eMedicine Specialties > Neurology > Seizures and Epilepsy
Posttraumatic Epilepsy: Treatment & Medication
Updated: Oct 22, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
Treatment
Medical Care
Treatment of PTE does not require hospitalization. Admission may be needed for the treatment of status epilepticus or for videotelemetry to assist in the diagnosis.
Surgical Care
Surgical treatment is an option for PTE refractory to medication. The aim is precise identification and excision of the epileptogenic focus. This is often more difficult in cases of PTE than in other types of epilepsy.
Consultations
- Consult a neurologist to confirm the diagnosis.
- Consult a neuropsychologist to document the patient's baseline function before antiepileptic medication is started. Consultation with a neuropsychologist should be a part of the workup if surgery is considered.
Medication
Early PTS is treated with phenytoin, sodium valproate, or carbamazepine. In most cases, administering the medication via the intravenous (IV) route is desirable, as the patient is still in the recovery stage from the head injury; phenytoin is the drug of choice for IV administration. No evidence suggests that antiepileptic drugs (AEDs) influence the incidence of late PTS; therefore, prophylaxis has no place in caring for patients with head injuries. However, AEDs are effective in patients who develop PTE.
The main drugs used for PTE are valproate and carbamazepine. To the authors' knowledge, no randomized controlled studies have been performed to prove that one is better than the other. Some also recommend phenytoin4 , but it seems to increase the risk of impairing cognitive function. A retrospective study that compared phenytoin and levetiracetam in patients after craniotomy found that levetiracetam was better tolerated and therefore more likely to be used long term.5 Levetiracetam has also been studied in patients with severe traumatic brain injuries; a recent small study suggested that it was as effective as phenytoin in preventing early seizures, but the amount of seizure activity seen on EEG monitoring was higher in the levetiracetam group.
Anticonvulsants
These agents prevent seizure recurrence and terminate clinical and electrical seizure activity.
Sodium valproate (Depakote, Depakene, Depacon
Chemically unrelated to other antiseizure drugs. Mechanism of action not established; may be related to increased brain levels of GABA or to enhanced GABA action. May potentiate postsynaptic GABA responses, affect potassium channel, or have direct membrane-stabilizing effect. For conversion to monotherapy, concomitant AED dose ordinarily reduced by about 25% q2wk. Reduction may start with therapy or delayed 1-2 wk if seizures possible with reduction; closely monitor patients during this time for increased seizure frequency.
As adjunctive therapy, may be added to regimen at 10-15 mg/kg/d. May increase by 5-10 mg/kg/wk for optimal clinical response. Optimal clinical response usually achieved at <60 mg/kg/d.
Adult
600 mg/d PO divided bid, preferably after food; increase by 200 mg/d at 3-d intervals; not to exceed 2.5 g/d (20-30 mg/kg/d)
Pediatric
<2 years: Not recommended; risk of fatal hepatotoxicity
>2 years: 20 mg/kg/d PO initially in divided doses; can be increased, not to exceed 35 mg/kg/d
Cimetidine, salicylates, felbamate, and erythromycin may increase toxicity; rifampin may reduce levels significantly; in children, salicylates decrease protein binding and metabolism; may result in variable changes of carbamazepine concentrations, with loss of seizure control; may increase diazepam and ethosuximide toxicity (monitor closely); may increase phenobarbital and phenytoin levels, and either may decrease levels; may displace warfarin from protein-binding sites (perform coagulation tests); may increase zidovudine levels in HIV-positive patients
Documented hypersensitivity; active liver disease; porphyria; family history of hepatic dysfunction
Pregnancy
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions
Thrombocytopenia and abnormal coagulation reported; risk of thrombocytopenia increases significantly at total trough plasma concentrations >110 (women) or >135 (men) mcg/mL; before therapy, periodically, and before surgery, determine platelet counts and bleeding time; reduce dose or discontinue if hemorrhage, bruising, or hemostasis or coagulation disorder occur. Monitor for hepatotoxicity (perform LFTs periodically); hyperammonemia may occur, resulting in hepatotoxicity; monitor closely for malaise, weakness, facial edema, anorexia, jaundice, and vomiting; may cause drowsiness
Carbamazepine (Tegretol)
Indicated for complex partial seizures. May block posttetanic potentiation by reducing summation of temporal stimulation. After therapeutic response, may reduce dose to minimum effective level or discontinue at least once q3mo.
Adult
100-200 mg PO qd/bid; slowly increase to usual dose of 0.8-1.2 g/d in divided doses; not to exceed 1.6-2 g/d
Pediatric
<1 year: 100-200 mg/d PO in divided doses
1-5 years: 200-400 mg/d PO in divided doses
10-15 years: 0.6-1g/d PO in divided doses
Danazol may increase serum levels significantly (avoid within 30 d if possible); cimetidine may increase toxicity, especially if taken in first 4 wk; may decrease primidone, lamotrigine (via hepatic enzyme induction), and phenobarbital levels (coadministration may increase levels); lamotrigine may increase levels of active metabolites, leading to symptoms of cerebellar dysfunction
Documented hypersensitivity; AV conduction abnormalities (unless paced); porphyria; history of bone marrow depression; concurrent MAOIs
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
In first trimester, risk of teratogenesis, including neural tube defects, may be increased; in third trimester, manufacturer advises prophylactic vitamin K-1 for mother before delivery (and for neonate) because of risk of neonatal bleeding; counseling, screening, and folate supplements advised. Initiation should be gradual; caution with increased IOP; obtain CBC counts and serum iron level before treatment, during first 2 mo and then yearly or biyearly; can cause drowsiness, dizziness, and blurred vision; caution while driving or performing other tasks requiring alertness
Phenytoin (Dilantin)
May act in motor cortex, inhibiting spread of seizure activity; may inhibit activity of brainstem centers responsible for tonic phase of grand mal seizures.
Individualize dose. Administer larger dose before sleep if cannot be divided equally. To minimize GI irritation, administer with or immediately pc. Rapid injection or direct IV injection may cause severe hypotension or CNS depression.
Adult
IV loading dose for patients who have not received phenytoin in preceding 7 days: 10-15 mg/kg; rate not to exceed 50 mg/min (25 mg/min in elderly)
Maintenance dose: 4-7 mg/kg/d PO/IV
Pediatric
IV loading dose: 15-18 mg/kg; rate not to exceed 0.5-1 mg/kg/min or 50 mg/min; in infants, do not give via scalp vein
Maintenance dose: 5 mg/kg/d PO/IV divided bid, adjust on basis of clinical signs and serum concentrations
Amiodarone, benzodiazepines, chloramphenicol, cimetidine, fluconazole, isoniazid, metronidazole, miconazole, phenylbutazone, succinimides, sulfonamides, omeprazole, phenacemide, disulfiram, ethanol (acute ingestion), trimethoprim, and valproic acid may increase toxicity; barbiturates, diazoxide, ethanol (chronic ingestion), rifampin, antacids, charcoal, carbamazepine, theophylline, and sucralfate may decrease effects; may decrease effects of acetaminophen, corticosteroids, dicumarol, disopyramide, doxycycline, estrogens, haloperidol, amiodarone, carbamazepine, cardiac glycosides, quinidine, theophylline, methadone, metyrapone, mexiletine, oral contraceptives, valproic acid
May aggravate typical absence seizures; reduce dose in hepatic impairment; sinoatrial block; Adams-Stokes syndrome; second- or third-degree AV block
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Rapid IV infusion may cause death from cardiac arrest marked by QRS widening; narrow therapeutic index, and relationship between dose and plasma concentration nonlinear (must monitor plasma levels); avoid abrupt withdrawal; perform CBC counts and urinalyses at start and monthly for several months to monitor for blood dyscrasias; discontinue if skin rash occurs and do not resume if exfoliative, bullous, or purpuric; caution in acute intermittent porphyria and diabetes (may elevate blood glucose level); discontinue if hepatic dysfunction occurs
More on Posttraumatic Epilepsy |
| Overview: Posttraumatic Epilepsy |
| Differential Diagnoses & Workup: Posttraumatic Epilepsy |
 Treatment & Medication: Posttraumatic Epilepsy |
| Follow-up: Posttraumatic Epilepsy |
| References |
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References
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Further Reading
Keywords
PTE, head injury, head trauma, posttraumatic seizure, PTS, traumatic brain injury, TBI
