A separate comorbid problem is the psychosis that can emerge as a complication of an epileptic event. A key symptom of an impending psychotic episode during the postical period is insomnia. "Always alert the patient's family to call you if the patient reports having insomnia. Insomnia during this time heralds psychosis," Kanner told the audience.
"Postical psychosis can be aborted with early pharmacologic intervention," he said, and related a case study in which the patient's family was instructed to administer 2 mg of risperidone(Drug information on risperidone) (Risperdal) to the patient at the first sign of insomnia after a cluster of generalized tonic-clonic seizures and titrate up to 4 mg/d for the next 2 days, followed by 1 mg/d for an additional 2 days. Postictal psychosis can also evolve into interictal psychosis, necessitating regular use of an antipsychotic.
In patients with epilepsy who experience psychotic episodes, atypical antipsychotic agents are recommended over conventional agents because the risk of extrapyramidal adverse effects is low, they do not raise serum prolactin levels, and they may have mood-stabilizing properties--none of which can be said for conventional agents. Antipsychotic agents in general can exacerbate seizure activity, however. Chlorpromazine(Drug information on chlorpromazine) (Thorazine) at dosages exceeding 1000 mg/d and clozapine (Clozaril) at dosages exceeding 600 mg/d are the worst offenders, said Kanner. He added that among the older agents, haloperidol(Drug information on haloperidol) (Haldol) and molindone(Drug information on molindone) (Moban) are less likely to aggravate seizure activity.
In addition, antipsychotic agents can have additive toxic effects in combination with antiepileptic agents, such as phenytoin(Drug information on phenytoin) (Dilantin, Phenytek). "Therefore, when antipsychotic drugs are used in patients with epilepsy, the dose should be escalated slowly, and with certain drugs, lower doses should be used," Kanner instructed.
ADHD and epilepsyThe prevalence of ADHD in children with epilepsy is particularly high and it may also be high in adults with epilepsy, although documentation about its prevalence in adult patients with epilepsy is lacking. Whereas ADHD prevalence in the general pediatric population is 4% to 12%, prevalence among children with epilepsy is 20% to 60%, reported Kanner. The prevalence of adult ADHD in the general population is 2% to 7%. "The high rate of ADHD among persons with epilepsy leads us to ask--as we are asking about depression--are ADHD and epilepsy linked?" said Kanner.
"The DSM-IV criteria for diagnosis of adult ADHD are based on 3 critical elements: childhood onset; presence of significant symptoms; and impairment in at least 2 domains, including school or work, social interaction, or home life," he continued. It can be treated with CNS stimulants, "which don't cause seizures, although the idea has been that they do." He noted, however, that enzyme-inducing antiepileptic drugs increase clearance of amphetamine compounds such as dextroamphetamine (Dexedrine) and magnesium pemoline (Cylert).
Other interventions include atomoxetine(Drug information on atomoxetine) (Strattera) and tricyclic antidepressants such as imipramine(Drug information on imipramine) (Tofranil) and desipramine (Norpramin, Pertofrane). Tricyclics should be started at low doses and slowly titrated up. Furthermore, it should be noted that enzyme-inducing antiepileptic drugs will cause tricyclic levels to drop.
This article was originally published in Applied Neurology.
