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Biomedical subjects

S Shinnar

Publications and source records attributed to S Shinnar.

At least 91 records · Page 5Linked to original sources
PubMed1995

Gabapentin toxicity in children manifesting as behavioral changes.

Pediatric experience with gabapentin (GBP), a new antiepileptic drug (AED), is limited. We described 3 learning disabled children, 1 aged 7 and 2 aged 10 years, with intractable partial seizures who developed severe behavioral problems while receiving modest doses of GBP. The children became hyperactive and had explosive outburst consisting of aggressive and oppositional behavior. The behavioral problems were sufficiently severe to require discontinuation of GBP despite moderately improved seizure control.

Acetates↗
PubMed1995

The genetics of idiopathic generalized epilepsies of adolescent onset: differences between juvenile myoclonic epilepsy and epilepsy with random grand mal and with awakening grand mal.

Both linkage and association studies provide strong evidence that a gene locus on chromosome 6 is involved in the expression of juvenile myoclonic epilepsy (JME), an adolescent-onset form of primary idiopathic generalized epilepsy (IGE). This epilepsy-related gene locus, designated EJM-1, may also influence the expression of other forms of IGE. We report here evidence that at least one form of epilepsy that is similar to JME--pure, adolescent-onset grand mal epilepsy in which the seizures occur at any time during waking--is not linked to the EJM-1 locus. However, we also have evidence that another form of pure, adolescent-onset grand mal that occurs on awakening is linked to the EJM-1 locus and may be genetically the same as JME. This work suggests that clinically similar epileptic syndromes may have different genetic bases and underscores the critical importance of careful clinical observations in studying the genetics of the epilepsies.

Adolescent↗
PubMed1994

Discontinuing antiepileptic drugs in children with epilepsy: a prospective study.

In a prospective study, antiepileptic drugs were discontinued in 264 children with epilepsy after a mean seizure-free interval of 2.9 years. They were then followed for a mean of 58 months to ascertain whether seizures recurred. Seizures recurred in 95 (36%) of the children. Etiology was a significant predictor of outcome (relative risk [RR] = 1.81). On multivariable analysis, significant factors in the idiopathic group included age at onset above 12 years (RR = 5.4), a family history of seizures (RR = 3.1), the presence of slowing on the electroencephalogram prior to medication withdrawal (RR = 2.4), and a history of atypical febrile seizures (RR = 2.8). Specific epileptic syndromes such as juvenile myoclonic epilepsy and benign rolandic epilepsy were also significant predictors of outcome. In the remote symptomatic group, significant predictors of outcome included age at onset older than 12 years (RR = 3.6), moderate to severe mental retardation (IQ < 50) (RR = 2.8), a history of atypical febrile seizures (RR = 2.0), and a history of absence seizures (RR = 0.4). The majority of children with epilepsy in remission while on antiepileptic drug therapy will remain seizure free when medications are withdrawn. A few readily available parameters distinguish those with a good prognosis from those in whom seizures are likely to recur. These data provide the framework for the clinical decision making for withdrawal of medications in these children.

Anticonvulsants↗
PubMed1994

Relapse following discontinuation of antiepileptic drugs: a meta-analysis.

The estimates in the literature of the risk of seizure relapse after antiepileptic medications are withdrawn range from less than 10% to nearly 70%. There is also little coherence regarding predictors of successful medication withdrawal. We performed a meta-analysis of the published literature to date to determine the risk of relapse at 1 and 2 years after discontinuation of medications and to examine the strength of association between the risk of relapse and three commonly assessed clinical factors: age of onset of epilepsy, presence of an underlying neurologic condition, and an abnormal EEG. We established criteria for inclusion of a study in the analysis, and 25 studies met these criteria. Overall, the risk of relapse at 1 year was 0.25 (95% CI, 0.21 to 0.30) and at 2 years it was 0.29 (95% CI, 0.24 to 0.34). Relative to epilepsy of childhood onset, epilepsy of adolescent onset was associated with a relative risk of relapse of 1.79 (95% CI, 1.46 to 2.19). Compared with childhood-onset epilepsy, adult-onset epilepsy was associated with a relative risk of 1.34 (95% CI, 1.00 to 1.81). Patients with remote symptomatic seizures were more likely to relapse than patients with idiopathic seizures; the relative risk was 1.55 (95% CI, 1.21 to 1.98). An abnormal EEG was associated with a relative risk of 1.45 (95% CI, 1.18 to 1.79). Although these figures help provide an estimate of an individual's likelihood of relapse, they should not be used as the sole basis on which to make the decision on discontinuation of medications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

The contributions of epidemiology to the understanding of childhood seizures and epilepsy.

Up through the 1960s, studies of epilepsy were based on patients seen in tertiary referral centers, many of whom had refractory epilepsy. Based on these early studies, epilepsy was believed to be a chronic, progressive, and incurable disorder. Seizures were thought to cause damage and result in further seizures. Clinical management of children with seizures reflected these beliefs. Over the last 25 to 30 years, epidemiologic studies have demonstrated that, contrary to these earlier beliefs, the prognosis of most childhood seizures and epilepsy is excellent. Prognosis is largely determined by the underlying etiology and not the seizures themselves. The differences in the assessment of the prognosis of seizures derived from the earlier studies versus the later epidemiologic studies are largely due to several biases that occurred in the earlier studies. These biases are explained. Several examples are provided of how the epidemiologic studies have greatly altered the prevailing views regarding the prognosis of seizures, and, by doing so, the management of seizures.

Anticonvulsants↗
PubMed1994

Does antiepileptic drug therapy alter the prognosis of childhood seizures and prevent the development of chronic epilepsy?

Most children with epilepsy are treated with antiepileptic drugs. The effect of these medications on the evolution of the epileptic disorder is controversial. Medications can prevent seizures in acute encephalopathies, reduce febrile seizures recurrences, and control epilepsy. They do not appear to prevent epilepsy following acute brain injury. Kinding and secondary epileptogenesis remain of uncertain significance in humans. Many studies suggest that medications do not alter the development of chronic epilepsy; however, they may improve cognitive function in specific epilepsy syndromes and change the quality of life of people with epilepsy.

Journal Article↗
PubMed1993

Convulsive status epilepticus in children.

Status epilepticus (SE) occurs most commonly in infancy and childhood. Children with prior neurological abnormalities are most susceptible. More than 90% of cases are convulsive and the majority are generalized. SE may occur in the setting of an acute illness, in patients with established epilepsy or as a first unprovoked seizure. The etiology can be classified as idiopathic, remote symptomatic, febrile, acute symptomatic, or associated with a progressive encephalopathy. The morbidity and mortality of status have dramatically declined in recent years. Overall mortality in recent pediatric series was 3-10%, with almost all fatalities associated with acute central nervous system insults or progressive neurologic disorders. Neurological sequelae in children with idiopathic or febrile status are rare. Neurologically normal children with SE as their first unprovoked seizure have the same risk of experiencing subsequent seizures of any type as children who present with a brief first seizure. The risk of recurrent episodes of convulsive SE approaches 50% in neurologically abnormal children but is very low in neurologically normal children. The favorable outcome of SE in children may be related to advances in therapy and to the resistance of the immature brain to damage from seizures.

Adult↗
PubMed1993

New-onset seizures in an elderly hospitalized population.

We studied 80 hospitalized patients over 60 years old with either new-onset or newly diagnosed seizures that were generalized tonic-clonic in approximately half the cases and partial with or without secondary generalization in the other half. The etiology of seizures was acute symptomatic in 33 (41%), remote symptomatic in 32 (40%), progressive encephalopathy in nine (11%), and idiopathic in six (8%). Convulsive status epilepticus occurred in five cases (6%). The most common single cause of seizures was infarction or hemorrhage (54%). Morbidity and mortality were highest in the acute symptomatic group (p < 0.03). Nine (11%) of the subjects died within 3 months of admission, including two of the five with status epilepticus. Of the patients with acute symptomatic etiologies, 21% died compared with 6% of those in the remote symptomatic group. New neurologic deficits were present in eight (11%) of the 71 who survived, including five acute symptomatic, one remote symptomatic, and two progressive encephalopathy cases. No patient with idiopathic seizures died or had new neurologic deficits. We conclude that seizures in the elderly requiring hospitalization occur mainly with acute and remote symptomatic neurologic insults and are associated with a significant morbidity and mortality. In the absence of any associated neurologic insults, the morbidity is low.

Aged↗
PubMed1993

Sleep state and the risk of seizure recurrence following a first unprovoked seizure in childhood.

In a prospective study, we have followed 347 children identified at the time of a first unprovoked seizure for a mean of 46 months. To date, 135 (39%) have experienced a seizure recurrence. In this study, we analyzed recurrence risk as a function of whether the child was asleep or awake at the time of the first seizure. The cumulative recurrence risks for children whose first seizure occurred in sleep was 28% at 0.5 years, 39% at 1 year, 53% at 2 years, and 55% at 4 years, compared with recurrence risks of 18%, 23%, 30%, and 35% at the same intervals in children whose first seizure occurred while awake (p < 0.001). The association of a first seizure during sleep with an increased recurrence risk was present primarily in children with idiopathic seizures. It occurred in both those with a normal and an abnormal EEG. On multivariable analysis, sleep state, etiology, and the EEG were statistically significant predictors of recurrence risk. In children who experienced a seizure recurrence, the recurrences occurred in the same sleep state in 73% of the cases (p < 0.0001). This was also true of subsequent recurrences. We conclude that the occurrence of a first seizure in sleep is associated with an increased risk of recurrence. Subsequent seizures, if they do occur, usually occur in the same sleep state as the initial seizure.

Adolescent↗
PubMed1992

A prospective study of recurrent febrile seizures.

BACKGROUND: Febrile seizures occur in about 2 to 4 percent of all children, approximately one third of whom will have recurrent febrile seizures. Little is known about predictors of recurrence. METHODS: In this prospective study, we identified 347 children (1 month to 10 years of age) who presented with a first febrile seizure at one of four pediatric emergency departments. Information about these children was collected from medical records and interviews with the parents, and the children were followed for a median of 20 months to ascertain whether febrile seizures recurred. RESULTS: Recurrent febrile seizures occurred in 94 of the 347 children (27 percent) with a cumulative risk of 25 percent at one year and 30 percent at two years. The duration of fever before the initial seizure was associated with the risk of recurrence at one year: for fever lasting less than 1 hour, the risk of recurrence was 44 percent; for fever lasting 1 to 24 hours, 23 percent; and for fever lasting more than 24 hours, 13 percent (P less than 0.001). With each degree of increase in temperature (in degrees Fahrenheit), from 101 degrees F (38.3 degrees C) to greater than or equal to 105 degrees F (40.6 degrees C), the risk of recurrence at one year declined, from 35 percent to 30, 26, 20, and 13 percent (P for trend = 0.024). An age of less than 18 months and a family history of febrile seizures were also associated with an increased risk of recurrence. A family history of epilepsy, complex febrile seizures, and neurodevelopmental abnormalities did not increase the risk of recurrent febrile seizures. CONCLUSIONS: A shorter duration of fever before the initial febrile seizure and a lower temperature are associated with an increased risk of recurrence in children who have febrile seizures.

Age Factors↗
PubMed1992

Headaches in children younger than 7 years of age.

Headache in young children is frequently a cause of concern to parents and physicians. We have reviewed our experience with 104 children with onset of headaches prior to 7 years of age seen by age 9 years. Headaches could be classified in more than 90% of cases. The most common headache type in this population referred to a child neurologist was migraine that constituted 75% of the cases. Seventy-two of 78 cases were common migraine. Posttraumatic headaches accounted for an additional 12%. Associated symptoms such as autonomic signs, nausea, and vomiting were common, particularly in the migraine group. Neuroimaging studies when performed did not reveal any significant abnormalities. Other laboratory tests were also generally unhelpful. No child has gone on to develop new neurologic abnormalities or evidence of an intracranial tumor. We conclude that even in young children headaches are generally benign. Even in this population, neuroimaging studies have a very low yield in the absence of other symptoms and findings and are not always indicated.

Child↗
PubMed1992

Recurrent status epilepticus in children.

Status epilepticus is an uncommon but life-threatening seizure. Little is known about the risk of recurrent status epilepticus in patients who present with an initial episode. To determine the risk of recurrent status epilepticus in children, we prospectively followed 95 children, identified at the time of their first episode of status epilepticus, for a mean of 29.0 months (range, 4-60 months). The patients' ages ranged from 1 month to 18 years (mean, 4.6 years). The cause of the status epilepticus was classified as idiopathic (n = 24), remote symptomatic (n = 18), febrile (n = 29), acute symptomatic (n = 18), or progressive neurological disorder (n = 6). Sixteen children (17%) had at least 2 episodes of status epilepticus. The risk of recurrent status was 4% (n = 1) in the idiopathic group, 44% (n = 8) in the remote symptomatic group, 3% (n = 1) in the febrile group, 11% (n = 2) in the acute symptomatic group, and 67% (n = 4) in those with progressive neurological disease. Recurrent status epilepticus occurred primarily in neurologically abnormal children. While neurologically abnormal children accounted for 34% (n = 32) of all children with status epilepticus, they comprised 88% (n = 14) of the children with recurrent status epilepticus (p less than 0.001) and all 5 of the children with multiple (greater than or equal to 3) episodes of status (p less than 0.001). Fifteen of 16 children with recurrent status epilepticus were being treated with antiepileptic drugs at the time of recurrence. The morbidity and mortality of status epilepticus were low.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticonvulsants↗
PubMed1992

Applying stigma theory to epilepsy: a test of a conceptual model.

Tested a theoretical model that sought to explain the association of stigma to self-esteem among adolescents with epilepsy. The model depicted hypothesized relationships among several characteristics of epilepsy (seizure type, seizure frequency, and duration of epilepsy), perceived stigma, management of disclosure, and self-esteem. Subjects were 64 adolescents 12 to 20 years old with idiopathic epilepsy. In a hierarchical multiple regression analysis, variables were entered into the equation in the order specified a priori by the model. Results showed that the data supported some hypotheses tested in the model: (a) Seizure type and seizure frequency predicted low self-esteem, and (b) the belief that epilepsy is stigmatizing predicted low self-esteem. However, several relationships of major theoretical significance were not realized. Explanations for why some aspects of stigma theory were not supported by the data are offered.

Adaptation, Psychological↗
PubMed1992

Childhood onset cluster headaches.

Cluster headaches are rare in childhood. We identified 35 patients with cluster headaches starting at or before 18 years of age, including 7 patients with onset prior to age 10. All patients met the criteria of the International Headache Society for episodic or chronic cluster headaches. Patients experienced cluster headaches for as long as 20 years before seeking medical attention and required many medical contacts to establish the correct diagnosis. The clinical features of cluster headaches during childhood were similar to those which typically occur in adult life. Cluster headache patterns changed over 18 years of follow up. The frequency and duration of cluster periods increased in 14 subjects. The frequency of single headache attacks during cluster periods also increased in a similar number of subjects. We conclude that cluster headaches starting in childhood or adolescence closely resemble the adult form of the disease. In many patients, the frequency and duration of cluster periods and the frequency of the individual headache episodes increased over time. Cluster headache represent a treatable under-recognized cause of severe headaches in childhood and adolescence.

Adolescent↗
PubMed1992

Fluent aphasia in children: definition and natural history.

We compared the course of a preschool child we followed for 4 years with published reports of 24 children with fluent aphasia. Our patient spoke fluently within 3 weeks of the injury. She was severely anomic and made many semantic paraphasic errors. Unlike other children with fluent aphasia, her prosody of speech was impaired initially, and her spontaneous language was dominated by stock phrases. Residual deficits include chronic impairment of auditory comprehension, repetition, and word retrieval. She has more disfluencies in spontaneous speech 4 years after her head injury than acutely. School achievement in reading and mathematics remains below age level. Attention to the timing of recovery of fluent speech and to the characteristics of receptive and expressive language over time will permit more accurate description of fluent aphasia in childhood.

Achievement↗