11 research outputs found
Prognosis and therapy of tumor-related versus non-tumor-related status epilepticus: a systematic review and meta-analysis
Prognosis and therapy of tumor-related versus non-tumor-related status epilepticus: a systematic review and meta-analysis.
BACKGROUND: Status epilepticus (SE) is a medical emergency with high mortality rates. Of all SE's, 7% are caused by a brain tumor. Clinical guidelines on the management of SE do not make a distinction between tumor-related SE and SE due to other causes. However, pathophysiological research points towards specific mechanisms of epilepsy in brain tumors. We investigated whether clinical features support a distinct profile of tumor-related SE by looking at measures of severity and response to treatment. METHODS: Systematic review of the literature and meta-analysis of studies on adult SE that report separate data for tumor-related SE and non-tumor-related SE on the following outcomes: short-term mortality, long-term morbidity, duration of SE, and efficacy of anticonvulsant intervention. RESULTS: Fourteen studies on outcome of SE were included. Tumor-related SE was associated with higher mortality than non-tumor-related SE (17.2% versus 11.2%, RR 1.53, 95%-CI 1.24-1.90). After exclusion of patients with hypoxic-ischemic encephalopathy (a group with a known poor prognosis) from the non-tumor-group, the difference in mortality increased (17.2% versus 6.6%; RR 2.78, 95%-CI 2.21 - 3.47). Regarding long-term morbidity and duration of SE there were insufficient data. We did not find studies that systematically compared effects of therapy for SE between tumor- and non-tumor-related SE. CONCLUSIONS: Based on - mostly retrospective - available studies, short-term mortality seems higher in tumor-related SE than in SE due to other causes. Further studies on the outcome and efficacy of different therapeutic regimens in tumor-related SE are needed, to clarify whether tumor-related SE should be regarded as a distinct clinical entity
Figuring out drawing-induced epilepsy
Rare reflex epilepsies are a clinical curiosity but may also give insight into neurocognitive processes. The authors present a patient whose seizures were precipitated by drawing but not by writing. This dissociation complements previous reports on selective impairment of writing. EEG revealed a focus in the right frontal lobe with parietal spread. This is in accord with current cognitive and neural network models of drawing.status: publishe
Do clinicians use more question marks?
OBJECTIVE: To quantify the use of question marks in titles of published studies. DESIGN AND SETTING: Literature review. PARTICIPANTS: All Pubmed publications between 1 January 2013 and 31 December 2013 with an available abstract. Papers were classified as being clinical when the search terms clin*, med* or patient* were found anywhere in the paper's title, abstract or the journal's name. Other papers were considered controls. As a verification, clinical journals were compared to non-clinical journals in two different approaches. Also, 50 highest impact journals were explored for publisher group dependent differences. MAIN OUTCOME MEASURE: Total number of question marks in titles. RESULTS: A total of 368,362 papers were classified as clinical and 596,889 as controls. Clinical papers had question marks in 3.9% (95% confidence interval 3.8-4.0%) of titles and other papers in 2.3% (confidence interval 2.3-2.3%; p < 0.001). These findings could be verified for clinical journals compared to non-clinical journals. Different percentages between four publisher groups were found (p < 0.01). CONCLUSION: We found more question marks in titles of clinical papers than in other papers. This could suggest that clinicians often have a question-driven approach to research and scientists in more fundamental research a hypothesis-driven approach. An alternative explanation is that clinicians like catchy titles. Publishing groups might have pro- and anti-question mark policies
Do clinicians use more question marks?
OBJECTIVE: To quantify the use of question marks in titles of published studies. DESIGN AND SETTING: Literature review. PARTICIPANTS: All Pubmed publications between 1 January 2013 and 31 December 2013 with an available abstract. Papers were classified as being clinical when the search terms clin*, med* or patient* were found anywhere in the paper's title, abstract or the journal's name. Other papers were considered controls. As a verification, clinical journals were compared to non-clinical journals in two different approaches. Also, 50 highest impact journals were explored for publisher group dependent differences. MAIN OUTCOME MEASURE: Total number of question marks in titles. RESULTS: A total of 368,362 papers were classified as clinical and 596,889 as controls. Clinical papers had question marks in 3.9% (95% confidence interval 3.8-4.0%) of titles and other papers in 2.3% (confidence interval 2.3-2.3%; p < 0.001). These findings could be verified for clinical journals compared to non-clinical journals. Different percentages between four publisher groups were found (p < 0.01). CONCLUSION: We found more question marks in titles of clinical papers than in other papers. This could suggest that clinicians often have a question-driven approach to research and scientists in more fundamental research a hypothesis-driven approach. An alternative explanation is that clinicians like catchy titles. Publishing groups might have pro- and anti-question mark policies
Working memory deficits after resection of the dorsolateral prefrontal cortex predicted by functional magnetic resonance imaging and electrocortical stimulation mapping. Case report
Electrocortical stimulation mapping (ESM) is the clinical standard for localizing critical sensorimotor and language functions, but other functions can be assessed with this technique as well. The authors describe an 8-year-old girl with a left frontal desmoplastic gangliocytoma and medically intractable epilepsy who underwent a chronic invasive recording using electrode grids. Prior to electrode implantation, functional magnetic resonance (fMR) imaging was performed using a research protocol that included a working memory task. The ESM procedure interfered with working memory at a dorsolateral prefrontal site as predicted by fMR imaging, but because this site was part of the epileptogenic region, it was included in the resection. Since the operation the patient has been seizure free and her overall cognitive performance has improved. Yet she shows a selective impairment in working memory tasks that has persisted for over two years, indicating that the area identified using fMR imaging and ESM was critically involved in working memory. Her performance did improve, however, suggesting that compensatory mechanisms took place. This case reveals an important and perhaps critical function of the dorsolateral prefrontal cortex. Work continues to assess the specific cognitive functions subserved by the region identified with fMR imaging and ESM.status: publishe
EEG-fMRI correlation patterns in the presurgical evaluation of focal epilepsy: a comparison with electrocorticographic data and surgical outcome measures
Intracranial Recordings Reveal Unique Shape and Timing of Responses in Human Visual Cortex during Illusory Visual Events
During binocular rivalry, perception spontaneously changes without any alteration to the visual stimulus. What neural events bring about this illusion that a constant stimulus is changing? We recorded from intracranial electrodes placed on the occipital and posterior temporal cortex of two patients with epilepsy while they experienced illusory changes of a face-house binocular-rivalry stimulus or observed a control stimulus that physically changed. We performed within-patient comparisons of broadband high-frequency responses, focusing on single epochs recorded along the ventral processing stream. We found transient face- and house-selective responses localized to the same electrodes for illusory and physical changes, but the temporal characteristics of these responses markedly differed. In comparison with physical changes, responses to illusory changes were longer lasting, in particular exhibiting a characteristic slow rise. Furthermore, the temporal order of responses across the visual hierarchy was reversed for illusory as compared to physical changes: for illusory changes, higher order fusiform and parahippocampal regions responded before lower order occipital regions. Our tentative interpretation of these findings is that two stages underlie the initiation of illusory changes: a destabilization stage in which activity associated with the impending change gradually accumulates across the visual hierarchy, ultimately graduating in a top-down cascade of activity that may stabilize the new perceptual interpretation of the stimulus.status: publishe
Electrocorticographic dissociation of alpha and beta rhythmic activity in the human sensorimotor system
This study uses electrocorticography in humans to assess how alpha- and beta-band rhythms modulate excitability of the sensorimotor cortex during psychophysically-controlled movement imagery. Both rhythms displayed effector-specific modulations, tracked spectral markers of action potentials in the local neuronal population, and showed spatially systematic phase relationships (traveling waves). Yet, alpha- and beta-band rhythms differed in their anatomical and functional properties, were weakly correlated, and traveled along opposite directions across the sensorimotor cortex. Increased alpha-band power in the somatosensory cortex ipsilateral to the selected arm was associated with spatially-unspecific inhibition. Decreased beta-band power over contralateral motor cortex was associated with a focal shift from relative inhibition to excitation. These observations indicate the relevance of both inhibition and disinhibition mechanisms for precise spatiotemporal coordination of movement-related neuronal populations, and illustrate how those mechanisms are implemented through the substantially different neurophysiological properties of sensorimotor alpha- and beta-band rhythms
Electrocorticographic dissociation of alpha and beta rhythmic activity in the human sensorimotor system
This study uses electrocorticography in humans to assess how alpha- and beta-band rhythms modulate excitability of the sensorimotor cortex during psychophysically-controlled movement imagery. Both rhythms displayed effector-specific modulations, tracked spectral markers of action potentials in the local neuronal population, and showed spatially systematic phase relationships (traveling waves). Yet, alpha- and beta-band rhythms differed in their anatomical and functional properties, were weakly correlated, and traveled along opposite directions across the sensorimotor cortex. Increased alpha-band power in the somatosensory cortex ipsilateral to the selected arm was associated with spatially-unspecific inhibition. Decreased beta-band power over contralateral motor cortex was associated with a focal shift from relative inhibition to excitation. These observations indicate the relevance of both inhibition and disinhibition mechanisms for precise spatiotemporal coordination of movement-related neuronal populations, and illustrate how those mechanisms are implemented through the substantially different neurophysiological properties of sensorimotor alpha- and beta-band rhythms