Nisha Kanani, David Cherney
• Primary Care: Epilepsy. Browne T. R., Holmes G.
L. NEJM; 344:1145-1151, Apr 12, 2001.
• Current Concepts: Patients with refractory seizures.
Devinsky O. NEJM; 340: 1565-1570, May 20, 1999
• Consensus statements: Medical management of
epilepsy. Neurology; 51(5 suppl4): S39-43, Nov 01
• Textbook of clinical neurology. Greenberg
• Canadian Driving Guidelines Online
1. First seizure evaluation in adults
2. Seizure classification
3. Management options
• 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
• Seizure: transient disturbance in
cerebral function caused by
abnormal neuronal discharge
• Epilepsy: group of disorders
represented by recurrent seizures
(3% lifetime prevalence)
1) Is this a seizure?
2) What type of seizure is this? (implications
3) Is there an underlying cause?
Is this a Seizure? Seizure Mimics:
1) Classic migraines
• include transient neurologic symptoms (as in partial seizures).
• epilepsy patients twice as likely to have migraines.
• Postural, flaccid paralysis, pre-syncope symptoms, no post-ictal
• May have fasiculations (convulsive syncope)
• Usually no LOC unless basilar stroke, usually negative findings not
positive. Sometimes confusing if post-ictal Todd’s paralysis
• 10-45% of patients with refractory epilepsy. Look for history of
abuse. Patients can have both.
5) Movement disorders
Is there an underlying cause?
(rule out secondary causes of seizures)
1o neurologic disorder Systemic disorder
•Head trauma •Hypoglycemia
•Vascular malformations •Hepatic encephalopathy
•Meningitis/encephalitis •Drug OD/withdrawal
• Witness testimony is key!
• Triggers, ictal behaviors, LOC,
behaviour during seizure and the
• Seizure precipitants or triggers:
– strong emotions, intense exercise, flashing
lights, and loud music (often immediately
before the seizure)
– fever, menstruation, lack of sleep, and
Ask about . . .
Drugs, alcohol, constitutional symptoms,
HIV risk factors, fever, head trauma.
Family History (absence and myoclonic
seizures may be inherited)
• Generally unrevealing
• Look for signs of disorders associated with
• Head trauma, meningismus, sinus infection.
• Focal or diffuse neurological abnormalities.
• Mental status abnormalities suggest lesions in
the anterior frontal, parietal, or temporal
• Evaluate for lateralizing abnormalities:
weakness, hyperreflexia, positive Babinski sign
• 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).
• 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
• 50% of patients with epilepsy have
normal single EEG
• 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
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
• CT findings agreed with the results of
neurological examination in 82 percent
Ramirez-Lassepas, et al. Value of computed tomographic scan in the evaluation of
adult patients after their first seizure. Ann Neurol 1984; 15:536.
• All patients should receive
• 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.
When to initiate Antiepileptic drug
1) Two or more seizures
2) Single seizure secondary to identified CNS
lesion with an epileptogenic focus
3) Consider if significant occupational risk if
patient suffers a second event.
4) Consider if single seizure event with one or
more risk factors for recurrent seizures
5) Consider in the elderly patient with increased
risk of seizure related morbidity (age,
prolonged post-ictal state)
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
• 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
Antiepileptic Drugs of Choice
Primary Generalized Atypical Absence,
Tonic-Clonic Partial Absence Myoclonic, Atonic
First-Line Valproic acid Carbamazepine Ethosuximide Valproic acid
Carbamezepine Phenytoin Valproate
Alternatives Lamotrigine Gabapentin Lamotrigine Lamotrigine
Primidone Topiramate Clonazepam Topiramate
Phenobarbital Tiagabine Clonazepam
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
• Majority of patients are controlled with single
• 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
Principles of Treatment
• 20-35% of patients with epilepsy have persistent
seizures despite medical therapy.
• If poor control with maximal dose, monotherapy with
• Continue to administer first drug until a full dose of
second drug reached, then gradually withdraw first
• If monotherapy with two drugs fail, patient may need
re-evaluation (repeat MRI/EEG) before polytherapy
commenced (1998 guidelines).
• Idiosyncratic toxicity:
– rash, bone marrow suppression, or
• Require laboratory tests (e.g.,
complete blood count and liver
– during initial dosing and titration
Other management issues:
• Impact on independence, self-esteem,
• 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.
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
• Management after 1st seizure
involves lots of discussion with
patient about risks/benefits
• Remember impact on driving: tell
• When in doubt about management
(especially medications), get a