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The relationship between free radicals and scavenger enzymes, and the disorders called the neuronal ceroid-lipofuscinoses, has long been an argumentative one. Recent evidence would seem to support the fact that such a relationship might exist but that it is indirect. The relationship does not seem due to an inborn error of free radical scavenger enzyme metabolism. Anticonvulsants play a role, as they influence free radical generating systems. At this juncture, no one has studied the relationship of anticonvulsant therapy, neuronal ceroid-lipofuscinosis, and the free radical-scavenging enzyme system, and their interplay. We have studied a large number of patients with epilepsy who are on either monotherapeutic or polytherapeutic regimens of most of the common anticonvulsants. We have found excessive free radical production in many of these patients, ranging from minor effects in the simpler anticonvulsants when used monotherapeutically, to more complex changes in polytherapeutic combinations. Likewise, we have found subtle and inconsistent findings in the free radical-scavenging enzyme system in a variety of examples of neuronal ceroid-lipofuscinosis. When refractory seizure disorders stimulate the vigorous use of polytherapy with a variety of free radical-facilitating anticonvulsants, free radical production becomes deleterious. Likewise, in certain types of neuronal ceroid-lipofuscinosis, polypharmacy with anticonvulsants, by enhancing the production of free radicals or suppressing scavenging enzymes, tends to be deleterious and induces a worsening in the disease process.

Thirty-seven patients with previously untreated absence seizures were treated with ethosuximide. Seizures were completely controlled in 7 patients (19 percent); 90 to 100 percent control was achieved in 18 patients (49 percent) and 50 to 100 percent control in 35 (95 percent). Plasma ethosuximide concentration increased with dose, but variability in the plasma concentration produced by a given ethosuximide dose made it impossible to predict a patient's plasma concentration from the dose. The therapeutic range of plasma ethosuximide concentration was 40 to 100 mug per milliliter. Patients with evidence of structural central nervous system abnormalities responded as well or better to the drug as patients without such evidence. Ethosuximide did not impair psychometric performance, but rather resulted in improved performance in 17 cases. The side effects of ethosuximide were minor, and rarely required withdrawal of the drug.

Subacute sclerosing panencephalitis (SSPE) is a progressive, essentially untreatable, disease of the nervous system. When first described in the 20th Century, it was characterized more for its neuropathological features than for its pathophysiology or cause. It was not until the 1960s that a clear relationship to the measles virus was established. It is now thought that this uncommon infectious encephalopathy is caused by a "slow," altered or persistent form of the wild measles virus which has harbored in the nervous system for years. Then a "breakout" occurs and the more lytic and virulent organisms produce the progressive and spreading inflammatory and destructive lesions which are confined to the nervous system. Epidemiological study of the disease confirms its relationship to measles. In the years since the development of national measles immunization programs, there has been a dramatic decline in the incidence of measles exanthem and until recently a corresponding decline in the incidence of SSPE. In recent years there has been a mild to moderate increase in cases of SSPE as reported to the USA/International SSPE Registry. As yet, there has not been a totally effective treatment. The purpose of this paper is to give an overall review on SSPE and its relationship to measles. This review will include a prospectus of its history, considerations as to its etiology, correlation of clinicopathological features, and thoughts on the past and present epidemiology and treatment.

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Clonazepam, a chlorinated derivative of nitrazepam, was administered to 10 children with absence seizures. Serum concentrations were measured after 8 weeks of treatment, at steady state. Seizure frequency reports and the 12-hour telemetered electroencephalogram were studied before and after 8 weeks of treatment to determine the frequency and duration of generalized spike-wave paroxysms. The clonazepam dosage ranged from 0.028 to 0.111 mg per kilogram and was reflected in serum levels ranging from 13 to 72 ng per milliliter, with an excellent correlation between dose and serum level. Eight of the 10 patients showed a significant decrease in seizure frequency, with three experiencing no seizures at all. Six patients had side effects, predominantly drowsiness and ataxia. This preliminary study shows clonazepam to be useful in the treatment of absence seizures in children and to merit further study.

During the past five years, 15 patients with subacute sclerosing panencephalitis (SSPE) were treated with inosiplex. Using a disability index specifically designed for the disease, this study monitored the course of SSPE in each patient before and during inosiplex therapy. Posttreatment follow-up ranged from 2 to 144 months. Inosiplex had an apparently beneficial effect on morbidity and mortality in 10 of the 15 patients tested. Eight improved immediately after treatment, 2 had a delayed improvement, and 1 patient stabilized. Four patients followed a typical course for SSPE and died a mean 9 months after onset. Treatment was not associated with adverse reactions. Due to its low risk-benefit ratio, inosiplex is recommended for continuous use in SSPE even after extended remissions.