Relapse of herpes encephalitis after acyclovir therapy: report of two new cases and review of the literature.

Relapse of herpes simplex virus (HSV) encephalitis following acyclovir therapy has been reported infrequently in children beyond the neonatal period. The pathogenic mechanism of the recurrence is not fully understood. We report two new cases that support a mechanism of latent HSV infection with reactivation of the disease. Our patients were 2 years (#1) and 8 months (#2) old at initial infection. Both presented with fever, lethargy, focal seizures, and focal motor abnormalities. Serum HSV antibodies (Abs) were negative. The patients were treated with acyclovir for 14 and 21 days, respectively. They were readmitted at 1 month, and 4 days after discharge, respectively, with recurrent lethargy, seizures, and choreo-athetoid movements. Serum and CSF HSV Abs were significantly increased. CSF PCR was positive. In patient # 2 acyclovir-sensitive HSV was isolated from a brain biopsy. Both patients were re-treated with acyclovir, but progressed to a neurovegetative state. In our cases, latent HSV infection and reactivation is the most likely explanation for recurrent encephalitis. The immuno-pathogenic mechanisms of the infection recurrence are discussed. Based on the reported cases in the literature, patients younger than 2 years of age and with lower total dose of acyclovir treatments have a higher risk of recurrence.

Comparison of MRI and MRA findings in children with a variety of neurologic conditions.

The role of MRA in the evaluation of children is evolving. We compared MRA and MRI in children with a variety of neurologic conditions to determine when MRA provides positive, cost-beneficial information. A total of 114 patients were retrospectively studied. MRA and MRI were performed and compared. MRA was abnormal in 34 (30%) of 114 patients: five (83%) of six with Menkes' disease, four (33%) of 12 with sickle cell disease, 12 (38%) of 32 with vascular malformations, one (6%) of 17 with headaches, seven (24%) of 24 with new focal deficits, one (10%) of 10 with seizures, and four (31%) of 13 with miscellaneous diagnoses. MRA and MRI were concordant in 73 (64%) of 114. Maximum concordance was in patients with Menkes' disease (100%) and minimum in those with new focal deficits (50%). The best MRA cost/benefit ratios were obtained in patients with Menkes' disease, vascular malformations, and sickle cell disease. A normal MRI usually forecasted a normal MRA. However, abnormal MRI findings did not always predict MRA abnormalities. Positive, cost-beneficial information is provided by MRA mostly in conditions known to involve the cerebral vasculature. Indications to perform MRA should be based on the neurologic diagnosis and MRI findings.

West syndrome in tuberous sclerosis complex.

West syndrome occurs commonly in children with tuberous sclerosis complex and is associated with a grave prognosis for cognitive and seizure outcomes. We sought to determine the epilepsy outcome of children with tuberous sclerosis complex and West syndrome and whether EEG, MRI, or steroid therapy duration were different in those whose epilepsy improved compared with those with intractable seizures. Seventeen patients with tuberous sclerosis complex and West syndrome were identified. For each patient, two sets of clinical evaluations, EEG and MRI data, and treatment information separated by at least 12 months were obtained. The patients were divided into two seizure outcome groups. EEG, MRI, and treatment data were compared between the groups. The intellectual deficiency was either severe (76%) or moderate (24%). Seizure control improved in 10 and worsened in seven, without mortality (follow-up range = 12-216 months). No significant differences in EEG background, MRI findings, or steroid treatment duration were evident between the groups. The difference in EEG-sleep approached statistical significance (P = 0.06). Our findings did not confirm reports of high mortality and poor epilepsy outcome in intellectually deficient children with West syndrome and tuberous sclerosis complex. EEG sleep was the best indicator of seizure control and approached statistical significance. The duration of steroid therapy had no influence on seizure control.

Tuberous sclerosis complex and epilepsy: prognostic significance of electroencephalography and magnetic resonance imaging.

Tuberous sclerosis complex is a disease that affects many organs, including the central nervous system. Nervous system involvement in the form of hamartomas often results in seizures. In this study we wanted to determine the outcome of epilepsy in tuberous sclerosis complex and determine whether interictal electroencephalograms (EEGs) and hamartoma burden as seen with magnetic resonance imaging (MRI) are predictive of degree of seizure control. The study population consisted of 30 patients. For each patient two sets of EEG and MRI data, separated by at least 12 months, and information on seizure frequency at time of data collection were obtained. Sensitivity, specificity, and positive and negative predictive values of various EEG and MRI findings were determined. Seizure control improved in 20 and worsened in 10 patients. In relation to seizure control, the specificity of an abnormal sleep EEG and the positive predictive value of normal sleep EEG were 100%. MRI and EEG background were neither sensitive nor specific for predicting seizure control. A majority of children with tuberous sclerosis complex can achieve good seizure control. The sleep EEG is helpful in predicting eventual seizure control.

Long-term computer-assisted outpatient electroencephalogram monitoring in children and adolescents.

The aims of this study were (1) to define the role of long-term computer-assisted outpatient electroencephalographic monitoring (COEEG) in children and adolescents with known or suspected epilepsy, and (2) to compare COEEG data with routine interictal electroencephalograms (EEG). We performed 18-channel COEEG in 84 children and adolescents with diagnosed (group 1, n = 49) or suspected (group 2, n = 35) epilepsy. Mean recording time was 1.4 days. Overall, COEEG was useful in 87% of patients. In group 1, events were recorded in 73% of patients and were electrographic seizures in 45%. In group 2, events were detected in 86% of patients and were electrographic seizures in 17%. Nocturnal and partial seizures predominated. Seizure diagnosis and classification by COEEG was concordant with interictal EEG findings in 19% and discordant in 63% of patients. COEEG is a useful technique for the diagnosis of epileptic and nonepileptic events among selected children and adolescents. When compared to routine interictal EEG, COEEG could offer additional accuracy in the classification of seizures in pediatric patients.

Patterns of hematopoietic lineage involvement in children with neurofibromatosis type 1 and malignant myeloid disorders.

Children with neurofibromatosis type 1 (NF1) are at increased risk of developing malignant myeloid disorders, particularly juvenile chronic myelogenous leukemia/juvenile myelomonocytic leukemia (JCML/JMML). We investigated bone marrows from 11 such patients (8 boys and 3 girls) and detected allelic losses at the NF1 locus in 4 of them and probable losses in 2 others. To determine which hematopoietic cell lineages were derived from the abnormal clones, Epstein-Barr virus (EBV)-transformed cell lines and CD34+ cells were analyzed from 3 children with JCML with allelic losses in unfractionated marrow. CD34 cells from these 3 patients lacked the normal NF1 allele, whereas EBV cell lines retained it. Erythroblasts plucked from the burst-forming unit-erythroid colonies of one of these children lacked the normal NF1 allele. We also studied a 10-month-old boy with NF1 who developed an unusual myeloproliferative syndrome. His bone marrow and EBV cell line both showed loss of the normal NF1 allele. In our series and in the literature, male sex and maternal transmission of NF1 were associated with the highest risk of myeloid leukemia. These data (1) provide strong genetic evidence that NF1 functions as a tumor-suppressor in early myelopoiesis, (2) confirm the clonal nature of JCML/JMML, (3) suggest that the elevation in fetal hemoglobin seen in JCML/JMML is a result of primary involvement of erythroid progenitors in the malignant clone, (4) show consistent loss of NF1 in the CD34 cells of affected children and show that the malignant clone may also give rise to pre-B cells in some cases, and (5) implicate epigenetic factors in the development of leukemia in children with NF1.

Comparison of coronal sphenoidal versus standard anteroposterior temporal montage in the EEG recording of temporal lobe seizures.

Chronic sphenoidal electrodes were developed to facilitate the recording and localization of temporal lobe seizures during long term monitoring. Many reports demonstrate their utility in displaying temporal interictal epileptiform activity, but there have been few direct comparisons of sphenoidal electrodes and surface temporal recordings actually. We compared simultaneous portions of 74 EEG recordings of temporal lobe seizures (from 42 patients), with one portion including sphenoidal electrodes in a coronal montage and one with a standard anterior posterior temporal montage. Separated tracings were reviewed by readers blinded to the other portion of the tracing. The coronal sphenoidal montage allowed recognition of temporal lobe seizures inapparent with standard surface temporal electrodes in 19% of seizures and led to an earlier identification (usually by > or = 5 s) of the onset in 70% of seizures. Indwelling, flexible sphenoidal electrodes assist in ambulatory recording of temporal lobe seizures, both in demonstrating the presence of seizures and in determining the localization and time of seizure onset.

Diagnostic value of pediatric outpatient video-EEG.

Outpatient video-electroencephalography (OVEEG) was performed in 100 infants, children, and adolescents with diagnosed (group I, n = 64) or suspected (group II, n = 36) epilepsy. Median monitoring duration was 4 hours. Indications for OVEEG in group I were classification of seizures, reported seizure exacerbation, or onset of new signs. OVEEG indications in group II were repetitive paroxysmal and stereotyped signs of myoclonic movements, fixed gaze, abnormal behavior, or nonmyoclonic motor activity. In group I patients, symptomatic events were recorded in 89%, half of which were seizures. Among group II patients, events were recorded in 67% and were seizures in 22%. Overall, OVEEG was successful in 83% of patients. Compared to a 24-hour inpatient admission for video-EEG monitoring, OVEEG represented cost reductions of 55-80% per patient. We conclude that OVEEG is a cost-effective, useful alternative to continuous inpatient video-EEG monitoring in the investigation of selected infants, children, and adolescents with diagnosed or suspected epilepsy.

Neonatal adrenoleukodystrophy presenting as infantile progressive spinal muscular atrophy.

Two siblings with neonatal adrenoleukodystrophy are described. The signs and laboratory data documenting infantile progressive spinal muscular atrophy included the initial presentation of 1 sibling with neonatal adrenoleukodystrophy. These patients indicate that neonatal adrenoleukodystrophy should be considered in the differential diagnosis of infantile progressive spinal muscular atrophy.

Benign neonatal seizures.

Benign neonatal seizures is a rare but increasingly recognized syndrome characterized by seizures in the neonatal or infantile period. Two forms are recognized: familial and nonfamilial. In both instances, the seizures may be quite severe, and status epilepticus is common. The nonfamilial form is characterized by idiopathic, self-limited seizures occurring in previously normal neonates. The seizures most commonly occur at day 5 and have been called "fifth-day fits" by some authors. Familial seizures most frequently have their onset during the first week of life, but onset may occur as late as early infancy. These seizures may recur for several months before resolving. No cause is found for the seizures, and the patient appears healthy during the interictal period. The family history reveals benign neonatal seizures in other family members. Although the prognosis is favorable in both syndromes, seizures may occasionally occur later in life in the familial form. The familial form of benign neonatal seizures is autosomal dominant, and the gene has been localized to chromosome 20.