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Benign Rolandic Epilepsy: Less Than Benign After All?


 

BRECKENRIDGE, COLO. — Benign rolandic epilepsy may not be so benign after all, C. Akos Szabo, M.D., said at a conference on epilepsy syndromes sponsored by the University of Texas at San Antonio.

It's true at least 90% of patients with this common and distinctive form of childhood epilepsy go into remission by their teenage years. But there is a subset, perhaps 10%, who develop deficits in verbal memory and language skills as well as behavioral problems including attention-deficit hyperactivity disorder (ADHD) and impulsivity, explained Dr. Szabo, a neurologist who directs the epilepsy surgery program at the university's South Texas Comprehensive Epilepsy Center.

The big question is: Are the interictal epileptic EEG discharges (IEDs) in children with benign rolandic epilepsy causally related to neuropsychiatric and behavioral problems, or are both the IEDs and the behavioral problems due to a common underlying neurologic dysfunction? The corollary issue is whether treating the IEDs with antiepileptic drugs (AEDs) will prevent these problems. The answers are unknown.

Relevant to these issues is a recent study by investigators at J.W. Goethe University in Frankfurt, Germany, reporting an increased prevalence of rolandic spikes in the EEGs of 483 consecutive children without epilepsy who met diagnostic criteria for ADHD as determined by experienced child psychiatrists, Dr. Szabo said.

Martin Holtmann, M.D., and his colleagues detected rolandic spikes in 6% of the ADHD patients, compared with 2% of a control group consisting of 3,726 normal children. Eighty percent with ADHD plus spikes had right-sided or bilateral epileptiform discharges.

ADHD in children with rolandic spikes was diagnosed at a significantly younger age than in those without EEG discharges. They were also more likely to be diagnosed with ADHD-combined type than ADHD-inattentive type. ADHD patients with rolandic spikes also were more likely to develop new-onset seizures during follow-up (Epilepsia 2003;44:1241–4).

The German investigators raised the possibility that rolandic spikes or their underlying causal defect might increase vulnerability to ADHD, advance onset of the behavioral disorder, or aggravate its course.

They added that the treatment implications of their findings remain unclear.

If ADHD symptoms in some patients are in fact related to their focal epileptic discharges, there is the possibility that antiepileptic drug therapy in lieu of or in combination with conventional stimulant therapy might ameliorate the neuropsychologic deficits of ADHD.

Another question worthy of prospective studies is whether long-term stimulant therapy might promote seizures in ADHD children with rolandic spikes.

Benign rolandic epilepsy is the most common epilepsy of childhood, accounting for roughly one-quarter of cases in school-aged children. Peak age of onset is 8–9 years. Although benign rolandic epilepsy clearly has a strong genetic component, a recent twin study by investigators at the University of Melbourne (Australia) produced data disputing the long-held belief that it is inherited in autosomal dominant fashion (Ann. Neurol. 2004;56:129–32). Rather, it is probably a polygenic disorder, Dr. Szabo said.

It's called “rolandic” epilepsy because the clinical symptoms point to involvement of the lower portion of the central gyrus of Rolando.

Common features include oropharyngeal somatosensory symptoms, facial motor seizures during drowsiness, and brief nocturnal generalized tonic-clonic seizures. Roughly two-thirds of patients experience 2–10 seizures in their lifetime.

The easily recognized EEG pattern shows centrotemporal high-voltage sharp waves with a transverse dipole activated by drowsiness and stage II sleep.

Dr. Szabo said he usually does not treat mildly affected children. Otherwise, monotherapy using agents effective for focal seizures is typically sufficient. Carbamazepine is the most widely utilized drug.

Europeans have reported excellent results treating affected children with sulthiame, a drug not marketed in the United States.

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