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Biomedical subjects

S Shinnar

Publications and source records attributed to S Shinnar.

At least 109 records · Page 6Linked to original sources

The risk of seizure recurrence following a first unprovoked seizure: a quantitative review.

Knowledge of the recurrence risk following a first unprovoked seizure and the predictors of that risk are necessary for rational treatment decisions. Published estimates of recurrence risk range from 23% to 71%. In a meta-analysis of 16 reports, three methodologic factors explained much of the reported variation: (1) study inclusion criteria, ie, whether patients were enrolled at the time of their first seizure or if patients with prior seizures were included; (2) retrospective versus prospective ascertainment of patients; (3) the interval between the first seizure and the time at which risk was assessed. The average recurrence risk across the 16 studies was 51%. The risk was 40% and 52% in prospective and retrospective studies that employed first-seizure methods and 67% in non-first seizure studies. At or near 2 years following the first seizure, the recurrence risk was 36% and 47% in prospective and retrospective first-seizure studies. The distribution of prognostic factors was also important. Seizure etiology and the EEG were the strongest predictors of recurrence distinguishing between patient subgroups, with recurrence risks as low as 24% and as high as 65%. Partial seizures were associated with an increased recurrence risk, but not consistently. There is considerable agreement among studies concerning the recurrence risk following a first seizure, and much of the discrepancies among studies can be explained by differences in study methods and distributions of important prognostic factors.

Age Factors↗

Autistic and dysphasic children. I: Clinical characteristics.

Autism and dysphasia are behaviorally defined disorders of higher cerebral function which in preschool children share the common core symptom of impairment of language. In this study we describe the clinical characteristics of 314 autistic and 237 dysphasic nonautistic children evaluated by one child neurologist. There was no significant difference between autistic and dysphasic children in gestational age, birth weight, or prevalence of associated medical disorders, all of which were infrequent, although a positive history of resuscitation or ventilatory support was more common in dysphasic than autistic children (P = .03). As a group autistic children are more likely than dysphasic children to have language subtypes affecting central processing and formulation, a family history of psychiatric disorders and autism, and a history of regression of language and behavior. After excluding 12 girls with autistic symptoms who met the clinical criteria for Rett syndrome, we found that there was no significant difference in the number of autistic and dysphasic children with an abnormal sensorimotor examination. Girls with autism were more likely than boys to have severe mental deficiency (38% of autistic girls vs 23% of boys) (P = 0.012) and a motor deficit (27% vs 11%) (P = .0009).

Aphasia↗

Autistic and dysphasic children. II: Epilepsy.

In a previously described population of 314 autistic and 237 dysphasic nonautistic children, after exclusion of 12 autistic girls with Rett syndrome, 14% (42 of 302) of autistic children and 8% (19 of 237) of dysphasic children had epilepsy (P = .03). The major risk factors for epilepsy were severe mental deficiency and the combination of severe mental deficiency with a motor deficit. In autistic children without severe mental deficiency, motor deficit, associated perinatal or medical disorder, or a positive family history of epilepsy, epilepsy occurred in 6% (10 of 160) which was analogous to the 8% (14 of 168) found in similar dysphasic nonautistic children. The language subtype of verbal auditory agnosia is associated with the highest risk of epilepsy in autistic (41%, 7 of 17) and dysphasic (58%, 7 of 12) children. The higher percentage of epilepsy in autistic girls, 24% (18 of 74) compared with boys 11% (25 of 228) (P = .003), is attributed to the increased prevalence of cognitive and motor deficit in girls. Once the risk attributable to associated cognitive and motor disabilities is taken into account, there is no difference in the risk of epilepsy between autistic and nonautistic dysphasic children.

Aphasia↗

Predictors of recurrent febrile seizures: a metaanalytic review.

The 1980 National Institutes of Health Consensus Development Conference on Febrile Seizures identified five circumstances in which it might be appropriate to consider anticonvulsant prophylaxis after a first febrile seizure: (1) a focal or prolonged seizure, (2) neurologic abnormalities, (3) afebrile seizures in a first-degree relative, (4) age less than 1 year, and (5) multiple seizures occurring within 24 hours. We performed a metaanalysis of 14 published reports to evaluate the strength of association between each of these indications and recurrent febrile seizures. Young age at onset (less than or equal to 1 year) and a family history of febrile seizures (not listed in the recommendations) each distinguished between groups with approximately a 30% versus a 50% risk of recurrence. Family history of afebrile seizures was not consistently associated with an increased risk. Focal, prolonged, and multiple seizures were associated with only a small increment in risk of recurrence. The data were not adequate to assess the risk associated with neurologic abnormalities. By considering children with combinations of risk factors, some studies were able to distinguish between groups with very low and very high recurrence risks. Only age at onset was consistently predictive of having more than one recurrence. These results suggest that the great majority of children who have a febrile seizure do not need anticonvulsant treatment even if one of the factors listed in the Consensus Statement is present, and that the rationale and indications for treating febrile seizures need to be reconsidered.

Age Factors↗

Febrile status epilepticus.

As part of a study of status epilepticus in children (Maytal J, Shinnar S, Moshe SL, Alvarez LA. Pediatrics. 1989; 83:323-331); 44 children with febrile convulsions lasting more than 30 minutes were followed for a mean of 28 months (range 4 to 72). Thirty children were followed prospectively. Children with prior afebrile seizures or evidence of acute central nervous system infection were excluded. Nine (20%) children had prior neurological deficits. The duration of the febrile seizure was 0.5 to 1 hour in 41 cases (85%), 1 to 2 hours in 5 (10%), and greater than 2 hours in 2 children (5%). No child died or developed new neurological deficits following the seizures. The risk of recurrent seizures was increased, but only in the group with prior neurological abnormality. Six (66%) of these children had subsequent febrile seizures compared with 12 (34%) of the normal children (P = .08). Three (33%) had recurrent febrile status epilepticus compared with only 1 (3%) normal child (P = .023). The 2 children in the prospective arm of the study with recurrent febrile status epilepticus were both neurologically abnormal (P = .035). All 3 of the children who subsequently had afebrile seizures (2 prospective) were neurologically abnormal (P = .006 overall, P = .035 for prospective only). It is concluded that the occurrence of febrile status epilepticus in a neurologically impaired child is a risk factor for subsequent febrile as well as afebrile seizures. The occurrence of febrile status epilepticus in an otherwise normal child does not significantly increase the risk for subsequent febrile (brief or prolonged) or afebrile seizures in the first few years following the episode.

Child↗

Risk of seizure recurrence following a first unprovoked seizure in childhood: a prospective study.

In a prospective study, 283 children who presented with a first unprovoked seizure were followed for a mean of 30 months from the time of first seizure. Subsequent seizures were experienced by 101 children (36%). The cumulative risk of seizure recurrence for the entire study group was 26% at 12 months, 36% at 24 months, 40% at 36 months, and 42% at 48 months. The cumulative risk of recurrence in the 47 children with a remote symptomatic first seizure was 37%, 53%, and 60% at 12, 24, and 36 months, respectively, compared with a cumulative risk of 24%, 33%, and 36% at 12, 24, and 36 months, respectively, in the 236 children who had had an idiopathic first seizure (P less than .01). In children with an idiopathic first seizure, the electroencephalogram was the most important predictor of recurrence. The cumulative risk of recurrence in the 81 children with abnormal electroencephalograms was 41%, 54%, and 56% at 12, 24 and 36 months, respectively, but only 15%, 23%, and 26% at 12, 24, and 36 months, respectively, in the 138 children with normal electroencephalograms (P less than .001). A history of epilepsy in a first-degree relative was a significant risk factor only in idiopathic cases with abnormal electroencephalograms. In children with a remote symptomatic first seizure, either a history of prior febrile seizures or the occurrence of a partial seizure were significant predictors of recurrence. Age at first seizure and duration of seizure did not affect recurrence risk in either the idiopathic or remote symptomatic group. A total of 84% of the children were not treated with antiepileptic drugs or were treated for less than 2 weeks. Only 9% were treated for longer than 3 months. Treatment did not affect the risk of recurrence. The results suggest that, even without treatment, the majority of children with a first unprovoked seizure will not experiment a recurrence. Children with an idiopathic first seizure and a normal electroencephalogram have a particularly favorable prognosis.

Adolescent↗

Ethical issues in the use of anencephalic infants as organ donors.

For many, the ethical issues raised in the previous sections are sufficient to justify opposition to tampering with either the dead-donor rule or the definition of death in general and the use of anencephalic infants as organ donors in particular regardless of how many organs could be procured. Others will see it as a question of balancing the relative costs and benefits of the proposal. Given, the likely bad consequences and meager benefits, these protocols are difficult to justify on those grounds as well. The proposals of waiting until brain death has occurred also pose some serious, though not necessarily insurmountable, ethical problems. With supportive care, however, anencephalic infants do not become brain dead in the first week of life. Given the declining incidence of anencephaly, the issue regarding anencephalic infants will probably become moot in the next few years. As the need for organ donors continues to grow, we will undoubtedly be faced with future proposals to harvest vital organs from other "unique" categories of dying or severely impaired patients. We believe that the current dead donor rule and the strict "whole-brain" definition of death are sound public policy and good ethics and should remain the cornerstone of future decisions in this field.

Anencephaly↗

Low morbidity and mortality of status epilepticus in children.

In an ongoing study of status epilepticus, 193 children with status epilepticus of varying causes have been followed up for a mean period of 13.2 months. Of these, 97 patients were recruited prospectively. The patients' ages ranged from 1 month to 18 years (mean, 5.0 years). The cause of the status epilepticus was classified as idiopathic in 46 cases, remote symptomatic in 45, febrile in 46, acute symptomatic in 45, and progressive neurologic in 11. The mortality and incidence of sequelae following status epilepticus was low and primarily a function of etiology. Seven children died within 3 months of having the seizure. New neurologic deficits were found in 17 (9.1%) of the 186 survivors. All of the deaths and 15 of the 17 sequelae occurred in the 56 children with acute or progressive neurologic insults. Only two of the 137 children with other causes sustained any new deficits (P less than .001). Duration of the status epilepticus affected outcome only within the acute symptomatic group (P less than .05). Neurologic sequelae occurred in 29% of infants younger than 1 year of age, 11% of children 1 to 3 years of age, and 6% of children older than 3 years of age. However, this was a reflection of the greater incidence of acute neurologic disease in the younger age groups. Within each cause, age did not affect outcome. Of the 193 children, 61 (32%) had a history of prior unprovoked seizures. Of the 125 surviving children with no history of prior unprovoked seizures, 37 (30%) had subsequent unprovoked seizures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Elevation of serum beta-hexosaminidase and alpha-D-mannosidase in type 2 Gaucher disease: a clinical and biochemical study.

We report a case of a black infant who died at 9 months of age with clinical and pathological findings consistent with the acute neuronopathic form of Gaucher disease (Type 2). Analysis of peripheral blood platelets obtained from this child demonstrated very low levels of beta-glucosidase activity. beta-hexosaminidase (HEX) activity in the serum, however, was 30 times greater than the level in control sera and 15 times greater than the level observed in individuals affected with the chronic form of Gaucher disease (Type 1). Similarly, alpha-D-mannosidase (MANN) activity in the proband's serum was significantly elevated when compared with controls, and chronic Gaucher disease patients. We postulate that the cause of the elevation of these lysosomal enzymes is similar to the cause of elevation in Type 1 individuals but that patients with Type 2 Gaucher disease have a more serious cellular defect.

Blood Platelets↗

Antiepileptic drugs in adolescents.

Adolescence is a critical developmental period in which major metabolic changes occur. The majority of adolescents with epilepsy can be fully controlled with medications and can lead productive lives. A knowledge of basic principles of pharmacotherapy with AEDs will enable the physician to treat effectively most adolescents with epilepsy.

Adaptation, Psychological↗

Venous malformation mimicking a posterior fossa tumor in a young child.

Symptomatic venous malformations are uncommon at any age. They are extremely rare in the first decade of life. We describe a 3.5-year-old child with a cerebellar venous malformation presenting with a subacute course mimicking the more common posterior fossa tumors. The child's symptoms were due to a posterior fossa hemorrhage; she subsequently did well. The clinical, CT, angiographic, and pathologic features are described. Venous malformations should be included in the differential diagnosis of young children with evidence of posterior fossa disease.

Cerebellar Neoplasms↗

External hydrocephalus: radiologic spectrum and differentiation from cerebral atrophy.

External hydrocephalus (EH) is a condition in which infants with rapidly enlarging heads are found to have a CT scan that shows widening of the subarachnoid space with mild or no ventricular dilation. In this study, 74 infants with EH associated with a variety of conditions were examined clinically and with CT scans to identify the radiologic features of the condition as well as to understand its clinical and radiologic evolution. Some of these CT scans were compared with those of patients with cerebral atrophy. The characteristic CT findings in EH were bifrontal widening of the subarachnoid space and widened interhemispheric fissure frontally with only mild enlargement of the rest of the subarachnoid space. Occasional mild to moderate ventriculomegaly was also present. In most cases the radiologic findings could be distinguished from those seen in cerebral atrophy, even without the clinical history of an enlarging head. The cases of cerebral atrophy showed prominent sulci throughout without disproportionate bifrontal widening of the subarachnoid space. Two major groups of infants are identified. The largest group (47) consisted of infants with primary megaloencephaly. Megaloencephaly was idiopathic in 40 infants, many of whom (19) met the criteria for benign familial macrocephaly. Others (7) had a clearly defined genetic syndrome. The radiologic abnormalities in these infants usually disappear by 2 years of age. The other major group (14) consisted of infants who sustained CNS or systemic insults such as subdural hematomas (8) or meningitis (3), which cause impaired CSF absorption. Thirteen premature infants with EH were also identified. It is concluded that EH is an age-related self-limited condition occurring in infants with open cranial sutures and that usually resolves without intervention by 2-3 years of age.

Atrophy↗

Idiopathic external hydrocephalus: natural history and relationship to benign familial macrocephaly.

External hydrocephalus was identified in 63 infants. The 36 infants in whom external hydrocephalus was idiopathic constitute the study population. The group was homogeneous. Although not all were macrocephalic at birth, the head circumference exceeded the 95th percentile in all cases by 1 year of age, and subsequent head growth was parallel to the 95th percentile. The head computed tomographic scan showed a characteristic picture of a prominent interhemispheric fissure, a collection of subarachnoid fluid over the frontal convexities, and prominent basal cisternae. Mild ventriculomegaly was present in ten cases. These abnormalities resolved after 18 to 24 months of age. No infant required therapy for the condition. Development was normal in 32 infants, suspect in three, and clearly abnormal in only one of the 36 infants. However, of the 32 infants with normal development, 14 were found to be delayed in gross motor development and five in language development at a prior time. There was a family history of macrocephaly in 88% of cases. Several families had a mixture of members with external hydrocephalus and benign familial macrocephaly throughout several generations. These findings suggest that idiopathic external hydrocephalus is a relatively benign, self-limited condition that resolves without treatment and is closely related to benign familial macrocephaly.

Black People↗