151 research outputs found
Darstellung des Fasciculus Arcuatus durch deterministische Faserbahnenberechnungen aus diffusionsgewichteteten MR-Aufnahmen im Rahmen einer retrospektiven Studie
Diffusion Tensor Imaging (kurz DTI) ist Gegenstand aktueller Forschung, um subkortikale neuronale Netzwerke in Ihrer Anatomie und Funktion zu verstehen. Durch den Vorteil der Nicht-InvasivitĂ€t und der kurzen Untersuchungszeit fĂŒr den Patienten im Vergleich zur etablierten funktionellen Magnetresonanztomographie (kurz fMRT), sollte die klinische Relevanz zum Beispiel fĂŒr eine prĂ€operative neurochirurgische Diagnostik eruiert werden. Insbesondere kortikale Hirnregionen und Assoziationsfasern, die im Zusammenhang mit Sprachproduktion und SprachverstĂ€ndnis stehen, mĂŒssen bei neurochirurgischen Eingriffen möglichst geschont werden. Mehrere Forschungsgruppen konnten bereits relevante Assoziationsfasern innerhalb der weiĂen Hirnsubstanz, zu der der Fasciculus Arcuatus zĂ€hlt, mittels Fasertraktographie darstellen und in Zusammenhang mit den Ergebnissen etablierter fMRT-Methoden zur Identifikation von kortikalen Spracharealen bringen.
Aus diesen Ăberlegung ergaben sich drei Zielsetzungen fĂŒr diese Arbeit. Als erstes Ziel sollte ein Fasertraktographie-Algorithmus entworfen werden, der mithilfe weniger Datenprozessierungsschritte aus den Diffusionsdaten den Arcuatus Fasciculus als wichtige Assoziationsfaser der SprachdomĂ€ne identifiziert und welcher zudem fĂŒr Patienten mit neuropathologischen Erkrankungen verwendbar ist. Als zweite Zielsetzung sollte untersucht werden, ob eine strukturelle interhemisphĂ€rische Seitendifferenz in der Anzahl der zum Arcuatus Fasciculus zugehörigen Fasern gefunden werden kann. Die dritte Zielsetzung widmet sich der Untersuchung der Sprachdominanz des Patienten im Rahmen dessen die Seitendifferenz in Anzahl der Fasern mit den funktionellen Ergebnissen aus der fMRT korreliert werden.
DiffusionsdatensĂ€tze von 34 Patienten mit epileptischen Erkrankungen und extra- sowie intraaxialen Hirntumoren wurden mittels deterministischer Fasertraktographie verarbeitet, um fĂŒr jeden Patienten die Gesamtheit der zerebralen Faserbahnen zu identifizieren. AnschlieĂend wurde aus dieser Gesamtheit mittels weniger Prozessierungsschritte der Arcuatus Fasciculus fĂŒr beide HemisphĂ€ren getrennt dargestellt und die Anzahl der zugehörigen Fasern bestimmt. Bei sechs Patienten konnten aufgrund mangelnder DatenqualitĂ€t nicht ausreichend Faserbahnen im Arcuatus Fasciculus erfasst werden. Die Ergebnisse der restlichen 28 Patienten wurden mit den zugehörigen fMRT-Befunde korreliert.
Der in dieser Arbeit aufgefĂŒhrte Algorithmus zur Fasertraktographie des Arcuatus Fasciculus konnte anhand weniger Datenverarbeitungsschritte bei 28 von 34 Patienten der Arcuatus Fasciculus fĂŒr beide HemisphĂ€ren darstellen. AuĂerdem konnte gezeigt werden, dass eine individuelle Platzierung von Regions-of-Interest die SensitivitĂ€t fĂŒr die Erfassung der neuronalen Fasern erhöht. ZusĂ€tzlich fanden sich bei 25 von 28 Patienten interhemisphĂ€rische Unterschiede von mehr als 10 Fasern, sodass eine Untersuchung der Sprachdominanz anhand dieser Differenzen möglich ist. SchlieĂlich konnte gezeigt werden, dass in 91% der FĂ€lle die interhemisphĂ€rische Seitendifferenz im Fasertraktographie mit den funktionellen Seitendifferenzen im fMRT ĂŒbereinstimmt.
Daher demonstriert diese Arbeit die klinische Relevanz der DTI als nicht-invasive Bildgebung subkortikaler Sprachnetzwerke zu Forschungszwecken und zur prĂ€operativen Diagnostik vor neurochirurgischen und interventionellen Eingriffen. Durch Anpassung des Algorithmus kann der Anwendungsbereich auf andere subkortikale Netzwerke erweitert und durch Anwendung an gröĂeren und definierten Patientengruppen die Signifikanz der Ergebnisse gesichert werden
Development of the Cauda Equina Syndrome Core Outcome Set for research studies
Abstract Chapter1: Cauda Equina Syndrome (CES) is an emergency condition that requires acute intervention and can lead to permanent neurological deficit in working age adults. A Core Outcome Set (COS) is the minimum set of outcomes that should be reported in any future research study within a specific disease area. A COS for patients with CES will be developed for use in future research studies. Chapter 2&3: A systematic literature review (SLR) was performed using PRISMA guidelines to document the outcomes used in CES studies. A total of 1873 studies were identified of which 61 met the inclusion criteria. There were 737 verbatim outcome terms reported. There was significant heterogeneity in the outcomes reported for studies after surgery for CES patients. The duration from the start of the CES to the operation was also analysed in these studies. There was significant heterogeneity in the reporting and definition of the timing to intervention in CES. Chapter 4: The outcomes of importance to patients and the lived experience of CES considering its severity was elicited through semi structured qualitative interviews. A sampling frame was used, interviews were consented for, audio recorded and transcribed for thematic analysis using NVivo. Data saturation was achieved with 22 participants. Initially, 260 verbatim outcome terms were identified- 43 of which were not identified in the SLR. Further in depth analysis revealed 4 themes of 1) varying priorities of physical health, 2) a fragmented healthcare service 3) the process of adjustment, and 4) anticipatory anxiety and diminished sense of self-worth. Chapter 5: Outcomes were combined and condensed from the SLR and from the qualitative interviews with CES patients. This resulted in 37 outcomes that were rated through two rounds of an international Delphi survey. The Delphi survey included 172 participants (104 patients, 68 healthcare professionals) who completed both rounds. The results were presented at an international consensus meeting attended by 34 key stakeholders (16 patients and 18 healthcare professionals). Sixteen outcomes were chosen for inclusion in the COS. They are incontinence of urine, urinary retention, sensation of bladder fullness, faecal incontinence, physical ability to have sexual intercourse, perineal sensation, sensation in genitals, leg muscle strength, pain due to abnormal sensation of non-painful stimulus, complications, global quality of life, occupational role functioning, social functioning, ability to do daily activities, mobility and walking and low mood and depression. Chapter 6: The COS was obtained by a transparent international consensus process involving healthcare professionals and patients with CES as key stakeholders. This COS is recommended for use in CES studies as the minimum set of outcomes to be collected
QuittyLink:Using Smartphones for Personal Counseling to Help People Quit Smoking
We present the design and evaluation of a smartphone app, QuittyLink, designed to help smokers reduce or stop smoking. Smoking cigarettes is a serious health risk and people who wish to quit often struggle to do so. It is well known that the most effective method of assisting smoking cessation is personal face-to-face counseling. However, this approach is only used by very few people wishing to quit for reasons such as inconvenience and personal shyness. In response to this we have created an app that provides personal counseling to users on their smartphone. The counseling content is authored by smoking cessation experts and is based on the userâs personal data and recent actual smoking behaviors collected through the smartphone. We deployed the QuittyLink app with people in their everyday lives to study how personal counseling on mobile phones would influence their smoking behaviors. We found that both the personal counseling and the ability to visualize and reflect on their own self-tracked smoking behaviors helped them form strategies to improve their ability to quit. Author Keywords Smoking cessation; health behavior change; mobile apps; personal counseling; self-tracking; interaction design. ACM Classification Keywords H.5.m. Information interfaces and presentation (e.g., HCI)
Protocol for the development of a core outcome set for cauda equina syndrome: systematic literature review, qualitative interviews, Delphi survey and consensus meeting
Incidental intracranial meningiomas: a systematic review and meta-analysis of prognostic factors and outcomes (vol 142, pg 211, 2019)
BackgroundIncidental discovery accounts for 30% of newly-diagnosed intracranial meningiomas. There is no consensus on their optimal management. This review aimed to evaluate the outcomes of different management strategies for these tumors.MethodsUsing established systematic review methods, six databases were scanned up to September 2017. Pooled event proportions were estimated using a random effects model. Meta-regression of prognostic factors was performed using individual patient data.ResultsTwenty studies (2130 patients) were included. Initial management strategies at diagnosis were: surgery (27.3%), stereotactic radiosurgery (22.0%) and active monitoring (50.7%) with a weighted mean follow-up of 49.5Â months (SDâ=â29.3). The definition of meningioma growth and monitoring regimens varied widely impeding relevant meta-analysis. The pooled risk of symptom development in patients actively monitored was 8.1% (95% CI 2.7-16.1). Associated factors were peritumoral edema (OR 8.72 [95% CI 0.35-14.90]) and meningioma diameterââ„â3Â cm (OR 34.90 [95% CI 5.17-160.40]). The pooled proportion of intervention after a duration of active monitoring was 24.8% (95% CI 7.5-48.0). Weighted mean time-to-intervention was 24.8Â months (SDâ=â18.2). The pooled risks of morbidity following surgery and radiosurgery, accounting for cross-over, were 11.8% (95% CI 3.7-23.5) and 32.0% (95% CI 10.6-70.5) respectively. The pooled proportion of operated meningioma being WHO grade I was 94.0% (95% CI 88.2-97.9).ConclusionThe management of incidental meningioma varies widely. Most patients who clinically or radiologically progressed did so within 5Â years of diagnosis. Intervention at diagnosis may lead to unnecessary overtreatment. Prospective data is needed to develop a risk calculator to better inform management strategies
More questions than answers to the diagnosis and management of cauda equina syndrome-Authors' reply
No abstract available
Presentation, management, and outcomes of cauda equina syndrome up to one year after surgery, using clinician and participant reporting: A multi-centre prospective cohort study.
BACKGROUND: Cauda equina syndrome (CES) results from nerve root compression in the lumbosacral spine, usually due to a prolapsed intervertebral disc. Evidence for management of CES is limited by its infrequent occurrence and lack of standardised clinical definitions and outcome measures. METHODS: This is a prospective multi-centre observational cohort study of adults with CES in the UK. We assessed presentation, investigation, management, and all Core Outcome Set domains up to one year post-operatively using clinician and participant reporting. Univariable and multivariable associations with the Oswestry Disability Index (ODI) and urinary outcomes were investigated. FINDINGS: In 621 participants with CES, catheterisation for urinary retention was required pre-operatively in 31% (191/615). At discharge, only 13% (78/616) required a catheter. Median time to surgery from symptom onset was 3 days (IQR:1-8) with 32% (175/545) undergoing surgery within 48 h. Earlier surgery was associated with catheterisation (OR:2.2, 95%CI:1.5-3.3) but not with admission ODI or radiological compression. In multivariable analyses catheter requirement at discharge was associated with pre-operative catheterisation (OR:10.6, 95%CI:5.8-20.4) and one-year ODI was associated with presentation ODI (r = 0.3, 95%CI:0.2-0.4), but neither outcome was associated with time to surgery or radiological compression. Additional healthcare services were required by 65% (320/490) during one year follow up. INTERPRETATION: Post-operative functional improvement occurred even in those presenting with urinary retention. There was no association between outcomes and time to surgery in this observational study. Significant healthcare needs remained post-operatively. FUNDING: DCN Endowment Fund funded study administration. Castor EDC provided database use. No other study funding was received
Nestin-expressing cell types in the temporal lobe and hippocampus: Morphology, differentiation, and proliferative capacity
Nestin is expressed in immature neuroepithelial and progenitor cell types and transiently upregulated in proliferative neuroglial cells responding to acute brain injury, including following seizures. In 36 temporal lobe specimens from patients with temporal lobe epilepsy (age range 8-60 years) we studied the number, distribution and morphology of nestin-expressing cells in the pes, hippocampus body, parahippocampal gyrus, amygdala, temporal cortex and pole compared to post mortem control tissues from 26 cases (age range 12 gestational weeks to 76 years). The proliferative fraction of nestin-expressing cells was also evaluated in selected regions, including recognized niches, using MCM2. Their differentiation was explored with neuronal (DCX, mushashi, ÎČIII tubulin, NeuN) and glial (GFAP, GFAPdelta, glutamine synthetase , aquaporin4) markers, both in sections and following culture. Findings were correlated with clinical parameters. A stereotypical pattern in the distribution and range of morphologies of nestin-expressing cells was observed, reminiscent of patterns in the developing brain, with increased densities in epilepsy compared to adult controls (p<0.001). Findings included MCM2-positive radial glial-like cells in the periventricular white matter and rows of nestin-expressing cells in the hippocampal fimbria and sulcus. Nestin cells represented 29% of the hippocampal proliferative fraction in epilepsy cases; 20% co-expressed ÎČIII tubulin in culture compared to 28% with GFAP, but they mainly lacked glial maturation (aquaporin 4 or glutamine synthetase expression). Significant correlations were noted between age at surgery, memory deficits and NEC populations. Temporal lobe nestin-expressing cells with ongoing proliferative capacity likely represent vestiges of developmental migratory streams and resident reactive cell populations of potential relevance to hippocampal epileptogenesis, temporal lobe pathology and co-morbidities, including memory decline
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