CSF Pulse Pressure and B Waves

2005 ◽  
Vol 103 (4) ◽  
pp. 767-768 ◽  
Author(s):  
Zofia Czosnyka ◽  
Marek Czosnyka ◽  
John D. Pickard
Keyword(s):  
Pulse Pressure ◽  
Pressure Coefficient ◽  
Joint Effect ◽  
Physical Parameters ◽  
Wave Analysis ◽  
Short Term ◽  
Content Type ◽  
Pulse Pressure Method ◽  
Fine Print

Abstract Object. The appearance of numerous B waves during intracranial pressure (ICP) registration in patients with idiopathic adult hydrocephalus syndrome (IAHS) is considered to predict good outcome after shunt surgery. The aim of this study was to describe which physical parameters of the cerebrospinal fluid (CSF) system B-waves reflect and to find a method that could replace long-term B-wave analysis. Methods. Ten patients with IAHS were subjected to long-term registration of ICP and a lumbar constant-pressure infusion test. The B-wave presence, CSF outflow resistance (Rout), and relative pulse pressure coefficient (RPPC) were assessed using computerized analysis. The RPPC was introduced as a parameter reflecting the joint effect of elastance and pulsatory volume changes on ICP and was determined by relating ICP pulse amplitudes to mean ICP. Conclusions. The B-wave presence on ICP registration correlates strongly with RPPC (r = 0.91, p < 0.001, 10 patients) but not with CSF Rout. This correlation indicates that B waves—like RPPC—primarily reflect the ability of the CSF system to reallocate and store liquid rather than absorb it. The RPPC-assessing lumbar short-term CSF pulse pressure method could replace the intracranial long-term B-wave analysis.

Cerebrospinal fluid pulse pressure method: a possible substitute for the examination of B waves

2004 ◽  
Vol 101 (6) ◽  
pp. 944-950 ◽  
Author(s):  
Niklas Lenfeldt ◽  
Nina Andersson ◽  
Aina Ågren-Wilsson ◽  
A. Tommy Bergenheim ◽  
Lars-Owe D. Koskinen ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Pulse Pressure ◽  
Pressure Coefficient ◽  
Physical Parameters ◽  
Wave Analysis ◽  
Content Type ◽  
Pressure Method ◽  
Pulse Pressure Method ◽  
Fine Print

Object. The appearance of numerous B waves during intracranial pressure (ICP) registration in patients with idiopathic adult hydrocephalus syndrome (IAHS) is considered to predict good outcome after shunt surgery. The aim of this study was to describe which physical parameters of the cerebrospinal fluid (CSF) system B-waves reflect and to find a method that could replace long-term B-wave analysis. Methods. Ten patients with IAHS were subjected to long-term registration of ICP and a lumbar constant-pressure infusion test. The B-wave presence, CSF outflow resistance (Rout), and relative pulse pressure coefficient (RPPC) were assessed using computerized analysis. The RPPC was introduced as a parameter reflecting the joint effect of elastance and pulsatory volume changes on ICP and was determined by relating ICP pulse amplitudes to mean ICP. Conclusions. The B-wave presence on ICP registration correlates strongly with RPPC (r = 0.91, p < 0.001, 10 patients) but not with CSF Rout. This correlation indicates that B waves—like RPPC—primarily reflect the ability of the CSF system to reallocate and store liquid rather than absorb it. The RPPC-assessing lumbar short-term CSF pulse pressure method could replace the intracranial long-term B-wave analysis.

Relief of pain by transcutaneous stimulation

1975 ◽  
Vol 42 (3) ◽  
pp. 308-314 ◽  
Author(s):  
John D. Loeser ◽  
Richard G. Black ◽  
Amalia Christman
Keyword(s):  
Chronic Pain ◽  
Sensory Input ◽  
Therapeutic Modality ◽  
Short Term ◽  
Content Type ◽  
Transcutaneous Stimulation ◽  
Painful Area ◽  
Fine Print ◽  
Stimulation Of

✓ A series of 198 patients with chronic pain of diverse etiology was carefully analyzed for epidemiologic and descriptive factors which might influence the response to transcutaneous stimulation. The overall series included 12½% with long-term success, and 68% with partial or short-term relief. There were no consistent specific diagnoses, or epidemiologic or descriptive factors that made good results from stimulation predictable. Stimulation of the painful area itself was not always necessary for pain relief. Favorable responses to transcutaneous stimulation were usually correlated with the continued existence of significant sensory input from the painful region. The authors conclude that transcutaneous stimulation is a valuable therapeutic modality for some patients with chronic pain.

Long-term neurological, visual, and endocrine outcomes following transnasal resection of craniopharyngioma

2005 ◽  
Vol 102 (4) ◽  
pp. 650-657 ◽  
Author(s):  
Indro Chakrabarti ◽  
Arun P. Amar ◽  
William Couldwell ◽  
Martin H. Weiss
Keyword(s):  
Short Term Memory ◽  
Gh Deficiency ◽  
Memory Loss ◽  
Magnetic Resonance Images ◽  
Endocrine Function ◽  
Short Term ◽  
Term Memory ◽  
Content Type ◽  
Fine Print

Object. The authors report on a cohort of patients with craniopharyngioma treated principally through transnasal (TN) resection and followed up for a minimum of 5 years. More specifically, they evaluate the role of the TN approach in the management of craniopharyngioma. Methods. Between 1984 and 1994, 68 patients underwent TN resection of craniopharyngiomas at the University of Southern California. The tumor was at least partially cystic in 88% of cases. Four tumors were purely intrasellar, 53 had intra- and suprasellar components, and 11 were exclusively suprasellar. During the same period, 18 patients underwent transcranial (TC) resection of purely suprasellar craniopharyngiomas. Long-term neurological, visual, and endocrine outcomes were reviewed for all patients. In 61 (90%) of 68 patients in the TN group, total resection was achieved, according to 3-month postoperative magnetic resonance images, although four patients suffered a recurrence. Three (43%) of the seven tumors that had been partially resected were enlarged on serial imaging. Fifty-four (87%) of 62 patients with preoperative visual loss experienced improvement in one or both eyes, but two patients (3%) with exclusively suprasellar tumors experienced postoperative visual worsening in one or both eyes. New instances of postoperative endocrinopathy (that is, not present preoperatively) occurred as follows: hypogonadism (eight of 22 cases), growth hormone (GH) deficiency (four of 18 cases), hypothyroidism (11 of 49 cases), hypocortisolemia (nine of 52 cases), and diabetes insipidus (DI; four of 61 cases). One case each of hypocortisolemia and hypothyroidism resolved after surgery. Hyperphagia occurred in 27 (40%) of 68 patients. One patient had short-term memory loss. Postoperative complications included one case of cerebrospinal fluid leak. Among the 18 patients in the TC group, 11 had complete resections. In one case (9%) the tumors recurred. Three (43%) of the seven subtotally resected tumors grew during the follow-up interval. Vision improved in 11 (61%) of 18 cases and worsened in three (17%) as a result of surgery. New instances of postoperative endocrinopathy occurred as follows: hypogonadism (one of six cases), GH deficiency (four of seven cases), hypothyroidism (11 of 14 cases), hypocortisolemia (eight of 15 cases), and DI (nine of 16 cases). No instance of preoperative endocrinopathy was corrected through TC surgery. Four patients (22%) exhibited short-term memory loss and 11 (61%) had hyperphagia after surgery. When compared with those in the TC group, patients in the TN group had shorter hospital stays. Conclusions. Use of the TN approach can render good outcomes in properly selected patients with craniopharyngioma, particularly when the tumor is cystic. Even in mostly suprasellar cases, an extended TN approach can afford complete resection. Note that endocrine function often worsens after surgery and that postoperative obesity can be a significant problem.

Principles of preparation of vein bypass grafts to maximize patency

1987 ◽  
Vol 66 (2) ◽  
pp. 172-180 ◽  
Author(s):  
Thoralf M. Sundt ◽  
Thoralf M. Sundt
Keyword(s):  
Vitamin K Antagonists ◽  
Coronary Bypass ◽  
Short Term ◽  
Aneurysmal Dilatation ◽  
Content Type ◽  
Vein Bypass ◽  
Harvesting Techniques ◽  
Fine Print ◽  
Vein Harvesting

✓ Experience in cardiovascular and peripheral vascular surgery with saphenous vein bypass conduits is reviewed. It is clear that meticulous technique and graft preparation are crucial to short-term and long-term patency. The risk of early thrombosis is related to damage to the graft 's native intima, graft flow, and coagulability of the patient 's blood. Attention to atraumatic harvesting techniques and perfection of anastomoses are crucial to minimizing intimal damage. Graft inflow and outflow are fundamental principles. The use of vitamin K antagonists and platelet inhibitors may improve graft survival. Subacute occlusion is related to structural alterations in the grafts themselves. These include intimal hyperplasia and medial fibrosis as the grafts become “arterialized,” valve fibrosis, aneurysmal dilatation, clamp stenosis, and suture stenosis. Long-term patency is threatened primarily by atherosclerosis in the graft itself. There is some evidence that care in vein harvesting and implantation as well as the use of anticoagulant agents affect the development of this complication. A technique for graft preparation is presented that is based on the experience of the authors in harvesting grafts for both cerebral and coronary bypass conduits.

Dual-isotope single-photon emission computerized tomography scanning in patients with glioblastoma multiforme: association with patient survival and histopathological characteristics of tumor after high-dose radiotherapy

1998 ◽  
Vol 89 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Richard B. Schwartz ◽  
B. Leonard Holman ◽  
Joseph F. Polak ◽  
Basem M. Garada ◽  
Marc S. Schwartz ◽  
...  
Keyword(s):  
Survival Rate ◽  
Glioblastoma Multiforme ◽  
Single Photon ◽  
Photon Emission ◽  
High Dose ◽  
Term Survival ◽  
Content Type ◽  
Dual Isotope ◽  
Fine Print

Object. The study was conducted to determine the association between dual-isotope single-photon emission computerized tomography (SPECT) scanning and histopathological findings of tumor recurrence and survival in patients treated with high-dose radiotherapy for glioblastoma multiforme. Methods. Studies in which SPECT with 201Tl and 99mTc-hexamethypropyleneamine oxime (HMPAO) were used were performed 1 day before reoperation in 47 patients with glioblastoma multiforme who had previously been treated by surgery and high-dose radiotherapy. Maximum uptake of 201Tl in the lesion was expressed as a ratio to that in the contralateral scalp, and uptake of 99mTc-HMPAO was expressed as a ratio to that in the cerebellar cortex. Patients were stratified into groups based on the maximum radioisotope uptake values in their tumor beds. The significance of differences in patient gender, histological characteristics of tissue at reoperation, and SPECT uptake group with respect to 1-year survival was elucidated by using the chi-square statistic. Comparisons of patient ages and time to tumor recurrence as functions of 1-year survival were made using the t-test. Survival data at 1 year were presented according to the Kaplan—Meier method, and the significance of potential differences was evaluated using the log-rank method. The effects of different variables (tumor type, time to recurrence, and SPECT grouping) on long-term survival were evaluated using Cox proportional models that controlled for age and gender. All patients in Group I (201Tl ratio < 2 and 99mTc-HMPAO ratio < 0.5) showed radiation changes in their biopsy specimens: they had an 83.3% 1-year survival rate. Group II patients (201T1 ratio < 2 and 99mTc-HMPAO ratio of ≥ 0.5 or 201Tl ratio between 2 and 3.5 regardless of 99mTc-HMPAO ratio) had predominantly infiltrating tumor (66.6%); they had a 29.2% 1-year survival rate. Almost all of the patients in Group III (201Tl ratio > 3.5 and 99mTc-HMPAO ratio ≥ 0.5) had solid tumor (88.2%) and they had a 6.7% 1-year survival rate. Histological data were associated with 1-year survival (p < 0.01); however, SPECT grouping was more closely associated with 1-year survival (p < 0.001) and was the only variable significantly associated with long-term survival (p < 0.005). Conclusions. Dual-isotope SPECT data correlate with histopathological findings made at reoperation and with survival in patients with malignant gliomas after surgical and high-dose radiation therapy.

Long-term hearing preservation after surgery for vestibular schwannoma

2005 ◽  
Vol 102 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Simone A. Betchen ◽  
Jane Walsh ◽  
Kalmon D. Post
Keyword(s):  
Hearing Preservation ◽  
Magnetic Resonance Images ◽  
Class I ◽  
Repeated Testing ◽  
Content Type ◽  
Factors Influencing ◽  
Long Term Preservation ◽  
Fine Print

Object. Vestibular schwannomas (VSs) are now amenable to resection with excellent hearing preservation rates. It remains unclear whether immediately postoperative hearing is a durable result and will not diminish over time. The aim of this study was to determine the rate of long-term preservation of functional hearing following surgery for a VS and to examine factors influencing hearing preservation. Methods. All patients eligible for hearing preservation (Gardner—Robertson Class I or II) who had undergone resection of a VS by a single surgeon were reviewed retrospectively. Follow-up audiograms and magnetic resonance images were obtained. Of 142 patients deemed eligible for hearing preservation surgery, 38 had immediate postoperative hearing confirmed by an audiogram. In these patients with preserved hearing, the audiographic results demonstrated functional hearing in 30 (85.7%) of 35 patients who underwent repeated testing at a mean follow-up time of 7 years. Delayed hearing loss occurred in five (14.3%) of the 35 patients and did not correlate significantly with the size of the tumor. Hearing improved one Gardner—Robertson class postoperatively in three (7.9%) of the 38 patients. Conclusions. Long-term functional hearing was maintained in 85.7% of patients when it was preserved immediately postoperatively and the result was independent of tumor size. The results of this study emphasize that long-term preservation of functional hearing is a realistic goal following VS surgery and should be attempted in all patients in whom preoperative hearing is determined to be Gardner—Robertson Class I or II.

The chicken and egg story of a call centre in Malaysia

2021 ◽  
Vol 11 (3) ◽  
pp. 1-25
Author(s):  
Alan Fun-Foo Chan ◽  
Keng-Kok Tee ◽  
Thanuja Rathakrishnan ◽  
Jo Ann Ho ◽  
Siew-Imm Ng
Keyword(s):  
Undergraduate Students ◽  
Call Centre ◽  
Short Term ◽  
Content Type ◽  
Security Technologies ◽  
Academic Level ◽  
Key Account ◽  
Substandard Performance ◽  
Alternative Solutions

Learning outcomes After attempting the case, users are able to: analyse issues and problems faced by a call centre in Malaysia. Determine the root causes of the problems faced by call centre employees and generate alternative solutions to solve the problems faced by the company and to ensure the sustainability of the business. Case overview/synopsis This case was about the challenges faced by Daniel, the General Manager of an integrated security protection system company, Secure First (SF). Despite investing in the latest security technologies, conducting a major overhaul of the procedures, introducing an enhanced digital system at the call centre and providing training to the call agents, it was on the verge of losing its important long-term client due to its substandard performance. The client experienced major losses due to break-ins. After a thorough investigation, the problem surfaced in their call centre. Most of the staff were not familiar with the newly adopted system. The circumstances worsened when many of the call centre’s senior employees were tendering their resignations. The case discusses the aspect of employee satisfaction, staff performance that led to the turnover issue amongst employees in a call centre. The case explores what short-term and long-term strategies could Daniel suggest to change the call centre’s course to retain SF’s key account in times of desperation. Complexity academic level This case has a moderate level of difficulty and may be used in undergraduate students. Supplementary materials Teaching notes are available for educators only. Subject code CSS 6: Human resource management.

Contemporaneous or causal? Evaluating the triumvirate of insolvency risk, capitalization and efficiency in Indian commercial banking

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Navendu Prakash ◽  
Shveta Singh ◽  
Seema Sharma
Keyword(s):  
Cost Efficiency ◽  
Banking Sector ◽  
Generalized Method Of Moments ◽  
Commercial Banking ◽  
Seemingly Unrelated Regression ◽  
Bank Capital ◽  
Short Term ◽  
Content Type ◽  
Insolvency Risk

PurposeThis paper empirically examines the short-term and long-term associations between risk, capital and efficiency (R-C-E) in the Indian banking sector across 2008–2019 to answer the presence of causation or contemporaneousness in the R-C-E nexus.Design/methodology/approachThe paper focuses on three objectives. First, the authors determine short-term causality in the risk–efficiency relationship by studying the simultaneous influence of a wide array of banking risks on DEA-based technical and cost efficiency in static and dynamic situations. Second, the authors introduce bank capital and contemporaneously determine the interplay between R-C-E using seemingly unrelated regression equation (SURE) and three-staged least squares (3SLS). Last, the authors assess stability in inter-temporal associations using Granger causality in an autoregressive distributed lag (ARDL) generalized method of moments (GMM) framework.FindingsThe authors contend that high capital buffers reduce insolvency risk and increase bank stability. Technically efficient banks carry lesser equity buffers, suggesting a trade-off between capital and efficiency. However, capitalization makes banks more technically efficient but not cost-efficient, implying that over-capitalization creates cost inefficiencies, which, in line with the cost skimping hypothesis, forces banks to undertake risk. Concerning causal relationships, the authors conclude that inefficiency Granger-causes insolvency and increases bank risk. Further, steady increases in capital precede technical and cost efficiency improvements. The converse also holds as more efficient banks depict temporal increases in capitalization levels.Originality/valueThe paper is perhaps the first that acknowledges the influence of the “time” perspective on the R-C-E nexus in an emerging economy and advocates that prudential regulations must focus on short-term and long-term intricacies among the triumvirate to foster a stable banking environment.

Labor lawsuits and debt maturity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Omer Unsal
Keyword(s):  
Chief Executive ◽  
Debt Maturity ◽  
Employee Relations ◽  
Short Term ◽  
Content Type ◽  
Negative Effect ◽  
Debt Market ◽  
Legal Fees

Purpose This paper aims to investigate how firms’ relationships with employees define their debt maturity. The authors empirically test the role of employee litigations in influencing firms’ choice of short-term versus long-term debt. The authors study employee relations by analyzing the importance of the workplace environment on capital structure. Design/methodology/approach The author’s test hypotheses using a sample of US publicly traded firms between 2000 and 2017, including 3,056 unique firms with 4,256 unique chief executive officer, adopting the fixed effect panel model. Findings The authors document that employee litigations have a significant negative effect on the use of short-term debt and a significant positive affect on long-term debt. Employee litigations, along with legal fees, outcomes and charging parties, matter the most in explaining debt maturity. In addition, frequently sued firms abandon the short-term debt market and use less shareholders’ equity to finance their operations while relying more on the longer debt market. Originality/value To the best of the authors’ knowledge, this is the first study to examine the role of employee mistreatment in debt maturity choice. The study extends the lawsuit and finance literature by examining unique, hand-collected data sets of employee lawsuits, allegations, violations, settlements, charging parties, case outcomes and case durations.

The transition of a socio-technical system to a smart grid: illustrated with the Indian electricity network

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lakshminarayana Kompella
Keyword(s):  
Technical System ◽  
Transition Theory ◽  
Short Term ◽  
Indian States ◽  
Content Type ◽  
External Pressures ◽  
Policy Systems ◽  
Transition Trajectory ◽  
Practical Implications

Purpose This paper aims to explain transitions in a socio-technical system characterized by non-economic entities that influence economic activity, i.e. embeddedness and coalitions. The selected socio-technical system is an Indian electric network with an interventionist policy. Its embeddedness and coalitions drive the transition. The insights from such analysis expand socio-technical transition theory and provide valuable insights to practitioners in their policymaking. Design/methodology/approach The authors need to observe the effects of non-economic institutions in their setting. Moreover, in India, the regional policies influence decision-making; therefore, selected two Indian states. The two Indian states, along with their non-economic entities, provided diverse analytic and heuristic views. Findings The findings show that coalitions, with their embeddedness in the absence of any mediating policy systems, act as external pressures and influence innovation and the socio-technical system’s transition trajectory. Their coalitions’ embeddedness follows a shaping, not selection logic. Thereby influence innovations in cumulating as stable designs. Such an approach provides benefits in the short-term but not in the long-term. Research limitations/implications The study selected two states and examined two of the four trajectories. By considering other states, the authors can obtain more renewable energy investments and further insights into the transformational trajectory. Practical implications The study highlights the coalition dynamics specific to the Indian electric power network and its transition trajectories. The non-economic entities influenced transition trajectories, innovation and policymaking of the socio-technical system. Originality/value The study expands the socio-technical transition theory by including embeddedness. The embeddedness brings a shaping logic instead of a selection logic.

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