolence and conversion to carbamazepine (CBZ). CBZ resulted in seizure reduction despite high doses and gabapentin was added. Seizures worsened and she became “shakey” in the morning on awakening. A sleep-deprived EEG was obtained and revealed the following.

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Figure: EEG demonstrating a single generalized polyspike-and-wave in second 2 and brief burst of generalized spike-and-waves in second 7


What is the importance of classification?

Classification systems use terminology and concepts of seizure onset to organize knowledge of the types of epilepsy. Lateralizing features are not uncommon in generalize seizures and definitions to distinguish focal and generalized seizures have been recently been revised1. In this case, “pseudo-resistance” to AEDs occurred from misclassification and inappropriate drug selection. Generalized (genetic) epilepsy syndromes such as Juvenile Myoclonic Epilepsy may not respond to narrow-spectrum AEDs used to treat focal seizures or provoke new types of seizures (myoclonic jerks) as in this case. AED substitution with lamotrigine led to complete control of all seizures.

References

  1. Berg AT, Berkovic SF, Brodie MJ et al. Revised terminology and concepts for organziation of seizures and epilepsies: Report of the ILAE Commission on Classification and Terminology, 2005-2009. Epilepsia 2010;51(4):676-685.
Authored By: 
William O. Tatum DO
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Authored Date: 
11/2010