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Biomedical subjects

S Shinnar

Publications and source records attributed to S Shinnar.

At least 19 recordsLinked to original sources
PubMed2005

Identifying seizure clusters in patients with epilepsy.

Clinicians often encounter patients whose neurologic attacks appear to cluster. In a daily diary study, the authors explored whether clustering is a true phenomenon in epilepsy and can be identified in the clinical setting. Nearly half the subjects experienced at least one episode of three or more seizures in 24 hours; 20% also met a statistical clustering criterion. Utilizing the clinical definition of clustering should identify all seizure clusterers, and false positives can be determined with diary data.

Adult↗
PubMed2005

Predicting long-term seizure outcome after resective epilepsy surgery: the multicenter study.

BACKGROUND: In a seven-center prospective observational study of resective epilepsy surgery, the authors examined probability and predictors of entering 2-year remission and the risk of subsequent relapse. METHODS: Patients aged 12 years and over were enrolled at time of referral for epilepsy surgery, and underwent standardized evaluation, treatment, and follow-up procedures. The authors defined seizure remission as 2 years completely seizure-free after hospital discharge with or without auras, and relapse as any seizures after 2-year remission. The authors examined type of surgery, seizure, clinical and demographic variables, and localization study results with respect to prediction of seizure remission or relapse, using chi2 and proportional hazards analysis. RESULTS: Of 396 operated patients, 339 were followed over 2 years, and 223 (66%) experienced 2-year remission, not significantly different between medial temporal (68%) and neocortical (50%) resections. In multivariable models, only absence of generalized tonic-clonic seizures and presence of hippocampal atrophy were significantly and independently associated with remission, and only in the medial temporal resection group. Fifty-five patients relapsed after 2-year remission, again not significantly different between medial temporal (25%) and neocortical (19%) resections. Only delay to remission predicted relapse, and only in medial temporal patients. CONCLUSION: Hippocampal atrophy and a history of absence of generalized tonic clonic seizures were the sole predictors of 2-year remission, and only for medial temporal resections.

Adolescent↗
PubMed2005

Epileptiform EEG abnormalities in children with language regression.

The authors examined the records of 149 children with language regression (LR) who had overnight EEG monitoring. Children with isolated LR had a higher frequency of epileptiform abnormalities (60%) than those with LR in the context of autistic regression (31%, p = 0.002) and also a higher rate of clinical seizures (33% vs 8%, p < 0.001). EEG abnormalities in the LR only group were also more prominent. This suggests two subtypes of language regression.

Action Potentials↗
PubMed2004

Status epilepticus after the initial diagnosis of epilepsy in children.

OBJECTIVES: To determine the risk and predictors of status epilepticus in children after they have been diagnosed with epilepsy. METHODS: In a prospective community-based cohort study of 613 children, the occurrence of status epilepticus after the initial diagnosis of epilepsy was ascertained. Parents were called every 3 months, and interval medical records were reviewed every 6 months. Predictors of primary interest included a history of status before the diagnosis of epilepsy, age at onset, underlying etiology, and epilepsy syndrome. Data were analyzed with chi2 tests, Kaplan-Meier analyses, and Cox proportional hazards models. RESULTS: Of 613 children followed a median of 8.0 years, 58 (9.5%) had > or =1 episode of status epilepticus during follow-up evaluation. The first episode occurred a median of 2.5 years after initial diagnosis (range, <1 month to 8.8 years). A history of previous status epilepticus was strongly associated with subsequent status epilepticus (18/56 [32.1%] vs 40/557 [7.2%]; p < 0.0001). Younger age at onset and symptomatic etiology contributed independently to the risk of status epilepticus. Mortality was higher in children with status epilepticus before diagnosis, largely secondary to underlying cause. CONCLUSIONS: Status epilepticus occurs in approximately 10% of children after initial diagnosis of epilepsy. Status epilepticus before initial diagnosis, young age at onset, and symptomatic etiology independently influence the risk of status epilepticus. In those without status epilepticus before diagnosis, the risk is modest and is realized over a prolonged period. For children at highest risk, maintaining abortive therapy in the home may be a reasonable precaution.

Adolescent↗
PubMed2004

Practice parameter: medical treatment of infantile spasms: report of the American Academy of Neurology and the Child Neurology Society.

OBJECTIVE: To determine the current best practice for treatment of infantile spasms in children. METHODS: Database searches of MEDLINE from 1966 and EMBASE from 1980 and searches of reference lists of retrieved articles were performed. Inclusion criteria were the documented presence of infantile spasms and hypsarrhythmia. Outcome measures included complete cessation of spasms, resolution of hypsarrhythmia, relapse rate, developmental outcome, and presence or absence of epilepsy or an epileptiform EEG. One hundred fifty-nine articles were selected for detailed review. Recommendations were based on a four-tiered classification scheme. RESULTS: Adrenocorticotropic hormone (ACTH) is probably effective for the short-term treatment of infantile spasms, but there is insufficient evidence to recommend the optimum dosage and duration of treatment. There is insufficient evidence to determine whether oral corticosteroids are effective. Vigabatrin is possibly effective for the short-term treatment of infantile spasm and is possibly also effective for children with tuberous sclerosis. Concerns about retinal toxicity suggest that serial ophthalmologic screening is required in patients on vigabatrin; however, the data are insufficient to make recommendations regarding the frequency or type of screening. There is insufficient evidence to recommend any other treatment of infantile spasms. There is insufficient evidence to conclude that successful treatment of infantile spasms improves the long-term prognosis. CONCLUSIONS: ACTH is probably an effective agent in the short-term treatment of infantile spasms. Vigabatrin is possibly effective.

Administration, Oral↗
PubMed2003

Initial outcomes in the Multicenter Study of Epilepsy Surgery.

OBJECTIVE: To obtain prospective data regarding seizures, anxiety, depression, and quality of life (QOL) outcomes after resective epilepsy surgery. METHODS: The authors characterized resective epilepsy surgery patients prospectively at yearly intervals for seizure outcome, QOL, anxiety, and depression, using standardized instruments and patient interviews. RESULTS: Of 396 patients who underwent resective surgical procedures, 355 were followed for at least 1 year. Of these, 75% achieved a 1-year remission at some time during follow-up; patients with medial temporal (77%) were more likely than neocortical resections (56%) to achieve remission (p = 0.01). Relapse occurred in 59 (22%) patients who remitted, more often in medial temporal (24%) than neocortical (4%) resected patients (p = 0.02). QOL, anxiety, and depression all improved dramatically within 3 months after surgery (p < 0.0001), with no significant difference based on seizure outcome. After 3 months, QOL in seizure-free patients further improved gradually, and patients with seizures showed gradual declines. By 12 and 24 months, overall QOL and its epilepsy-targeted and physical health domains were significantly different in the two outcome groups. (Anxiety and depression scores also gradually diverged, with improvements in seizure-free and declines in continued seizure groups, but differences were not significant.) CONCLUSION: Resective surgery for treatment of epilepsy significantly reduces seizures, most strikingly after medial temporal resection (77% 1 year remission) compared to neocortical resection (56% 1 year remission). Resective epilepsy surgery has a gradual but lasting effect on QOL, but minimal effects on anxiety and depression. Longer follow-up will be essential to determine ultimate seizure, QOL, and psychiatric outcomes of epilepsy surgery.

Adolescent↗
PubMed2003

How long does it take for partial epilepsy to become intractable?

BACKGROUND: Much remains unknown about the natural history of intractable localization-related epilepsy, including how long it typically takes before intractability becomes evident. This information could guide the design of future studies, resolve certain discrepancies in the literature, and provide more accurate information about long-term prognosis. METHODS: Individuals evaluated for resective surgery for refractory localization-related epilepsy were prospectively identified at the time of initial surgical evaluation at seven surgical centers (between 1996 and 2001). The latency time between onset of epilepsy and failure of second medication and history of remission (>/=1 year seizure-free) before surgical evaluation were examined with respect to age at onset, hippocampal atrophy, febrile seizures, and surgical site. RESULTS: In the 333 patients included in the analysis, latency time was 9.1 years (range 0 to 48) and 26% reported a prior remission before surgery. A prior remission of >/=5 years was reported by 8.5% of study participants. Younger age at onset was strongly associated with longer latency time (p < 0.0001) and higher probability of past remission (p < 0.0001). In multivariable analyses, age at onset remained as the most important explanatory variable of both latency time and prior remission. CONCLUSIONS: A substantial proportion of localization-related epilepsy may not become clearly intractable for many years after onset. This is especially true of epilepsy of childhood and early adolescent onset. If prospective studies confirm these findings and the underlying mechanisms behind these associations become understood, this raises the possibility of considering interventions that might interrupt such a process and some day prevent some forms of epilepsy from becoming intractable.

Adolescent↗
PubMed2003

Practice parameter: treatment of the child with a first unprovoked seizure: Report of the Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society.

The Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society develop practice parameters as strategies for patient management based on analysis of evidence regarding risks and benefits. This parameter reviews published literature relevant to the decision to begin treatment after a child or adolescent experiences a first unprovoked seizure and presents evidence-based practice recommendations. Reasons why treatment may be considered are discussed. Evidence is reviewed concerning risk of recurrence as well as effect of treatment on prevention of recurrence and development of chronic epilepsy. Studies of side effects of anticonvulsants commonly used to treat seizures in children are also reviewed. Relevant articles are classified according to the Quality Standards Subcommittee classification scheme. Treatment after a first unprovoked seizure appears to decrease the risk of a second seizure, but there are few data from studies involving only children. There appears to be no benefit of treatment with regard to the prognosis for long-term seizure remission. Antiepileptic drugs (AED) carry risks of side effects that are particularly important in children. The decision as to whether or not to treat children and adolescents who have experienced a first unprovoked seizure must be based on a risk-benefit assessment that weighs the risk of having another seizure against the risk of chronic AED therapy. The decision should be individualized and take into account both medical issues and patient and family preference.

Adolescent↗
PubMed2002

Alteration of the cortical motor map in a patient with intractable focal seizures.

Patients with epilepsia partialis continua may develop progressive neurological deficits of unclear origin. It is possible that repetitive epileptic spikes induce plastic changes in the cortex analogous to the changes observed following direct microstimulation. A child is reported with focal cortical dysplasia, intractable focal seizures, worsening hemiparesis, and alteration of the cortical motor map over time. At age 7, he underwent cortical motor mapping before partial resection of a seizure focus within the right postcentral gyrus. No deficits were present after surgery, and seizure frequency declined by more than 90%. Seizures subsequently worsened and a progressive left hemiparesis developed. Cortical remapping at age 12 showed motor centres for left arm, face, and eye movements in an unusual configuration. The location of the motor representation of the face differed from the location obtained at age 7. This case provides direct electrophysiological evidence of reorganisation of the cortical motor map in the human brain.

Child↗
PubMed2001

Early development of intractable epilepsy in children: a prospective study.

BACKGROUND: Little is known about early prediction of intractable epilepsy (IE) in children. Such information could help guide the early use of new therapies in selected patients. METHODS: Children with newly diagnosed epilepsy (n = 613) were prospectively identified from child neurology practices in Connecticut (1993--1997) and followed-up for the occurrence of IE (failure of > or = 2 drugs, > or = 1 seizure/month, over 18 months) [corrected]. Etiology and epilepsy syndromes were classified per International League Against Epilepsy guidelines. RESULTS: The median follow-up is 4.8 years, and 599 (97.7%) have been followed for more than 18 months. Sixty children (10.0%) have met the criteria for IE, including 34.6% with cryptogenic/symptomatic generalized, 2.7% with idiopathic, 10.7% with other localization-related, and 8.2% with unclassified epilepsy (p < 0.0001). After multivariable adjustment for epilepsy syndrome, initial seizure frequency (p < 0.0001), focal EEG slowing (p = 0.02), and acute symptomatic or neonatal status epilepticus (p = 0.001) were associated with an increased risk of IE, and age at onset between 5 and 9 years was associated with a lowered risk (p = 0.03). The absolute number of seizures and unprovoked or febrile status epilepticus were not associated substantially with IE. CONCLUSIONS: Approximately 10% of children meet criteria for IE early in the course of their epilepsy. Cryptogenic/symptomatic generalized syndromes carry the highest risk and idiopathic syndromes the lowest. Half of IE occurs in children with nonidiopathic localization-related syndromes. Initial seizure frequency is highly predictive of IE. By contrast, absolute number of seizures and unprovoked or febrile status epilepticus are not.

Age of Onset↗
PubMed2001

Initiation and discontinuation of antiepileptic drugs.

The issues of when to initiate and discontinue antiepileptic drugs (AEDs) are reviewed using an approach that emphasizes weighing the relative risks and benefits of the therapeutic decisions. The majority of children and adults who present with a first unprovoked seizure will not experience further seizures. Treatment reduces recurrence risk but does not alter long-term prognosis. Treatment should be deferred until a second seizure has occurred. The majority of children and adults who are seizure free for two or more years on medications will remain so when medications are withdrawn. The risk of reoccurrence is somewhat higher in adults. The consequences of recurrence are much more significant in adults. Most children who are seizure free on medications should have at least one attempt at medication withdrawal. In adults, the decisions need to be individualized based on a variety of factors including age, sex, occupation, and the presence or absence of risk factors for reoccurrence.

Anticonvulsants↗
PubMed2001

Language regression in childhood.

Language regression is observed both in autistic regression and as part of acquired epileptic aphasia (Landau-Kleffner Syndrome). We prospectively identified 177 children with language regression at four major medical centers, and their clinical characteristics were recorded. Their mean age at regression was 22.8 months. The mean time-to-specialist referral was 38 months of age. Most children (88%) met criteria for autism or manifested autistic features. Males (P = 0.02) and children less than 3 years of age who regressed (P = 0.016) had a higher probability of developing autistic behaviors. Seizures were more common in children who regressed after they reached 3 years of age (P < 0.001), and children with seizures were less likely to have associated autistic regression (P < 0.001). Electroencephalogram abnormalities were reported in 37% of patients and were more common in children with seizures (P < 0.001). At last follow-up, language function was impaired in 88% of the children, although some improvement was noted in 57%. We conclude that the loss of previously acquired language at any age, even if that language only includes a few words or communicative gestures, is often associated with a more global regression in cognition and/or behavior and has serious implications for future function. Early identification and referral of these children is necessary to allow for diagnosis and intervention.

Brain↗
PubMed2001

Defining early seizure outcomes in pediatric epilepsy: the good, the bad and the in-between.

PURPOSE: To examine different approaches to classifying seizure outcomes. METHODS: In a prospective cohort study of children (N=613) with newly diagnosed epilepsy, seizure outcomes at 2 years were classified as 'good' (> or =1 year remission), 'bad' or 'intractable' (> or = AED failures, > or =1 seizure/month over > or =18 months), and 'indeterminate' (neither 'good' nor 'bad'). Outcomes at 2 years were compared to outcomes in those followed 4 or more years. The associations of three commonly studied prognostic factors, etiology, age at onset, and syndromic grouping with the three-level outcome were assessed. RESULTS: 595 (97.1%) children were followed > or =2 years. A 'good', indeterminate, and 'bad' outcome was present in 314 (52.8%), 235 (38.3%), and 46 (7.7%) children. Problems with treatment were recorded in 64.7% of the indeterminate group. In 390 children followed > or =4 years, early 'good' and 'bad' outcomes persisted in approximately 80%. About half of those with indeterminate 2-year outcomes later achieved remission, 8% met criteria for intractability, and 37% remained indeterminate. Most of the associations with etiology, age, and syndrome were due to variation in the proportion that met criteria for intractability and not remission. CONCLUSIONS: Many children have indeterminate outcomes, often in association with treatment issues. Clearly 'good' and 'bad' early outcomes can be identified and persist > or =2 years later. In the absence of pharmaco-resistance, lack of early remission (indeterminate outcome) is usually not associated with a bad outcome, at least over the next few years.

Adolescent↗
PubMed2001

Neuroimaging abnormalities in children with an apparent first unprovoked seizure.

OBJECTIVE: To determine the incidence and type of neuroimaging abnormalities in children presenting with a first seizure. METHODS: In a prospective observational study, 411 children with a first afebrile seizure were seen between 1983 and 1992. Imaging studies were performed in 218 (53%). For this analysis we examined the most sensitive neuroimaging study performed which included 159 computed tomography scans and 59 magnetic resonance imagings (MRI). RESULTS: Four children were found to have lesions requiring intervention (brain tumor in two, neurocysticercosis in two). The remaining 407 were enrolled in a follow-up study of children with a first unprovoked seizure. After a mean follow-up of >10 years, none have developed clinical evidence of a tumor. In these 411 children, 45 (21%) of 218 imaging studies were abnormal. The most common abnormalities were focal encephalomalacia (n=16) and cerebral dysgenesis (n=11). Although children with partial seizures were more likely to be imaged (64%) than children with generalized seizures (43%) (P<0.001), the fraction of abnormal imaging studies was similar in both groups. Six children with a normal neurological examination who were initially classified as cryptogenic were subsequently found to have errors of cerebral migration on MRI. The incidence of lesions requiring acute intervention in children presenting with a first seizure is low. A significant proportion will have neuroimaging abnormalities particularly on MRI. CONCLUSIONS: Neuroimaging should be considered in any child with a first seizure who does not have an idiopathic form of epilepsy.

Adolescent↗
PubMed2001

Status epilepticus and tiagabine therapy: review of safety data and epidemiologic comparisons.

PURPOSE: To determine whether an increased risk of status epilepticus (SE) and complex partial status epilepticus (CPSE) is associated with tiagabine (TGB) therapy. METHODS: Thirteen cases in which an EEG, performed on patients with altered mental status taking TGB, was reported to demonstrate spike-and-wave discharges (SWDs) were reviewed by a panel of experts. In addition, all cases of suspected SE from TGB clinical trials were reviewed. The occurrence of SE in four epidemiologic cohorts from Rochester, Minnesota, Turku, Finland, Bronx, New York, and New Haven, Connecticut was analyzed as an external comparison. RESULTS: Review of the 13 cases with reported SWDs found that the majority had had prior EEGs with similar findings, and only three were thought to have electrographic evidence of SE. There was no difference in the frequency of SE or CPSE in the placebo-controlled clinical trials between the TGB-treated (1.0% SE, 0.8% CPSE) and placebo-treated (1.5% SE, 1.5% CPSE) groups. The 5% frequency of SE and 3% frequency of CPSE in the TGB-treated patients in the long-term safety studies, which included 2,248 patients, were very similar to the rates of occurrence of SE and CPSE in the four external cohorts. The major risk factor for the occurrence of SE and CPSE in all groups was a prior episode of SE (p < 0.0001). CONCLUSIONS: Over a 3-year period, SE will occur in 5-10% of patients with epilepsy not in remission. At highest risk are those who have had a prior episode of SE. Treatment with TGB in recommended doses does not increase the risk of SE in patients with partial seizures.

Adolescent↗
PubMed2001

Short-term outcomes of children with febrile status epilepticus.

Febrile status epilepticus (SE) represents the extreme end of the complex febrile seizure spectrum. If there are significant sequelae to febrile seizures, they should be more common in this group. We have prospectively identified 180 children aged 1 month to 10 years who presented with febrile SE over a 10-year period in Bronx, New York, and Richmond, Virginia. They were compared with 244 children who presented with their first febrile seizure (not SE) in a prospective study done in the Bronx. The mean age of the children with febrile SE was 1.92 years, and of the comparison group, 1.85 years. Duration of SE was 30-59 min in 103 (58%), 60-119 min in 43 (24%), and > or =120 min in 34 (18%). Focal features were present in 64 (35%) of cases. There were no deaths and no cases of new cognitive or motor handicap. Children with febrile SE were more likely to be neurologically abnormal (20% vs. 5%; p < 0.001), to have a history of neonatal seizures (3% vs. 0; p = 0.006) and a family history of epilepsy (11% vs. 5%; p = 0.05) and less likely to have a family history of febrile seizures (15% vs. 27%; p = 0.01) than were children in the comparison group. The short-term morbidity and mortality of febrile SE are low. There are differences in the types of children who have febrile SE compared with those who experience briefer febrile seizures. Long-term follow-up of this cohort may provide insight into the relationship of prolonged febrile seizures and subsequent mesial temporal sclerosis.

Age Distribution↗
PubMed2001

Two-year remission and subsequent relapse in children with newly diagnosed epilepsy.

PURPOSE: Although remission is the ultimate measure of seizure control in epilepsy, and epilepsy syndrome should largely determine this outcome, little is known about the relative importance of syndrome versus other factors traditionally examined as predictors of remission or of relapse after remission. The purpose of this study was to examine remission and relapse with respect to the epilepsy syndrome and other factors traditionally considered with respect to seizure outcome. METHODS: A prospectively identified cohort of 613 children with newly diagnosed epilepsy was assembled and is actively being followed to determine seizure outcomes. Epilepsy syndrome and etiology were classified at diagnosis and again 2 years later. Remission was defined as 2 years completely seizure-free, and relapse as the recurrence of seizures after remission. Multivariable analysis was performed with the Cox proportional hazards model. RESULTS: Five hundred ninety-four of the original 613 children were followed > or = 2 years (median follow-up, 5 years). Remission occurred in 442 (74%), of whom 107 (24%) relapsed. On multivariable analysis, idiopathic generalized syndromes and age at onset between 5 and 9 years were associated with a substantially increased remission rate, whereas remote symptomatic etiology, family history of epilepsy, seizure frequency, and slowing on the initial EEG were associated with a decreased likelihood of attaining remission. Young onset age (<1 year) and seizure type were not important after adjustment for these predictors. Relapses occurred more often in association with focal slowing on the initial EEG and with juvenile myoclonic epilepsy. Benign rolandic epilepsy and age at onset <1 year were associated with markedly lower risks of relapse. About one fourth of relapses were apparently spontaneous while the child was taking medication with good compliance, and more than half occurred in children who were tapering or had fully stopped medication. CONCLUSIONS: A large proportion of children with epilepsy remit. Symptomatic etiology, family history, EEG slowing, and initial seizure frequency negatively influence, and age 5-9 years and idiopathic generalized epilepsy positively influence the probability of entering remission. Factors that most influence relapse tend to be different from those that influence remission.

Age Factors↗