Seizures and Epilepsy
Dr. Ali Alrefai
Associate Professor
Dept of Neuroscience
Concepts
Seizure: sudden temporary
change in brain function caused
by an abnormal rhythmic
excessive electrical discharge
Epilepsy: a state of recurrent
seizures
Epidemiology of Epilepsy
Lifetime risk of developing
epilepsy is 3.2%
10% of population experience
at least one seizure before the
age of 80 years
Higher prevalence at the
extremes of age
Seizure Type Versus
Epileptic Syndrome
A seizure type is determined by the
patient’s behavior and EEG pattern
during the ictal event
An epileptic syndrome is defined by
- Seizure type(s)
- Natural history
- EEG (ictal and interictal)
- Response to AEDs
- Etiology
Classification of Seizures
Partial seizures
- Simple partial seizures
- Complex partial seizures
Impaired consciousness at outset
Simple partial evolving to lost consciousness
- Partial seizures evolving to general
tonic-clonic seizures (GTCS)
Classification of Seizures
(cont.)
Generalized seizures
- Absence seizures
- Tonic-clonic seizures
- Myoclonic seizures
- Tonic seizures
- Clonic seizures
- Atonic seizures
Classification of Epilepsies
Partial Epilepsy Syndromes Generalized Epilepsy Syndromes
- Symptomatic - Symptomatic
•Lennox-Gastaut Syndrome
•Lesional epilepsy
•West’s Syndrome
•Mesial Temporal Sclerosis
•Progressive Myoclonic Epilepsy
•Neocortical Epilepsy
- Idiopathic(Genetic)
- Idiopathic(Genetic) •Juvenile myoclonic epilepsy
•Benign Rolandic Epilepsy •Generalized tonic clonic
•Benign occipital Epilepsy seizures upon awakening
Absence Seizure
Simple: abrupt onset and
cessation of motionless stare,
with unresponsiveness and no
post ictal state ( few-30 sec)
Complex:
typical+clonic/myoclonic activity
or automatism
Activated by hyperventilation
Generalized Tonic Clonic
Seizure
Prodrome: apathy, fatigue
No aura
Tonic phase: 10-15 sec, jaw snap shut,
spasm, cyanosis
Clonic phase: 1-2 min, rhythmic
generalized muscle contractions apnea,
increased BP
Terminal phase: coma, pupils react,
breathing resume
Post-ictal phase: confusion, somnolence
Complex Partial Seizures
Prodrome: Lethargy
Aura: common
Oral or motor automatism,
alteration of consciousness,
head and eye deviation,
contralateral twitching or clonic
movements, posturing
Frontal lobe seizures
are partial seizures
that can be easily
confused with
psychiatric disease
Epilepsy Risk Factors
Structural brain lesions
Degenerative diseases
Head trauma
CNS infections
Perinatal insults
Alcohol/drugs
HIE
Febrile seizures
Genetic factors
Diagnosing Epilepsy
History of recurrent seizures
- Differentiate epileptic from non-
epileptic fits
- Classify seizure type
- Determine etiology
Associated clinical features
Diagnostic testing
• EEG
• MRI
Epilepsy Treatment Choices
No treatment
Acute treatment only
Begin chronic AED
- Choose a first line therapy
Carbamazepine
Phenytoin
Valproate
Oxycarbamazepine
Rational Selection of AEDs
Efficacy Mechanisms of action
appropriate for No evidence of
broad spectrum of therapeutic tolerance
patients Favorable safety
- Partial onset profile
- Primary generalized Well tolerated
tonic-clonic
- Encephalopathic Monotherapy
generalized whenever possible
- Adults
Titration rate
- Women
- Children (all ages)
Classic Versus Newer
Anticonvulsants
Classic AEDs Newer AEDs
Phenobarbital Felbamate
Phenytoin Gabapentin
Lamotrigine
Primidone
Levetiracetam
Carbamazepine
Oxcarbazepine
Valproate Tiagabine
Ethosuximide Topiramate
Vigabitrin
Zonisamide
Choice and Use of Drugs
Partial
Generalized
Simple
Complex
Secondary
generalized
Tonic- Infantile
Tonic Myoclonic Atonic Spasms
Absence
clonic
PHT, CBZ, PB,
GBP, TGB, ACTH
LVT, OCBZ TPM? ESX
TGB?
VGB?
VPA, LTG, TPM, ZNS
FBM
Phenytoin
For partial and generalized Sz
^ Pt. bound, hepatic inducer
Side effects
- Dose related: ataxia, dysarthria,
nystagmus
- Idiosyncratic: hirsutism, gingival
hypertrophy, acne, coarsening
facial features
Valproic Acid
Strong metabolic inhibitor
For partial and generalized Sz
Strongly Teratogenic: spina
bifida
Side effects:
- somnolence, wt gain, tremor, hair
loss
- Pancreatitis, hepatotoxicity, blood
dyscrasias
Carbamazepine
Potent enzyme inducer
Mainly for partial seizures
Side effects:
- somnolence, dizziness, blurred
vision, diplopia’ nystagmus
- skin rash, hepatotxicity, blood
dyscrasias
New AED’s Side Effects
Felbamate: aplastic anemia, hepatic failure,
thromobocytopenia
Gabapentin: tremor, wt gain
Lamotrigine: rash,Stevens-Jonson syndrome,liver
failure
Topiramate: wt loss. kidney stones
Tiagabine: confusion, stupor, nervousness, depression
Vigabatril: retinal toxicity
Oxcarbazepine: hyponatremia
Levetiracetam: somnolence, dizziness
Zonisamide: kidney stones
Status Epilepticus
Seizures that are continuous or
recurrent for over 30 minutes
without either improvement in
clinical state or return to preictal
EEG
Simple partial SE; Convulsive SE;
NCS
Etiologies: AED, acute metabolic,
head injury, tumor, CNS infection,
stroke, drugs (prescribed &
abused), unknown
Management
Prehospital:
Positioning to prevent head
trauma & aspiration
Oxygen
IV access
Benzodiazepines
In-Hospital management
0-9 Minutes
Assess cardiorespiratory state (insert oral
airway,O2)
Start IV
Administer B1 & then glucose 25-50ml of D50
Obtain blood for AED levels & metabolic profile
Obtain history & brief neurological exam
Lorazepam 2mg over 2 minutes (max. 8-12mg)
Intubation
4-10 minutes
Begin infusion of PHT 20mg/kg
(not>50mg/min or 150mg/min of PHTE);
monitor ECG & BP
If seizures persist, obtain continuous
EEG, intubate if not intubated
Phenobarb. @ <100mg/min until sz stops
or maximum 20mg/kg
Initiate pentobarbiturate coma or
general anesthesia using agents familiar
to institution to obtain burst suppression
pattern on EEG
Other measures
CSF?: pleocytosis (<12 WBC), elevated
protein
CPK & rhabdomyolysis
DIC
Cardiac arrhythmia
Adequate padding
Correct metabolic abnormalities, acidosis