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The Anticonvulsants
Seizure Classification
Partial
Seizures : Focal
• Simple Partial Seizure
–Consciousness Not Impaired
–Convulsions limited to one limb
–Sensory hallucinations
–Common in older children and
adults
 Complex
Partial Seizure
• Consciousness is impaired briefly
• Automatisms present : Automatic
behaviors like lip smacking,
chewing
• Post seizure confusion : 1-2
minutes
 Partial
Become Generalized
• Consciousness is impaired
• Progressive seizure involvement
until a generalized tonic-clonic
seizure evolves
 Generalized
Seizures
• Absence Seizures (Petit Mal)
–Sudden, brief LOC
–Amnesia for a brief period
–Attacks last <30 seconds
–No confused state after seizure
–May occur many times per day
 Myoclonic
Seizures
–Sudden, lightening fast contractions
–Loss of consciousness may occur
–Can last seconds to minutes
 Clonic
Seizures
–Rhythmic, synchronized
contractions throughout the
entire body
–Loss of consciousness
 Tonic
Seizures
–generalized sustained muscle
contractions throughout the
body
–Loss of consciousness
 Tonic-Clonic
Seizures (Grand Mal)
–Major convulsions over the entire
body
–Contractions occur in an alternating
tonic and clonic pattern
–May loose bowel & bladder control
–LOC
–May be preceded by an aura or an
outcry
 Atonic
Seizures
–Sudden loss of postural tone
–Consciousness may be lost
Anticonvulsants
…A Plethora Of Drugs
 Hydantoins
 Barbiturates
 Iminostilbenes
 Succinimides
 Benzodiazepines
 Valproic
Acids
The Hydantoins
 Phenytoin
(Dilantin)
 Mephenytoin (Mesantoin)
 Ethotoin (Peganon)
 Phenacemide (Phenurone)
 Phenytoin
(Dilantin) - Prototypic
Drug
• Made in 1908
• Used for seizure control in 1938
• In therapeutic doses, no loss of
consciousness
Dilantin - Mechanism of Action
 Stabilizes
neural membranes
–Interferes w/ sodium ion
movement across the cell
–May prolong the refractory
period of excitable cells by
delaying the influx of potassium
ions
Hydantoins Adverse Side Effects
 Ataxia
 Hirsuitism
 Headache
 Dysarthria
 Nystagmus
 Gingival
Hyperplasia
The Barbiturates
 Phenobarbital
(Luminal)
 Mephobarbitol (Mebaral)
 Primidone (Myosline)
Mechanism Of Action
 Phenobarbital
- The Prototype
–Anticonvulsant at sub-hypnotic
doses
–Not addictive in therapeutic
doses
–Increases threshold for motor
cortex stimulation
–Reduces neurotransmitter
release thereby quieting the
brain
–May augment the effects of
GABA
–May inhibit the excitatory effects
of glutamate
Adverse Side Effects
 Ataxia
 Nystagmus
 Vitamin
K deficiency
 Folic acid deficiency
 Sedation which diminishes over
time
The Iminostilbenes
 Carbamazepine
(Tegretol)
Mechanism of Action
 Identical
action to the
Hydantoins
–Stabilizes the flux of sodium across
excitable membranes
–Inhibits the spread of seizure
signaling
–First used in 1974 in the U.S.
Adverse Side Effects
 Diplopia
 Drowsiness
 Ataxia
 Hematopoeitic
Suppression
• Aplastic anemia
• Leukopenia
• Thrombocytopenia
 Syndrome
of Inappropriate
Antidiuretic Hormone Secretion
(SIADH)
–Water retention
–Water intoxication
–Increased intraocular pressure
Succinimides
 Ethosuximide
(Zarontin)
 Methusuximide (Celontin)
 Phensuximide (Milontin)
Mechanism of Action
 Suppress
nerve signal
transmission in the motor cortex
 Increase the threshold for
stimulation
 Increase glucose transport to the
brain which decreases neuronal
excitability
Adverse Side Effects
 Ataxia
 Dizziness
 Euphoria
 Headaches
 Aplastic
Anemia
 Thrombocytopenia
 Agranulocytosis
 Leukopenia
 Decreased sexual drive
 Renal
and hepatic toxicity
 Alopecia
 Hirsuitism
 Gingival Hyperplasia
Stevens-Johnson Disease

Target Lesions On The Skin
–Central dark red zone with
blisters
–Encompassed by a pallor area
which is circumscribed by a red
rim
–Necrotic vasculitis may be
present (capillary damage)
–Bloody discharge from these
lesions
–May involve the eyes, mouth,
lips, tongue, throat, esophagus,
gut, bronchopulmonary tree
Cause ????
Benzodiazepines
 Diazepam
(Valium)
 Clonazepam (Klonopin)
 Clorazapate Dipotassium (Tranxene)
Mechanism of Action
 Enhance
the effect of GABA - An
inhibitory neurotransmitter
 Suppresses the spread of
seizure signaling produced by
epileptogenic foci
Adverse Side Effects
 Vertigo,
Ataxia,Syncope
 Drowsiness, Confusion
 Tremor, Weakness
Valproic Acids
 Valproate
Sodium (Depakene)
 Divalproex (Depakote)
Mechanism of Action
 Mechanism
of action is unknown
–Inhibits GABA Transaminase
–Inhibits Succinic Semialdehyde
Dehydrogenase
–Allows GABA to have a longer
half-life
Anticonvulsants - Medical Uses
 Used
to control seizures
 The Hydantoins
–Trigeminal neuralgia
–Cardiac arrhythmias
 Tegretol
–Trigeminal neuralgia
–Glossopharyngeal neuralgia
Clinical Considerations
Is the patient taking their
medications regularly ????
 Time the rehab session within 30
minutes of the last dose to decrease
the chances of seizures

 Are
there any external triggers
which could set off the seizure
??? (light, sound, fatigue, odors)
 Are the patients changing
medications or changing the
dose ???
 Are
the patients under unusual
stress - divorce, family deaths,
etc.
 Know the side effects of the
medications
 Have
a good seizure plan in the
clinic
 Train personnel to appropriately
respond to the seizure event