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Biomedical subjects

C Zahn

Publications and source records attributed to C Zahn.

10 recordsLinked to original sources
PubMed2004

Practice parameter: recurrent stroke with patent foramen ovale and atrial septal aneurysm: report of the Quality Standards Subcommittee of the American Academy of Neurology.

OBJECTIVES: 1) To evaluate the risk of subsequent stroke or death in patients with a cryptogenic stroke and a patent foramen ovale (PFO), atrial septal aneurysm (ASA), or both. 2) To establish the optimal method of stroke prevention in this population of patients. METHODS: MEDLINE, the Cochrane database of systematic reviews, key meeting abstracts from 1997 to 2002, and relevant reference lists were searched to select studies that prospectively collected outcome data in cryptogenic stroke patients with and without interatrial septal abnormalities. Studies were also selected that prospectively compared at least two treatment options. The quality of each study was graded (class I to IV) using a standard classification-of-evidence scheme for each question. Risk analyses were performed and data were pooled when appropriate. RESULTS: The literature search generated 129 articles of which only four fulfilled the inclusion and exclusion criteria. Two studies were graded class I, one study was graded class II, and one study was graded class IV for prognosis. Pooled results of the two class I and one class II studies demonstrated no increased risk of subsequent stroke or death in patients with PFO compared to those without (RR = 0.95, 95% CI 0.62 to 1.44). One class I study found increased risk of recurrent stroke in patients with PFO and ASA (annual rate = 3.8% versus 1.05%, RR = 2.98, 95% CI 1.17 to 7.58) but not increased risk of a composite of stroke and death (annual rate = 3.8% versus 1.8%, RR = 2.10, 95% CI 0.86 to 5.06). Regarding therapy, one study was graded class II, one study class III, and two studies class IV. Among patients with cryptogenic stroke and PFO or ASA, there was no significant difference in stroke or death rate in warfarin-treated patients relative to aspirin-treated patients and the confidence intervals were unable to rule out a benefit of one drug over the other (annual rate = 4.7% versus 8.9%, RR = 0.53, 95% CI 0.18 to 1.58). Minor bleeding rates were higher in the cohort of patients who received warfarin (22.9/100 patient-years versus 8.66/100 patient-years, rate ratio = 2.64, p < 0.001). No studies compared medical therapy with surgical or endovascular closure. CONCLUSION: PFO is not associated with increased risk of subsequent stroke or death among medically treated patients with cryptogenic stroke. However, both PFO and ASA possibly increase the risk of subsequent stroke (but not death) in medically treated patients younger than 55 years. In patients with a cryptogenic stroke and an atrial septal abnormality the evidence is insufficient to determine if warfarin or aspirin is superior in preventing recurrent stroke or death, but minor bleeding is more frequent with warfarin. There is insufficient evidence to evaluate the efficacy of surgical or endovascular closure.

Adult↗
PubMed2003

Practice parameter: temporal lobe and localized neocortical resections for epilepsy: report of the Quality Standards Subcommittee of the American Academy of Neurology, in association with the American Epilepsy Society and the American Association of Neurological Surgeons.

OBJECTIVES/METHODS: To examine evidence for effectiveness of anteromesial temporal lobe and localized neocortical resections for disabling complex partial seizures by systematic review and analysis of the literature since 1990. RESULTS: One intention-to-treat Class I randomized, controlled trial of surgery for mesial temporal lobe epilepsy found that 58% of patients randomized to be evaluated for surgical therapy (64% of those who received surgery) were free of disabling seizures and 10 to 15% were unimproved at the end of 1 year, compared with 8% free of disabling seizures in the group randomized to continued medical therapy. There was a significant improvement in quantitative quality-of-life scores and a trend toward better social function at the end of 1 year for patients in the surgical group, no surgical mortality, and infrequent morbidity. Twenty-four Class IV series of temporal lobe resections yielded essentially identical results. There are similar Class IV results for localized neocortical resections; no Class I or II studies are available. CONCLUSIONS: A single Class I study and 24 Class IV studies indicate that the benefits of anteromesial temporal lobe resection for disabling complex partial seizures is greater than continued treatment with antiepileptic drugs, and the risks are at least comparable. For patients who are compromised by such seizures, referral to an epilepsy surgery center should be strongly considered. Further studies are needed to determine if neocortical seizures benefit from surgery, and whether early surgical intervention should be the treatment of choice for certain surgically remediable epileptic syndromes.

Anticonvulsants↗
PubMed1999

Catamenial epilepsy: clinical aspects.

Many women with epilepsy (WWE) report changes in seizure frequency in relationship to their menstrual cycle. Evidence from animal experiments and studies in humans have demonstrated an ovarian steroid hormone effect on neuronal excitability, supporting a biologic basis for this fluctuation. The true scope of the problem as a health issue for WWE is unclear, and treatments have yet to be systematically evaluated. Further basic and clinical research is needed to clarify the etiology and pathogenesis of catamenial fluctuations in seizure frequency and to outline optimal management strategies.

Epilepsy↗
PubMed1998

Neurologic care of pregnant women with epilepsy.

Epilepsy is a common neurologic condition in women of reproductive age. Although their risks are greater than those for women in the general population, the majority of women with epilepsy have a good pregnancy outcome. An understanding of the risks and appropriate management of both the pregnancy and epilepsy in these patients is essential for their physicians. Health-care providers should discuss contraception and reproductive issues with all of their female patients with epilepsy as they enter reproductive age. Optimal care requires prepregnancy counseling, including information about contraception, dietary folate supplementation, and the risks related to pregnancy. Although antiepileptic drugs (AEDs) have been implicated as the major cause of teratogenesis in infants born to mothers with epilepsy, uncontrolled epilepsy is also associated with maternal and fetal risk. Therefore, optimal seizure control during pregnancy remains an important goal for women with epilepsy. Women with epilepsy should be counseled about breast-feeding their infants and supported in their decision. The recommendations in this article reflect those of a Practice Parameter developed by the American Academy of Neurology Quality Standards Subcommittee.

Abnormalities, Drug-Induced↗
PubMed1990

[Classification of hyperthyreosis using enzyme immunoassays for the detection of membrane and thyroglobulin antibodies].

Clinical signs and the determination of thyroid autoantibodies are usually used for the classification of hyperthyroidism. We examined the usefulness of two ELISA for the determination of membrane and thyroglobulin autoantibodies. 117 patients with Graves' disease, 53 patients with toxic goitre and 47 patients with unclear hyperthyroidism were inspected. The best classification into immunogenic and nonimmunogenic hyperthyroidism were achieved with the membrane antibodies at a borderline titre of greater than 1:400. The thyroglobulin antibodies were also useful and increased the security of the classification. We conclude that both tests are suitable for the classification of patients with hyperthyroidism and should be applied to the first diagnostic step in the immunological diagnostic of the thyroid.

Autoantibodies↗
PubMed1977

[Dose-dependent effects on phenobarbital on microsomal liver enzymes of chicken embryos (author's transl)].

Levels of cytochrome P-450 and the activities of amino-pyrinedemethylase and p-nitrophenol-UDP-glucuronyltransferase were measured in homogenates and microsomes of 16 to 19 day old chicken embryos exposed in ovo to phenobarbital. The activities of glucose-6-phosphatase were measured on the 19th day of incubation. After the highest dose of 3 X 8 mg phenobarbital, cytochrome P-450 increased 3-6fold, aminopyrinedemethylase activity 7fold and the activity of p-nitrophenol-UDP-glucuronyltransferase 3fold. Glucose-6-phosphatase activity was not increased but decreased. Corresponding to the given dose of phenobarbital (3X3, 3X4, 3X6, 3X8 mg) into the yolk sac an increase in enzyme activity levels mentioned above could as a rule be demonstrated at the level of p less than 0.0025. Calculated microsomal protein amounted to 43.0+/-6.5 mg/g liver.

Aminopyrine N-Demethylase↗
PubMedDate not supplied

Implementation of a change process to improve outcomes of patients admitted to epilepsy monitoring unit.

A continuous quality improvement in health care, combined with measurement of patient and organizational outcomes, is an international trend that promises improvement in meeting the needs of health care consumers in a cost-effective manner. A clinical improvement workshop was conducted in our institution to study the practical methods that can be used by clinical teams to improve the quality and value of health care. This workshop enabled the Epilepsy Team to identify change strategies that potentially could accelerate clinical improvement efforts in the epilepsy monitoring unit (EMU). The Team was able to develop, plan, and test improvements and link these improvements to patient outcomes.

Adult↗