1. Seizures Diagnosis and Management
Nisha Kanani, David Cherney
2004

2. Resources
Primary Care: Epilepsy. Browne T. R., Holmes G. L. NEJM; 344: , Apr 12, 2001.
Current Concepts: Patients with refractory seizures. Devinsky O. NEJM; 340: , May 20, 1999
Consensus statements: Medical management of epilepsy. Neurology; 51(5 suppl4): S39-43, Nov
Textbook of clinical neurology. Greenberg
Canadian Driving Guidelines Online

3. Objectives First seizure evaluation in adults Seizure classification
3. Management options

4. Case
32 y/o male taxi-driver is referred for evaluation of a “spell” while walking to the corner store, after which he was found on the ground.
Brought in by EMS to the ER
Subsequently sent home
What are you going to do and tell the patient?

5. Definitions
Seizure: transient disturbance in cerebral function caused by abnormal neuronal discharge
Epilepsy: group of disorders represented by recurrent seizures (3% lifetime prevalence)

6. Evaluating seizures: Is this a seizure?
What type of seizure is this? (implications on treatment)
Is there an underlying cause?

7. Is this a Seizure? Seizure Mimics:
Classic migraines
include transient neurologic symptoms (as in partial seizures).
epilepsy patients twice as likely to have migraines.
Syncope
Postural, flaccid paralysis, pre-syncope symptoms, no post-ictal state
May have fasiculations (convulsive syncope)
TIA
Usually no LOC unless basilar stroke, usually negative findings not positive. Sometimes confusing if post-ictal Todd’s paralysis
Pseudo-seizures
10-45% of patients with refractory epilepsy. Look for history of abuse. Patients can have both.
5) Movement disorders

9. Is there an underlying cause?
(rule out secondary causes of seizures)
1o neurologic disorder
Systemic disorder
Head trauma
Cancer
Hemorrage
Stroke
Vascular malformations
Meningitis/encephalitis
Hypoglycemia
Hyponatremia
Hypocalcemia
Uremia
Hepatic encephalopathy
Drug OD/withdrawal
Hyperosmolar states
Hyperthermia

10. History Witness testimony is key!
Triggers, ictal behaviors, LOC, behaviour during seizure and the postictal state.
Seizure precipitants or triggers:
strong emotions, intense exercise, flashing lights, and loud music (often immediately before the seizure)
fever, menstruation, lack of sleep, and stress

11. History
Ask about . . .
Drugs, alcohol, constitutional symptoms, HIV risk factors, fever, head trauma.
Family History (absence and myoclonic seizures may be inherited)

12. Physical examination Generally unrevealing
Look for signs of disorders associated with seizures.
Head trauma, meningismus, sinus infection.
Focal or diffuse neurological abnormalities.
Mental status abnormalities suggest lesions in the anterior frontal, parietal, or temporal lobes.
Evaluate for lateralizing abnormalities: weakness, hyperreflexia, positive Babinski sign

13. Laboratory evaluation
Glucose, calcium, magnesium, hematology studies, renal function tests, lytes toxicology screens.
Acute postictal changes: metabolic acidosis and leukocytosis, high CK
LP if risk factors for infection (fever, HIV positive).

14. Electroencephalography
Information provided:
Presence of abnormal electrical activity
Information of type of seizure disorder
Location of seizure focus
Perform study >48hrs after seizure
Include recordings during sleep, photic stimulation, hyperventilation.
50% of patients with epilepsy have normal single EEG

15. Electroencephalography
If normal and high suspicion, repeat study after sleep deprivation
10% of persons with true seizure with have normal multiple EEG studies
+EEG  likelihood of second seizure over two years

16. Neuroimaging in adults with 1st seizure
Retrospective review of 148 patients studied within 30 days of the seizure
Structural lesion was identified by CT in 55 (37 percent); 16 (11 percent) had metabolic seizures
CT findings agreed with the results of neurological examination in 82 percent of cases.
Ramirez-Lassepas, et al. Value of computed tomographic scan in the evaluation of adult patients after their first seizure. Ann Neurol 1984; 15:536.

17. Neuroimaging All patients should receive neuroimaging.
MRI preferred over CT to identify small lesions such as cortical dysplasias, infarcts, or tumors.
CT scan is suitable in emergency situations to exclude a mass lesion, hemorrhage, or large stroke.

18. When to initiate Antiepileptic drug therapy
Two or more seizures
Single seizure secondary to identified CNS lesion with an epileptogenic focus
Consider if significant occupational risk if patient suffers a second event.
Consider if single seizure event with one or more risk factors for recurrent seizures
Consider in the elderly patient with increased risk of seizure related morbidity (age, prolonged post-ictal state)

19. Risk of seizure recurrence in a patient with an apparently unprovoked or idiopathic seizure
31 to 71% risk in the first 12 months after the initial seizure.
Risk factors associated with recurrent seizures include the following:
(1) evidence of a structural lesion
(2) EEG abnormalities
(3) partial type seizure
(4) family history of seizures
(5) focal abnormalities on exam
Most patients with one or more of these risk factors should be treated

20. Antiepileptic Drugs of Choice
Primary Generalized Tonic-Clonic
Partial
Absence
Atypical Absence, Myoclonic, Atonic
First-Line
Valproic acid
Carbamezepine
Phenytoin
Carbamazepine Phenytoin
Ethosuximide Valproate
Valproic acid
Alternatives
Lamotrigine Primidone Phenobarbital
Gabapentin Topiramate
Tiagabine Primidone Phenobarbital
Lamotrigine Clonazepam
Lamotrigine Topiramate Clonazepam Felbamate

21. Principles of Treatment
Start with an average dose of a first line drug
Poor control? Address compliance, maximize drug dose, confirm right diagnosis (partial complex v.s generalized)
Majority of patients are controlled with single antiepileptic drug.
This drug can be gradually withdrawn if seizure free for two years.
Seizures recur in 25% of patients without risk factors and 50% of patients without risk factors.
The drug can be reduced by 25% every two to four weeks.

22. Principles of Treatment
20-35% of patients with epilepsy have persistent seizures despite medical therapy.
If poor control with maximal dose, monotherapy with second drug.
Continue to administer first drug until a full dose of second drug reached, then gradually withdraw first drug.
If monotherapy with two drugs fail, patient may need re-evaluation (repeat MRI/EEG) before polytherapy commenced (1998 guidelines).

23. Side effects Idiosyncratic toxicity:
rash, bone marrow suppression, or hepatotoxicity.
Require laboratory tests (e.g., complete blood count and liver function tests)
baseline
during initial dosing and titration

24. Other management issues:
Impact on independence, self-esteem, employment.
Driving regulations:
Private drivers cannot drive for 3 months after a single seizure.
Private drivers can resume driving after being seizure free for 12 months on medication.

25. Side effects
Canadian Guidelines

26. Neurologic Consultation (NEJM 2001)
Change in the type of seizure
Uncertain diagnosis (e.g. normal EEG)
Lack of seizure control in 3 months
Failure of two monotherapies
Patient is considering pregnancy
Prolonged post-ictal state
History of status epilepticus

27. Summary
Management after 1st seizure involves lots of discussion with patient about risks/benefits
Remember impact on driving: tell the ministry!
When in doubt about management (especially medications), get a neurologist involved