bluuebunny/crossref_metadata_2025 huggingface dataset:
Lipoprotein(a) Serum Concentration and Apolipoprotein(a) Phenotype Correlate With Severity and Presence of Ischemic Cerebrovascular Disease
Authors: Jürgens Günther , Taddei-Peters Wendy C. , Költringer Peter , Petek Walter , Chen Qi , Greilberger Joachim , Macomber Paul F. , Butman Bryan T. , Stead Andrew G. , Ransom Janet H.
Published: June 2011

Background and Purpose
Serum lipoprotein(a) [Lp(a)] levels are genetically determined and considered to be an independent risk factor for atherosclerosis. The aim of this study was to provide a complete analysis of Lp(a) serum levels, apolipoprotein(a) phenotypes, and other lipid parameters for different forms of severity of symptomatic ischemic cerebrovascular disorders as well as for different stages of carotid atherosclerosis.

Methods
Lp(a) concentration, apolipoprotein(a) phenotype, triglyceride, low-density lipoprotein, high-density lipoprotein, and total cholesterol levels of blind-coded specimens as well as degree of carotid artery stenosis were assessed in a consecutive series of patients with ischemic cerebrovascular disease. We evaluated 265 male (34%) and female (66%) patients (mean age, 51±7.4 years) with transient ischemic attack (55.8%), prolonged reversible ischemic neurological deficits (28.3%), and cerebral infarction (15.9%) as well as 288 male (30%) and female (70%) control subjects (mean age, 51±7.1 years). All subjects were white.

Results
Lp(a), total, and low-density lipoprotein cholesterol were statistically significantly elevated in all patients compared with control subjects. Lp(a) correlated with the severity of symptomatic cerebrovascular disease and the degree of carotid stenosis. Logistic regression analysis revealed Lp(a) as the best single marker for the presence of cerebrovascular disease (
P
<.001) followed by high-density lipoprotein cholesterol (
P
=.003) and triglycerides (
P
=.049). With a cutoff of 20 mg/dL of Lp(a), the odds ratio for a subject to have had ischemic stroke with elevated Lp(a) was 20.3 and 23.7 depending on the method of the Lp(a) estimation, whereas the odds ratio when the sonography score was >0 was 15.4. The investigation of the distribution of the apo(a) phenotypes revealed that 16.73% of the control subjects had major isoforms ≤580 kD molecular weight (B, F, S1, S2) versus 42.65% of the patients’ group (
P
<.001). These isoforms were also present in 14.71% of all individuals with a sonography score of 0 but in 52.30% of all individuals with a sonography score >0 (
P
<.001).

Conclusions
This case-control study shows that an elevated Lp(a) level is the primary factor associated with the presence of ischemic cerebrovascular disease and that the increased portion of the smaller-molecular-weight apo(a) isoforms in patients and individuals with a sonography score >0 points toward an inherited predisposition for this disease.
Undergraduate and Postgraduate Medical Education for Cerebrovascular Disease
Authors: Alberts Mark J.
Published: June 2011

Background and Purpose
There is a perception among some physicians that medical students and house officers receive little or no training in the diagnosis and treatment of patients with cerebrovascular disease. However, there is a paucity of data addressing the issue of medical education in this area. This study was performed to determine the quantity and type of undergraduate and postgraduate medical education on cerebrovascular disease that is presented to medical students and house officers.

Methods
This was a prospective questionnaire study sent to 40 mainly academic medical centers in the United States and Canada. Data were collected on the percentage of programs offering stroke education, percentage of medical students and house officers taking such courses, and the duration of teaching programs.

Results
Sixty-one percent of the programs had dedicated stroke teaching efforts during clinical rotations, averaging a total of 13.1 hours of didactic and clinical teaching. Medical students received approximately 5 hours of preclinical stroke instruction. Only 35% of the programs offered stroke training for house officers in their internal medicine program. Most programs (81%) offered stroke conferences and computer-based instruction.

Conclusions
At some institutions, medical students received a modest amount of stroke education during their clinical rotations. However, almost 40% of programs did not have required stroke education programs for medical students. Most internal medicine programs that we surveyed did not have specific stroke education efforts for house officers. Increased educational efforts in this area may be indicated.
Amino Acid Uptake in Ischemically Compromised Brain Tissue
Authors: Jacobs Andreas
Published: June 2011

Background and Purpose
Multitracer positron emission tomography (PET) was used to investigate local amino acid accumulation in brain tissue surrounding focal ischemia.

Methods
PET using
15
O-labeled oxygen and water for measuring cerebral metabolic rate of oxygen (CMRO
2
) and cerebral blood flow (CBF), C
15
O for determination of blood volume (CBV) and calculation of oxygen extraction fraction, and
l-[
11
C]methylmethionine (
11
C-MET) for the assessment of amino acid accumulation was applied in 14 patients (mean age, 52±9.1 years) with acute ischemic hemispheric stroke. Two multitracer PET studies were completed, the first 8 to 24 hours after onset of neurological symptoms and the follow-up study 14±1 days after the ischemic attack. Functional changes were compared with morphological damage on cranial CT or MRI. Three-dimensional matching and volume of interest evaluation procedures were used to study
11
C-MET accumulation in relation to various physiological variables in infarcted and noninfarcted tissue.

Results
Compared with contralateral mirror regions, initially increased regional
11
C-MET uptake (21.2±10.9%,
P
<.001) was found in patchy areas in the immediate vicinity of infarction as well as in distant areas within the same hemisphere. In those areas, regional CBF (−11.4±21.2%,
P
<.01) and oxygen extraction fraction (2.8±29.1%,
P
=NS) were highly variable, and regional CMRO
2
was preserved or slightly reduced (−12.4±16.0%,
P
<.001). CBF data comprised severely ischemic as well as high values (14.6 to 64.2 mL/100 g per minute). Cranial CT and coregistered MRI in five patients demonstrated preserved morphology. In all peri-infarct areas (n=62), the
11
C-MET uptake showed a positive correlation with ΔCMRO
2
as the relative improvement of ipsilateral CMRO
2
between the two PET studies (
r
=.378,
P
<.01). Particularly in areas with increased oxygen extraction fraction (n=42), the
11
C-MET uptake showed a mild correlation with CMRO
2
at follow-up measurement (
r
=.31,
P
<.05). In all peri-infarct areas,
11
C-MET uptake showed a negative correlation with oxygen extraction fraction (
r
=−.672,
P
<.001) and a positive correlation with CBF (
r
=.4,
P
=.001). In all infarcted and peri-infarct areas, normalized initial
11
C-MET uptake was positively correlated with CMRO
2
at follow-up (
r
=.603,
P
<.001).

Conclusions
Focal increases of
11
C-MET uptake seen in this study were generally mild. They might be seen in the core of ischemia, indicating breakdown of the blood-brain barrier with poor tissue prognosis, but they also frequently occurred during or after ischemic compromise in surviving brain tissue surrounding focal cerebral infarction, perhaps representing alterations of amino acid transport or protein synthesis in brain tissue with a favorable prognosis.
AMPA Antagonist LY293558 Does Not Affect the Severity of Hypoxic-Ischemic Injury in Newborn Pigs
Authors: LeBlanc Michael H. , Li Xin Qin , Huang Min , Patel Daksha M. , Smith Edward E.
Published: June 2011

Background and Purpose
LY293558 is a systemically active α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) excitatory amino acid antagonist. AMPA antagonists have shown promise in several adult hypoxic-ischemic brain injury models, and we wanted to see if this work could be extended to a newborn animal.

Methods
Seventy-six (β error <.10) 0- to 3-day-old piglets under 1.5% isoflurane anesthesia underwent placement of carotid snares and arterial and venous catheters. While paralyzed with succinylcholine under 0.5% isoflurane, 50% nitrous oxide, piglets were randomly assigned to receive either 5 mg/kg or 15 mg/kg of
LY293558
or saline at time −10 minutes and again 10 hours later. At time 0, both carotid arteries were clamped, and blood was withdrawn to reduce the blood pressure to two thirds of normal. At time 15 minutes, inspired oxygen was reduced to 6%. At time 30 minutes, the carotid snares were released, the withdrawn blood was reinfused, and the oxygen was switched to 100%. On the third day after the hypoxic-ischemic injury, the animals were killed by perfusion of the brain with 10% formalin. Brain pathology was scored by a blinded observer.

Results
There were no significant differences between the drug-treated and control groups.

Conclusions
The systemically active AMPA antagonist
LY293558
, when given at a dose of 5 mg/kg or 15 mg/kg before injury and 10 hours later, does not affect the severity of hypoxic-ischemic brain injury in newborn piglets. Neither AMPA receptor activity nor NMDA receptor activity are important in brain injury in this model.
Influence of Vascular Risk Factors for Atherosclerotic Carotid Artery Plaque Progression
Authors: Delcker A. , Diener H.C. , Wilhelm H.
Published: June 2011

Background and Purpose
Investigations regarding arteriosclerosis of carotid arteries showed an association between increased intima-media thickness and vascular risk factors. A newly developed three-dimensional ultrasound method increases the reproducibility of plaque volume measurements because more exact volume measurements can be performed with a reduction of the disadvantages of two-dimensional measurements. In a pilot study the influence of vascular risk factors on carotid artery plaque progression was examined.

Methods
Volumes of atherosclerotic plaques in carotid arteries in 54 patients were measured with a three-dimensional ultrasound system during a 12-month period to determine the relationship between progression or regression of plaque volume, vascular risk factors, dose of aspirin, and flow turbulence in the plaque region.

Results
A progression of plaque volume occurred in 67% (36/54) of all plaques. In no plaque was a regression of plaque volume seen. The optimal adjustment of all risk factors showed a significant influence on plaque progression (
r
=.31). Diastolic blood pressure was the strongest predictor of plaque progression (
P
<.01), followed by diabetes (
P
<.03). Turbulence in the plaque region was found in 78% of the patients in the progression group (n=36) versus 61% in the nonprogression group (n=18) but was not significant. Dose of aspirin (100 mg versus 250/300 mg) had no influence on plaque volume after 1 year.

Conclusions
Treatment of vascular risk factors reduces the progression of carotid artery plaque volume in three-dimensional ultrasound. The most important factor for plaque progression is a high diastolic blood pressure. Turbulence in the flow pattern and the examined doses of aspirin showed no significant influence.
Importance of Time-Window Overlap in the Detection and Analysis of Embolic Signals
Authors: Markus Hugh
Published: June 2011

Background and Purpose
The detection of asymptomatic embolic signals by Doppler ultrasound may offer a powerful investigational tool in the management of cerebrovascular disease. However, early studies, particularly in patients with carotid artery disease, have reported very different frequencies of embolic signals. While this may reflect differences in patient groups and the criteria used for embolic signal identification, the degree of time-window overlap may be important. If this is insufficient, some embolic signals may fall between two time windows and not appear on the spectral display. Furthermore, the use of nonrectangular time windows, such as the Hanning window, may result in variation of the intensity of an embolic signal depending on where it is detected within the time window.

Methods
To test the importance of this potential problem, the same 25 embolic signals recorded as the audio signal on digital audiotape were each played repeatedly through a transcranial Doppler ultrasound (TCD) system using fast Fourier transform analysis. An older system with no time-window overlap was used, and a more modern system was also used in which three different degrees of overlap were used: −9%, 27%, and 57%. The number of signals audible but not appearing on the spectral display was recorded. The variability in the relative intensity increase for the same embolic signal played repeatedly was estimated by calculating the coefficient of variation of the relative intensity increase.

Results
With the older system, 39/500 (7.8%) of embolic signals were missed. With the newer system, the number of embolic signals missed was fewer and decreased with increasing degrees of overlap (10/500 for −9% overlap, 1/500 for 27% overlap, and 0/500 for 57% overlap). For those setups in which embolic signals were missed, there was a highly significant relationship between duration of embolic signal and number of signals missed. In parallel with these results, the coefficient of variation of the relative intensity increase became progressively less with increasing degrees of time-window overlap. For all processing setups, the coefficient of variation was greater for the less intense and shorter duration signals, but this dependence, as estimated by the slope of the regression line, became less strong with higher degrees of overlap.

Conclusions
Inadequate degrees of fast Fourier transform time-window overlap will result in the failure of current TCD machines to detect embolic signals. Furthermore, this and the time windowing currently usually used may result in variability in the relative intensity increase of identical embolic signals. These factors need to be taken into account when comparing data on the frequencies of embolic signals recorded by different researchers and in the design of future TCD equipment.
Potential and Limitations of Transcranial Color-Coded Sonography in Stroke Patients
Authors: Seidel G. , Kaps M. , Gerriets T.
Published: June 2011

Background and Purpose
Transcranial color-coded duplex sonography (TCCS) enables visualization of the intracranial parenchymal structures and measurement of blood flow velocity in the basal cerebral arteries. The present study aims to evaluate prospectively the clinical usefulness of TCCS in patients with acute stroke.

Methods
Eighty-four consecutive patients with central nervous symptoms suggesting acute stroke were investigated within the first 48 hours after clinical onset. TCCS was performed with a 2.5-MHz sector transducer through the temporal bone window. CT was available in all patients.

Results
Forty-eight patients suffered from an infarction or a transient ischemic attack (TIA) in the territory of the middle cerebral artery (MCA). Fifteen of them showed an MCA occlusion, and 12 of the 15 developed recanalization during follow-up. Twelve revealed an increased, decreased, or oscillating flow pattern in the MCA main stem, and 21 patients had no ultrasonic abnormalities. The positive and negative predictive values of a pathological flow pattern in patients with MCA infarctions or TIA were .92 and .48, respectively. Fifteen patients suffered from an intracerebral hematoma, which could be diagnosed by TCCS in 14 cases. The positive and negative predictive values of a pathological parenchymal echo pattern were .88 and .96, respectively. Three patients suffered from an infarction and one from a TIA in the posterior cerebral artery territory. One female patient with an acute deterioration of a hemiparesis showed a glioma. The dropout rate due to an insufficient acoustic temporal bone window was 20% (17/84).

Conclusions
TCCS is a noninvasive bedside method that provides rapid and reliable data regarding stroke subtype and mechanism immediately after onset. Window failure is a serious limitation of this method.
Effect of Guglielmi Detachable Coils on Experimental Carotid Artery Aneurysms in Primates
Authors: Tenjin Hiroshi , Fushiki Shinji , Nakahara Yoshikazu , Masaki Hiroto , Matsuo Takamasa , Johnson Christopher M. , Ueda Satoshi
Published: June 2011

Background and Purpose
Clinical experience has established that intravascularly placed metal coils can be a useful treatment for cerebral vascular aneurysms. However, the mechanism by which the coils induce occlusion of the aneurysm is unclear. Appropriate use of this promising treatment modality requires basic understanding of the occlusive process. We used an animal model system of experimentally induced carotid aneurysms to investigate the initial events induced by Guglielmi detachable coils (GDCs), as well as the subsequent vascular changes induced by the coils over time.

Methods
We induced 23 aneurysms in the carotid arteries of 16 Japanese monkeys. Nineteen aneurysms were then occluded with GDCs placed via endovascular surgery; 4 aneurysms served as controls. We then used gross and microscopic pathological examination, angiography, and scanning electron microscopy to assess the effects of the GDC.

Results
In the first few hours after placement of the GDC in the experimental aneurysms, we observed leukocyte attachment and deposition of fibrinlike materials and other proteins. By 4 days after coil placement, leukocytes and fibroblasts were observed in the thrombus. By 2 weeks after coil placement, there was evidence of an endothelial-like covering of the coils. At 3 months after coil placement, we observed development of an arterial media in the occluded aneurysms.

Conclusions
The GDCs initiated a cellular response within several hours of aneurysm occlusion. By 2 weeks after coil placement, endothelialization was proceeding, and by 3 months after occlusion, remodeling of the aneurysm had progressed to produce a media-like structure in the former aneurysm.
Symptom Control, Communication With Health Professionals, and Hospital Care of Stroke Patients in the Last Year of Life as Reported by Surviving Family, Friends, and Officials
Authors: Addington-Hall Julia , Lay Margaret , Altmann Dan , McCarthy Mark
Published: June 2011

Background and Purpose
The needs of and appropriate service provision for patients dying from stroke have received little attention. The quality of care in the last year of life received by a population-based sample of stroke patients is described here, focusing on symptom control, communication with health professionals, and hospital care.

Methods
Secondary analysis was made of data from the Regional Study of Care for the Dying, a retrospective interview survey in 20 nationally representative English health districts. Subjects were 237 persons who died from stroke in 1990. Of informants, 20% were spouses, 48% relatives, 11% friends or neighbors, and 20% officials.

Results
More than half the patients were reported to have experienced pain (65%), mental confusion (51%), low mood (57%), and urinary incontinence (56%) in the last year of life. Pain control was inadequate: 51% of those treated for pain by hospital doctors and 45% of those treated by general practitioners were reported to have received treatment that relieved pain partially if at all. One third of respondents thought that hospital doctors had been too rushed (37%), and 25% thought that the patient had had insufficient choice about treatment. Two fifths had been unable to get all the information they had wanted about the patient’s condition.

Conclusions
Improvements in symptom control and psychosocial support for patients who die from stroke are needed, as is better communication between health professionals and patients and their families. Education of doctors and nurses working with stroke patients in the principles of palliative care may help ensure that all dying stroke patients receive high-quality care.
Central Benzodiazepine Receptor Distribution After Subcortical Hemorrhage Evaluated by Means of [
123
I]Iomazenil and SPECT
Authors: Hatazawa Jun , Shimosegawa Eku , Satoh Takao , Kanno Iwao , Uemura Kazuo
Published: June 2011

Background and Purpose
[
123
I]Iomazenil is a single-photon emission computed tomography (SPECT) tracer that selectively binds to central benzodiazepine receptor in the neuron membrane. With this ligand, we studied the central benzodiazepine receptor distribution in the cortex remote from subcortical hematoma in intracerebral hemorrhage patients.

Methods
Four patients with unilateral putaminal hemorrhage and one patient with right thalamic hemorrhage were studied (mean±1 SD age, 50.0±8.8 years). The initial volume of hematoma ranged from 4.3 to 31.0 mL (mean±1 SD, 17.5±12.3 mL). SPECT images obtained 3 hours after intravenous administration of [
123
I]iomazenil (167 MBq/750 ng) were analyzed. In three patients, perfusion was evaluated with [
123
I]IMP. On SPECT images, the radioactivity ratio of the ipsilateral to the contralateral cerebral cortex (I/C ratio) or of the contralateral to the ipsilateral cerebellar hemisphere (C/I ratio) was measured.

Results
The I/C ratio for iomazenil was significantly decreased compared with unity in the temporal lobe (0.84±0.08,
P
<.01) and the parietal lobe (0.87±0.10,
P
<.05), but the C/I ratio in the cerebellum (1.00±0.03) was not. The C/I ratio for perfusion in the cerebellar cortex (0.83±0.04,
P
<.01) was significantly decreased compared with that in normal subjects.

Conclusions
Central benzodiazepine receptor–[
123
I]iomazenil binding was decreased in the ipsilateral cerebral cortex remote from the subcortical hematoma. This preliminary result may facilitate further study of the potential damage of the cortical neurons remote from subcortical hematoma.
Interpretation of Embolic Phenomena During Carotid Endarterectomy
Authors: Smith Julia L. , Evans David H. , Fan Lingke , Gaunt Michael E. , London Nick J.M. , Bell Peter R.F. , Naylor A. Ross
Published: June 2011

Background and Purpose
Air and particulate emboli are a major source of morbidity during carotid endarterectomy (CEA); however, amplitude overload and poor time resolution have restricted the ability of transcranial Doppler ultrasound to differentiate between the two.

Methods
We have now overcome these two limitations by (1) rerouting embolic signals away from the audio frequency amplifier to avoid amplitude overload and (2) substituting the Wigner distribution function for the fast Fourier transform to improve time and frequency resolution. Thus, we can now accurately determine embolic duration and embolic velocity, the product of which is the sample volume length (SVL). This measurement represents the physical distance over which an embolic signal can be detected. The underlying hypothesis was that air reflected more ultrasound and would therefore be detected over a greater SVL.

Results
The median SVL (interquartile range) for 75 in vitro air emboli was 1.97 cm (range, 1.70 to 2.35) compared with 0.27 cm (range, 0.16 to 0.43) for 185 particulate emboli detected during the dissection phase of CEA. Off-line analysis on an additional 560 embolic signals detected during different phases of CEA suggested that 46 of 143 (32%) of emboli immediately after shunt insertion were particulate, as were 19 of 33 (58%) occurring during shunting, 28 of 78 (36%) after restoration of flow in the external carotid artery, 23 of 251 (9%) after restoration of flow in the internal carotid artery, and 55 of 55 (100%) of those emboli detected during the early recovery phase.

Conclusions
This development provides objective physical criteria upon which embolus characterization (particulate/air) can be based. This could have major implications for future patient monitoring with respect to modification of surgical technique and pharmacological intervention.
Cerebral Vasoreactivity Assessed With Transcranial Doppler and Regional Cerebral Blood Flow Measurements
Authors: Dahl Arve , Russell David , Rootwelt Kjell , Nyberg-Hansen Rolf , Kerty Emilia
Published: June 2011

Background and Purpose
To improve the assessment of cerebral vasoreactivity using acetazolamide (ACZ), we studied the time course of the response and the relationship between dose, response, and serum concentration.

Methods
Blood flow velocities were measured with the use of transcranial Doppler ultrasonography in one of the middle cerebral arteries of 48 healthy subjects after the intravenous administration of 1 to 1.6 g ACZ. In 34 subjects (group 1), velocities were measured every second minute to detect the maximum middle cerebral artery velocity increase. We also measured regional cerebral blood flow using single-photon emission computed tomography in 27 of the subjects in group 1 before and approximately 15 to 20 minutes after the ACZ injection. The serum concentration of ACZ was measured in 15 subjects. In the remaining 14 subjects (group 2), middle cerebral artery velocity measurements were made 10, 25, 30, and 45 minutes after ACZ administration to obtain information regarding the late time course of the response.

Results
In group 1 the plateau phase of the velocity response was reached 8 to 15 minutes after ACZ administration. A large range of velocity increase was observed, and a significant correlation was found between the maximum velocity increase and the dose and serum concentration of ACZ. In group 2 subjects, maximum velocities were maintained 30 minutes after the injection, but after 45 minutes velocities had decreased to 68% of their highest level. No significant relationship was found between dose or serum concentration of ACZ and the regional cerebral blood flow increase. The velocity increase after ACZ was similar in both older and younger subjects.

Conclusions
This study shows that cerebral vasoreactivity is best assessed 10 to 30 minutes after ACZ administration and that the dose should probably exceed 15 mg/kg if a maximum vasodilatory response in the cerebral circulation is to be obtained.
Differential Changes in α- and β-Adrenoceptors in the Cerebral Cortex and Hippocampus of the Mongolian Gerbil After Unilateral Brain Ischemia
Authors: Mizuki Tsunetaka , Kobayashi Hideyuki , Ueno Susumu , Nakashima Yasuhide , Kuroiwa Akio , Izumi Futoshi
Published: June 2011

Background and Purpose
Changes in adrenoceptors in the cerebral cortex and hippocampus of Mongolian gerbils after brain ischemia were investigated.

Methods
Twenty-four hours after unilateral occlusion of the common carotid artery, α
1
-, α
2
-, and β-receptors of the membrane fraction of the cerebral cortex or the hippocampus were analyzed by binding assay with the use of [
3
H]prazosin, [
3
H]
p
-aminoclonidine, and [
125
I]cyanopindolol as radioligands, respectively.

Results
In the cerebral cortex, the number of binding sites (B
max
) and the dissociation constant (
K
d
) of [
3
H]prazosin were not altered, whereas the B
max
value of [
3
H]
p
-aminoclonidine binding was decreased by 30% and that of [
125
I]cyanopindolol binding by 16% without a change in
K
d
values for the ligands. In the hippocampus, the B
max
values of [
3
H]prazosin, [
3
H]
p
-aminoclonidine, and [
125
I]cyanopindolol bindings were decreased by 21%, 53%, and 19%, respectively, but there was no change in the
K
d
values for the ligands. The bindings of [
3
H]prazosin and [
3
H]
p
-aminoclonidine of the contralateral side of the cerebral cortex and the hippocampus were not altered by ischemia, but that of [
125
I]cyanopindolol was decreased when compared with normal tissues.

Conclusions
These results show that ischemia results in a decrease in brain α
1
-, α
2
-, and β-adrenoceptors to various degrees, depending on the brain area and the types of receptors, and suggest that vulnerability of the brain to ischemia is different depending on brain areas and that the regulatory mechanisms of α
1
-, α
2
-, and β-receptors are different.
Decompressive Craniectomy for Cerebral Infarction
Authors: Forsting Michael , Reith Wolfgang , Schäbitz Wolf-Rüdiger , Heiland Sabine , von Kummer Rüdiger , Hacke Werner , Sartor Klaus
Published: June 2011

Background and Purpose
Acute ischemia in the territory of the carotid artery can lead to massive cerebral edema with raised intracranial pressure and progression to coma and death due to uncal, cingulate, or tonsillar herniation. Thus far, only anecdotal experience with supratentorial ischemia treated by decompressive craniectomy has been reported, and there are no published experimental data dealing with this kind of therapy in acute supratentorial stroke. In this study, we present our results on the effect of decompressive craniectomy in an endovascular model of cerebral infarction in rats.

Methods
Focal cerebral ischemia was induced in 50 rats using an endovascular occlusion technique of the middle cerebral artery. Decompressive craniectomy was performed in 30 animals: in 15 animals after 1 hour and in the remaining 15 animals 24 hours after vessel occlusion. Twenty animals were not treated by decompressive craniectomy (control group).

Results
Mortality in the nontreated group was 35%, whereas none of the animals treated by decompressive craniectomy died. Neurological behavior, weight loss, and infarction size were all significantly better in the animals treated by decompressive craniectomy, regardless of whether they had been treated after 1 or 24 hours (
P
<.01).

Conclusions
Our results suggest that decompressive craniectomy for cerebral ischemia not only reduces mortality but also significantly improves outcome and reduces infarction size, probably because of increased perfusion pressure through leptomeningeal collaterals. This experimental study suggests that a controlled study of decompressive craniectomy in patients with acute internal carotid or middle cerebral artery occlusion would be worthwhile. By performing decompressive craniectomy in a small, selected group of patients, neurosurgeons may play an important role in the management of these patients.
Arterial Wall Thickness Is Associated With Prevalent Cardiovascular Disease in Middle-Aged Adults
Authors: Burke Gregory L. , Evans Gregory W. , Riley Ward A. , Sharrett A. Richey , Howard George , Barnes Ralph W. , Rosamond Wayne , Crow Richard S. , Rautaharju Pentti M. , Heiss Gerardo
Published: June 2011

Background and Purpose
This study was done to assess the relationship between prevalent cardiovascular disease and arterial wall thickness in middle-aged US adults.

Methods
The association of preexisting coronary heart disease, cerebrovascular disease, and peripheral vascular disease with carotid and popliteal intimal-medial thickness (IMT) (measured by B-mode ultrasound) was assessed in 13 870 black and white men and women, aged 45 to 64, during the Atherosclerosis Risk in Communities (ARIC) Study baseline examination (1987 through 1989). Prevalent disease was determined according to both participant self-report and measurements at the baseline examination (including electrocardiogram, fasting blood glucose, and medication use).

Results
Across four race and gender strata, mean carotid far wall IMT was consistently greater in participants with prevalent clinical cardiovascular disease than in disease-free subjects. Similarly, the prevalence of cardiovascular disease was consistently greater in participants with progressively thicker IMT. The greatest differences in carotid IMT associated with prevalent disease were observed for reported symptomatic peripheral vascular disease (0.09 to 0.22 mm greater IMT in the four race-gender groups).

Conclusions
These data document the substantially greater arterial wall thickness observed in middle-aged adults with prevalent cardiovascular disease. Both carotid and popliteal arterial IMT were related to clinically manifest cardiovascular disease affecting distant vascular beds, such as the cerebral, peripheral, and coronary artery vascular beds.
Return to Work After Stroke
Authors: Saeki Satoru , Ogata Hajime , Okubo Toshiteru , Takahashi Ken , Hoshuyama Tsutomu
Published: June 2011

Background and Purpose
Few studies have reported the longitudinal trend of return to work after stroke. The purpose of our study was to evaluate the longitudinal trend of proportion of patients who return to work after stroke and further to examine the predictors of return to work while taking follow-up periods into consideration.

Methods
We conducted a retrospective cohort study on the association between characteristics of stroke patients at admission and return to work after first stroke, taking length of follow-up period into consideration (n=183). The patients were all younger than 65 years and were working at the time of their stroke. A follow-up questionnaire evaluated return to work and related information. Data were analyzed using the Kaplan-Meier method for curves of the proportion of return to work and Cox’s proportional hazards model for odds ratios of return to work.

Results
The curve of proportion of return to work had two steep slopes, and the proportion was at a maximum at 18 months from patient admission. The adjusted odds ratios of return to work for patients with normal muscle strength versus severe weakness, without apraxia versus with apraxia, and with white-collar versus blue-collar occupations were 5.16 (
P
<.05), 4.16 (
P
<.05), and 1.43 (.05<
P
<.10), respectively.

Conclusions
The increase of proportion of return to work after stroke was nonlinear, and this trend was referable to the social security systems available to the patients included in this study. Normal muscle strength and absence of apraxia were significant predictors of return to work after stroke. White-collar occupation showed a tendency to promote return to work.
Pain-Related and Electrically Stimulated Somatosensory Evoked Potentials in Patients With Stroke
Authors: Yamamoto Masahiko , Kachi Teruhiko , Igata Akihiro
Published: June 2011

Background and Purpose
Pain-related somatosensory evoked potentials (SEPs) were applied to study abnormality of pain sensation in stroke, together with electrically stimulated SEPs for deep sensation.

Methods
We recorded pain-related SEPs after CO
2
laser stimulation to the dorsum of the hand and electrically stimulated SEPs after median nerve stimulation at the wrist in 12 patients with stroke. We analyzed P340 in pain-related and parietal N20 in electrically stimulated SEPs.

Results
In 5 patients with a putaminal lesion, P340 was absent or its latency was delayed, and N20 was absent or reduced in amplitude. In 3 patients with a thalamic lesion, P340 and N20 showed various patterns according to the involved sites. In 4 patients with a lesion in the corona radiata, P340 and N20 were normal.

Conclusions
Abnormalities of P340 and N20 in the stroke location were related to impairment of the pain and vibration senses, respectively. Thus, pain-related and electrically stimulated SEPs were useful to investigate the sensory function of each structure in the central nervous system in patients with stroke.
Variability of Doppler Microembolic Signal Counts in Patients With Prosthetic Cardiac Valves
Authors: Georgiadis D. , Kaps M. , Siebler M. , Hill M. , König M. , Berg J. , Kahl M. , Zunker P. , Diehl B. , Ringelstein E. B.
Published: June 2011

Background and Purpose
The purpose of this study was the evaluation of intraobserver, interobserver, and intrasubject variability in the Doppler detection of microembolic signals in patients with mechanical prosthetic valves. Simultaneously, the feasibility of automated embolus detection by means of a neuronal network was investigated.

Methods
From 25 patients with mechanical prosthetic heart valves, single transcranial Doppler monitoring sessions of 30 minutes’ duration were recorded on videotape, randomized, and subsequently analyzed by eight independent trained observers from three centers. Three observers evaluated these tapes on three separate occasions, blinded to their previous results. An additional 48 patients with prosthetic heart valves were repetitively monitored with transcranial Doppler ultrasonography for 30 minutes three times within 1 year to examine the long-term variability in the occurrence of microembolic signals. Finally, in an effort to assess the short-term intrasubject variability, 20 patients were examined for 90 minutes, and the results of the three 30-minute periods were compared. The interobserver, intraobserver, and intrasubject (both short- and long-term) variability was evaluated.

Results
No significant differences in microembolic signal counts were found among the different observers, between the human observers and the neuronal network, or among the three separate evaluations of stored data by the same observer. The same was true for repeat examinations of the same patient (
P
>.05, Student’s two-paired
t
test and Friedman’s test).

Conclusions
The detection of microembolic signals in patients with prosthetic cardiac valves is a reproducible technique. The reliable performance of the neuronal network argues for a broader use of this device. The intrasubject stability of the microembolic rate over 1 year supports the concept that the underlying emboligenic process is associated with intrinsic mechanical properties of the valve implant and not due to a thromboembolic process in the heart.
Combined Perfusion and Diffusion-Weighted Magnetic Resonance Imaging in a Rat Model of Reversible Middle Cerebral Artery Occlusion
Authors: Müller Tomm B. , Haraldseth Olav , Jones Richard A. , Sebastiani Giovanni , Godtliebsen Fred , Lindboe Christian F. , Unsgård Geirmund
Published: June 2011

Background and Purpose
Diffusion-weighted imaging and dynamic first-pass bolus tracking of susceptibility contrast agents (perfusion imaging) are two new magnetic resonance imaging techniques that offer the possibility of early diagnosis of stroke. The present study was performed to evaluate the diagnostic information derived from these two methods in a rat model of temporary focal ischemia.

Methods
Fifteen male Wistar rats were assigned to 45 (n=7) or 120 minutes (n=8) of middle cerebral artery occlusion followed by reperfusion using the intraluminal filament technique. The diffusion-weighted images were collected, and areas of hyperintensity were compared with histologically assessed areas of ischemic injury. The magnetic resonance perfusion image series were postprocessed to produce topographic maps reflecting the maximum reduction in the signal obtained during the first passage of the contrast agent and the time delay between the arrival of the bolus and the point of maximum contrast-agent effect.

Results
Hyperintensity in diffusion-weighted images was demonstrated after 30 minutes of middle cerebral artery occlusion and was mainly expressed in the lateral caudoputamen and parts of the lower frontoparietal cortex. Reperfusion after 45 minutes of occlusion reduced the area of hyperintensity from 24.2% to 9.9% of hemispheric area. In the group with 120 minutes of occlusion, the hyperintense area increased from 24.4% to 29.1%. Relative to the nonischemic hemisphere, the changes in the topographic maps of maximum signal reduction occurred in the lateral caudoputamen and adjacent lower neocortical areas. Increased time delay to maximum effect, however, was seen also in the upper frontoparietal cortex.

Conclusions
Hyperintensity in diffusion-weighted images was reversible after 45 minutes but not after 120 minutes of middle cerebral artery occlusion. Analysis of the signal-reduction and time-delay parametric maps demonstrated regions of different perfusion changes in the ischemic hemisphere.
Stroke Due to Recurrent Ipsilateral Carotid Artery Dissection in a Young Adult
Authors: Goldstein Larry B. , Gray Linda , Hulette Christine M.
Published: June 2011

Background
Extracranial carotid artery dissection is a well-recognized cause of ischemic stroke. Recurrent carotid artery dissections are infrequent. Recurrent ipsilateral dissection has only rarely been documented and has not been pathologically verified.

Case Description
A 33-year-old woman presented with a left parieto-occipital ischemic stroke. Angiography demonstrated a pseudoaneurysm of the extracranial left internal carotid artery. There was no angiographic evidence of an underlying vasculopathy. The pseudoaneurysm was resected, and microscopic examination revealed features most consistent with fibromuscular dysplasia with areas of both chronic and recent dissection.

Conclusions
This case suggests that the frequency of fibromuscular dysplasia as a cause for “idiopathic” spontaneous carotid artery dissection may be higher than previously recognized and that recurrent embolization may occur in the setting of chronic dissection due to redissection of the previously involved vessel.
Superior Sagittal Sinus Thrombosis and Thyrotoxicosis
Authors: Siegert C.E.H. , Smelt A.H.M. , de Bruin T.W.A.
Published: June 2011

Background
Superior sagittal sinus thrombosis is an uncommon cerebrovascular accident that is frequently associated with diseases that may contribute to the development of thrombosis through hypercoagulability, stasis of the local blood stream, and abnormalities of the vessel wall. In approximately 25% of cases underlying diseases remain unrecognized.

Case Descriptions
Two patients with superior sagittal sinus thrombosis during a thyrotoxic phase of Graves’ disease are described. Both patients presented with hemiplegia, seizures, and a large goiter.

Conclusions
The development of superior sagittal sinus thrombosis is multifactorial. Patients with thyrotoxicosis and a large goiter may be predisposed to the development of superior sagittal sinus thrombosis through hypercoagulability and stasis of the local venous blood flow.
Massive Infarcts Involving the Territory of the Anterior Choroidal Artery and Cardioembolism
Authors: Levy R. , Duyckaerts C. , Hauw J.-J.
Published: June 2011

Background and Purpose
At neuropathological examination, the territory of the anterior choroidal artery is frequently found to be involved in massive infarcts of the internal carotid artery territory. The aim of our study was to analyze the clinical spectrum, the course, and the mechanism of these massive infarcts compared with the rare infarcts involving only the anterior choroidal artery territory.

Methods
Retrospective clinical examination and pathological study were performed in 35 patients with cerebral infarcts affecting at least the territory of the anterior choroidal artery.

Results
In no patient had the involvement of the anterior choroidal territory infarcts been recognized clinically, nor had the triad of clinical signs (hemiplegia, hemianesthesia, and hemianopsia) classically seen in infarcts restricted to this territory been found alone. Impairment of consciousness, cognitive disorders, or oculomotor palsies had been found in addition to one or more signs of the triad. This was probably related to the involvement of other territories (94%), especially the middle cerebral artery territory (68%) and the posterior cerebral artery territory (20%). The concomitant involvement of several territories was due most frequently to an occlusion of the internal carotid artery, which was found at autopsy in 74% of the patients. These occlusions were often associated with cardioembolism (54%). In contrast, artery-to-artery embolism (17%) and small-artery disease (6%) were seldom found. Only two cases of infarcts restricted to the anterior choroidal artery territory were observed.

Conclusions
The involvement of the territory of the anterior choroidal artery in massive infarcts was due mainly to a cardioembolic occlusion of the internal carotid artery.
Dietary Sodium, Potassium, Saturated Fat, Alcohol, and Stroke Mortality
Authors: Sasaki Satoshi , Zhang Xin-Hua , Kesteloot Hugo
Published: June 2011

Background and Purpose
Although positive relationships between blood pressure, dietary sodium, and stroke risk have been reported, studies on the relationship between dietary sodium and stroke mortality are scarce. A significant relationship between dietary saturated fatty acids (SFA) and stroke risk has not been reported in epidemiological studies. The purpose of this study was to examine the relationship between dietary sodium and SFA together with dietary potassium, alcohol, and stroke risk.

Methods
The sex- and age-specific stroke mortality rates (log-transformed) for the age classes 45 to 54, 55 to 64, and 65 to 74 years for the period between 1986 and 1988 were obtained from World Health Organization statistics. The 24-hour urinary excretion levels of sodium (U-Na) and of potassium (U-K), dietary SFA intake levels, and alcohol consumption levels were obtained from dietary surveys performed in 17 countries. The relationships between stroke mortality and the dietary variables were examined by Pearson correlation and multiple regression analysis.

Results
The highest degree of correlation, both in Pearson correlation and multiple regression analysis, was found between U-Na and log-stroke mortality (
P
<.01 to
P
<.001). In multiple regression analysis, U-Na (
P
<.01 to
P
<.001), SFA (
P
<.05 to
P
<.01), and alcohol (
P
<.05) independently, significantly, and positively correlated with log-stroke mortality rates, and U-K correlated negatively (
P
<.05). The exceptions were SFA in both sexes in the age class 45 to 54 years, alcohol in both sexes in the age class 45 to 54 years and in women in the age class 55 to 64 years, and U-K in women in the age class 65 to 74 years.

Conclusions
These results suggest that dietary factors, especially sodium and SFA, are of primary importance as determinants of stroke mortality at the population level.
Patient Falls in Stroke Rehabilitation
Authors: Nyberg Lars , Gustafson Yngve
Published: June 2011

Background and Purpose
The risk of falls is very high among stroke patients, and falling is a major complication in stroke rehabilitation. This study aimed to investigate the incidence, characteristics, and consequences of falls in an inpatient stroke rehabilitation setting.

Methods
One hundred sixty-one patients consecutively admitted to a geriatric stroke rehabilitation unit were studied. Falls that occurred during their rehabilitation stay were prospectively registered and analyzed.

Results
Sixty-two of the patients (39%) suffered falls. The total number of falls was 153, which corresponds to an incidence rate of 159 falls per 10 000 patient-days. Most falls occurred during transfers or from sitting in a wheelchair or on some other kind of furniture. Seventeen falls (11%) were classified as the result of extrinsic mechanisms, 49 (32%) were intrinsic falls, 39 (25%) occurred in a nonbipedal position (while sitting or lying), and 48 falls (31%) remained unclassified. No injury was observed in 109 of 153 incidents (71%), whereas 6 falls (4%) involved fractures or other serious injury.

Conclusions
Since falls are so frequent, they must be considered a significant problem in stroke rehabilitation. Fall prevention strategies should therefore be developed and included in rehabilitation programs.