bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure reactivity as a guide in the treatment of cerebral perfusion pressure in patients with brain trauma
Authors: Howells Tim , Elf Kristin , Jones Patricia A. , Ronne-Engström Elisabeth , Piper Ian , Nilsson Pelle , Andrews Peter , Enblad Per 
Published: May 2009

Object. The aim of this study was to compare the effects of two different treatment protocols on physiological characteristics and outcome in patients with brain trauma. One protocol was primarily oriented toward reducing intracranial pressure (ICP), and the other primarily on maintaining cerebral perfusion pressure (CPP).
Methods. A series of 67 patients in Uppsala were treated according to a protocol aimed at keeping ICP less than 20 mm Hg and, as a secondary target, CPP at approximately 60 mm Hg. Another series of 64 patients in Edinburgh were treated according to a protocol aimed primarily at maintaining CPP greater than 70 mm Hg and, secondarily, ICP less than 25 mm Hg for the first 24 hours and 30 mm Hg subsequently.
The ICP and CPP insults were assessed as the percentage of monitoring time that ICP was greater than or equal to 20 mm Hg and CPP less than 60 mm Hg, respectively. Pressure reactivity in each patient was assessed based on the slope of the regression line relating mean arterial blood pressure (MABP) to ICP. Outcome was analyzed at 6 months according to the Glasgow Outcome Scale (GOS).
The prognostic value of secondary insults and pressure reactivity was determined using linear methods and a neural network. In patients treated according to the CPP-oriented protocol, even short durations of CPP insults were strong predictors of death. In patients treated according to the ICP-oriented protocol, even long durations of CPP insult—mostly in the range of 50 to 60 mm Hg—were significant predictors of favorable outcome (GOS Score 4 or 5). Among those who had undergone ICP-oriented treatment, pressure-passive patients (MABP/ICP slope ≥ 0.13) had a better outcome. Among those who had undergone CPP-oriented treatment, the more pressure-active (MABP/ICP slope < 0.13) patients had a better outcome.
Conclusions. Based on data from this study, the authors concluded that ICP-oriented therapy should be used in patients whose slope of the MABP/ICP regression line is at least 0.13, that is, in pressure-passive patients. If the slope is less than 0.13, then hypertensive CPP therapy is likely to produce a better outcome.
Diffusion tensor analysis of peritumoral edema using lambda chart analysis indicative of the heterogeneity of the microstructure within edema
Authors: Morita Ken-ichi , Matsuzawa Hitoshi , Fujii Yukihiko , Tanaka Ryuichi , Kwee Ingrid L. , Nakada Tsutomu 
Published: May 2009

Object. Histopathological studies indicate that cerebral edema associated with tumors (peritumoral edema) does not represent a single pathophysiological or clinical entity. In this study the authors investigated peritumoral edema by performing lambda chart analysis (LCA), a noninvasive technique that can be used to make visible and analyze apparent water diffusivity in tissues in vivo, and assessed the utility of LCA in differentiating high-grade gliomas from nonglial tumors.
Methods. The water diffusivity characteristics of peritumoral edema associated with four tumor groups—12 high-grade gliomas, five low-grade gliomas, 11 metastatic tumors, and 15 meningiomas—were assessed in 43 patients by performing magnetic resonance imaging with the aid of a 3-tesla magnetic resonance imaging system. In all tumor groups, peritumoral edema exhibited greater trace values and reduced anisotropy compared with normal white matter. Edema associated with high-grade gliomas had significantly higher trace values than edema associated with the other three tumor groups, although the anisotropic angles of those groups were comparable.
Conclusions. Lambda chart analysis identified two distinct types of peritumoral edema: edema associated with high-grade gliomas and edema associated with low-grade gliomas or nonglial tumors. The apparent water diffusivity was significantly greater in high-grade gliomas, whereas the anisotropy in these lesions was comparable to that of edema in other tumors. These findings indicated that water movement in areas of edema, predominantly in the extracellular spaces, was less restricted in high-grade gliomas, a phenomenon that likely reflected the destruction of the extracellular matrix ultrastructure by malignant cell infiltration and consequently greater water diffusion. Although preliminary, this study indicates that LCA could be used as a clinical tool for differentiating high-grade gliomas and for evaluating the extent of cellular infiltration.
Optical coherence tomography: a new method to assess aneurysm healing
Authors: Thorell William E. , Chow Michael M. , Prayson Richard A. , Shure Mark A. , Jeon Sung W. , Huang David , Zeynalov Emil , Woo Henry H. , Rasmussen Peter A. , Rollins Andrew M. , Masaryk Thomas J. 
Published: May 2009

Object. Aneurysmal subarachnoid hemorrhage affects approximately 10/100,000 people per year. Endovascular coil embolization is used increasingly to treat cerebral aneurysms and its safety and durability is rapidly developing. The long-term durability of coil embolization of cerebral aneurysms remains in question; patients treated using this modality require multiple follow-up angiography studies and occasional repeated treatments.
Methods. Optical coherence tomography (OCT) is an emerging imaging modality that uses backscattered light to produce high-resolution tomography of optically accessible biological tissues such as the eye, luminal surface of blood vessels, and gastrointestinal tract. Vascular OCT probes in the form of imaging microwires are presently available—although not Food and Drug Administration—approved—and may be adapted for use in the cerebral circulation. In this study the authors describe the initial use of OCT to make visible the neck of aneurysms created in a canine model and treated with coil embolization. Optical coherence tomography images demonstrate changes that correlate with the histological findings of healing at the aneurysm neck and thus may be capable of demonstrating human cerebral aneurysm healing.
Conclusions. Optical coherence tomography may obviate the need for subsequent follow-up angiography studies as well as aid in the understanding of endovascular tissue healing. Data in this study demonstrate that further investigation of in vivo imaging with such probes is warranted.
Quantified aneurysm shape and rupture risk
Authors: Raghavan Madhavan L. , Ma Baoshun , Harbaugh Robert E. 
Published: May 2009

Object. The authors investigated whether quantified shape or size indices could better discriminate between ruptured and unruptured aneurysms.
Methods. Several custom algorithms were created to quantifiy the size and shape indices of intracranial aneurysms by using three-dimensional computerized tomography angiography models of the brain vasculature. Data from 27 patients with ruptured or unruptured aneurysms were evaluated in a blinded fashion to determine whether aneurysm size or shape better discriminated between the ruptured and unruptured groups. Five size and eight shape indices were calculated for each aneurysm. Two-tailed independent Student t-tests (significance p < 0.05) were used to determine statistically significant differences between ruptured and unruptured aneurysm groups for all 13 indices. Receiver-operating characteristic—area under curve analyses were performed for all indices to quantify the predictability of each index and to identify optimal threshold values. None of the five size indices were significantly different between the ruptured and unruptured aneurysms. Five of the eight shape indices were significantly different between the two lesion groups, and two other shape indices showed a trend toward discriminating between ruptured and unruptured aneurysms, although these differences did not reach statistical significance.
Conclusions. Quantified shape is more effective than size in discriminating between ruptured and unruptured aneurysms. Further investigation will determine whether quantified aneurysm shape will prove to be a reliable predictor of aneurysm rupture.
Multicentric pleomorphic xanthoastrocytoma in a patient with neurofibromatosis Type 1
Authors: Saikali Stephan , Strat Anne Le , Heckly Anne , Stock Nathalie , Scarabin Jean-Marie , Hamlat Abderrahmane 
Published: May 2009

✓ The authors report an unusual case of multicentric pleomorphic xanthoastrocytoma (PXA) in a 36-year-old woman with neurofibromatosis Type 1 (NF1). Both lesions were diagnosed as PXA but demonstrated different neuroimaging features and very different outcomes. Although the occipital lesion was cured surgically, the cerebellar tumor recurred three times and underwent malignant transformation into an anaplastic oligodendroglioma.
The authors discuss the causes of PXA and suggest that it could originate from common bipotential precursor cells with two phenotypes.
Femoral nerve palsy secondary to traumatic pseudoaneurysm and iliacus hematoma
Authors: Rochman Adam S. , Vitarbo Elizabeth , Levi Allan D. 
Published: May 2009

✓ The authors report a case of traumatic femoral nerve palsy caused by a pseudoaneurysm of the iliolumbar artery and a iliacus muscle hematoma. This case report details not only the classic history and physical findings seen in patients such as this one, but also illustrates an unusual source of the hematoma and a discussion of its treatment.
A 20-year-old man was assaulted and presented to the authors's institution with a 1-week history of severe pain in the left anterior thigh and groin, weakness in the left quadriceps muscle, and numbness in the anterior thigh and medial distal leg. Imaging studies demonstrated a large, 9.4 × 6.4 × 5.2-cm iliacus hematoma as well as a pseudoaneurysm originating from the left iliolumbar artery. The patient underwent angiographic embolization of the pseudoaneurysm followed by surgical evacuation of the hematoma. The embolization was performed before surgery to prevent any possible rebleeding from the pseudoaneurysm during evacuation of the hematoma.
Femoral nerve palsy caused by traumatic iliacus hematoma is an infrequent diagnosis often missed because of its insidious presentation. In this case, embolization of the iliolumbar artery pseudoaneurysm followed by surgical evacuation of the hematoma resulted in a nearly full recovery of the femoral nerve as of the last follow-up examination.
Stereotactic gamma knife surgery for trigeminal neuralgia: detailed analysis of treatment response
Authors: Tawk Rabih G. , Duffy-Fronckowiak Mary , Scott Bryan E. , Alberico Ronald A. , Diaz Aidnag Z. , Podgorsak Matthew B. , Plunkett Robert J. , Fenstermaker Robert A. 
Published: May 2009

Object. The purpose of this study was to assess the durability and completeness of pain relief in patients treated using stereotactic gamma knife surgery (GKS) for trigeminal neuralgia (TN).
Methods. Thirty-eight patients with refractory TN were treated with stereotactic GKS. All patients received a prescription radiation dose of 35, 40, or 45 Gy to the 50% isodose surface through a 4-mm collimator helmet. The group was assessed regularly based on physician-directed interviews for a median follow up of 24 months (range 6–27 months). Pain relief was classified as excellent (no pain without medication), good (well-controlled pain with continued medication), fair (decreased but residual pain with continued medication), or poor (unimproved or increased pain with the same or increased medication).
Three months after treatment, pain relief was good or excellent in 71% of patients. By 24 months post-GKS, 50% of the original cohort had poor pain relief, 21% continued to have either excellent or good relief, 3% had fair relief, and 26% had not reached the 24-month follow up. Based on their status at the last follow up, 29% of patients had excellent and 16% had good pain relief. Thirty-seven percent experienced facial numbness, which was dose related. In addition, there was a significantly higher rate of complete pain relief in patients who had facial numbness following treatment (p = 0.003).
Conclusions. Stereotactic GKS is an effective treatment in patients with TN; however, the durability of pain relief and the time to treatment response are limiting factors. As with other types of ablative treatment, facial numbness is strongly associated with better treatment response.
Age, intracranial pressure, autoregulation, and outcome after brain trauma
Authors: Czosnyka Marek , Balestreri Marcella , Steiner Luzius , Smielewski Piotr , Hutchinson Peter J. , Matta Basil , Pickard John D. 
Published: May 2009

Object. The object of this study was to investigate whether a failure of cerebrovascular autoregulation contributes to the relationship between age and outcome in patients following head injury.
Methods. Data obtained from continuous bedside monitoring of intracranial pressure (ICP), arterial blood pressure (ABP), and cerebral perfusion pressure (CPP = ABP — ICP) in 358 patients with head injuries and intermittent monitoring of transcranial Doppler blood flow velocity (FV) in the middle cerebral artery in 237 patients were analyzed retrospectively. Indices used to describe cerebral autoregulation and pressure reactivity were calculated as correlation coefficients between slow waves of systolic FV and CPP (autoregulation index [ARI]) and between ABP and ICP (pressure reactivity index [PRI]).
Older patients had worse outcomes after brain trauma than younger patients (p = 0.00001), despite the fact that the older patients had higher initial Glasgow Coma Scale scores (p = 0.006). When age was considered as an independent variable, it appeared that ICP decreased with age (p = 0.005), resulting in an increasing mean CPP (p = 0.0005). Blood FV was not dependent on age (p = 0.58). Indices of autoregulation and pressure reactivity demonstrated a deterioration in cerebrovascular control with advancing age (PRI: p = 0.003; ARI: p = 0.007).
Conclusions. An age-related decline in cerebrovascular autoregulation was associated with a relative deterioration in outcome in elderly patients following head trauma.
The use of indomethacin in the treatment of plateau waves: effects on cerebral perfusion and oxygenation
Authors: Imberti Roberto , Fuardo Marinella , Bellinzona Guido , Pagani Michele , Langer Martin 
Published: May 2009

Object. Plateau waves are sudden and steep increases in intracranial pressure (ICP) that can develop in patients with cerebral injuries, reduced pressure—volume compensatory reserve, and preserved autoregulation. They are caused by cerebral vasodilation in response to a reduction in cerebral perfusion and are associated with increased cerebral blood volume and reduced cerebral blood flow.
The authors evaluated the hypothesis that administration of indomethacin, a potent cerebral arteriolar vasoconstrictor, could interrupt the vicious cycle that occurs during plateau waves, extinguishing these waves and, ultimately, restoring cerebral perfusion and oxygenation.
Methods. Plateau waves developed in nine patients, seven with severe traumatic brain injury and two with intraparenchymal hemorrhage. One to four episodes of plateau waves per patient were treated with indomethacin (15–20 mg), which was delivered by an intravenous bolus injection. Each patient's mean arterial blood flow (MABP), ICP, cerebral perfusion pressure (CPP), and cerebral tissue PO2 were continuously monitored and the data obtained were stored in a personal computer. Each patient's jugular venous O2 saturation (SjvO2) and venoarterial difference in PCO2 were evaluated by intermittent blood sampling. During five episodes of plateau waves, middle cerebral artery flow velocities were evaluated by transcranial Doppler ultrasonography.
Indomethacin extinguished all plateau waves. On average, the ICP decreased from an initial value of 58.9 ± 11.6 mm Hg to 21.2 ± 8.6 and 25.8 ± 13.7 mm Hg after 5 and 10 minutes, respectively (p < 0.01). The MABP did not change significantly. As a consequence the CPP increased by 98 and 81% after 5 and 10 minutes, respectively (p < 0.01). Five and 10 minutes after indomethacin was administered, SjvO2 increased from an initial value of 50 ± 10.5% to 62 ± 7.6 and 59.9 ± 9.3%, respectively (p < 0.01); the cerebral tissue PO2 increased from an initial value of 13.4 ± 10.6 mm Hg to 23.6 ± 9.58 and 21.9 ± 9.2 mm Hg, respectively (p < 0.05); and the venous—arterial PCO2 decreased significantly. The mean and diastolic flow velocities increased significantly, whereas the pulsatility index decreased from 1.39 ± 0.56 to 1.09 ± 0.4 at 5 minutes and 1.06 ± 0.36 at 10 minutes (p < 0.05).
Conclusions. The findings confirm that plateau waves are caused by vasodilation and show that indomethacin, by constricting the cerebral arteries, is effective in extinguishing plateau waves, ultimately restoring cerebral perfusion and oxygenation.
Intracerebral microdialysis in severe brain trauma: the importance of catheter location
Authors: Engström Martin , Polito Angelo , Reinstrup Peter , Romner Bertil , Ryding Erik , Ungerstedt Urban , Nordström Carl-Henrik 
Published: May 2009

Object. Intracerebral microdialysis has attracted increasing interest as a monitoring technique during neurological/neurosurgical intensive care. The purpose of this study was to compare cerebral energy metabolism, an indicator of secondary excitotoxic injury and cell membrane degradation close to focal traumatic lesions (“penumbra zones”) and in remote and apparently intact brain regions of the ipsilateral and contralateral hemispheres.
Methods. The study included 22 consecutive patients with a mean age 44 ± 17 years and an estimated postresuscitation Glasgow Coma Scale motor score less than 5. Altogether 40 microdialysis catheters with radiopaque tips were inserted. Two catheters could not be localized on postoperative computerized tomography (CT) scans and were excluded from the analysis. The perfusates were analyzed at the patient's bedside for levels of glucose, pyruvate, lactate, glutamate, and glycerol with the aid of a CMA 600 Analyzer.
The positions of eight (22%) of the 36 catheters were reclassified after a review of findings on CT scans. Except for pyruvate the values of all biochemical variables and the lactate/pyruvate (L/P) ratio were significantly different in the penumbra zone when compared with mean values found in “normal” tissue ipsilateral to the parenchymal damage and in contralateral normal tissue (p < 0.001). In the penumbra zone a slow normalization of the L/P ratio and levels of glutamate and glycerol were observed. In normal tissue these parameters remained within normal limits.
Conclusions. Data obtained from intracerebral microdialysis can be correctly interpreted only if the locations of the catheters as they relate to focal brain lesions are visualized. A “biochemical penumbra zone” surrounds focal traumatic brain lesions. It remains to be proven whether therapeutic interventions can protect the penumbra zone from permanent damage.
Asymptomatic microbleeds in moyamoya disease: T2*-weighted gradient-echo magnetic resonance imaging study
Authors: Kikuta Ken-Ichiro , Takagi Yasushi , Nozaki Kazuhiko , Hanakawa Takashi , Okada Tsutomu , Mikuni Nobuhro , Miki Yukio , Fushimi Yasutaka , Yamamoto Akira , Yamada Keisuke , Fukuyama Hidenao , Hashimoto Nobuo 
Published: May 2009

Object. The aim of this study was to investigate the incidence of asymptomatic microbleeds (MBs) in patients with moyamoya disease (MMD) by using a 3-tesla magnetic resonance (MR) imaging unit.
Methods. Data on 63 patients hospitalized with MMD between 1999 and 2004 were retrospectively examined to determine the incidence of asymptomatic MBs. Gradient-echo T2*-weighted MR imaging studies obtained using 3- and 1.5-tesla units were available in 25 patients. These patients consisted of five men and 20 women, ranging in age from 17 to 66 years (mean age 41 ± 14 years). Ischemic MMD was diagnosed in 18 patients, and hemorrhagic MMD in seven. The incidence of MBs was also evaluated using the same 3-tesla MR imaging unit in 34 healthy volunteers including seven men and 27 women, ranging in age from 18 to 71 years (mean age 33 ± 12 years). Using the 3-tesla MR unit, asymptomatic MBs were demonstrated in 11 patients (44%); they were detected in seven patients (28%) by using the 1.5-tesla unit. In the 3-tesla MR studies in healthy individuals, MBs were found in two patients (5.8%). Based on 3-tesla MR studies, the incidence of MBs was significantly higher in patients with MMD compared with that in healthy individuals. Asymptomatic MBs were demonstrated in eight (44%) of 18 patients with ischemic MMD and three (43%) of seven patients with hemorrhagic MMD.
Conclusions. Microbleeds are significantly more common in patients with MMD than in healthy individuals regardless of the disease type. The evaluation of MBs with T2*-weighted 3-tesla MR imaging might contribute to the treatment of MMD.
The Short Form—12 and the measurement of health status in patients with cerebral aneurysms: performance, validity, and reliability
Authors: King Joseph T. , Horowitz Michael B. , Kassam Amin B. , Yonas Howard , Roberts Mark S. 
Published: May 2009

Object. Cerebral aneurysms can affect a patient's health status by rupture and stroke, impingement on neural structures, treatment side effects, or psychological stress. The authors assessed the performance, validity, and reliability of the Short Form—12 (SF-12), a self-administered written survey instrument, to assess health status in patients with cerebral aneurysms.
Methods. A cohort of 170 patients with cerebral aneurysms who were seen at a neurosurgery clinic underwent structured interviews including measurement of their health statuses (SF-12 physical component summary [PCS] and mental component summary [MCS]), functional status (Glasgow Outcome Scale score, modified Rankin Scale score, and Barthel Index), and mental health (Hospital Anxiety and Depression Scale score). The SF-12 scores were compared with US population norms by performing t-tests with unequal variances. The validity of the SF-12 was assessed by comparing the PCS and MCS scores with each patient's functional status and mental health scores by using rank-order methods. Inter-item reliability was assessed using the Cronbach alpha statistic.
Patients with cerebral aneurysms had decreased health status PCS and MCS scores when compared with population norms (p < 0.001 for all). A history of subarachnoid hemorrhage (SAH) (p = 0.006) and previous surgical or endovascular treatment (p = 0.047) was associated with worse PCS scores. The validity of the SF-12 was supported by the relationship between the PCS and MCS scores and the patient's functional status and mental health (p < 0.001 for all). The reliability of the SF-12 was documented by the Cronbach alpha statistic (α = 0.76).
Conclusions. Patients with cerebral aneurysms have a diminished physical and mental health status as measured using the SF-12. The presence of SAH and aneurysm treatment are associated with a worse physical health status. The SF-12 is a valid and reliable instrument for measuring health status in patients with cerebral aneurysms.