AEDs (1) PDF

AEDs 1. Dilantin (Phenytoin)/ Cerebyx (Phosphenytoin) a. Therapeutic Levels i. NO increase in in fast activities (unlike benzos and barbiturates) ii. Mixed data on influence on IEDs iii. Withdrawal of AEDs used often to provoke seizures in EMUs...

AEDs 1. Dilantin (Phenytoin)/ Cerebyx (Phosphenytoin) a. Therapeutic Levels i. NO increase in in fast activities (unlike benzos and barbiturates) ii. Mixed data on influence on IEDs iii. Withdrawal of AEDs used often to provoke seizures in EMUs iv. Increase in theta-range slow waves b. Toxic Levels i. Marked diffused delta activity ii. Paroxysmal slow wave abnormalities iii. Cerebellar atrophy c. Chronic Use i. Cerebellar atrophy ii. Chronic Phenytoin Encephalopathy 1. Changes in seizure pattern and ↑ tonic & ↑ opisthotonic components iii. Lowered PDR frequency iv. Gum hypertrophy and coarsening of facial features d. Acute Intoxication i. Cerebellovestibular dysfunction; can be confused with cerebellar tumor ii. Altered higher cognitive function, pyramidal signs, several extra-pyramidal movement disorders iii. May exacerbate epileptic seizures 2. Tegretol (Carbamazepine) a. May cause diffuse slowing b. No change in background frequency – minimal effect on EEG c. Generalized paroxysmal activity, including spikes, can be increased d. Toxicity i. Can be sensitively demonstrated by color vision tests ii. Clinical signs 1. Ataxia 2. Nystagmus 3. Diplopia 4. Drowsiness 5. EEG diffuse slowing 6. May exacerbate seizures 3. Depakote (Valproic Acid/Valproate) a. Therapeutic Doses i. No significant change in Background Activity or, diffuse slowing, depending on source ii. Reduction, even disappearance of generalized spikes along with seizure reduction 1. Photosensitive spikes disappear b. Toxic Levels  i. Marked diffuse slowing ii. High variability in prognosis of suicide attempts 1. Tiredness à à à c. Side Effects i. Fatal liver failure 4. Lamictal (lamotrigine) a. RASH is most common cause of withdrawal i. Limited in administration to children, since RASH can be potentially life- threatening b. In NON-epileptic patients, EEG show widespread attenuation but no slowing c. NO slowing in epileptic patients! d. Has marked decreasing effect on occurrence and frequency of spontaneous and photosensitive generalized spikes and waves, spike-and-wave discharges e. Toxicity - No serious toxicity but only prolongation of QRS 5. Topamax (topiramate) a. Powerful AED in partial & childhood epilepsies b. Multiple modes of action c. No reports of EEG correlate 6. Lithium (not an AED) a. Can lead to diverse & prominent EEG changes b. EEG i. PDR Slowing & ↑ diffuse slowing ii. Intermittent rhythmic delta, most prominent in frontal or occipital regions iii. Triphasics iv. Occasional spikes & frontal slowing should NOT be considered evidence of structural lesion v. Intoxication 1. EEG abnormalities are marked a. Diffuse slow waves b. Triphasics c. Multifocal epileptiform discharges 7. Zarontin (ethosuximide) a. Main AED for Absence Epilepsy being replaced by Depakote and Lamictal b. Side Effects i. Somnolence ii. Lethargy iii. Emotional instability iv. Altered vigilance on EEG