We evaluated adenine arabinoside (vidarabine) for treatment of herpes simplex encephalitis in a placebo-controlled study. In 28 cases proved by isolation of Type 1 virus from brain biopsy, treatment reduced mortality from 70 to 28 per cent (P = 0.03), and over 50 per cent of treated survivors had no or only moderately debilitating neurologic sequelae. This improvement was achieved without evidence of acute drug toxicity. Thus, adenine arabinoside has a good therapeutic index (efficacy/toxicity) for the treatment of Type 1 herpes simplex encephalitis. However, the drug must be given early in the course of infection before the advent of coma to have a beneficial effect. Moreover, it should be coupled with brain biopsy for specific diagnosis to avoid unnecessary treatment of nonresponsive encephalitides that can mimic herpes simplex.

We prospectively compared neuropsychologic functioning and clinical indicators of neurotoxicity in 49 consecutive childhood leukemia patients in long-term continuous complete remission (CR) who had received two different regimens of CNS prophylaxis by random assignment. Twenty-three patients were treated with 1,800 cGy cranial radiation and intrathecal methotrexate (RT group) and 26 with parenteral methotrexate only (MTX group). Over half of the RT group had somnolence syndrome, and four developed cerebral calcifications late in their clinical course. Abnormal electroencephalograms (EEGs) were seen in 15 patients in the MTX group, and six had early, transient white-matter hypodensities apparent on computed tomographic (CT) scans. Mean scores on standard tests of intelligence and academic achievement, administered after remission induction and again at a median of 6 years after treatment cessation, did not differ significantly between the two groups. However, statistically significant decreases in overall and verbal intelligence quotients (IQs) and in arithmetic achievement were found within both treatment groups. Sixteen of 26 in the MTX group and 14 of the 23 in the RT group had clinically important decreases (greater than or equal to 15 points) on one or more neuropsychologic measures. These changes did not correlate with findings on CT scans, EEGs, or other clinical signs of neurotoxicity. We conclude that 1,800 cGy cranial radiation and parenteral methotrexate, as used in this study, are associated with comparable decreases in neuropsychologic function.

We evaluated adenine arabinoside treatment of herpes zoster in immunodeficient patients in a randomized, controlled crossover study. The two study groups had similar characteristics. In spite of rapid natural healing, those receiving adenine arabinoside over the first five days had accelerated clearance of virus from vesicles (P = 0.01), and cessation of new vesicle formation (P = 0.004), and a shorter time to total pustulation (P = 0.001). Factors modifying the response to therapy included age, underlying disease, and the duration of zoster prior to therapy. Clinical toxicity was minimal. Laboratory assessment of bone-marrow, liver and renal function showed insignificant alterations as a result of therapy. These studies show that adenine arabinoside is a drug with promise for therapy of systemic herpes zoster in immunocompromised patients. It is most efficacious when administered during the first six days of disease (P = 0.001) to those who have reticuloendothelial neoplasia (P = 0.001) and are less than 38 years of age (P = 0.001).

Cerebrospinal fluid from 582 persons was analyzed by a double-antibody radioimmunoassay for the presence of material cross-reactive with peptide 43-88 of human myelin basic protein (BP). In a group of 104 patients with multiple sclerosis (MS), 23 of 33 individuals clinically judged to have had an exacereation within two weeks prior to the time CSF was obtained had detectable material ranging from 2 to 200 ng/ml. In the remaining 71 MS patients who either were stable or had had an exacerbation more than two weeks before, only 1 patient had a marginally elevated level of immunoreactive material. CSF from 53 persons with cerebrovascular disease was studied, and 13 of 29 with recent infarctions had values of 2 to 540 ng/ml. The degree of elevation in strokes generally paralleled the predicted volume of the lesion, but the amounts detected did not correlate quite so closely temporally with onset as they did with the periods of active disease in MS. Of the remaining 425 patients, 29 had immunoreactive material of 2 to 400 ng/ml in their CSF. Most of these patients with detectable material had acute diseases known to affect the myelin sheath. Eight of 10 persons with acute disseminated encephalomyelitis had no detectable material. The presence in CSF of material cross-reactive with BP peptide 43-88 does not have diagnostic specificity for MS but can be used as a means for determining recent myelin injury. The type of BP peptide formed and mechanisms for clearance of BP and BP peptides may be important in determining the biological consequences following release of this potentially immunogenic material from the central nervous system.