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Biomedical subjects

K B Nelson

Publications and source records attributed to K B Nelson.

At least 73 records · Page 4Linked to original sources
PubMed1986

Do seizures in children cause intellectual deterioration?

We studied whether the occurrence of seizures in childhood affected intellectual performance. We compared the full-scale IQs at seven years of age of children who had experienced one or more nonfebrile seizures with the IQs of their seizure-free siblings who were tested at the same age in a large longitudinal study. Among 98 children with seizures, the mean score on IQ tests at seven years was not significantly different from the mean score of their siblings. Mental retardation was more common among the children with seizures, but the excess was accounted for by children who had neurologic abnormalities before the first seizure. We also examined the IQ before and after the onset of seizures in 62 children whose first seizure occurred in the interval between psychometric examinations given at four and seven years of age. The IQ at seven years in the children with seizures did not differ significantly from that in controls matched for IQ (as determined at the four-year assessment), sex, race, and socioeconomic status. Thus, in both the sibling-control comparison and the comparisons made between controls and subjects before and after the onset of seizures, the occurrence of nonfebrile seizures was not associated with a significant change in full-scale IQ.

Anticonvulsants↗
PubMed1986

Survey on the management of febrile seizures.

A survey regarding the management of the child with febrile seizures was mailed to 10 000 child neurologists, neurologists, pediatricians, and family and general practitioners. The response rate varied by specialty; overall, slightly more than half the physicians responded. One third or less of physicians prescribed anticonvulsive therapy only at the time of febrile illness, although this practice was much less common among recent graduates. If children had lengthy or focal seizures, the majority of physicians in all specialties either prescribed long-term treatment or referred for consultation. Long-term daily anticonvulsant therapy was prescribed most frequently by child neurologists and least often by general practitioners, who most often referred for consultation. Rate of hospitalization also differed according to specialty. The results of the survey indicate that the management of a child with febrile seizures may differ depending on the specialty of the attending physician.

Anticonvulsants↗
PubMed1986

Antecedents of seizure disorders in early childhood.

One or more nonfebrile seizures occurred between the ages of 1 month and 7 years in eight per 1000 white and in nine per 1000 black children enrolled in a large prospective study. We examined hundreds of prenatal and perinatal factors as predictors of childhood seizure disorders. Congenital malformations of the fetus (cerebral and noncerebral), family history of certain neurologic disorders, and neonatal seizures were the major predictors identified. Forty percent of children with postneonatal seizures and 68% of children with minor motor seizures had one or more of these risk factors compared with 21% of the seizure-free population. More than half of the children with minor motor seizures and a third of the infants with neonatal seizures had congenital malformations. Based on the prenatal and perinatal factors examined, prediction of postneonatal seizures carried a high rate of false-positive identification, indicating that our knowledge of the etiology of childhood seizure disorders is still very limited.

Child↗
PubMed1985

Predictors of low and very low birth weight and the relation of these to cerebral palsy.

In a large prospective study, we investigated predictors of moderately low (1,501 to 2,500 g) and very low (less than 1,501 g) birth weight. Maternal age, height, and socioeconomic status, related to moderately low birth weight on univariate analysis, were not on multivariate analysis significant predictors for either low-birth-weight outcome. The leading predictors of very low birth weight were low weight (less than 2,000 g) of last live birth, fetal malformation, nonwhite race, early vaginal bleeding, cigarette smoking, and chorionitis. Some of these were also predictors of moderately low birth weight. About 20% of births under 1,501 g could be attributed to chorionitis, a characteristic of less than 3% of the births. Of the major predictors of low birth weight, only prolonged rupture of membranes, chorionitis, and congenital malformations contributed to the risk of cerebral palsy beyond their contribution to the risk of low birth weight.

Cerebral Palsy↗
PubMed1985

Antecedents of cerebral palsy. I. Univariate analysis of risks.

A large prospective study investigated prenatal and perinatal antecedents of chronic motor dysfunction (cerebral palsy [CP]), evaluating approximately 400 characteristics of the mothers, pregnancies, or deliveries. In addition to confirming some, but not all, of the classic risk factors for CP, this study observed relatively large increases in the CP rate in association with maternal mental retardation, seizure disorders, hyperthyroidism, or with the administration of thyroid hormone and estrogen in pregnancy. Some risk factors were predictive of CP only insofar as they were associated with low birth weight or low Apgar scores. Among factors not significantly related to CP rate were maternal age, parity, socioeconomic status, smoking history, maternal diabetes, first trimester vaginal bleeding, kidney or bladder infection, moderate hypertension, long cord, use of anesthetic agents, or use of oxytoxics for initiation or augmentation of labor. Duration of labor, whether precipitate or prolonged, was not a risk factor for CP.

Anti-Bacterial Agents↗
PubMed1984

Obstetric complications as risk factors for cerebral palsy or seizure disorders.

In a prospective study, late obstetric complications were common, one or more occurring in 62% of 51,285 pregnancies. We examined these complications as risk factors for cerebral palsy (CP) or nonfebrile seizure disorders. Certain complications were associated with an increased rate of CP, but in babies over 2,500 g, the observed rate of CP did not exceed 2% following any condition evaluated. For most conditions, the CP rate was highest in the small subgroup of children who had five-minute Apgar scores of 3 or less. Most babies over 2,500 g born after each complication achieved five-minute Apgar scores of 7 or higher, and for them the risk of CP was not significantly greater than in children whose births were uncomplicated. Neither the complications considered nor Apgar scores were important antecedents of nonfebrile seizure disorders in children free of CP.

Apgar Score↗
PubMed1984

Age at onset of seizures in young children.

Age at onset of seizures in young children and its relationship to factors such as prior neurological status and neurological outcome were examined. Of 52,360 children, 39,270 of whom were followed for the full 7 years, a total of 2,635 experienced one or more seizures between birth and 7 years of age. The incidence of nonfebrile convulsions was highest in the first year of life, especially in the first month. Children with neonatal seizures who later developed nonfebrile seizures did so early, two-thirds by 6 months and three-quarters by 1 year of age. Children with neurological or developmental abnormality assessed in the first year of life did not have their first seizure earlier than children without abnormality. Neurological abnormality in the first year of life before any seizure, and the presence of minor motor seizures, were associated with an increased rate of mental retardation and cerebral palsy at age 7, but early age at onset appeared to have little prognostic value regarding intellectual function, cerebral palsy, and epilepsy.

Age Factors↗
PubMed1984

The risk of recurrence of nonfebrile seizures in children.

In a prospective study, the risk of recurrence after a first postneonatal nonfebrile seizure was 61% by age 7 years. The risk of recurrence for nonsymptomatic seizures was considerably higher than for seizures attributed to immediate precipitating factors. Focal motor seizures were more likely than generalized motor seizures to recur. Children who had prior neonatal seizures were at greater risk for nonfebrile recurrence than children with no prior seizure. Family history and neurodevelopmental status were not significantly related to recurrence risk. Almost 90% of recurrences took place within 1 year, and 96% within 2 years.

Child↗
PubMed1983

Seizures following childhood immunizations.

In 1.4% of children who experienced a seizure during the first seven years of life, the seizure followed within two weeks of an immunization procedure. We report 40 postimmunization seizures in 39 children enrolled in the Collaborative Perinatal Project. Ten seizures followed diphtheria-pertussis-tetanus (DPT) immunization, and 10 followed measles immunization. All but one of the seizures were associated with fever, often high. Thirty-seven seizures lasted less than 30 minutes. More than half of the children had a personal or immediate-family history of febrile seizures. One of the children had a right focal seizure lasting six hours after DPT immunization and had a significant speech deficit on long-term follow-up. No child developed epilepsy, and results in all children with brief seizures were normal on neurologic and cognitive examination at 7 years of age. Both in clinical presentation and generally benign outcome, these immunization-related seizures closely resemble febrile seizures, which are common in early childhood.

Child↗
PubMed1983

The natural history of febrile seizures.

Febrile seizures are a common occurrence in early childhood and most children who experience them do well. This article reviews the clinical characteristics of febrile seizures, and summarizes the relevant clinical and laboratory research. The natural history of febrile seizures, the recurrence rate, and frequency of later epilepsy or intellectual handicap is presented, and controversies in evaluation and treatment are discussed.

Animals↗
PubMed1982

Maternal seizure disorder, outcome of pregnancy, and neurologic abnormalities in the children.

Among 45,000 pregnant women, 21.4 per 1000 (2.1%) reported at least one seizure before or during pregnancy. During the study pregnancy, 4.4 per 1000 had a noneclamptic seizure, and another 4.5 per 1000 had one in the 5 years preceding the study. Stillbirth, microcephaly, mental retardation, and nonfebrile seizure disorders occurred with heightened frequency in the offspring of women with seizure disorders; low birthweight, neonatal seizures, and first-year deaths were not more common. Approximately 80% of the women with seizure disorders had infants with none of the unfavorable outcomes studied. The observational nature of this and other clinical studies on this topic makes it difficult to evaluate the role of medical therapy in the outcome.

Anticonvulsants↗
PubMed1982

Children who "outgrew' cerebral palsy.

A diagnosis of cerebral palsy was made for 229 one-year-old children enrolled in a large longitudinal study. Of these children, 118 were free of motor handicap at the age of 7 years. Mild early cerebral palsy, and the monoparetic, ataxic/dyskinetic, and diplegic forms of the disorder, resolved with high frequency. Normalization of motor signs was observed more frequently in black than in white children. However, 13% of white children and 25% of black children whose motor signs resolved were mentally retarded (IQ below 70) at 7 years of age. Nonfebrile seizures, abnormalities in speech articulation and extraocular movements, and certain abnormalities of behavior were more frequent among children who "outgrew" cerebral palsy than in the general population of the study.

Age Factors↗
PubMed1981

Early recognition of infants at high risk for cerebral palsy: examination at age four months.

More than 32,000 children in a prenatally-defined cohort were examined four months after birth, and were re-examined at the age of seven years to determine the presence of cerebral palsy. Observations from the examination at four months were investigated as predictors of cerebral palsy, and the most reliable individual sign was increased muscle tone in neck, arms, legs or trunk. On completion of the physical examination at four months, the neurological status of each infant was assessed. Of the children considered to be normal, one in 1000 had cerebral palsy by the age of seven years, compared with one in 100 of those thought to be suspect. Of the children who had been definitely neurologically abnormal at four months, one in seven had disabling cerebral palsy by early school-age. The predictive power of abnormal physical findings increased with the number of abnormal findings with failure to meet motor milestones. Four-month-old infants who passed all milestone measures had a very low rate of later cerebral palsy, even if they had had abnormal physical findings. Examination of four-month-old infants permits the clinician to recognize children at widely different levels of risk of chronic motor handicap.

Body Height↗
PubMed1981

Apgar scores as predictors of chronic neurologic disability.

Apgar scores were recorded at one and five minutes for approximately 49,000 infants, and at ten, 15, and 20 minutes for babies who did not achieve a score of 8 or higher at five minutes. These children were followed to the age of 7 years. Low Apgar scores were risk factors for cerebral palsy, but 55% of children with later cerebral palsy had Apgar scores of 7 to 10 at one minute, and 73% scored 7 to 10 at five minutes. Of 99 children who had Apgar scores of 0 to 3 at ten, 15, or 20 minutes and survived, 12 (12%) had later cerebral palsy; 11 of the 12 were also mentally retarded (in ten, IQ less than 50) and half had seizure disorders. Eight children who survived after having very low late Apgar scores and who did not have cerebral palsy had lesser but significant disabilities. Of the children who had Apgar scores of 0 to 3 at ten minutes or later and survived, 80% were free of major handicap at early school age.

Apgar Score↗
PubMed1980

Sample selection and the natural history of disease. Studies of febrile seizures.

We have compared published reports on the frequency of unfavorable sequelae in a common disorder of childhood, febrile seizures, as ascertained from hospital clinics or referral units, with the frequency as reported from population-based studies. Studies on defined populations, in which the attempt was made to recognize and follow up all affected persons regardless of medical care sought for the condition, are in close agreement and indicate relatively low rates of unfavorable sequelae. Clinic-based studies of febrile seizures have reported disparate results, including high frequencies of adverse outcomes. A possible explanation is that patients in clinic-based studies may not be representative of persons with the disorder in the general population.

Adolescent↗
PubMed1979

Birth weight and gestational age in children with cerebral palsy or seizure disorders.

Birth weight and gestational age of single-born children with cerebral palsy (CP) and those with seizure disorders were compared with norms for 40,000 single-born children in the same prospectively identified population. Low birth-weight and short gestation were important risk factors for CP, but these characteristics were uncommon, and the majority of children with CP were of normal birth weight and term gestational age. Preterm children with CP by age 7 years tended to have been even smaller at birth than was appropriate for their short gestions. Among term infants with later CP, the birth weights of the majority were appropriate for dates, but a subgroup were noticeably small for dates at term. Low birth weight, preterm birth, and smallness for dates at term were not significantly related to the risk of seizure disorders in children free of CP.

Birth Weight↗