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Biomedical subjects

S Wiebe

Publications and source records attributed to S Wiebe.

At least 19 recordsLinked to original sources
PubMed2006

Practice parameter: prediction of outcome in comatose survivors after cardiopulmonary resuscitation (an evidence-based review) [RETIRED]: report of the Quality Standards Subcommittee of the American Academy of Neurology.

OBJECTIVE: To systematically review outcomes in comatose survivors after cardiac arrest and cardiopulmonary resuscitation (CPR). METHODS: The authors analyzed studies (1966 to 2006) that explored predictors of death or unconsciousness after 1 month or unconsciousness or severe disability after 6 months. RESULTS: The authors identified four class I studies, three class II studies, and five class III studies on clinical findings and circumstances. The indicators of poor outcome after CPR are absent pupillary light response or corneal reflexes, and extensor or no motor response to pain after 3 days of observation (level A), and myoclonus status epilepticus (level B). Prognosis cannot be based on circumstances of CPR (level B) or elevated body temperature (level C). The authors identified one class I, one class II, and nine class III studies on electrophysiology. Bilateral absent cortical responses on somatosensory evoked potential studies recorded 3 days after CPR predicted poor outcome (level B). Burst suppression or generalized epileptiform discharges on EEG predicted poor outcomes but with insufficient prognostic accuracy (level C). The authors identified one class I, 11 class III, and three class IV studies on biochemical markers. Serum neuron-specific enolase higher than 33 microg/L predicted poor outcome (level B). Ten class IV studies on brain monitoring and neuroimaging did not provide data to support or refute usefulness in prognostication (level U). CONCLUSION: Pupillary light response, corneal reflexes, motor responses to pain, myoclonus status epilepticus, serum neuron-specific enolase, and somatosensory evoked potential studies can reliably assist in accurately predicting poor outcome in comatose patients after cardiopulmonary resuscitation for cardiac arrest.

Cardiopulmonary Resuscitation↗
PubMed2006

Sleep apnea in patients with myasthenia gravis.

To assess the prevalence of obstructive sleep apnea (OSA) in myasthenia gravis, the authors identified patients at risk of OSA using the multivariable apnea prediction index. OSA was diagnosed with polysomnography. The prevalence of OSA was 36% compared to an expected prevalence of 15 to 20% in the general population. When including the presence of daytime sleepiness (OSA syndrome), the prevalence was 11% compared to 3% in the general population.

Adult↗
PubMed2006

Hippocampal electrical stimulation in mesial temporal lobe epilepsy.

BACKGROUND: Adjustable, reversible therapies are needed for patients with pharmacoresistant epilepsy. Electrical stimulation of the hippocampus has been proposed as a possible treatment for mesial temporal lobe epilepsy (MTLE). METHODS: Four patients with refractory MTLE whose risk to memory contraindicated temporal lobe resection underwent implantation of a chronic stimulating depth electrode along the axis of the left hippocampus. The authors used continuous, subthreshold electrical stimulation (90 microsec, 190 Hz) and a double blind, multiple cross-over, randomized controlled design, consisting of three treatment pairs, each containing two 1-month treatment periods. During each treatment pair the stimulator was randomly turned ON 1 month and OFF 1 month. Outcomes were assessed at monthly intervals in a double blind manner, using standardized instruments and accounting for a washout period. The authors compared outcomes between ON, OFF, and baseline periods. RESULTS: Hippocampal stimulation produced a median reduction in seizures of 15%. All but one patient's seizures improved; however, the results did not reach significance. Effects seemed to carry over into the OFF period, and an implantation effect cannot be ruled out. The authors found no significant differences in other outcomes. There were no adverse effects. One patient has been treated for 4 years and continues to experience substantial long-term seizure improvement. CONCLUSION: The authors demonstrate important beneficial trends, some long-term benefits, and absence of adverse effects of hippocampal electrical stimulation in mesial temporal lobe epilepsy. However, the effect sizes observed were smaller than those reported in non-randomized, unblinded studies.

Adult↗
PubMed2005

Event-related potential measures of the disruptive effects of trains of auditory stimuli during waking and sleeping states.

Acoustic backup alarms have been reported to particularly disrupt sleep. The present study simulated backup alarms by presenting trains of five consecutive 500 ms duration audible tones, with the time between the onset of each tone being 1 s and the time between trains (offset to onset) between 15 and 20 s. In different conditions, the tones were set at either 80 or 60 dB sound pressure level (SPL). Twelve young adults spent two consecutive nights in the laboratory. Stimuli were presented only on the second night. Measures of traditional sleep architecture (sleep stages) were not affected by the acoustic trains. Event-related potentials were also measured following presentation of the stimuli. In the waking state, the initial 80 dB stimulus elicited a large amplitude N1, peaking at about 100 ms, followed by a positive peak, P3, peaking at about 325 ms. N1 was attenuated following presentation of the 60 dB stimulus. The amplitude of N1 was much reduced following presentation of the subsequent second to fifth stimuli in the train. During non-rapid eye movement (NREM) sleep, the initial 80 dB stimulus elicited a large and later negativity (N350) that was reduced in amplitude for the 60 dB stimulus. A K-Complex (a composite N350 and a much larger N550) was elicited following 35% of the initial 80 dB tones and 12% of the initial 60 dB tones. The amplitude of N550 did not, however, significantly vary as a function of stimulus SPL. During REM sleep, N1 continued to be elicited by the initial louder stimulus, but the later positive wave was not apparent. A late negativity peaking at about 350 ms was, however, apparent. When queried the next morning, subjects rarely indicated that the stimulus presentations disturbed their sleep. This might be because of the absence of the late positivity. The presence of the long latency negativities (N350 and N550) might serve to protect sleep from obtrusive sound during sleep.

Acoustic Stimulation↗
PubMed2004

Intensive chemotherapy with idarubicin, cytarabine, etoposide, and G-CSF priming in patients with advanced myelodysplastic syndrome and high-risk acute myeloid leukemia.

In an attempt to improve the complete remission (CR) rates and to prolong the remission duration especially in elderly patients > 50 years of age, we have used a combination chemotherapy of idarubicin (10 mg/m2 IV x 3 days), cytarabine (AraC, 100 mg/m2 CIVI x 7d), and etoposide (100 mg/m2 x 5 days) in combination with granulocyte colony-stimulating factor (G-CSF) priming [5 mg/kg SQ day 1 until absolute neutrophil count (ANC) recovery] for remission induction. Responding patients received two consolidation courses of idarubicin, AraC, and etoposide, followed by a late consolidation course of intermediate-dose AraC (600 mg/m2 IV every 12 h x 5 days) and amsacrine (60 mg/m2 IV x 5 days). A total of 112 patients (57 male/55 female) with a median age of 58 years (range: 22-75) have been entered and are evaluable for response: 19 refractory anemia with excess of blast cells in transformation (RAEB-T), 84 acute myeloid leukemia (AML) evolving from myelodysplastic syndrome (MDS), and 9 secondary AML after chemotherapy/radiotherapy. The overall CR rate was 62%, partial remission (PR) rate 10%, treatment failure 16%, and early death rate 12%. The CR rate was higher in patients < or = 60 years (68 vs 55%), mainly due to a lower early death rate (5 vs 21%, p<0.001). After a median follow-up of 58 months, the median overall survival is 14.5% and median duration of relapse-free survival 8 months. After 60 months, the probability of CR patients to still be in CR and alive is 16% (20% in patients < or = 60 years and 13% in patients >60 years), while the probability of overall survival is 12% (15% in patients < or = 60 years and 9% in patients > 60 years). Compared to our previous trial (AML-MDS Study 01-92) which was done with identical chemotherapy but no G-CSF priming in 110 patients with RAEB-T, AML after MDS, or secondary AML (identical median age, age range, and distribution of subtypes), the CR rate in all patients, as well as CR rate, overall survival, and relapse-free survival in patients > 60 years have significantly been improved. Thus, intensive chemotherapy with G-CSF priming is both well tolerated and highly effective for remission induction in these high-risk patients.

Acute Disease↗
PubMed2004

Predictors of epilepsy surgery outcome: a meta-analysis.

The potential efficacy of temporal and extratemporal resection in patients with partial epilepsy uncontrolled by anti-epileptic drugs is undisputed. However, there are still uncertainties about which patients will benefit most. A systematic review of the available literature has been undertaken by four pairs of reviewers to assess the overall outcome of epilepsy surgery and to identify factors better correlated to seizure outcome. A Medline search for studies on epilepsy surgery published since 1984 was performed. Studies were included if they had a well-defined population and design, a sample size of at least 30 patients, an MRI performed in least 90% of cases, an expected duration of follow-up of at least one year, and a post-operative outcome measured as seizure remission. A good outcome was considered as seizure control or seizure-free status for at least one year or Engel class I. Based on the review of 47 articles meeting all the eligibility criteria, febrile seizures (odds ratio, OR, 0.48; 95% confidence interval, CI, 0.27-0.83), mesial temporal sclerosis (OR 0.47; 95% CI 0.35-0.64), tumors (OR 0.58; 95% CI 0.42-0.80), abnormal MRI (OR 0.44; 95% CI 0.29-0.65), EEG/MRI concordance (OR 0.52; 95% CI 0.32-0.83), and extensive surgical resection (OR 0.24; 95% CI 0.16-0.36) were the strongest prognostic indicators of seizure remission (positive predictors); by contrast, post-operative discharges (OR 2.41; 95% CI 1.37-4.27) and intracranial monitoring (OR 2.72; 95% CI 1.60-4.60) predicted an unfavorable prognosis (negative predictors). Firm conclusions cannot be drawn for extent of resection, EEG/MRI concordance and post-operative discharges for the heterogeneity of study results. Neuromigrational defects, CNS infections, vascular lesions, interictal spikes, and side of resection did not affect the chance of seizure remission after surgery. Despite a number of limitations, the results of the review provide some insight into the selection of the best surgical candidates in clinical practice but raise concerns on the quality of published reports, and may serve as the basis for the identification of better standards to assess surgical outcome in observational studies.

Adolescent↗
PubMed2003

Seizure identification by clinical description in temporal lobe epilepsy: how accurate are we?

OBJECTIVE: To determine the accuracy of the clinical history performed by epileptologists in the identification of seizures in patients with suspected temporal lobe epilepsy. METHODS: The clinical and EEG telemetry (EEGT) monitoring data of 88 patients with suspected refractory temporal lobe seizures referred for evaluation of epilepsy surgery were prospectively evaluated. All clinical events obtained by history in these patients were adjudicated as being a seizure or not by two blinded (without access to EEG data) independent epileptologists. Each clinical event was then matched with the corresponding clinical event recorded with EEG telemetry in the epilepsy monitoring unit (gold standard). Sensitivity, specificity, overall accuracy, predictive value, and interrater agreement for the clinical assessment were obtained. RESULTS: Of 357 clinically different events, 175 (49%) were reproduced in the epilepsy monitoring unit. Only 10 events were misidentified by history as being a seizure or not, resulting in an overall clinical accuracy of 94%. Epileptologists' sensitivity for seizure identification was 96% (95% CI 92, 98%) but specificity was only 50% (95% CI 22, 79%). Accuracy for complex partial seizures and generalized seizures was higher than for simple partial seizures (SPS). Misidentification occurred only with SPS and nonepileptic events. Agreement beyond chance among epileptologists was good. CONCLUSION: In this selected group of patients with temporal lobe epilepsy, seizure identification by clinical history is highly accurate. Epileptologists rarely miss seizures (high sensitivity) but more often overcall nonepileptic events as seizures (low specificity).

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↗
PubMed2002

Clinically important change in quality of life in epilepsy.

BACKGROUND: Health related quality of life (HRQOL) is increasingly recognised as an important outcome in epilepsy. However, interpretation of HRQOL data is difficult because there is no agreement on what constitutes a clinically important change in the scores of the various instruments. OBJECTIVES: To determine the minimum clinically important change, and small, medium, and large changes, in broadly used epilepsy specific and generic HRQOL instruments. METHODS: Patients with difficult to control focal epilepsy (n = 136) completed the QOLIE-89, QOLIE-31, SF-36, and HUI-III questionnaires twice, six months apart. Patient centred estimates of minimum important change, and of small, medium, and large change, were assessed on self administered 15 point global rating scales. Using regression analysis, the change in each HRQOL instrument that corresponded to the various categories of change determined by patients was obtained. The results were validated in a subgroup of patients tested at baseline and at nine months. RESULTS: The minimum important change was 10.1 for QOLIE-89, 11.8 for QOLIE-31, 4.6 for SF-36 MCS, 3.0 for SF-36 physical composite score, and 0.15 for HUI-III. All instruments differentiated between no change and minimum important change with precision, and QOLIE-89 and QOLIE-31 also distinguished accurately between minimum important change and medium or large change. Baseline HRQOL scores and the type of treatment (surgical or medical) had no impact on any of the estimates, and the results were replicated in the validation sample. CONCLUSIONS: These estimates of minimum important change, and small, medium, and large changes, in four HRQOL instruments in patients with epilepsy are robust and can distinguish accurately among different levels of change. The estimates allow for categorisation of patients into various levels of change in HRQOL, and will be of use in assessing the effect of interventions in individual patients.

Activities of Daily Living↗
PubMed2001

A randomized, controlled trial of surgery for temporal-lobe epilepsy.

BACKGROUND: Randomized trials of surgery for epilepsy have not been conducted, because of the difficulties involved in designing and implementing feasible studies. The lack of data supporting the therapeutic usefulness of surgery precludes making strong recommendations for patients with epilepsy. We conducted a randomized, controlled trial to assess the efficacy and safety of surgery for temporal-lobe epilepsy. METHODS: Eighty patients with temporal-lobe epilepsy were randomly assigned to surgery (40 patients) or treatment with antiepileptic drugs for one year (40 patients). Optimal medical therapy and primary outcomes were assessed by epileptologists who were unaware of the patients' treatment assignments. The primary outcome was freedom from seizures that impair awareness of self and surroundings. Secondary outcomes were the frequency and severity of seizures, the quality of life, disability, and death. RESULTS: At one year, the cumulative proportion of patients who were free of seizures impairing awareness was 58 percent in the surgical group and 8 percent in the medical group (P<0.001). The patients in the surgical group had fewer seizures impairing awareness and a significantly better quality of life (P<0.001 for both comparisons) than the patients in the medical group. Four patients (10 percent) had adverse effects of surgery. One patient in the medical group died. CONCLUSIONS: In temporal-lobe epilepsy, surgery is superior to prolonged medical therapy. Randomized trials of surgery for epilepsy are feasible and appear to yield precise estimates of treatment effects.

Adult↗
PubMed2001

Temporal epileptogenesis: localizing value of scalp and subdural interictal and ictal EEG data.

PURPOSE: To determine the value of scalp epileptiform EEG data and subdural interictal spikes in localizing temporal epileptogenesis among patients requiring invasive recordings. For this delineation, we related such factors to site of subdural seizure origin in 27 consecutive patients. METHODS: Patients with temporal lobe epilepsy whose non-invasive lateralizing data were inconclusive and therefore required subdural electroencephalography were studied. All patients had (a) 24-h scalp telemetered EEGs, (b) adequate bitemporal subdural placements with an inferomesial line extending from a posterior burr hole anteriorly to <2.5 cm from anterior uncus and a lateral line reaching within 2.5 cm of the temporal tip, and (c) > or =2 subdurally recorded seizures. RESULTS: Three hundred one (96%) of 314 subdurally recorded clinical seizures involving all 27 patients arose from a discrete focus; 266 (85%) arose from mesial temporal regions, which was the origin of the majority of seizures in 24 (89%) patients. The majority of subdural seizures arose ipsilateral to the majority of scalp EEG spikes in 22 (81%) of 27, and most subdural seizures of 15 (75%) of 20 arose ipsilateral to scalp seizures. Lateralization of interictal subdural spikes correlated with that of subdural seizures in 74-92% of patients, depending on the method of spike compilation: for example, most subdural seizures arose from the same lobe of most consistent principal temporal spikes in 92% of patients. These indices of epileptogenesis also appeared more commonly on the side of effective (> or =90% improvement) temporal lobectomy than contralaterally in the following proportions: most consistent principal subdural spikes, 86% of patients ipsilateral vs. 9% contralateral; scalp-recorded clinical seizures, 55% vs. 18%; scalp EEG spikes, 45% vs. 9%. CONCLUSIONS: Even among patients whose scalp data are sufficiently complex to require invasive recording for clarification, lateralization of temporal scalp interictal and ictal epileptiform activity and subdural interictal spikes should be included when assessing the side of temporal epileptogenesis.

Brain Mapping↗
PubMed2001

Changes in quality of life in epilepsy: how large must they be to be real?

PURPOSE: The study goal was to assess the magnitude of change in generic and epilepsy-specific health-related quality-of-life (HRQOL) instruments needed to exclude chance or error at various levels of certainty in patients with medically refractory epilepsy. METHODS: Forty patients with temporal lobe epilepsy and clearly defined criteria of clinical stability received HRQOL measurements twice, 3 months apart, using the Quality of Life in Epilepsy Inventory-89 and -31 (QOLIE-89 and QOLIE-31), Liverpool Impact of Epilepsy, adverse drug events, seizure severity scales, and the Generic Health Utilities Index (HUI-III). Standard error of measurement and test-retest reliability were obtained for all scales and for QOLIE-89 subscales. Using the Reliable Change Index described by Jacobson and Truax, we assessed the magnitude of change required by HRQOL instruments to be 90 and 95% certain that real change has occurred, as opposed to change due to chance or measurement error. RESULTS: Clinical features, point estimates and distribution of HRQOL measures, and test-retest reliability (all > 0.70) were similar to those previously reported. Score changes of +/-13 points in QOLIE-89, +/-15 in QOLIE-31, +/-6.3 in Liverpool seizure severity-ictal, +/-11 in Liverpool adverse drug events, +/-0.25 in HUI-III, and +/-9.5 in impact of epilepsy exclude chance or measurement error with 90% certainty. These correspond, respectively, to 13, 15, 17, 18, 25, and 32% of the potential range of change of each instrument. CONCLUSIONS: Threshold values for real change varied considerably among HRQOL tools but were relatively small for QOLIE-89, QOLIE-31, Liverpool Seizure Severity, and adverse drug events. In some instruments, even relatively large changes cannot rule out chance or measurement error. The relation between the Reliable Change Index and other measures of change and its distinction from measures of minimum clinically important change are discussed.

Adult↗
PubMed2000

Epidemiology of temporal lobe epilepsy.

To fulfill its task of informed clinical decision making and resource allocation, epidemiological studies in epilepsy must adhere to a series of methodological standards. These are reviewed. Because seizure and epilepsy classification systems may be viewed as extensions of the diagnosis, they have direct implications in the acquisition and interpretation of epidemiologic data. The International League Against Epilepsy (ILAE) classification systems are analyzed in this light. Finally, the lack of Canadian epidemiological studies is addressed, and the relevance and potential of Canadian epidemiological data in epilepsy is discussed.

Canada↗
PubMed2000

Seizure control as an indicator of therapeutic usefulness.

Seizure control, in addition to quality of life, is an important outcome after epilepsy surgery. However, seizure measurement is not straightforward. We explore some important difficulties in obtaining unbiased, reliable estimates of seizure frequency, and discuss aspects of data analysis as it pertains to validity and clinical meaningfulness. As seizure severity is an integral component of seizure outcome assessment, we discuss aspects of measurement of this outcome. Suggestions for improving validity are offered, based on the literature and on methodological common sense. Finally, we look at the Canadian perspective and the potential for adopting methodology that allows for data pooling and for more powerful analyses.

Epilepsy↗
PubMed2000

Measuring quality of life in epilepsy surgery patients.

Treatment of chronic conditions often entails trade-offs between benefits and risks or side effects. This is of particular importance in epilepsy. Consequently, assessment of effectiveness must incorporate this trade-off as perceived by the recipient of the intervention, ie., the patient. Measurement of health related quality of life (HRQOL) aims at capturing such patient-centred effects of therapy. Conceptual aspects of HRQOL are described and issues relevant to outcomes of epilepsy surgery are addressed. Finally, practical aspects of measurement in the context of epilepsy surgery are discussed.

Epilepsy↗
PubMed2000

Psychological adjustment to success and to failure following epilepsy surgery.

Treatment-refractory epilepsy can directly impair psychological adjustment and quality of life. Epilepsy surgery is viewed by the patient as a stressful life event, arrived at after extensive deliberation. It is accompanied by expectations and anxiety for patients and their families. We suggest that the success of epilepsy surgery (as reflected by patient-perceived impact on quality of life) depends not only on reduced seizure frequency, but on personality factors and psychosocial issues. This paper reviews our research on these factors, along with suggestions for psychological assessment (of quality of life, and of personality) and psychological treatment. Studies of quality of life in patients undergoing temporal lobectomy are also examined. Finally, factors leading to the perception of "failed" epilepsy surgery are considered, along with suggested ways to manage such cases.

Adaptation, Psychological↗