A seizure disorder of sudden discharge of cerebral neurons
What is an episode of neurologic dysfunction, often accompanied by motor activity such as convulsions, and emotional/sensory change called?
What's etiology for epilepsy?
Majority of patients have idiopathic epilepsy - no known cause
What are the 2 broad groups of epilepsy?
- Partial epilepsies
- Generalized epilepsies
What is the most common type of epilepsy?
What are the 2 subtypes of partial epilepsy?
- Simple partial
- Complex partial
Define Simple partial epilepsy.
Seizures caused by a group of hyperactive neurons confined to a single locus in the brain
Describe some characteristics of simple partial epilepsy.
- Seizure lasts for only a few seconds
- Individual does not lose consciousness
- Often exhibits abnormal activity of a single limb or muscle group
- Can occur at any age
Define complex partial epilepsy.
Seizures exhibit complex sensory hallucinations, mental distortion and loss of consciousness
What are some characteristics of complex patial epilepsy?
- Aura, seizure lasts for 3-5 minutes
- Full consciousness is slow to return
- AKA psychomotor or temporal lobe seizures
- 80% have initial seizure prior to 20 years of age
What are the 2 subtypes of generalized epilepsies, and what's common about generalized epilepsies?
- Tonic-clonic (grand mal)
- Absence (petit mal)
Consciousness is lost with both types of seizures
What is the most dramatic form of epilepsy?
Tonic-clonic (grand mal)
What's a characteristic of tonic-clonic (grand mal)?
After seizure with loss of consciousness, it's followed by tonic then clonic phases (convulsive twitching)
What do the terms tonic and clonic mean?
- Tonic - producing/restoring normal tone, continuous tension
- Clonic - contraction/relaxation of muscle
What's the major motor activity of tonic-clonic (grand mal) epilepsy?
Fall to the floor, tonic rigidity, chronic jerking of face and limbs
What is a tonic-clonic seizure followed by?
A period of confusion and exhaustion, comatose, headache, drowsiness
What is an aura?
Brief period of heightened sensory activity prior to the onset of the seizure, characterized by numbness, nausea or unusual sensitivity to light, odor, sound
Define absence (petit mal).
Seizures involve an abrupt and brief loss of consciousness (10-30 seconds)
What are the characteristics of absence (petit mal)?
- Onset occurs at 3-5 years old and lasts until puberty
No aura, patient stares and has rapid eye-blinking for 3-5 seconds, quickly returns to normal
What is status epilepticus?
Seizures are continuous or rapidly recurrent, and can be life-threatening
What happens when you have a patient that has status epilepticus in your dental office?
Give injection of diazepam (Valium)
May also use lorazepam (Ativan) and midazolam (Versed) parenterally
What are the goals for the drug therapy for epilepsy?
- To control seizures (frequency)
- Minimize adverse reactions
What is the mechanism of the drug therapy for epilespy?
Prevent the spread of abnormal electric discharges in the brain without causing excessive drowsiness
What type of drugs are drugs used to treat epilepsy?
CNS depressents - a life long medication
What are the dosing considerations of anti-convulsants?
- Narrow therapeutic index - titrate dose carefully, monitor blood levels
- Most anticonvulsants stimulate liver microsomal enzymes (inducers)
What can the metabolism of anticonvulsants do?
Saturate liver microsomal enzymes
What happens to the elimination kinetics of anticonvulsants?
- At low doses - 1st order elimination
- After saturation - converts to zero order and blood level increases abruptly
What are the common side effects of anticonvulsants?
CNS depression - impaired learning, tolerance, behavioral alteration, exacerbation of another seizure not being treated
CNS depression is additive with other CNS depressents - opioids, alcohol = bad!
GI effects - Nausea, vomiting, diarrhea
What would you prescribe a patient for dental pain if he or she is taking anticonvulsants?
NSAIDS - but may be gastric irritants