1. Diagnosing Seizures and Epilepsy
FACES Conference
October 27, 2007

2. Definitions
Seizure: the clinical manifestation of an abnormal and excessive excitation of a population of neurons in the brain
Epilepsy: recurrent unprovoked seizures

3. Questions Raised by a First Seizure
Seizure or not?
Focal onset?
Evidence of CNS dysfunction?
Identifiable precipitant?
Seizure type? Syndrome type?
Studies?
Start antiepileptic drug (AED)?

4. Reject (syncope, breath holding, loss of consciousness [LOC])
Diagnosis of Seizures
Potential diagnosis
of seizures
Seizures
Reject (syncope, breath holding, loss of consciousness [LOC])
Acute cause?
Yes No
Acute symptomatic
Unprovoked
Febrile convulsions
Only one
More than one
Solitary seizure
Epilepsy
Annegers JF. In: Wyllie E, ed. The Treatment of Epilepsy: Principles and Practice. 2nd ed. Baltimore, Md: Williams & Wilkins; 1997:

5. Etiology of Seizures and Epilepsy, Rochester, MN 1935 – 1984*
Idiopathic/ cryptogenic
65.5%
Vascular 10.9%
Congenital 8.0%
Trauma 5.5%
Neoplastic 4.1%
Degenerative 3.5%
Infection 2.5%
*Data from a 50-year population-based study. Use of newer imaging and other diagnostic techniques might alter some percentages.
Adapted with permission from Hauser WA, et al. Epilepsia. 1993;34:

6. Seizure Types Absence Tonic-clonic Tonic Clonic Myoclonic Atonic
Single
Recurrent
Nonepileptic
Epileptic
Syncope
Migraine
Psychogenic
Toxic
Cerebrovascular
Metabolic
Generalized
Partial
Absence
Tonic-clonic
Tonic
Clonic
Myoclonic
Atonic
Simple
Complex
Secondarily
Generalized
Adapted from International League Against Epilepsy. Epilepsia. 1981:22:

7. DIAGNOSING: THE ESSENTIALS
Initial visit
EEG
Imaging
MRI
MEG
PET
SPECT

8. INITIAL VISIT Medical History Exam Impression Treatment plan
EEG studies
Imaging studies
Bloodwork
Cognitive testing
Medication

9. MEDICAL HISTORY Seizure description Provoking factors Risk factors
Other medical, surgical, psychiatric, and social history
Allergies
Medications
***Bring family member or friend who has witnessed seizure and knows history***

10. Risk Factors for Epilepsy
Risk ratio
LVH = left ventricular hypertrophy.
*Protective.
Hesdorffer DC, Verity CM. In: Engel J Jr, Pedley TA, eds. Epilepsy: A Comprehensive Textbook ; vol 1. Philadelphia, Pa: Lippincott-Raven Publishers; 1997:59-67.

11. EXAMINATION GENERAL PHYSICAL Vital signs Weight, height
Head circumference
General appearance
Mood
Heart
Lungs
Musculoskeletal
Abdomen
NEUROLOGICAL
Mental status
- attention
- memory
- language
Cranial nerves
Motor
Sensory
Reflexes
Coordination
Gait

12. TREATMENT PLAN Bloodwork EEG Brain imaging Cognitive testing
Other testing
Medications
Referrals
Follow up appointment

13. EEG Electroencephalogram
The most specific test for diagnosing epilepsy

14. EEG TYPES Routine EEG In office Lasts 1 hour Ambulatory EEG
Applied in office, worn home
Lasts hours
Video EEG
In hospital
Lasts several days

15. VIDEO EEG Allows for correlation of EEG change with behavior
Confirm diagnosis of epilepsy
Confirm seizure type
Choose correct medication
Make safe and rapid medication adjustments
Assess for seizures in sleep

16. MRI Magnetic Resonance Imaging

17. MEG Magnetoencephalogram

18. PET Positron Emission Tomography
Arrows point to abnormalities

19. SPECT Single Photon Emission Computed Tomography
Newton MR, et al. J Neurol Neurosurg Psychiatry. 1992;55:

20. Summary: Epilepsy testing
EEG is the most specific test for diagnosing
MRI is the imaging tool of choice, extremely useful in partial epilepsy
PET, SPECT, MEG are important for localization of seizure focus, often used in presurgical evaluations
Other testing as indicated

22. Barriers to Accurate Diagnosis of Epilepsy
Dependence on unwitnessed events
Insufficient history/description of events
Possibility that physiologic (eg, syncope) or psychogenic events are mimicking seizures
Reliance on prior diagnosis
Overinterpretation of EEG
Brodie MJ, French JA. Lancet. 2000;356: