Epilepsy - Block 1 Flashcards
What is a seizure?
a transient alteration of behavior due to the disordered, synchronous, and rhythmic firing of populations of brain neurons
What is epilepsy?
a chronic brain disorder characterized by recurrent (≥ 2) seizures that are unprovoked
What can cause acute symptomatic sz?
- Neurologic insult
- Metabolic disorder
* Electrolyte imbalances: Hyponatremia (<115 mmol/L); Hypocalcemia (<5 mmol/L); Hypomagnesemia (<0.8 mg/dL)
* Hypo- or hyper-glycemia - Medication
- Alcohol and toxics
What are the medications that cause seizures?
- Beta lactams
- Fluroroquinolones
- Theophylline
- Bupropion
- Second gen clozapine
- Lithium
- Meperidine, morphine, propoxyphene
- Tramadol
What are the causes of epilepsy?
- Genetic
- Structural
- Infection
- Metabolic
- Immune
- Idiopathic
Descibe the age onset of epilepsy?
Before age 2: Fever, hereditary or congenital neurologic disorders, birth injuries, and inherited or acquired metabolic disorders
Ages 2 to 14: Idiopathic seizure disorders
Adults: Cerebral trauma, alcohol withdrawal, tumors, strokes, and an unknown cause (in 50%)
Older people: Tumors and strokes
What are the 2 facotrs that contribute to the development of epilepsy?
- Hyperexcitability
- Hypersynchronization
What are the phases of a seizure?
- Prodromal: hours/days before seizure
- Aural: deja vu, jamais vu, odd smells, tastes, dz
- Ictal: first sx to end of seizure
- Recovery: confusion, lack of consciousness
What are the 2 classes of seizure types?
- Focal: One side
- Generalized: Both sides
- Unclassified
How are seizures classified?
- Onset
- If focal, must identify aware or impaired if known (if unknown omit). Don’t have to identify this for generalized since impaired awareness is implied
- First sign or symptom
What is the difference between focal aware and focal impaired awareness sz?
FA: simple partial sz
FIA: complex partial sz
Another name for focal to bilateral tonic clonic?
partial onset with secondary generalization or secondarily generalized tonic–clonic (GTC) seizure
What is most commonly seen in focal aware sz?
Aura
What is the most common form of generalized motor sz?
Tonic clonic (grand mal)
What are the oresentations of generalized nonmotor sz?
Absense: Abrupt onset and offset of impaired consciousness
* Duration is about 2 to 30 seconds
* No postictal confusion or lethargy
What is the tx goal for sz?
No seizures, no ADRs
How should we treat sz?
What are the tx for sz?
Non pharm: Diet, vagus nerve stim, surgery, support groups
Pharm: ASD (1st, 2nd, 3rd)
What type of diet is used for epilepsy?
Ketogenic: high in fats and low carbs and proteins -> acidosis and ketosis
What are the forms of ketogenic diets?
- Classic (4:1 (90% fat and 10% protein and carbohydrate) with restricted calories and fluids
- Modified Atkins (1:1 (65% fat, 25% protein, and 10% carbohydrate)
- Low glycemic index (least ADRs)
What is vagal nerve stimi?
Implantable and non-implantable options for refractory and generalized sz
ADR: hoarseness, voice alteration, increased cough, pharyngitis, dyspnea, dyspepsia, and nausea
Why do seizures occur?
- Def of inhibitory GABA
- Excess of excitatory NT glutamate
What are the MOA of AED meds?
reduce abnormal electrical activity by:
1. Increasing GABA
1. Decreasing glutamate
1. Blocking/altering calcium channels – reduces transmission of electrical signal
1. Blocking sodium channels – reduces neuronal firing rate
What are the factors to consider for tx?
- The most tolerable adverse effect profile, considering patient-specific factors including age and gender
- ASD can also treat patient’s comorbid conditions (topiramate: neuropathy, Pregabalin, carbamazepine: bipolar disorder)
- DDI
What are the considerations for women taking AED?
- menstrual cycle influences on seizure activity
- drug interactions betweeN contraceptives and antiepileptic drugs
- teratogenicity of antiepileptic drugs
Med for generalized onset tonic clonic?
- Lamotrigiene
- Valproic
Med for focal sz?
- Lamotrigine
- Carbamazepine
- Phenytoin
- Levetiracetam
- Oxcarbazepine
Med of typical absence?
- Valprioc
- Ethosuximide
Med for atypical absence, myoclonic, atonic?
- Valproic
- Lamotrigine
- Topiramate
ASD ADRs?
All AEDs increase risk of CNS depression
Idiocratic: drug rashes (carbamazepine, phenytoin, phenobarbital, lamotrigine)
Long term: Osteomalacia and porosis (carbamazepine, phenytoin, phenobarbital, oxcarbazepine, felbamate, valproate)
What are the 1st gen ASD?
Carbamazepine, clonazepam, ethosuximide, phenobarbital, phenytoin, primidone, valproate
ADR of first gen?
Carbamazepine – BOXED WARNINGS OF BLOOD DYSCRASIAS AND FATAL DERM RXNS; hyponatremia
Phenobarbital - Hyperactivity in children
Phenytoin (chronic) - Gingival hyperplasia and osteoporosis
Valproate - many AEs including thrombocytopenia and well-known teratogenicity
What are the 2nd gen?
Felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, zonisamide
What can prevent OC from working?
Oxcarbazepine and topiramate
What drug is effected by OC?
Lamotrigine
What should be avoided in patients with sulfa allergy?
Zonisamide
ADR of 2nd gen?
Lower incidence of CNS ADRs; considered better tolerated with the exception of topiramate and zonisamide
Felbamate – could cause acute liver failure, aplastic anemia
Tiagabine – has been associated with new onset seizures and SE
Lamotrigine – can cause rash but can progress to SJS
What are the 3rd gen ASD?
Brivaracetam, cannabadiol, cenobamate, clobazam, eslicarbazepine, fenfluramine, lacosamide, perampanel, pregabalin, rufinamide, stiripentol, and vigabatrin
What medications are approved for specific epilepsy syndromes?
Cannabadiol, clobazam, fenfluramine, rufinamide, stiripentol, and vigabatrin
WHat are the ADR of 3rd gen?
Perampanel – BOXED WARNING: monitor for life-threatening psych/behavioral changesincluding aggression, hostility, irritability, anger, and homicidal ideation and threats (can occur with and without prior psych history or prior aggressive behavior)
Cenobamate – DRESS with fast titration; QT interval shortening, appendicitis
Fenfluramine – BOXED WARNING: risk of valvular heart disease and PAH
Vigabatrin - Most serious in this gen effects on vision, aggravate seizures, pts with history of psych conditions may develop psychiatric effects
Medication for elderly?
Due to age, more likely to be on multiple medications (polypharmacy), have hypoalbuminemia and decreased renal/hepatic function, and change in body mass
Lamotrigine
Medication for youth?
TDM
Medication for women?
Consider potential for an unplanned as well as planned pregnancy and teratogenicity of ASDs
Epileptic women taking ASDs and OCs are recommended to use other forms of birth control
Medications to avoid in pregnancy?
Valproate and topiramate
Pregnancy and lactation increases clearance of what drugs?
lamotrigine, carbamazepine, phenytoin, oxcarbazepine, and levetiracetam
What are the teratogenic profiles of ASD?
How much folic acid is given to pregnant patients?
1-4 mg QD
What is the most common reason for tx failure?
Med adherence
What ADRs should we assess?
Idiosyncratic - serious rash (ie, SJS, TEN), hematologic dyscrasias, electrolyte abnormalities
Laboratory assessment (complete blood cell (CBC) counts, chemistries, and liver function tests) baseline and after initiation of ASDs
Long-term effects: Screen for osteoporosis, neuropathy, and gingival hyperplasia (phenytoin)
What do we do during a seizure?
How do we improve QoL?
- Limit driving
- Economic security
- Sz diary
- Safety
- Social isolation
- Stigma
What are common sz triggers?
- Sleep deprivation
- Flashing lights
- Alcohol
- Stress
- Menstration
- Meds
- Missed med
What are the approaches to tx at follow up?
Monotherapy is preffered
* If not seizure free, switch to second ASD as monotherapy
* If not seizure free, dual ASD therapy may be necessary: Adjunctive ASD should be gradually added:
When do we dc ASD?
Seizures free for many years (2-5yr) + low risk of recurrence = ASD withdrawal may be considered
