bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal profile of vertebrobasilar territory infarction. Prognostic implications.
Authors: Patrick B K , Ramirez-Lassepas M , Synder B D
Published: June 2011

To determine the type and prognostic significance of the various temporal profiles of vertebrobasilar territory infarction, 39 consecutive patients were studied. The following profiles were identified: 1) coma from onset, 5 patients; 2) sudden onset followed by stabilization, 12 patients; 3) gradual onset reaching stabilization within 24 hours, 7 patients; 4) gradual onset with progression beyond 24 hours, 2 patients, and; 5) delayed worsening after stabilization, 13 patients. Patients in Group 1 and those with unstable courses, Groups 4 and 5, had poor outcomes with mortality of 100 and 27 percent, respectively. Mortality for Groups 2 and 3 was 5 percent. Overall, hospital mortality was 25.6 percent. Demographic data, risk factors, presenting symptoms and type of neurologic deficit, other than coma, had no correlation with mortality, degree of disability and long term survival. At follow up of 6 to 52 months, median 24, only 7 percent of the survivors had recurrent cerebrovascular events; 2 patients (7%) died due to nonvascular causes and 72 percent of patients re-examined (20 of 28) were either neurologically normal or had only minimal deficits.
Abrupt change in head position and cerebral infarction.
Authors: Sherman D G , Hart R G , Easton J D
Published: June 2011

Eight patients are described who developed infarctions in the vertebral-basilar artery distribution following chiropractic neck manipulation or spontaneous head turning. The angiographic and autopsy findings indicate that injury to the intima of the vertebral artery at the atlantoaxial joint forms a nidus for thrombus formation which may propogate or embolize to involve other vessels in the vertebral-basilar system and result in progressive brainstem infarction. The role of anticoagulation in these patients is discussed.
Management of patients with established ("completed") cerebral infarction.
Authors: Buonanno F , Toole J F
Published: June 2011

Management of patients with sudden neurological deficit must be based on complete knowledge of the underlying cause. In about 80% of such patients, a careful history and examination will lead to a precise etiologic and anatomic diagnosis. If the deficit is vascular in etiology, therapy and prognosis depend on its stage of evolution.
Traumatic dissection of the internal carotid artery treated by ECIC anastomosis.
Authors: Bergquist B J , Boone S C , Whaley R A
Published: June 2011

A patient with traumatic dissection of the left internal carotid artery (ICA) was treated by extracranial-intracranial (ECIC) anastomosis. Anastomosis was performed because the near total occlusion of the left ICA was associated with a cerebral transient ischemic attack. At surgery, an embolus was found in a cortical branch of the middle cerebral artery and was removed at the time of the ECIC. Traumatic dissection of the ICA is briefly reviewed.
Influence of factor VIII/von Willebrand factor protein (F VIII/vWF) and F VIII/vWF-poor cryoprecipitate on post-ischemic microvascular reperfusion in the central nervous system.
Authors: Hallenbeck J M , Furlow T W , Gralnick H R
Published: June 2011

To test the hypothesis that plasma contains native constituents capable of impairing microcirculatory flow in zones of acute ischemic tissue damage, we performed 14C-antipyrine autoradiographic blood flow studies in splenectomized dogs subjected to 35 min of cerebrospinal fluid compression ischemia followed by 30 min of recirculation to the neuraxis. The animals were anticoagulated with heparin and were divided into 4 groups by exposure to various measures before induction of ischemia. Groups 1 and 2 served for comparison with the other groups and underwent, respectively, no glass-wool filtration and glass-wool filtration via an arteriovenous shunt. Post-ischemic brain blood flows in Group 1 were low and focal zones of greatly impaired reperfusion were present. In Group 2, post-ischemic brain blood flows were high and focal perfusion impairment did not occur. Group 3 received homologous purified factor VIII/von Willebrand factor protein (F VIII/vWF) after glass-wool filtration but before induction of ischemia; Group 4 received F VIII/vWF-poor cryoprecipitate at the same time point. The purpose of administering the plasma preparations was to check for the presence of activity that nullified the enhancement of post-ischemic reperfusion expected after exposure to glass-wool. The results indicate that activity deleterious to post-ischemic reperfusion primarily resides in the F VIII/vWF fraction of cryoprecipitate. The F VIII/vWF-poor cryoprecipitate infusate, containing 250 to 800-fold more protein than the F VIII/vWF fraction, produced an intermediate reduction of blood flow.
Chronic common carotid occlusion.
Authors: Podore P C , Rob C G , DeWeese J A , Green R M
Published: June 2011

Twelve patients with chronic common carotid artery (CCA) occlusion were studied. There were 8 patients with TIAs (3 hemispheric and 5 vertebral-basilar), one with a completed stroke, and 3 were asymptomatic. The ipsilateral internal carotid artery (ICA) was confirmed patent in 6 patients at the time of operation, although angiograms had demonstrated patency in only two. The ipsilateral external carotid artery (ECA) was patent in all but one patient. Arterial reconstructions were done on 7 patients. The carotid bifurcation was revascularized by subclavian-to-carotid bypass grafts in 5 patients, 3 with vertebral-basilar (V-B) TIAs, one with hemispheric TIAs, and one with a completed stroke. Vertebral revascularization was done on 2 patients, one with V-B TIAs and one who was asymptomatic. All revascularized patients had satisfactory results. Symptomatic patients can be treated by cerebral revascularization through either the ICA, if patent, the ECA via the ophthalmic collaterals, or through the vertebrals when hypoperfused. The ICA is preferentially revascularized and exploration often reveals a patent ICA that was not visualized angiographically. Recently, directional Doppler studies have proved useful in determining ICA patency.
Decreasing trend in incidence and mortality from stroke in Hisayama residents, Japan.
Authors: Ueda K , Omae T , Hirota Y , Takeshita M , Katsuki S , Tanaka K , Enjoji M
Published: June 2011

The incidence and mortality from stroke during the period 1961 to 1976, among 1,621 subjects aged 40 and over at entry, in Hisayama community, Kyushu Island, Japan, were analyzed. A major age-related decline in the incidence of cerebral infarction occurred in both sexes. The average annual incidence of cerebral infarction also fell continuously in both sexes throughout the whole observation period. The 5-year annual mortality rate from cerebral hemorrhage also showed a decrease in men, but fluctuated in women. The 5-year mortality from cerebral infarction slightly increased in both sexes.
Comparison between hydrogen clearance and microsphere technique for rCBF measurement.
Authors: Heiss W D , Traupe H
Published: June 2011

Regional cerebral blood flow was measured repeatedly in anesthetized and immobilized cats under various experimental conditions by recording the clearance of inhaled hydrogen with inserted platinum electrodes and by recording the distribution of 15 mu microspheres labeled with 3 different radioisotopes. The values for both methods in normal cortical tissue were comparable (75.7 +/- 23.5 ml/100 g min for H2-clearance; 67.6 +/- 26.2 ml/100 g min for microsphere technique), but were below those recorded in awake cats. With both methods the values could be reliably reproduced (correlation coefficient between measurements: 0.903 for H2-clearance, 0.754 for microsphere technique). During ischemia induced by temporary occlusion of the middle cerebral artery the microsphere technique usually yielded higher flow values than the H2-clearance, and did not indicate severe ischemia in 6 out of 20 instances. After restoration of flow, hyperperfusion was observed by the microsphere technique in 2 cases only while H2-clearance indicated hyperemia in 6 instances. This limited comparability between the 2 methods was also expressed in a low correlation coefficient (0.486) calculated from 139 flow values obtained simultaneously with both methods. The discrepancy between the methods under pathological conditions might be due mainly to the different recording volumes: while Pt-electrodes record H2-clearance from a few mm3 or less, tissue samples of 300-700 mg were necessary for the microsphere technique and inhomogeneities of flow may thereby escape detection. The technique for measuring cerebral blood flow in an experimental setup should be selected according to the requirements of the study and according to the limitations of the various methods.
Lipoprotein abnormalities in the pathogenesis of cerebral infarction and transient ischemic attack.
Authors: Murai A , Tanaka T , Miyahara T , Kameyama M
Published: June 2011

HDL-cholesterol levels were determined by a heparin-Ca precipitation method in 89 survivors of cerebral infarction (CI) (75 males, 14 females) and 14 patients with transient ischemic attacks (TIA) (8 males, 6 females). The mean values of HDL-cholesterol concentration and HDL:LDL-cholesterol ratio for both sexes of CI patients were significantly lower than those of the healthy controls (37 males, 14 females). These values for CI patients were significantly lower than in patients with various diseases excluding cardiovascular disease, hepatic disease, hyperlipidemia, diabetes mellitus and degenerative disorders of the nervous system (46 males, 43 females). In patients with TIA, these differences were statistically significant only for men. Based on the patient's history, clinical signs and symptoms and the findings of computerized tomography and 4-vessel angiography, male CI patients were divided into 2 sub-groups, CI believed to be in the distribution of a perforating artery and CI in the distribution of a cortical artery; it was found that the HDL-cholesterol level and HDL:LDL-cholesterol ratio were significantly lower in the cortical artery group than in the perforating artery group, suggesting that these lipoprotein abnormalities may play a part in the pathogenesis of CI, particularly of the cortical artery area infarction.
Concordance of inhalation rCBFs with clinical evidence of cerebral ischemia.
Authors: Ewing J R , Keating E G , Sheehe P R , Hodge C J , Chipman M , Brooks C T
Published: June 2011

Using the 133-Xenon inhalation technique, cerebral blood flow (CBF) and hemispheric blood flow (HBF) were determined serially in 45 patients with acute stroke undergoing pharmacologic trials and in 8 transient ischemic attacks (TIA) schedules for superficial temporal-middle cerebral artery anastomoses. Both patient populations had lower blood flow than a control group of similar ages. Patients in both populations with lateralized clinical signs demonstrated an asymmetry in HBF which corresponded to their clinical signs. In the stroke population, the trend we expected over time toward development of asymmetrical HBF as the non-infarcted hemisphere recovered from diaschisis did not appear.
Arterial supply of the feline motor cortex.
Authors: Thompson F J , Campbell M L
Published: June 2011

The arterial supply of the feline motor cortex is derived from both the anterior and middle cerebral arteries. The anterior cerebral artery supplies most of cortical area 6 (premotor cortex), the intrafundal cruciate and medial postcruciate cortex, (hindlimb motor cortex), and the midline and medial portions of the sensory areas 3a-7. The middle cerebral artery supplies the lateral prorean cortex, (lateral premotor cortex), precruciate and lateral sigmoid cortex, (forelimb motor cortex), and the remainder of the coronal and Sylvian cortical areas.
Abnormalities of gaze in cerebrovascular disease.
Authors: Pedersen R A , Troost B T
Published: June 2011

Disorders of ocular motility may occur after injury at several levels of the neuraxis. Unilateral supranuclear disorders of gaze tend to be transient; bilateral disorders more enduring. Nuclear disorders of gaze also tend to be enduring and are frequently present in association with long tract signs and cranial nerve palsies on opposite sides of the body. Nystagmus is a reliable sign of posterior fossa or peripheral eight nerve pathology. Familiarity with these concepts may help the clinician answer questions regarding localization and prognosis.
Accuracy of bedside diagnosis in stroke.
Authors: von Arbin M , Britton M , de Faire U , Helmers C , Miah K , Murray V
Published: June 2011

The clinical diagnosis of the type of acute cerebrovascular diseases is often considered unreliable, although this has not been validated prospectively in representative patients. The accuracy of bedside diagnostics was, therefore, tested in 206 patients consecutively admitted to the Stroke Unit of the Serafimerlasarettet in Stockholm. Bedside diagnosis turned out to be correct in 69%. In 24% the diagnoses were altered after hospital investigation and in the remaining 7% no defined preliminary and/or final diagnosis could be made. When the diagnoses were considered "fairly certain" they were accurate in 87%, compared to 53% when regarded as only "probable". The diagnostic accuracy improved during the period studied. Sensitivity in identifying hemorrhages was much lower (39%) than for cerebral infarctions (83%). It is suggested that new investigational methods should be compared with what can be accomplished with bedside methods alone.
Use of combined oculoplethysmography, carotid phonoangiography and Doppler in the non-invasive diagnosis of extracranial carotid occlusive disease.
Authors: Kapsch D , Cook L , Lichti E , Silver D
Published: June 2011

One hundred and eight patients were studied with fluid-filled oculoplethysmography and carotid phonoangiography (OPG-CPA) and by arteriography. Thirty-two patients also had "Doppler evaluation" of supraorbital arterial flow. The OPG-CPA correctly predicted the degree of occlusion in 76% of the involved vessels, including the degree of occlusion of each carotid for each patient (63%). The OPG-CPA identified at least one obstructing carotid lesion in 51 of the 56 (91%) patients with obstructing lesions demonstrated by arteriography. On a per patient basis, which requires that both carotids be correctly assessed, the OPG-CPA had a false negative rate of 9.6% and false positive rate of 50%. The supraorbital artery "Doppler evaluation" had an accuracy rate of 66%, a per patient false negative rate of 50%, and a per patient false positive rate of 12%. The OPG-CPA and supraorbital artery "Doppler evaluation" are adjunctive tests for evaluating patients with cerebral vascular insufficiency and should not, at present, replace arteriography in symptomatic patients or in certain asymptomatic patients.
Evaluation of cerebrovascular Doppler examination and oculopneumoplethysmography in a clinical perspective.
Authors: Lynch T G , Wright C B , Miller E V , Slaymaker E E
Published: June 2011

The cerebrovascular Doppler examination (CDE) and oculopneumoplethysmography (OPG-Gee) were compared in a single population group with no statistically significant difference found between the 2 studies. There appeared to be an advantage to combinant testing, for when the results of the 2 studies were concordant there was an accuracy of 94% and a false negative rate of 8%. Clinical correlation was available in 96% of the patients, providing adequate evidence to support the adjuvant role of non-invasive screening in the evaluation of symptomatic individuals. The percentage of false negative studies and the incidence of ulcerative disease make a diagnostic role impractical at present. For the asymptomatic individual, the diagnostic role of non-invasive screening seems justified. The false negative studies in the present series were confined to those vessels with 50-70% stenoses, which are difficult to assess angiographically and may be better characterized by hemodynamic evaluations.
Headache in cerebral embolic disease.
Authors: Auerbach S H , Butler R B , Levine H L
Published: June 2011

A patient is presented who had severe headache and then developed a stuttering course of clinical neurological deficits. Arteriography demonstrated an ipsilateral proximal middle cerebral embolus. With recurrence of symptoms, repeat arteriography showed another, more proximal embolus with areas of distal occlusion. The headache probably occurred when the embolus became lodged in a pain sensitive cerebral vessel at the base of the brain. The subsequent stuttering neurological deficits were due to fragmentation of the embolus as well as recurrence.
Arterial hypertension injures brain capillaries. Definition of the lesions. Possible pathogenesis.
Authors: Garcia J H , Ben-David E , Conger K A , Geer J C , Hollander W
Published: June 2011

Systemic hypertension (secondary to aortic coarctation) produces in monkeys, multifocal brain lesions where capillaries show increased diameter, endothelial degeneration and deposition of collagen and other substances in the basement membrane. In one animal, capillary changes were detected as early as 8 weeks after induction of hypertension. Similar capillary alterations were demonstrated in brain samples of hypertensive humans obtained at autopsy. We suggest that the above abnormalities may be the result of successive episodes of regional ischemia and/or hyperperfusion. Validation of these observations requires careful evaluation of additional human and animal brains.
Carotid system transient ischemic attacks: clinical, racial, and angiographic correlations.
Authors: Russo L S
Published: June 2011

The records and cerebral angiograms of 50 consecutive patients admitted to a large city hospital with a diagnosis of carotid system transient ischemic attacks were reviewed in an effort to determine the prevalence of demonstrable carotid artery disease in this population. Of these, 21 had a demonstrable abnormality in the extracranial carotid artery appropriate to their symptoms. Of the 29 with no abnormality in the extracranial portion of the appropriate carotid artery, 21 had a totally normal arteriogram, and 8 showed abnormality either in the non-appropriate carotid or in the intracranial portion of the appropriate carotid artery. Chi-square analysis of the angiographic data and various clinical factors was carried out. Of the 29 patients with no abnormality in the appropriate artery, 18 were black and 11 were white. Of the 21 patients with an abnormal appropriate artery, 7 were black and 14 were white (p less than 0.05). No other clinical factor correlated with high rate of angiographic abnormality.
Mechanisms and timing of deaths from cerebral infarction.
Authors: Bounds J V , Wiebers D O , Whisnant J P , Okazaki H
Published: June 2011

Clinicopathologic correlations were reviewed in 100 cases of recent cerebral infarctions in the internal carotid artery distribution. The most frequent cause of death was transtentorial herniation, followed in frequency by pneumonia, cardiac causes, and pulmonary embolism. Thirty-six percent of all patients and 47% of those with transtentorial herniation died within 48 hours of cerebral infarction. Of the treatable extracerebral causes of death determined at autopsy, only 34% were recorded premortem in the clinician's death summary.
Fenestrations in the internal elastic lamina at bifurcations of human cerebral arteries.
Authors: Campbell G J , Roach M R
Published: June 2011

Measurements of fenestrations (or windows) in the internal elastic lamina at the bifurcation of human cerebral arteries, were obtained from photomicrographs (scanning electron microscope). Thirteen of 28 bifurcations revealed regions of enlarged fenestrations among the normal fenestrations in the vicinity of the apex. The mean diameter of the enlarged fenestrations (7.0 +/- 0.34 SEM micrometer) was significantly greater than the mean diameter (2.1 +/- 0.13 SEM micrometer) of the normal fenestrations. The number of fenestrations per sq mm was less (2606 +/- 284 SEM per sq mm) for the enlarged fenestrations than for the normal fenestrations (4518 +/- 397 SEM per sq mm). The proportion of the area of internal elastic lamina comprised of fenestrations increased to 15.0 +/- 1.1 SEM percent for the enlarged fenestrations from a mean of 1.8 +/- 0.16 SEM percent for the normal fenestrations. Fenestrations from bifurcations without enlarged fenestrations, demonstrated characteristics similar to the normal fenestrations. More than 80% of the specimens exhibited a gap in the internal elastic lamina in the apical region of the bifurcation. Based on a comparison of stress concentration factors, we propose that the presence of enlarged fenestrations represents a weakness in the internal elastic lamina at the bifurcation apex which may contribute to the initiation of microaneurysms.
Constrictive endarteropathy following experimental subarachnoid hemorrhage.
Authors: Clower B R , Smith R R , Haining J L , Lockard J
Published: June 2011

Rhesus monkeys were subjected to subarachnoid hemorrhage by either the introduction of blood into the subarachnoid space or by mechanically rupturing the middle cerebral artery. Local cerebral blood flow, vascular compliance studies, and histological studies (light and electron microscope) were made of the vessels of all animals. In animals hemorrhaged via vascular rupture, subintimal swelling and thickening was minimally present by 3 days, becoming progressively more severe by one month. Such changes consisted of severe subintimal proliferation, fibrosis of the medial smooth muscle layer and interruption of the internal elastic membrane. Cells in the subintimal proliferative areas examined by electronmicroscopy were seen to have ultrastructural characteristics of smooth muscle. In the subarachnoid-injected hemorrhaged animals, there was no evidence of intimal proliferation or other vascular changes, which was also true of all control vessels. There was a decrease in wall elasticity of vessels exposed to mechanical rupture when compared to those exposed only to injected subarachnoid blood or normal vessels. Local cerebral blood flow was affected very little following the 2 methods of subarachnoid hemorrhage.
Sensitivity of rCBF to focal lesions.
Authors: Halsey J H , Nakai K , Wariyar B
Published: June 2011

The ability of the 133Xenon inhalation method to lateralize cerebral infarctions visible on CT scan was tested in 39 patients. At each of 7 hemispheric regions the flow rate in the lesioned hemisphere was divided by that in the unaffected hemisphere and this ratio was compared with the corresponding ratio for normal subjects. The fast compartment relative flow f1 correctly lateralized the lesion in only 6 patients with no false lateralizations. If the fast compartment relative weight w1 was also considered, the correct lateralizations were increased to about 50%. With the less well-known ISI and the Fractional Flow considered together, the laterality of the lesion was identified correctly in 85% of cases, with no false lateralizations.
Transient ischemic attacks and strokes with recovery prognosis and investigation.
Authors: Humphrey P R , Marshall J
Published: June 2011

This study analyzes 234 patients who recovered from an initial ischemic episode. The object was to see if the duration of the first episode influenced the chance of finding a treatable lesion or the chance of a further episode. The initial episodes varied from less than 5 minutes to longer than 3 weeks. There seemed to be no fundamental difference between transient ischemic attacks (TIAs) (less than 24 hours) and strokes which recover. However, 51% of those whose initial episode lasted less than 5 minutes had a subsequent stroke compared to 28% of those with an initial episode of more than 24 hours duration. Thirty percent of the former group who had angiograms had an operable lesion against 10% in the latter group. It seems that angiography has sufficiently high yield to be warranted in all patients where the initial attack lasted less than 30 minutes. In those with longer attacks the yield from angiography was much lower and noninvasive techniques should be considered in these patients, where available, prior to consideration for angiography. Investigation should be based on the degree of functional recovery and not on the arbitrary time division which normally divides TIAs and strokes. Bruits were the most reliable clinical indicators of stenosis. However the presence of intermittent claudication, hypertension and age over 50 were all more common in those with carotid stenosis.
Platelet embolism in rabbit brain.
Authors: Passero S , Battistini N , Fieschi C
Published: June 2011

Transient cerebral ischemia was induced in rabbits by selective infusion of arachidonic acid (0.35 mg/kg in 15 sec) into the internal carotid artery. Platelet emboli caused transient ischemia of the brain, reaching a maximum within a few seconds after injection. After embolism the EEG flattened, blood flow stopped in almost the entire injected hemisphere, cortical pH gradually fell from 7.31 +/- 0.09 to 7.05 +/- 0.10 and cortical K+ activity rose from 4.7 +/- 1.8 to 12.7 +/- 6.4 mmol/kg H2O. Complete ischemia lasted 3-5 min; then cerebral circulation was gradually restored without reactive hyperemia. Forty-five min after embolization, circulation had been resumed in almost the entire injected hemisphere, whereas metabolic changes were still disturbed. Eighty percent of the animals recovered complete neurological function and 20% showed permanent damage confirmed by histological examination after 1 week of recovery.
Evaluation of occlusive cerebrovascular disease using ultrasonic quantitative flow measurement.
Authors: Mizukami M , Yamaguchi K , Yunoki K
Published: June 2011

Eighty-four patients with cerebrovascular disease were studied by cerebral angiography and a prototype Doppler device, ultrasonic quantitative flow measurement (UQFM), that provides data from which absolute common carotid flow can be determined. The UQFM showed significantly lower flows in 23 patients who had complete occlusion of the internal carotid artery on the affected side (p less than 0.001). In 11 patients with occlusion of hte middle cerebral artery at its origin and in 5 with branch occlusions, the blood flow in the ipsilateral common carotid artery was also significantly lower (p less than 0.01). There was no significant difference between blood flow on the 2 sides in 9 patients with stenosis of middle cerebral artery and in 7 with stenosis of internal carotid artery. Due to the small number of patients no definite conclusion can be drawn. The UQFM is thought to be useful not only in screening for occlusive cerebrovascular disease but also to help understand better the mechanisms of ischemia in the presence of carotid lesions.
Ventricular fibrillation in the cat: a model for global cerebral ischemia.
Authors: Todd M M , Dunlop B J , Shapiro H M , Chadwick H C , Powell H C
Published: June 2011

A minimally invasive and standardized means of resuscitating cats from defined periods of ventricular fibrillation (VF) has been developed using methods little different from human cardiopulmonary resuscitation techniques. After a 12 min arrest, the rate of successful resuscitation is greater than 90%, witha resuscitation time of 2.5 +/- 0.7 (SD) min, and a 7 day survival of 70%. All deaths could be related to a specific electroencephalographic event observed acutely post-resuscitation, and were not due to obvious non-neurologic complications. The post-arrest variation in a variety of parameters (blood pressure, blood gases, etc.) was minimal, and the degree of neurologic damage was severe enough to permit evaluation. Such a model is clinically relevant, and may be useful in studying the pathophysiology of global ischemia, and assessing different types of post-arrest therapy.
Changes in frequency of cerebrovascular diseases in Oslo, Norway, 1958-1977. An autopsy study.
Authors: Torvik A , Stenwig J T
Published: June 2011

The frequency of lethal stroke was examined over a 20-year period in a large collection of autopsy material and was compared with the official mortality statistics for the same period. The frequency of lethal stroke in the autopsy material was calculated as a percentage of the total number of autopsied patients in the corresponding age groups. The frequency of strokes found in mortality statistics was calculated as a percentage of all deaths in the corresponding age groups. In the autopsy material the over-all stroke frequency fell by 14 percent. For patients between 40 and 69 years the decline was 25 percent while for patients over 70 years only a minor drop was observed. The most marked decline was 25 percent while for patients over 70 years only a minor drop was observed. The most marked decline was found for intracerebral hemorrhage which decreased by 70 percent in patients between 40 and 69 and by 33 percent for those over 70. For brain infarction the decline was 32 percent in the youngest age group while patients over 70 showed no decrease at all. MOrtality statistics showed a steady decline in the frequency of stroke death and the overall figures in the 2 sources were similar. Figures fo the stroke sub-groups (brain infarction and intracranial hemorrhage) were markedly different from those found in the autopsy records. Frequency of hemorrhage was several times greater than that of infarction in mortality statistics while the reverse was true in the autopsy records. The sources of error are discusses for both materials. It is concluded that the over-all figures for stroke deaths are largely reliable for both autopsy records and mortality statistics. In the mortality statistics the separate figures for hemorrhages and infarction were not correct and long term changes in frequency of these conditions would be interpreted with caution. The figures from the autopsy material are considered to be more reliable and it is concluded that the decline in hemorrhage and infarction described is real.
Vascular supply pattern to rat caudatoputamen and globus pallidus: scanning electronmicroscopic study of vascular endocasts of stroke-prone vessels.
Authors: Rieke G K , Bowers D E , Penn P
Published: June 2011

The caudatoputamen (CP) and globus pallidus (GP) are supplied by vessels often involved with stroke in both rat and human. The pattern of vascular supply to the CP and GP in rat has, in contrast to humans, been only partially described. The vascular pattern to the rat CP and GP is described utilizing vascular endocasts and scanning electronmicroscopy in aging, normotensive rats. Endocasts were produced by intra-cardiac infusion of Batson's Corrosion Compound. The vascular pattern is complex, involving 1) recurrent vessels from the anterior cerebral artery, 2) branches from the arterial circle rostral or caudal to the origin of the middle cerebral artery (MCA), 3) up to 6 branches from the MCA, and 4) 2 major branches from the caudal part of the arterial circle. The vessels in groups 1--3 were serpentine, their luminal diameters abruptly reduced at branch points, and the angle of departure from the parent vessels approximated 90 degrees. These vessels supplied much of the CP and GP, while group 4 supplied the caudal CP with vessels arranged in a lattice-like fashion from the 2 penetrating parental arteries.
Complications of lumbar puncture followed by anticoagulation.
Authors: Ruff R L , Dougherty J H
Published: June 2011

The complications associated with lumbar puncture (LP) were compared in 2 groups of 342 patients. The first group of patients was anticoagulated after the LP, and the second was not. The incidence of minor headache or back pain was similar in the 2 groups (Group 1--62%, Group 2--64%). The anticoagulated patients had a higher incidence of paraparesis (Group 1, 5 patients, Group 2, No patients; p less than .05) and severe back or lumbosacral radicular pain lasting more than 48 hours (Group 1, 18 patients, Group 2, 6 patients; p less than .025). Seven of the anticoagulated patients developed spinal hematomas (5 with paraparesis, 2 with severe back pain). Among the anticoagulated patients the risk of a major complication was increased by a traumatic LP (p less than .001), starting anticoagulation within one hour of the LP (p less than .001), or aspirin treatment at the time of the LP (p less than .001). This study suggests that if LP is done, delaying anticoagulation for at least one hour and avoiding concurrent aspirin therapy may decrease the risk of developing an extraparenchymal spinal hematoma.
Balloon catheter as a model of cerebral emboli in humans.
Authors: Gács G , Mérei F T , Bodosi M
Published: June 2011

A striking similarity has been found between the distribution of occlusions in various cerebral arteries and the statistical regularity of the pathways of balloon drifting freely in the blood stream. Based on the assumption that the course of a balloon is determined by the same hydrodynamic laws as that of an embolus of similar size, it is concluded that the majority of occlusions of the cerebral arteries are of embolic origin. Emboli, then, might also be an explanation for most of the TIAs.
Retinal vascular autoregulation in normal subjects.
Authors: Tachibana H , Gotoh F , Ishikawa Y
Published: June 2011

The retinal arterial diameter and its response to changes in perfusion pressure were measured by means of a fundus camera in 65 normal subjects. A reduction of effective MABP was induced by a postural change from a recumbent to an erect position. A small but significant increase in retinal arterial diameter was observed by reduction of the perfusion pressure in all subjects. The reduction of retinal arterial reactivity in response to blood pressure changes (-% change in diameter/delta effective MABP) was significantly correlated with advancing age (p less than 0.01). No significant correlations were observed between the retinal arterial reactivity, magnitude of the retinal arterial diameter (range: 60-140 mu), and systemic blood pressure (range of MABP: 75-110 mmHg). These results indicate that the retinal artery has an autoregulatory mechanism which is influenced by aging.
The hemodynamic effect of STA-MCA bypass.
Authors: Halsey J H , Morawetz R B , Blauenstein U W
Published: June 2011

rCBF was measured by 133Xenon inhalation at rest and during pCO2 manipulation in 19 patients prior to and at various times after STA-MCA bypass surgery. The resting flow increased gradually postoperatively, seemingly more due to progressive clinical recovery from the original neurologic disability than due to the surgical intervention. CO2 reactivity increased in some patients, more in those who preoperatively had the poorest reactivity. The negative relationship between preoperative reactivity and postoperative change in reactivity was highly significant. These observations are consistent with the interpretation that the surgery did not significantly affect the resting flow level but did augment the collateral reserve in those cases in which it had been most severely impaired by the arterial lesion.
The effect of haematocrit on cerebral perfusion and clinical status following carotid occlusion in the gerbil.
Authors: Pollock S , Tsitsopoulos P , Harrison M J
Published: June 2011

The effect of haematocrit on the sequelae of carotid occlusion has been studied in the gerbil stroke model. In 72 animals one carotid artery was clipped. After 30 minutes, the area of cerebral hemisphere filling with a carbon suspension administered intravenously was measured on coronal brain slices and related to the haematocrit. Exchange transfusion of autologous packed red blood cells or plasma produced a haematocrit range of 26% to 59%. At high haematocrit a larger area of non perfusion was more commonly encountered, and the anterior cerebral artery territory was more frequently affected along with that of the middle cerebral. Fifty-seven animals had temporary occlusion of both carotid arteries. Survival was adversely affected at high haematocrit. The role of haematocrit in affecting the pathophysiology of cerebral ischaemia is discussed.
Reduction of the cerebral protective effect of hypothermia by oligemic hypotension during hypoxia in the rat.
Authors: Keykhah M M , Welsh F A , Hagerdal M , Harp J R
Published: June 2011

The effect of arterial hypotension on cerebral cortical tissue levels of adenosine triphosphate (ATP), phosphocreatine (PGr), lactate, and reduced nicotinamide adenine dinucleotide (NADH) was studied in male Wistar rats with unilateral carotid ligation exposed to arterial by hypoxia (PaO2 25 torr) for 20 min. while the body temperature was maintained at 32 degrees C and 27 degrees C. Brain metabolite levels were normal in normotensive hypothermic animals exposed to hypoxia, but reduction in arterial pressure to 75 torr caused a significant (p less than 0.05) decrease in ATP and PCr values and a significant increase in lactate and NADH levels. These changes were comparable to those of normothermic normotensive, hypoxic animals. Furthermore, there was no significant differences in the brain metabolite levels between the two hypotensive hypoxic groups. These results indicate that arterial hypotension severely alters the cerebral protective effect of hypothermia against injury caused by hypoxia, and that further reduction in body temperature (from 32 degrees C to 27 degrees C) will not prevent the harmful effect of hypoxia upon the brain in hypotensive rats.
Survival and recurrence following stroke. The Framingham study.
Authors: Sacco R L , Wolf P A , Kannel W B , McNamara P M
Published: June 2011

Survival and recurrences after stroke were assessed prospectively in a general population sample of 5184 subjects followed biennially for 26 years. Initial strokes occurred in 198 men and 196 women. There were 84 second and 27 third strokes and 223 deaths reported. Thirty day case-fatality rates for initial strokes were: 15% (33/222) for brain infarction, 16% (10/63) for cerebral embolus, 46% (18/39) for subarachnoid hemorrhage, and 82% (14/17) for intracerebral hemorrhage. Cumulative, age-adjusted 5 year survival rates for brain infarction were reduced by pre-stroke cardiac disease (coronary heart disease and/or congestive heart failure) and hypertension prior to initial stroke from .85 to .35 in men and .70 and .56 in women. Hypertension alone reduced survival from .85 to .51 in men, but not in women. Recurrences were primarily of the same type as the initial stroke. Cumulative 5 year recurrence rate for brain infarction was .42 for men, almost double that for women. Rates were reduced by excluding hypertensives and those with combined cardiac comorbidity and hypertension. Thus, risk of death or recurrence after stroke is substantial and profoundly influenced by sex and by cardiac comorbidity and hypertension present prior to the initial event.
Treatment of acute focal cerebral ischemia with propranolol.
Authors: Little J R , Latchaw J P , Slugg R M , Lesser R P , Stowe N T
Published: June 2011

Propranolol has been found to have a protective effect in experimental myocardial ischemia. Protection of ischemic kidneys was subsequently demonstrated following treatment with propranolol and its weaker beta blocking isomer, d-propranolol. The objective of the present investigation was to study the effects of propranolol (i.e., racemic d,1 mixture) and d-propranolol upon regional cerebral blood flow (rCBF) and early ischemic changes following experimental middle cerebral artery (MCA) occlusion. Thirty adult cats, lightly anesthetized with ketamine hydrochloride, underwent 3 hours or right MCA occlusion. Ten cats were untreated. Ten cats were given a continuous infusion of propranolol (1 mg/kg/hr) for 4 hours beginning 1 hour before MCA occlusion and a 4 mg/kg bolus immediately before occlusion. Ten cats were given a continuous infusion of d-propranolol (0.5 mg/kg/hr) for 4 hours beginning 1 hour before MCA occlusion and a 2 mg/kg bolus immediately before occlusion. The therapeutic agents were injected directly into the right carotid artery. The rCBF in the right Sylvian region was not significantly different in the 3 groups. EEG changes also were similar. Carbon filling defects were found to be smallest in the d-propranolol-treated group. Light microscopic studies demonstrated a reduction in infarct size in the propranolol and d-propranolol groups. The findings of the investigation indicated that propranolol and d-propranolol do not have a deleterious effect on rCBF after MCA occlusion and suggested that these agents have a protective effect upon ischemic cerebral tissue.
Measurement of rCBF by H2 clearance: theoretical analysis of diffusion effects.
Authors: Pearce R A , Adams J M
Published: June 2011

Although experimental evidence now indicates that diffusion of hydrogen can influence the measured clearance curves from which local blood flow is inferred, its exact role has not yet been well defined. For this reason we have developed a theoretical treatment of the effects of diffusion near a boundary separating regions of inhomogeneous perfusion (e.g. the gray-matter interface), and reexamined the appropriateness of the currently used bi-exponential model. Using our model, we confirmed empirical estimates of important diffusion effects up to approximately 2 mm from an inhomogeneity, and further refined the concept of spatial resolution. We also showed that fitting data to bi-exponential curves may be incorrect and lead to inaccurate results. We conclude from these studies that diffusion does indeed have an important effect on the clearance curves measured near an inhomogeneity.
Cerebral ischemia in young patients: it is associated with mitral valve prolapse and abnormal platelet activity in vivo?
Authors: Scharf R E , Hennerici M , Bluschke V , Lueck J , Kladetzky R G
Published: June 2011

The etiology of cerebrovascular disease (CDV) in young patients is difficult to establish if the common causes of a focal neurological deficit are excluded by appropriate investigations. Since in some observations prolapse of the mitral-valve (MVP), alterations of platelet function, or both have been linked with cerebral ischemic events, we studied the in vivo platelet release reaction and the incidence of MVP in 47 patients (12 males, 35 females) under 45 years of age with TIA or stroke of unknown cause and in an age- and sex-matched control group. The mean plasma beta-thromboglobulin (beta-TG) level of the patients (mean = 54.9 +/- 31.4 ng/ml) was significantly higher than that of the controls (mean = 20.6 /- 6.9 ng/ml, p less than 0.001). MVP was demonstrated in 13 of 47 patients in contrast to 4 of the controls (p less than 0.01). However, the beta-T levels of patients with MVP (n = 13, 52.9 +/- 25.5 ng/ml) did not differ from those of patients without MVP (n = 34, 55.7 +/- 33.7 ng/ml) significantly (p less than 0.4). Our results confirm that the incidence of MVP is higher in young patients with cerebral ischemia of unknown cause than in asymptomatic controls. The significantly elevated plasma beta-TG concentrations in the patient's group indicate an increased platelet activity in vivo. Since there was no significant difference between beta-TG levels of patients with and without MVP, the mitral-valve abnormality can not be the cause for the altered platelet activity.
Measurement of regional blood flow using hydrogen gas generated by electrolysis.
Authors: Koshu K , Kamiyama K , Oka N , Endo S , Takaku A , Saito T
Published: June 2011

Electrochemically generated hydrogen gas was used to measure local blood flow by Stosseck et al. The data obtained by their method, however, did not correlate well with those obtained by hydrogen inhalation. We have modified the equation proposed by Stosseck, prolonging the stimulus duration in order to increase the amount of hydrogen generated. In dog white matter the resulting clearance curves were formed to be monoexponential both in the living animal as well as after circulatory arrest when all the clearance is by diffusion away from the electrode. The values calculated by our equation correlated well with those obtained by hydrogen inhalation.
Response of local blood flow in the caudate nucleus of the cat to intraventricular administration of histamine.
Authors: De Ley G , Weyne J , Demeester G , Leusen I
Published: June 2011

The effect of intraventricular histamine on blood flow in the caudate nucleus of the cat was studied by means of the hydrogen clearance technique. Bilateral ventriculo-cisternal perfusion was installed. After a control period during which both lateral ventricles were perfused with mock CSF with the same composition, the drug under study was added to one side (experimental side) while the other side was perfused further with the control mock SCF (control side). At each point in time, blood flow at the experimental side was compared to that at the control side. Histamine (10(-3) M) caused a severe vasodilatation and this effect was completely antagonised by the H2-receptor blocker cimetidine (10(-2) M). Cimetidine had no vasoactive effects of itself in the concentration used. The H2-receptor agonist Dimaprit (10(-3) M) had a vasodilator effect although less important than histamine. Indirect evidence was gained that H1-receptors are not active in the vascular bed under study.
An animal model of cerebral infarction. Homologous blood clot emboli in rats.
Authors: Kudo M , Aoyama A , Ichimori S , Fukunaga N
Published: June 2011

An experimental model of cerebral infarction is created in rats by intracarotid injection of their homologous blood clots. This is the first small animal model in which embolization was achieved by homologous blood clots. The infarcts were produced predominantly in the territory of the middle cerebral artery. The low mortality rate and excellent reproduction rate make possible the correlative study of morphological, biochemical, and metabolic parameters at selected points in time to reconstruct the pathogenesis and natural history of focal cerebral ischemia and its relation to blood elements.
Secular trends in mortality for cerebrovascular diseases in Japan, 1960 to 1979.
Authors: Tanaka H , Tanaka Y , Hayashi M , Ueda Y , Date C , Baba T , Shoji H , Horimoto T , Owada K
Published: June 2011

In Japan the age-adjusted death rate from cerebrovascular diseases has decreased for both males and females since 1965. This downward trend accelerated in 1971. This is not due to artifacts such as changes in diagnostic methods of stroke and in rules for coding cause of death on death certificates. The progress and spread of detection, treatment and control of hypertension appears to have been the greatest contributing factor. Furthermore, improvement in the dietary habits, that is, a decrease in salt intake and an appropriate increase in the amount of animal fat and protein taken are also considered to have contributed to the decline in stroke mortality. The regional difference in the standardized mortality ratio for stroke markedly observed in 1960 was still seen even in the 1970's, but the difference became smaller. Mechanization of farming works may be partly accountable for the decrease in the regional difference.
Diverging trends in cerebrovascular disease and ischaemic heart disease mortality.
Authors: Haberman S , Capildeo R , Rose F C
Published: June 2011

The trends in age adjusted and age and sex specific mortality rates for the period 1968-1980 are compared for ischaemic heart disease and cerebrovascular disease. For both sexes and at all ages over 45 the mortality rates for cerebrovascular disease have fallen significantly. However, the mortality rates for ischaemic heart disease are rising significantly for males aged 55-64 and females aged 45-64. The divergence in trend is particularly noticeable for females aged 45-64. Possible hypotheses are discussed explaining this divergence in trend between two cardiovascular diseases of assumed similar aetiology.