Patient Information
Stabilizing Epilepsy
When clusters of nerve cells in the brain send the wrong signals, a person may have strange sensations and emotions, behave oddly, or have violent...
EEG and Brain Imaging
All patients with epilepsy should be evaluated with an EEG, and for those with focal epilepsy or undefined epilepsy, with an imaging study of the brain, preferably an MRI. These results should be reviewed at each visit. The EEG may show focal features that are related to neurophysiologic dysfunction, such as slowing that is not definitely epileptiform in character, or show focal spike or sharp waves that are epileptiform in character. Generalized abnormalities may include generalized slowing that is not an epileptiform feature or frontocentral spike wave patterns that are epileptiform in character. The EEG cannot rule out epilepsy, but can rule in the likelihood of epilepsy when definite epileptiform features are present.
Brain imaging can define many conditions that can cause focal epilepsy, and an MRI is more sensitive for defining a number of these conditions (cavernous angiomas, hippocampal sclerosis, developmental migration disorders, and low-grade neoplasms). Significant trauma with signal abnormalities to suggest prior bleeding predispose to epilepsy. When patients are refractory to medical therapy and have imaging findings concordant with EEG onset of seizures, then surgery can be a better treatment.
Adverse Effects
Broad-spectrum drug treatments are efficacious for either generalized or focal seizures, whereas narrow-spectrum treatments are most efficacious for focal seizures (Table 1). The choice of a seizure medication is based on the patient’s seizure type(s) and other comorbid conditions.7 For example, a patient with epilepsy and migraines may do better with a seizure medication that also is used for migraine prophylaxis (valproate or topiramate). In general, seizure control is unlikely to be achieved if patients fail the first 2 medications tried.8 Treating with > 1 medication may improve seizure control but may increase AEs. A review of current seizure medications and their AEs can be found on the ECoE website (http://www.epilepsy.va.gov/Provider_Education.asp).
In VA cooperative studies that evaluated seizure medications, the most common reason for discontinuing a drug was the combination of ineffectiveness and AEs.9-11 Addressing AEs is a quality measure for the care of patients with epilepsy. Adverse effects may be dose dependent or idiosyncratic (rashes). Drug levels may help in determining dose-dependent AEs; for example, diplopia with carbamazepine levels above 10 μg/mL. Each patient may have susceptibility to medication AEs that do not exactly match therapeutic levels. When patients have AEs, a reduction in dose or trial of an alternative medication is advised.
Uncontrollable Epilepsy
About one-third of people with epilepsy have uncontrolled seizures, known as medically intractable epilepsy, which may be identified early in their clinical course by failure of the first 2 tolerated medications.8 Patients should be referred to an epilepsy center so their epilepsy can be defined by video EEG monitoring to capture seizures. Unfortunately, in the VA system, this route is often delayed, and patients may not be diagnosed appropriately for years.12 Some of these patients may be considered treatment failures because the right medications were not tried (eg, generalized epilepsy that is treated with narrow-spectrum seizure medications). Juvenile myoclonic epilepsy often may not be controlled by phenytoin or carbamazepine, but valproate, lamotrigine, levetiracetam, and zonisamide may be more effective.
Other patients may not have epilepsy but have psychogenic nonepileptic seizures (PNES). These behavioral seizures do not have an EEG epileptiform correlate. About 25% of patients who undergo prolonged video EEG monitoring have PNES, and seizure medications do not treat these events.12 A smaller percentage of patients have both epileptic and nonepileptic seizures (5%-15%). Psychogenic nonepileptic seizures often occur within the context of traumatic exposure(s) or previous physical or sexual abuse.
In the VA population, PNES is more often associated with PTSD or head trauma history than in patients with epilepsy.13,14 To confirm the diagnosis of PNES, video-EEG capture of the patient’s seizures is required. Because of the increased number of combat veterans with TBI and PTSD, the diagnosis of epilepsy may be difficult without video-EEG monitoring. Management consists of addressing the underlying conversion disorder and recognition and treatment of comorbidities, such as mood, anxiety, personality, or PTSD. Recently, cognitive behavioral-informed psychotherapy (CB-ip) has been shown to be effective in patients with PNES and is available through the VA national telemental health center and at some ECoE sites.15
If a patient with uncontrolled epilepsy has focal seizures, surgical therapy is more likely to result in seizure control than will medical therapy.16,17 This is especially true when other testing, including MRI, positron emission tomography, and neuropsychiatric evaluation, point to a concordance of localization. These patients should be evaluated in a center that can provide surgical therapy and if necessary also record seizures with invasive techniques using electrodes placed directly over the cortex or into the brain to sample deeper structures like the hippocampus or amygdala. Patients who are refractory should be considered for reevaluation every 2 years by a comprehensive epilepsy center.
Unfortunately, some patients have seizures that begin in eloquent cortex, which if removed, leads to undesirable neurologic loss or multifocal seizure onset. In these patients, seizure frequency can be reduced by vagus nerve stimulation or intracranial responsive neurostimulation.18,19