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Biomedical subjects

B B Wannamaker

Publications and source records attributed to B B Wannamaker.

16 recordsLinked to original sources

Incidence of spikes and paroxysmal rhythmic events in overnight ambulatory computer-assisted EEGs of normal subjects: a multicenter study.

The incidences of spikes and paroxysmal rhythmic events (PREs) in 10-h overnight EEGs of normal adult volunteers (n=135) were studied at 11 sites with a computer-assisted ambulatory EEG monitoring system with automatic spike and PRE detection. Spikes were evident in the overnight EEG of 1 subject (0.7%), and PREs were apparent in the overnight EEG of the same subject (0.7%). The incidences of spikes of 24 other subjects with a history of migraine and/or a family history of epilepsy were 12.5 and 13.3%, respectively. The overnight EEGs of these subjects were significantly more likely to show spikes than the overnight EEGs of subjects without migraine or a family history of epilepsy.

Adolescent

Sudden unexplained death in epilepsy: observations from a large clinical development program.

PURPOSE: The present study was conducted to determine the rate of sudden unexplained death in epilepsy (SUDEP) in a well-defined cohort of patients included in the lamotrigine (LTG) clinical development database. METHODS: A panel of scientists experienced in the area of SUDEP was assembled and provided with case summaries on all deaths (n = 45) reported during the initial clinical development of LTG. The panel developed a set of criteria for classifying cases as SUDEP (definite or highly probable), possible SUDEP, or non-SUDEP. This classification algorithm was then applied to the LTG cases, and SUDEP rates were calculated using patient-years of exposure as the denominator. RESULTS: At the time of the study, 4,700 patients (5,747 patient-years of exposure) were included in the worldwide LTG clinical trials database. In this cohort, 45 deaths were reported. Eighteen were judged by the panel to be SUDEP, 6 were defined as possible SUDEP, 20 were judged to be due to other causes (non-SUDEP), and 1 lacked sufficient data from which to make a classification. The overall SUDEP rate (definite/ highly probable SUDEP and possible SUDEP combined) was calculated to be 3.5 in 1,000 patient-years of exposure to LTG. CONCLUSIONS: The rate of SUDEP in this cohort of patients was comparable to the rate that would be expected in young adults with severe epilepsy (the subgroup of patients believed to be at highest risk of SUDEP). The data suggest that the rate of SUDEP in the LTG clinical development program is a function of the clinical trial population and is unrelated to drug treatment.

Adolescent

Current strategies in the medical management of epilepsy.

Epilepsy is a fascinating disorder reflective of ongoing brain activity which at times is disordered. There have been significant advances in the understanding of the pharmacology of antiepileptic drugs such that effective treatment is feasible. Understanding the epilepsies and the phenomena of epileptic seizures will permit one to successfully deal with the major issues around these syndromes and lead to a very rewarding outcome.

Adult

Serum prolactin and cortisol levels in evaluation of pseudoepileptic seizures.

In 6 patients with epilepsy, a twofold increase in serum prolactin levels followed true epileptic seizures, but no significant change followed pseudoepileptic attacks in 6 other patients. Serum prolactin concentration is a useful biochemical marker to distinguish between epileptic and pseudoepileptic seizures. Serum cortisol levels also increased after epileptic seizures, but diurnal and individual variations render the cortisol level a less reliable indicator of such attacks.

Diagnosis, Differential

Autonomic nervous system and epilepsy.

Seizures frequently manifest autonomic dysfunction clinically, and seizure discharges commonly spread into and involve autonomic pathways. These associations are direct and simple in some instances, and the result of multiple indirect and complex relationships in others. Effects of epileptic discharge on the autonomic nervous system are mediated through the cortical, limbic, and hypothalamic systems. Some significant consequences of altered autonomic function include convulsive apnea, abnormal sexual function, and potentially fatal effects on the cardiovascular system.

Adult

Endocrine function following complex partial seizures.

Previous studies have demonstrated hyperprolactinemia following generalized tonic-clonic seizures and after electroconvulsive therapy. We found transient hyperprolactinemia following complex partial seizures but little change in serum gonadotropins, thyroid-stimulating hormone, growth hormone, or cortisol. Serum prolactin was invariably normal interictally. Postictal elevation of serum prolactin may represent a biochemical marker of complex partial seizures, and it offers a potential pathogenic mechanism for the sexual dysfunction that often complicates temporal lobe epilepsy.

Adult

Kinetics of a carbamazepine-ethosuximide interaction.

Carbamazepine and ethosuximide are used together to treat epileptic mixed-seizure patterns. Since carbamazepine has been shown to induce drug-metabolizing enzyme(s) in the liver, it follows that carbamazepine may alter ethosuximide disposition. Six normal subjects took one 250-mg ethosuximide capsule twice each day for 55 consecutive doses (study days 1 to 28) and one 200-mg carbamazepine tablet each evening from study days 11 to 27. Plasma samples were collected on study days 10, 17, 21, and 28. Mean steady-state concentrations of ethosuximide declined by 17% from a preinduction (study day 10) level of 32.2 +/- 5.6 micrograms/ml to a postinduction level of 26.8 +/- 5.2 micrograms/ml on study day 28. Ethosuximide clearance increased (alpha = 0.05) between study days 10 and 28 from 0.664 +/- 0.120 to 0.800 +/- 0.0154 l/hr. The time course of induction was analyzed using a kinetic induction theory. Ethosuximide half-life was lowered from mean - 53.7 +/- 11.5 hr (before induction) to mean = 44.6 +/- 10.7 hr (after induction); the difference between some subjects was large. These data show that ethosuximide disposition is altered by carbamazepine.

Adult

Improvement in antiepileptic drug levels following reduction of intervals between clinic visits.

Antiepileptic drug levels (AEDLs) may reflect how well patients adhere to prescribed medical regimens. Of 30 patients on stable drug regimens AEDLs were increased in 33% by decreasing clinic visit intervals from a mean of 3.4 months to 1.1 months. The testing situation was applied to patients who had AEDLs in the "therapeutic range" (n = 15) as well as those with one or more AEDLs below "therapeutic range" (n = 15). In the latter group 73% of patients showed improvement in AEDLs. Although a less reliable parameter, verbally reported seizure frequencies were also improved. Overall, the reduction in clinic visit interval could be expected to yield improvement in 46 to 80% (confidence interval = 95%). These patients responded equally well to physician and non-physician practitioners. This technique may be useful as an intervening measure for those patients who are noncompliant.

Adolescent

Prognostic implications of neuropsychological test performance for surgical treatment of epilepsy.

Surgical treatment of epilepsy is undertaken on the basis of prognostically favorable clinical and laboratory data. Analysis of neuropsychological test data obtained preoperatively and postoperatively from 14 surgically treated patients indicates that specific measures of neuropsychological test performance may provide prognostic information aside from the utility of this testing for lateralization and localization. An impairment Index which is derived from the extensive test battery was related to change of seizure frequency. The groups of patients which have an improved or seizure-free status postoperatively also have the least preoperative neuropsychological impairment. The group of patients which did not show improvement of seizure frequency had a younger mean age at onset of seizures (x = 6.7 years), while the group which was rendered seizure free had a later age at onset (x = 17.2 years). There was no relationship for the duration of seizures prior to surgery and the outcome following surgery.

Adolescent