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Biomedical subjects

E P Vining

Publications and source records attributed to E P Vining.

At least 19 recordsLinked to original sources
PubMed1997

Why would you remove half a brain? The outcome of 58 children after hemispherectomy-the Johns Hopkins experience: 1968 to 1996.

PURPOSE: To report the outcomes of the 58 hemispherectomies performed at Johns Hopkins between 1968 and January 1996. METHODS: Charts were reviewed of the 58 hemispherectomies performed at Johns Hopkins Medical Institutions by the Pediatric Epilepsy Group during the years 1968 to 1996. Twenty-seven operations were done for Rasmussen's syndrome, 24 operations for cortical dysplasias/hemimegalencephalies, and 7 for Sturge-Weber syndrome or other congenital vascular problems. Seizure control alone did not seem to adequately describe the outcomes of the procedure. Therefore, a score was constructed that included seizure frequency, motor disability, and intellectual handicap. This burden of illness score better described the child's handicap before and after surgery. RESULTS: Perioperative death occurred in 4 out of 58 children. Of the 54 surviving children, 54% (29/54) are seizure-free, 24% (13/54) have nonhandicapping seizures, and 23% (12/54) have residual seizures that interfere to some extent with function. Reduction in seizures was related to the etiology of the unilateral epilepsy. Eighty-nine percent of children with Rasmussen's, 67% of those with dysplasias, and 67% of the vascular group are seizure-free, or have occasional, nonhandicapping seizures. All operations were considered by the parents and the physicians to have been successful in decreasing the burden of illness. In 44 the procedure was very successful, in 7 it was moderately successful, and in 3 it was minimally successful. Success was related to the etiology, and early surgery was preferable. CONCLUSION: Hemispherectomy can be a valuable procedure for relieving the burden of seizures, the burden of medication, and the general dysfunction in children with severe or progressive unilateral cortical disease. Early hemispherectomy, although increasing the hemiparesis in children with Rasmussen's syndrome, relieves the burden of constant seizures and allows the child to return to a more normal life. In children with dysplasias, early surgery can allow the resumption of more normal development.

Adolescent↗
PubMed1997

The ketogenic diet: 1997.

There has been a dramatic resurgence of interest in the ketogenic diet during the past several years. For many children with difficult-to-control epilepsy, the diet presents an alternative approach to trying multiple medications. The ketogenic diet's current success rate, when properly executed, greatly exceeds that of the medications which have recently become available. Its side effects, both cognitive and allergic, appear fewer than most available medications. The ketogenic diet is also cheaper than most new anticonvulsants. Even though we now know that the diet works, we still do not know how it works. Nor do we know how most anticonvulsants work. The mechanism of action of the ketogenic diet appears to rely on a fundamental change in the brain's metabolism from that of a glucose-based energy substrate to a ketone-based substrate. This change is, in some fashion, critical to the maintenance of seizure threshold. Why should the source of the energy make a difference in seizure threshold? The change in seizure threshold appears to occur without affecting the brain's ability to carry out its normal complex functions. Could the brain's utilization of an energy substrate for seizure control be different from its utilization of energy for normal brain function? If so it should it be possible to study the metabolic differences between the two and develop a biochemistry of epilepsy, which is differentiated from the biochemistry of normal cognition and function. The ketogenic diet is successful in controlling or ameliorating a broad spectrum of seizure types and etiologies. Perhaps then, common metabolic pathways, independent of seizure type, are used in the initiation and spread of electrical seizures. Based on clinical experience and limited research data, it would appear that different seizures and different epilepsies must have metabolic pathways in common that make them susceptible to treatment with a common metabolic therapy. If we could understand how the ketogenic diet "works," how changing from a glucose substrate' to a ketone body substrate is anticonvulsant, then perhaps a medication could be developed that would simulate the biochemical effects of the ketogenic diet. Such an approach would be a major departure in the study of the neuroscience of epilepsy. The ketogenic diet offers a new paradigm to think about epilepsy and its treatment, and perhaps will stimulate new approaches to this still often devastating condition.

Adult↗
PubMed1996

Hemispherectomy: a hemidecortication approach and review of 52 cases.

Between 1975 and 1994, 52 hemispherectomies, of which two were anatomical and 50 hemidecortications, were performed at Johns Hopkins Medical Institutions. Eighteen patients were 2 years old or less. There were three perioperative mortalities and one patient died 9 months later from causes not related to surgery. One patient developed hydrocephalus 6 years postsurgery and has been treated effectively. Seizure control and the functional status of each patient were measured as outcome variables. Forty-six (96%) of the surviving patients were seizure free or had reduced seizures as of their last follow-up examination. Twenty-one individuals (44%) were participating in age-appropriate classes or working independently, 18 were classified as semiindependent, and nine children will likely depend on a lifetime of assisted living. The relationships between the outcome variables and the patient's age at surgery, the interval to surgery, and the etiology of the disease were compared. The authors' clinical experiences strongly suggest the importance of a multidisciplinary approach to patient selection and follow-up care. Moreover, anesthetic management of infant surgery is a major component of success.

Adolescent↗
PubMed1995

Speech-language outcomes of hemispherectomy in children and young adults.

Children and young adults who had undergone right or left hemispherectomy for intractable seizures after a period of normal language acquisition were compared with respect to scores on speech and language tests. The majority of the subjects had full scale IQs in the borderline to mentally retarded range. Language scores were computed in relation to estimated mental age, not chronological age. On this basis, the left hemispherectomized children were more likely to show syntactic comprehension and rapid-rate auditory processing deficits than the right hemispherectomized. The two groups were similar to one another and to normal children in speech production. The findings are discussed in relation to developmental language disorders.

Adolescent↗
PubMed1995

Renal arteries: clinical comparison of three-dimensional time-of-flight MR angiographic sequences and radiographic angiography.

PURPOSE: To prospectively compare three magnetic resonance (MR) angiographic techniques in the renal arteries. MATERIALS AND METHODS: Twenty-five adult patients underwent three-dimensional time-of-flight MR angiography with three different sequences: conventional, tilted optimized nonsaturating excitation (TONE), and selective inversion-recovery rapid gradient-echo (SIR-RAGE). Fifteen also underwent radiographic angiography. Stenosis grade measured with each MR angiographic technique was compared with that measured with radiographic angiography by using correlation coefficients. Visible artery lengths with each MR angiographic technique were compared by using the Turkey method. RESULTS: Correlation between stenosis grades with each MR angiographic technique and with radiographic angiography was good (P < .01). Stenosis was correctly excluded with SIR-RAGE findings in six patients. Mean visible artery length was greatest with SIR-RAGE (P < .01). CONCLUSION: SIR-RAGE depicts a greater length of renal artery than does conventional MR angiography. TONE also improved depiction of distal arteries. Normal SIR-RAGE findings were highly predictive of normal arteries.

Adult↗
PubMed1995

Febrile seizures: a decision-making analysis.

Febrile seizures are the most common type of seizures in childhood. Although febrile seizures may be frightening to observers, they are benign and do not cause death, neurologic damage, injury or learning disorders, and they rarely require medication. Parents of children who have febrile seizures, however, require considerable support, education and reassurance. Appropriate counseling by the physician requires knowledge of the natural history of febrile seizures. Treatment decisions should result from informed and appropriate decision-making about medication and potential risks.

Decision Support Techniques↗
PubMed1994

Pediatric seizures.

The initial management and treatment issues for seizures in children are discussed. The differential diagnosis is also reviewed. The decision concerning initiation of therapy depends on careful assessment of the potential risks and benefits. A therapeutic plan is outlined together with guidelines for using various medications.

Anticonvulsants↗
PubMed1994

The algorithmic complexity of neural spike trains increases during focal seizures.

The interspike interval spike trains of spontaneously active cortical neurons can display nonrandom internal structure. The degree of nonrandom structure can be quantified and was found to decrease during focal epileptic seizures. Greater statistical discrimination between the two physiological conditions (normal vs seizure) was obtained with measurements of context-free grammar complexity than by measures of the distribution of the interspike intervals such as the mean interval, its standard deviation, skewness, or kurtosis. An examination of fixed epoch data sets showed that two factors contribute to the complexity: the firing rate and the internal structure of the spike train. However, calculations with randomly shuffled surrogates of the original data sets showed that the complexity is not completely determined by the firing rate. The sequence-sensitive structure of the spike train is a significant contributor. By combining complexity measurements with statistically related surrogate data sets, it is possible to classify neurons according to the dynamical structure of their spike trains. This classification could not have been made on the basis of conventional distribution-determined measures. Computations with more sophisticated kinds of surrogate data show that the structure observed using complexity measures cannot be attributed to linearly correlated noise or to linearly correlated noise transformed by a static monotonic nonlinearity. The patterns in spike trains appear to reflect genuine nonlinear structure. The limitations of these results are also discussed. The results presented in this article do not, of themselves, establish the presence of a fine-structure encoding of neural information.

Algorithms↗
PubMed1994

Does carnitine administration improve the symptoms attributed to anticonvulsant medications?: a double-blinded, crossover study.

OBJECTIVE: This study was designed to assess the reported improvement in "well-being" perceived by parents when children who are taking anticonvulsant medications are administered carnitine. METHODOLOGY: Forty-seven children with seizures who were taking either valproic acid or carbamazepine were enrolled in a placebo-controlled, double-blinded, cross-over study of the effects of oral carnitine administration (100 mg/kilo) on their well-being as perceived by their parents. The well-being scores were assessed weekly by phone and in person at the start and end of each 4-week phase. RESULTS: The children's well-being scores improved weekly when either placebo or carnitine were administered. None of the analyses of improved well-being achieved statistical significance. CONCLUSION: We believe this study documents the necessity for controlled trials when assessing the subjective, beneficial effects of medications. Carnitine is expensive, costing approximately $.30/kilogram of body weight per day ($6 per day for a 20 kilo child). It would not appear warranted to administer carnitine prophylactically to children on anticonvulsant medications for alleviating common, nonspecific symptoms. Because there are no reliable clinical or laboratory tests of symptomatic carnitine deficiency caused by anticonvulsant administration, how to identify children in need of carnitine, and when to administer carnitine therapeutically to children receiving valproate or other anticonvulsants is unclear.

Carbamazepine↗
PubMed1993

An unusual paroxysmal EEG pattern in mixed focal/generalized epilepsies.

This report focuses on an unusual paroxysmal discharge: "compounded sharp waves," focal and mostly over frontotemporal regions, of high voltage, occurring mainly in sleep tracings of children with epileptic seizures. The duration of compounded sharp waves exceeds by far the maximum duration of classical sharp waves. In all of the three reported cases, there were also generalized-synchronous paroxysmal bursts and two children had spike-wave absences. The clinical significance of the focal discharge (in association with generalized bursts) remains unclear.

Adolescent↗
PubMed1992

Motor and sensory cortex in humans: topography studied with chronic subdural stimulation.

Classic neurosurgical teaching holds that once the Rolandic fissure (Rf) has been located, there are distinct differentiated primary motor and sensory functional units confined within a narrow cortical strip: Brodmann's Areas 4 and 6 for primary motor units in front of the Rf and 3, 1, and 2 for sensory units behind the Rf. To test this assumption, we examined in detail the records of cortical mapping done by electrical stimulation of the cerebral cortex via implanted subdural electrode grids in 35 patients with seizure disorders. Of 1381 stimulations of the electrode sites, 346 (25.1%) produced primary motor or motor-arrest and sensory responses in contralateral body parts: 56.8% were primary motor responses; 16.2% were motor-arrest; 22.5% were sensory; and the remaining 4.5% were mixed motor and sensory responses. Two-thirds (65.9%) of the primary motor responses were located within 10 mm of the Rf, and the remaining one-third (34.1%) were more than 10 mm anterior to the Rf or were posterior to the Rf. Furthermore, in the patient group with brain lesions, fewer than one-third (28.1%) of the responses were within the 10-mm narrow anterior strip. Our study reconfirmed that a significant number--at least one-third--of motor responses are distributed outside the classic narrow cortical strip. In patients with brain lesions, the motor representation is further displaced outside the narrow strip. This finding indicates that primary motor cortex may extend beyond the gyrus immediately anterior to the Rf.

Adolescent↗
PubMed1991

Multifocal independent epileptiform discharges in children: ictal correlates and surgical therapy.

We obtained continuous EEG/video recordings on four children who had the interictal EEG pattern of multifocal independent epileptiform discharges (MIED). The prominent feature of their evaluation was the evidence that their clinical seizures appeared to be of focal origin; 42/44 seizures were manifested by "fencing postures." Three patients subsequently underwent epilepsy surgery: one focal resection of superior frontal-parietal cortex and two hemidecorticectomies. Seizure control improved in all three patients, and one patient is now seizure-free. Our patients differ from those previously reported in that they had a predominance of tonic seizures and had no history of infantile spasms or Lennox-Gastaut syndrome. Some patients, such as ours, with MIED may have clinical seizures of more focal origin than might be expected from their interictal EEG and, therefore, may benefit from resective epilepsy surgery.

Adolescent↗
PubMed1990

Chaos, balance, and development: thoughts on selected childhood epilepsy syndromes.

Age-specific epilepsy syndromes raise important questions about developmental susceptibility to seizures and epileptogenesis and about the effect of seizures on function. The diagnosis and treatment of these syndromes has been enhanced by the use of modern science and technology. Epidemiologic studies have changed our approach to febrile convulsions. This developmental seizure disorder is benign and self-limited. We have been forced to think carefully about threshold, therapy, and whether other seizures in childhood may be equally benign. This framework of developmental specificity can also be applied to West syndrome, especially with respect to neurophysiology, neurochemistry, neuroimaging, and epidemiology--the types of seizures, clustering, variations associated with sleep, PET scans, and therapy. Rasmussen's syndrome and other unilateral developmental epilepsies are progressive but remain confined to a single hemisphere. However, they usually are devastating to global neurologic function. They are models for examining the impact of epilepsy in one pathologic hemisphere on the function of the entire brain. Current therapy for this condition is hemispherectomy. Recovery of function after this major surgery is striking and provides clues to brain organization. The analysis of these three syndromes provides windows on the dynamic, changing central nervous system of the child and may lead to better understanding and therapy for other seizure disorders.

Brain↗