bluuebunny/crossref_metadata_2025 huggingface dataset:
Prognosis for patients treated conservatively for spontaneous intracerebral hematomas.
Authors: Helweg-Larsen S , Sommer W , Strange P , Lester J , Boysen G
Published: June 2011

The long-term clinical and CT-outcome of 53 conservatively treated patients with spontaneous intracerebral hematomas (ICH) was studied in relation to the acute findings. The acute mortality of ICH was 27%. Determinant for the immediate prognosis was the level of consciousness and the volume of the hematoma. The crucial size was 50 ml with a mortality of 90% for hematomas larger and 10% for hematomas smaller than that. Intraventricular hemorrhage was a bad prognostic sign only in the ganglionic-thalamic hematomas. At follow-up at a median of 4 1/2 years after ICH, 30% of the total series had a completely normal neurological examination and 28% had resumed work. Thirteen per cent had minor neurological deficits and 17% had debilitating sequelae. During the follow-up period 7 patients had died, which indicates an excess mortality for ICH survivors. The CT findings at follow-up consisted of low density areas smaller than the original hematomas, focal atrophy, calcifications and porencephalic cysts. In 10% the CT scan revealed no trace of the previous hematoma.
Orthostatic transient ischemic attacks: a symptom of large vessel occlusion.
Authors: Somerville E R
Published: June 2011

Orthostatic transient ischemic attacks (TIA) are very much rarer than orthostatic generalized cerebral ischemia (syncope). A case is described and previous reports reviewed. Orthostatic TIA appears to occur only with large vessel occlusion. In these patients, collateral blood supply is marginal and unable to support normal postural autoregulation.
The practice of carotid endarterectomy in a large metropolitan area.
Authors: Brott T , Thalinger K
Published: June 2011

All carotid endarterectomies performed in the greater Cincinnati metropolitan area during 1980 were reviewed. For the 431 procedures performed in 16 hospitals, the operative stroke rate was 8.6% (37 of 431), and the operative mortality rate was 2.8% (12 of 431). The combined morbidity and mortality was 9.5% (41 of 431). Fifty percent of the procedures were done for asymptomatic carotid disease (216 of 431) and 50% were done for symptomatic carotid disease (215 of 431). The stroke rate was 5.6% for the asymptomatic patients and 11.6% for the symptomatic patients (difference significant, p less than 0.05). Neurosurgeons and vascular surgeons had similar surgical morbidity. All of the operative strokes involved the hemisphere ipsilateral to the endarterectomy. Fifty-seven percent of the operative strokes (21 of 37) occurred after a neurologically intact interval lasting hours to days. Four occurred following combined endarterectomy-coronary bypass surgery, and one was an intracerebral hemorrhage. The other late strokes (17) occurred without evidence for cardiac embolus or hemorrhage, consistent with a thrombogenic-embologenic operative site, and raising the question of need for adjunctive perioperative medical therapy.
Reactions of granular pericytes in a rabbit cerebrovascular ischemia model.
Authors: Jeynes B
Published: June 2011

This study was undertaken to examine some of the quantitative and qualitative changes which might occur in the cerebral granular pericyte population when comparing control and embolically stressed animals. Eight animals, male NZW 2-2.5 kg rabbits, were given intracarotid sublethal injections of human atheroma concentrated at 125 mg/ml. Eight others received 1 cc of sterile saline. Two hours after injection the brains were fixed with either neutral buffered formalin or 3% buffered glutaraldehyde by cardiac perfusion at 110 mmHg pressure. The brains were removed and sliced, anteroposteriorly, in 3 mm slices. Each slice from five brains for each condition was then processed for paraffin sectioning and staining with Hematoxylin and PAS. Two animals for each condition underwent the same treatments and were processed for frozen sectioning and staining with Oil Red O. One animal for each condition had each brain slice sectioned by vibratome (40 micrometers) and was processed appropriately and examined by either fluorescence microscopy, standard electron microscopy or acid phosphatase electron microscopy. In the groups stained with Hematoxylin and PAS, granular pericytes were counted for each of the first five levels of each brain for both the control and experimental conditions. The results of this study reconfirmed that these cells were granular pericytes; that is, they were autofluorescent and PAS positive; were surrounded by a basement membrane, were acid phosphatase positive and contained a heterogenous granular cytoplasmic inclusion population. Further, after ischemic insult, the number of granular pericytes increased significantly at two hours. It was also shown that these cells appeared capable of accumulating lipid components of the injected atheroma from the vessel lumen.
Malondialdehyde-like material and beta-thromboglobulin plasma levels in patients suffering from transient ischemic attacks.
Authors: Francesco V , Cesare A , Luigi I , Stefano F , Andrea G , Francesco B
Published: June 2011

Beta-thromboglobulin (betaTG) and malondialdehyde-like material (MDA-LM) plasma levels were studied in patients affected by transient ischemic attacks (TIA) after 2-4 months from the last episode. BetaTG and MDA-LM values were significantly higher in TIA patients than in 20 controls matched for age. No correlation between MDA-LM and betaTG was seen. This study suggests that in vivo platelet activation and, likely, increase of platelet cyclo-oxygenase activity can be detectable in TIA patients.
Decrease in cerebral blood flow in rats after experimental subarachnoid hemorrhage: a new animal model.
Authors: Solomon R A , Antunes J L , Chen R Y , Bland L , Chien S
Published: June 2011

There continues to be a need for good animal models of experimental subarachnoid hemorrhage (SAH). The rat would be an ideal subject in which to study SAH since it is inexpensive and easier to use than the larger laboratory animals. The present study was undertaken to determine if alterations of cerebral blood flow could be produced in the rat after experimental SAH, and thereby justify using the rat as a model for further study of SAH. Rats weighing between 450 and 500 grams underwent insertion of a cannula into the cisterna magna at least 5 days prior to physiological testing. One group of rats then received a 0.3 cc injection of fresh autologous arterial blood into the cisterna magna to simulate a SAH. Another group of rats received injection of an equal volume of mock CSF (buffered saline) into the cisterna magna. A third group of rats had no subarachnoid injections. In all three groups, blood flow to the cerebral hemispheres was measured with the labeled microsphere technique. Rats with experimental SAH showed a 40% decrease of cerebral blood flow, whereas rats with saline injections showed only a 15% decrease. Control rats had no changes of cerebral blood flow. These studies demonstrate that the rat is a potential experimental model for investigations into SAH.
Hemispheric blood flow in the rat after unilateral common carotid occlusion: evolution with time.
Authors: De Ley G , Nshimyumuremyi J B , Leusen I
Published: June 2011

Acute occlusion of one common carotid artery in the anesthetized normocapnic rat results in a moderate cerebral blood flow (CBF) decrease in both cerebral hemispheres. No asymmetrical perfusion is observed when the overall flow in each hemisphere is considered. The increase in blood flow which normally occurs in hypercapnia is strongly impaired in the cerebral hemisphere on the occluded side resulting in an important asymmetrical hemispheric perfusion. The days (1, 5, 15, 30) following unilateral carotid occlusion normal control CBF values are found in both hemispheres in normocapnic conditions. Hemispheric perfusion asymmetry in hypercapnia also becomes progressively less pronounced with time but a slight asymmetry still persists one month after unilateral carotid occlusion.
Platelet accumulation in regions of low blood flow during the postischemic period.
Authors: Obrenovitch T P , Hallenbeck J M
Published: June 2011

Various studies indicate that after a latent interval, a progressive focal deterioration of microvascular perfusion can develop in zones of acute damage to the central nervous system (CNS). In order to obtain reliable information concerning the possibility of platelet participation in this phenomenon, platelet deposition was investigated by means of 111Indium-labeled platelets, and compared with local cerebral blood flow (CBF) and cortical sensory evoked response (CSER). Studies were performed with a model of focal ischemia in which small volumes of air were injected selectively into one internal carotid artery of dogs anesthetized with alpha chloralose throughout the experiment. The ischemic period was followed by a 10-min, 60-min or 4-hr recovery period. The main result was a prominent and diffuse accumulation of platelets in zones of low CBF in dogs subjected to 4 hr recovery.
Cerebrovascular injuries induced by activation of platelets in vivo.
Authors: Fujimoto T , Suzuki H , Tanoue K , Fukushima Y , Yamazaki H
Published: June 2011

Intravascular platelet aggregation induced by ADP injection into the carotid artery of rabbits caused ipsilateral cerebrovascular injuries. We have observed the details of these in vivo vascular changes under the electron microscope. Intracytoplasmic vacuole (1.0-2.0 micron in diameter) formation and partial deendothelialization followed by platelet thrombus formation were characteristic changes in the middle cerebral artery. These vacuoles did not contain horseradish peroxidase (HRP) which was used as a marker of vascular permeability change. Compared with these phenomenon, increased vesicular (0.05-0.2 micron in diameter) transport was prominent, and vacuole formation was rarely seen in small vessels, namely, capillaries and arterioles in the cortex. Endothelial cell damage seemed to be more prominent in large arteries, but only the smaller vessels show marked extravasation of HRP-reaction product and perivascular edema. Blood levels of TXB2 and 6-keto PGF1 alpha were significantly increased 3 min after the ADP injection and returned to pre-injection levels at 60 min after. These results suggest that vasoactive substances resulting from platelet activation may play an important role in producing cerebrovascular injuries caused by platelet aggregation induced with ADP.
Fibromuscular dysplasia of cervico-cephalic arteries with multiple dissections and a carotid-cavernous fistula. A pathological study.
Authors: Bellot J , Gherardi R , Poirier J , Lacour P , Debrun G , Barbizet J
Published: June 2011

A rare case of widespread fibromuscular dysplasia (F.M.D.) is reported, involving the cervico-cephalic arteries associated with multiple dissections, saccular aneurysms and a carotid-cavernous fistula. A detailed post-mortem examination revealed FMD involvement of the intracranial vessels, not demonstrated by arteriography.
Constricting effect of leukotrienes on cerebral arterioles of mice.
Authors: Rosenblum W I
Published: June 2011

Three leukotrienes (LTB4, C4, D4) were locally applied to cerebral arterioles in doses varying from 3 X 10(-8) to 4 X 10(-7) M and each produced a dose related constriction. LTC was tested in the presence and absence of FPL-55712, a relatively specific inhibitor of leukotriene receptors. A low dose (10(-8) M) of FPL-55712 did markedly reduce the response to the LTC and did not significantly alter an equally pronounced constriction produced by norepinephrine. The constricting properties of the leukotrienes shown by our data support the suggestion that these products of lipoxygenase's action on arachidonic acid have the potential to modify cerebrovascular tone. This potential may be important in view of recent evidence showing that the brain can make significant amounts of leukotrienes from arachidonic acid.
Innervation of brain intraparenchymal vessels in subhuman primates: ultrastructural observations.
Authors: Briggs L , Garcia J H , Conger K A , Pinto de Moraes H , Geer J C , Hollander W
Published: June 2011

Sympathetic innervation of intraparenchymal blood vessels in the basal ganglia was demonstrated by transmission electron microscopy in arteries, arterioles, and capillaries of the subhuman primate brain. Small arteries (40-120 micron) and some arterioles (12-40 micron) are innervated only at branching sites. However, arterioles occasionally may be innervated at points distal to their origin. Capillary innervation was very infrequently observed.
A 1-4 year follow-up study of 306 cases of stroke.
Authors: Chen Q T , Ling R
Published: June 2011

To study the long-term prognosis of stroke, we performed annual follow-up examinations on 306 patients who had survived cerebrovascular accidents. All patients had been admitted to the Neurology Service, First Teaching Hospital, Beijing Medical College from January 1, 1976, to December 31, 1978, and were followed up for 1 to 4 years. The series included 217 cases of cerebral thrombosis, 54 of cerebral hemorrhage, and 35 of TIA. The life-table method was used to determine the cumulative survival rate (CSR), cumulative marked improvement rate (CMIR), and cumulative recurrence rate (CRR), for each of these three types of stroke. The main results were the following: 1. The prognosis was not significantly influenced by sex, BP level on admission, or type of cerebrovascular accident. 2. Age was an important prognostic factor. The survival rate decreased significantly in each successive age group. However, age was not a risk factor for recurrence or poor improvement. 3. The cumulative survival rate, cumulative marked improvement rate, and cumulative recurrence rate did not differ significantly among cerebral thrombosis, cerebral hemorrhage, and TIA.
Cerebral infarction in a young female following snake bite.
Authors: Bashir R , Jinkins J
Published: June 2011

We present a normal 13-year old female who developed left cerebral infarction following envenomation by the carpet viper (Echis carinatus). We have read of only one other case of cerebral infarction following viper envenomation (Viperi russelli). Possible mechanisms for cerebral infarction in these circumstances are discussed. It is believed that this complication may be more common than is reported in the literature.
Delayed cerebral ischemia following arteriography.
Authors: Fisher M , Sandler R , Weiner J M
Published: June 2011

Cerebral ischemic events associated with arteriography are usually attributed to catheter-induced emboli. We present three patients with cerebral ischemia occurring 6 to 48 hours post-arteriography. We suspected that alternate pathogenic mechanisms were in effect. To evaluate the possibility that sustained platelet activation occurs in association with arteriography, we measured the platelet-specific protein beta thromboglobulin (BTG) prior to and 24 hours following arteriography in two groups of patients. Group I had arteriography performed shortly after venipuncture, while Group II patients did not have arteriography between samples. Seven of eight Group I patients had an increase of BTG on day two, compared with two of eight group II patients (p less than 05). When compared to Group II changes, Group I had a significant increase of BTG on day two (p less than .05). We conclude that cerebral ischemic events associated with arteriography may occur on a delayed basis, and that platelet activation, manifested by increased BTG levels, may be one mechanism contributing to this phenomenon.
Upper limit of cerebral autoregulation during development of hypertension in spontaneously hypertensive rats--effect of sympathetic denervation.
Authors: Sadoshima S , Yoshida F , Ibayashi S , Shiokawa O , Fujishima M
Published: June 2011

The upper limit of cerebral autoregulation was studied in pre- or early established hypertension in spontaneously hypertensive rats (SHR). Cerebral blood flow (CBF) was measured with the hydrogen clearance method, and wall/lumen ratio of cerebral arteries was morphometrically measured with the freeze-substitution technique. To test autoregulation, phenylephrine was intravenously infused to cause stepwise increments of blood pressure. Unilateral superior cervical ganglionectomy was carried out to examine the effects of sympathetic denervation on CBF autoregulation and thickness of vascular wall. Resting blood pressure at 4 weeks, 3 months and 6 months of age were 89 +/- 3 mm Hg (mean +/- SEM), 140 +/- 6 and 165 +/- 6, respectively. Baseline CBF was slightly diminished with age; 50.6 +/- 9.2 ml/100 g/min at 4 weeks, 49.8 +/- 8.1 at 3 months and 44.1 +/- 5.6 at 6 months. The upper limit of autoregulation was markedly raised with age; 118 +/- 5 mm Hg at 4 weeks, 180 +/- 7 at 3 months and 208 +/- 10 at 6 months. Acute sympathetic denervation lowered the upper limits to 105 +/- 2, 162 +/- 4 and 185 +/- 7 mm Hg, respectively. On the other hand, in chronic denervation which was made at 4 weeks of age, the upper limit of autoregulation in the denervated hemisphere was slightly lower than that in innervated hemisphere at 2 months (165 +/- 5 and 178 +/- 6 mm Hg), and at 5 months (202 +/- 8 and 215 +/- 8 mm Hg) after ganglionectomy.(ABSTRACT TRUNCATED AT 250 WORDS)
A new model of bilateral hemispheric ischemia in the rat--three vessel occlusion model.
Authors: Kameyama M , Suzuki J , Shirane R , Ogawa A
Published: June 2011

A new model of bilateral hemispheric ischemia was created in the rat by occluding the common carotid arteries and the basilar artery; this resulted in consistent and severe impairment of the cerebral blood flow. The procedure for producing this model is described, and the results of EEG and autoradiography obtained by this model are compared to those obtained by the four-vessel occlusion model.
A model of selective experimental ischaemia in the primate thalamus.
Authors: Vajda J , Branston N M , Ladds A , Symon L
Published: June 2011

A model for studying changes in local CBF and evoked potentials in selective thalamic ischaemia has been developed. The arterial supply to the posterior thalamus (mainly from the posterior choroidal arteries) was occluded in the baboon using a transorbital approach to the region of prepontine and ambient cisterns. Local CBF was measured by the hydrogen clearance method using electrodes introduced into the nucleus ventralis posterior lateralis of thalamus as well as cortex on both sides. The production of focal ischaemia was demonstrated by a significant decrease in thalamic CBF and confirmed by examination of the brain perfused with carbon particles.
Actinomycin D suppresses the protective effect of dexamethasone in rats affected by global cerebral ischemia.
Authors: Tósaki A , Koltai M , Joó F , Adám G , Szerdahelyi P , Leprán I , Takáts I , Szekeres L
Published: June 2011

Simultaneous occlusion of both common carotid arteries in female Sprague-Dawley CFY rats produced characteristic symptoms of global cerebral ischemia, such as staggering, circling, convulsions, followed by coma and death. A close correlation existed among these symptoms and the elevation of water and Na+ content, appearing at the stage of staggering; Evans blue extravasation and diminution of K+ content, detected at circling; and the increase in Ca2+ content in the total brain tissue, manifesting itself at the phase of convulsions, indicating the development of cerebral edema due to ischemia. Dexamethasone given subcutaneously in a single 2.0 mg kg-1 dose 5 hours prior to the induction of global cerebral ischemia reduced considerably the morbidity and mortality, the alterations in water and electrolyte content, and albumin leakage in the brain tissue. Actinomycin D, in a dose of 0.5 mg kg-1 injected intravenously 1 hour before steroid treatment, abolished the beneficial effect. This finding suggests that de novo protein synthesis is involved in the cerebroprotective effect of dexamethasone.
Intracranial hemorrhages due to phenylpropanolamine.
Authors: Kikta D G , Devereaux M W , Chandar K
Published: June 2011

We describe 2 patients with intracranial hemorrhage after ingestion of diet pills containing phenylpropanolamine (PPA) in combination with caffeine. The first patient had bilateral simultaneous intracerebral hemorrhages, and the second had a subarachnoid hemorrhage. PPA is widely used most often without prescription and causes intracranial hemorrhage more often than has been realized. The mechanism may be induction of a transient hypertensive crisis.
Multiple transient ischemic attacks, lupus anticoagulant and verrucous endocarditis.
Authors: D'Alton J G , Preston D N , Bormanis J , Green M S , Kraag G R
Published: June 2011

A young adult with lupus anticoagulant and systemic lupus erythematosus had onset of multiple transient ischemic attacks four years after a major left hemispheric infarct. The symptoms were stereotyped, recurred several times daily over three years and ceased when aspirin was added to steroid therapy. It is speculated that her symptoms were due to recurrent embolism from the heart in the presence of a thrombotic state.
Cerebral amyloid angiopathy associated with giant cell arteritis: a case report.
Authors: Murphy M N , Sima A A
Published: June 2011

A case of cerebral amyloid angiopathy associated with granulomatous arteritis is presented with description of the microscopic, immunocytochemical and ultrastructural features. The amyloid proved to be of the AL-type, with failure to show reactivity with anti-AA, anti-prealbumin and anti-albumin. Antisera against SAP and IgG (AF) did show reactivity. Hence the immunologic characteristics of this amyloid differ from those of other known conditions and may therefore represent a new form of amyloid. The role of granulomatous arteritis in this case remains speculative.
Cerebral edema associated with craniectomy and arterial hypertension.
Authors: Hatashita S , Koike J , Sonokawa T , Ishii S
Published: June 2011

The present studies were performed to determine whether cerebral edema will develop as a consequence of arterial hypertension and/or craniectomy. Arterial hypertension was induced for 30 minutes by inflation of a balloon catheter situated in the descending aorta, and a parietal craniectomy was performed. The cerebral edema noticed was evaluated by macroscopic and microscopic observations, BBB permeability of HRP and Evans blue and water content. In addition, ICP was measured in the cisterna magna and ICPP by a catheter-tip transducer. In arterial hypertension or craniectomy alone, some small areas of Evans blue extravasation with increased water content were seen in the cortex, which corresponded to the occipito-parietal parts of the arterial boundary zones. In contrast, when arterial hypertension was combined with craniectomy, these lesions extended further into underlying white matter with increased water content. Forty-eight hours later, extensive brain edema with a shift of midline structures developed on the side of craniectomy which differed from that in arterial hypertension or craniectomy alone. It is suggested that some hydrostatic pressure gradients, particularly between blood vessel and surrounding extracellular space and among different areas within the brain parenchyma, may play an important role in the development of brain edema.
Chemiluminescence in hypoxic brain--the second report: cerebral protective effect of mannitol, vitamin E and glucocorticoid.
Authors: Suzuki J , Imaizumi S , Kayama T , Yoshimoto T
Published: June 2011

The effect of vitamin E, betamethasone and mannitol upon a series of pathological free radical reactions within hypoxic brain tissue was evaluated by the chemiluminescence method. Hypoxia was induced by arterial hypoxemia (PaO2 17-22 mmHg) with normocapnia (PaCO2 28-38 mmHg) and normotension (MABP 100-140 mmHg). 4% O2-96% N2 mixed gas was used to obtain the lowered PaO2. In the untreated group, increased chemiluminescence was measured in the hypoxic state and the early stage of the initial post-hypoxic state. In the groups administered vitamin E, betamethasone, mannitol and a combination of them reduced chemiluminescence was detected. To explore the reaction stage at which the drugs act in lipid peroxidation, chemiluminescence spectra was analyzed using the brain homogenate with the drugs added. Intensity peaks of the spectra were around at 480, 520-530, 570, 620-640, 680-700 nm before addition of the drugs. All the intensity peaks diminished after addition of vitamin E and betamethasone, but very little decrease occurred after mannitol. The lowered chemiluminescence value may indicate the free radical scavenging action of vitamin E, betamethasone and mannitol in vivo. Chemiluminescence spectrum analysis shows that vitamin E and betamethasone act on the late chain reaction following hydroperoxide and mannitol acts on the early reaction--generation of active oxygens.
Brainstem auditory evoked responses in brainstem infarction.
Authors: Faught E , Oh S J
Published: June 2011

Brainstem auditory evoked responses (BAERs) were recorded in 40 patients with clinically definite brainstem infarction, and results were compared to localizations from physical signs and CT scans. The BAER was abnormal in 92% of patients with evidence on physical examination of dysfunction of lateral structures in the pons or midbrain. Normal BAERs were seen with medially-situated or medullary lesions. When both rostrocaudal level and lateralization were considered, the BAER indicated damage in additional areas not evident on physical examination in 25% of patients. However, physical signs indicated damage in areas not reflected by the BAER in 22% of patients. Therefore, the BAER complements the localization obtained from physical findings. BAERs were abnormal in more of these patients than were CT scans, and thus are useful for confirmation of bedside impressions.
Epidemiologic studies of stroke in Shibata, a Japanese provincial city: preliminary report on risk factors for cerebral infarction.
Authors: Tanaka H , Hayashi M , Date C , Imai K , Asada M , Shoji H , Okazaki K , Yamamoto H , Yoshikawa K , Shimada T
Published: June 2011

A 6.5-year prospective study of cerebral infarction among residents 40 years and older was conducted at the Akadani-Ijimino district in Shibata City, Niigata Prefecture, Japan. The response rate for the initial examination was 85% of 1,182 males and 93% of 1,469 females. Nine hundred and sixty males and 1,339 females who were initially free of stroke were followed up from July 1977 through December 1983. Statistically significant risk factors for cerebral infarction appeared to be age, elevated blood pressure, high R, ST-T changes and atrial fibrillation on ECG, and albuminuria. The ECG abnormalities and albuminuria were due to the high blood pressure persisted over a long period of time. The strength of association of blood pressure with cerebral infarction got weak in comparison with other factors, and funduscopic changes which had been regarded as a risk factor for stroke in 1965-1974 did not reach statistical significance because of the spread of the community-based hypertension control. Even in 1977-1983 when Japanese dietary habits were westernized, neither hyperlipidemia nor obesity appeared to be related to the development of cerebral infarction.
Racial differences in the distribution of posterior circulation occlusive disease.
Authors: Gorelick P B , Caplan L R , Hier D B , Patel D , Langenberg P , Pessin M S , Biller J , Kornack D
Published: June 2011

We compared clinical and arteriographic features in 27 white and 24 black patients with symptomatic posterior circulation occlusive disease. The degree of arterial stenosis was measured independently by two examiners at 12 sites within the vertebrobasilar territory. Racial comparisons were made based upon the distribution of extra- and intracranial occlusive lesions and symptomatic sites of the lesions. White patients had significantly more angina pectoris, more lesions of the origin of the left vertebral artery and more high grade lesions of the extracranial vertebral arteries. Black patients had significantly higher mean diastolic blood pressure, more diabetes mellitus, more lesions of the distal basilar artery, more high grade lesions of intracranial branch vessels and more symptomatic intracranial branch disease. Race was found to be the only factor increasing the risk of intracranial posterior circulation occlusive disease. Knowledge of the contribution of race to the distribution of posterior circulation lesions will help guide evaluation and treatment strategies for patients with vertebrobasilar occlusive disease.
Arteriographic comparison of amaurosis fugax and hemispheric transient ischaemic attacks.
Authors: Harrison M J , Marshall J
Published: June 2011

The results of carotid angiography were compared in 53 patients with amaurosis fugax and 92 with hemispheric transient ischaemic attacks (TIAs). Evidence of extracranial disease was found in 71% of those with retinal ischaemia and these patients rarely had evidence of intracranial disease (11%) or normal angiograms (15%). By contrast patients with hemispheric symptoms less frequently showed disease of the cervical carotid artery (36%) and more often had intracranial disease (27%) or normal angiograms (35%). It is suggested that amaurosis fugax is usually due to emboli originating in the internal carotid artery but that the pathogenesis of cerebral TIAs in the carotid territory is more heterogeneous. These conclusions have implications for the design and interpretation of both medical and surgical trials.
Risk of stroke during coronary artery bypass graft surgery in patients with internal carotid artery disease documented by angiography.
Authors: Furlan A J , Craciun A R
Published: June 2011

We retrospectively identified 144 patients who underwent coronary artery bypass graft (CABG) surgery in the presence of angiographically documented greater than or equal to 50% internal carotid stenosis or occlusion. Of these, 115 patients had bilateral carotid lesions and received combined operations involving carotid endarterectomy on only one side. The remaining 29 patients, including 11 with bilateral carotid lesions, underwent coronary bypass alone. Nine cerebral infarcts occurred (6%), but only three strokes (2%) were appropriate to the cerebral hemisphere ipsilateral to unoperated carotid stenosis. There was one stroke (3%) among the 29 patients who did not undergo combined procedures. In the group of 115 patients with bilateral carotid disease who received unilateral combined carotid endarterectomy there were 8 perioperative strokes (7%), of which 6 were ipsilateral to the endarterectomy. Asymptomatic unilateral less than 90% ICA stenosis or ICA occlusion does not increase stroke risk during CABG surgery.
Cerebral platelet thromboembolism and thromboxane synthetase inhibition.
Authors: Fredriksson K , Rosén I , Johansson B B , Wieloch T
Published: June 2011

Platelet aggregating sodium arachidonate was slowly infused into the internal carotid artery (1 mg, 100 microliters, 1 microliter/s) of nitrous oxide anesthetized rats. The electroencephalographic activity recorded by a Cerebral Function Monitor from the injected hemisphere was reduced within minutes. The somatosensory evoked responses to contralateral electrical stimulation of the whisker area were eliminated on the same side in most cases when measured five and fifteen minutes after the infusion. The brain was frozen in situ with liquid nitrogen after fifteen minutes. Regional tissue analysis showed ipsilateral derangement of the cerebral energy state and increased lactate levels. Pretreatment with the platelet antiaggregating thromboxane synthetase inhibitor OKY-1581 (Sodium-3-4-(3-pyridylmethyl)phenyl-2-methyl-acrylate), 30 mg/kg i.v., fifteen minutes before the sodium arachidonate infusion prevented cerebral energy failure and elimination of the sensory evoked responses.
Amnestic syndrome and vertical gaze palsy: early detection of bilateral thalamic infarction by CT and NMR.
Authors: Swanson R A , Schmidley J W
Published: June 2011

A 27 year old woman with mitral valve prolapse presented with somnolence, bilateral Babinski signs, and grasp reflexes. As somnolence cleared, vertical gaze palsy and Korsakoffian memory deficit were apparent. Initial CT scan was normal, but NMR scan 24 hours after the onset of symptoms revealed prolonged T2 relaxation in medial thalami bilaterally, facilitating diagnosis of bithalamic infarction. Subsequent CT scans delineated infarction in the vascular territory of the paramedian thalamic arteries. Previous clinical reports and the neuro- and vascular anatomy underlying this syndrome are reviewed, including cases that suggest a relationship to the syndrome of transient global amnesia.
Correlation of local cerebral blood flow, glucose utilization, and tissue pH following a middle cerebral artery occlusion in the rat.
Authors: Sako K , Kobatake K , Yamamoto Y L , Diksic M
Published: June 2011

The use of three sets of the double-tracer autoradiographic technique to measure topographical changes of local cerebral blood flow (LCBF), glucose utilization (LCGU), and tissue pH following a 3 h middle cerebral artery (MCA) occlusion in the rat is described. In a sham-operated group of animals there was 10% reduction of LCBF and 7% reduction of LCGU in the most affected areas as compared to the contralateral homologous regions. However, the ratio of LCGU/LCBF in the affected areas remained within normal limits. In the MCA-occluded animals, LCGU showed a bimodal response to decreased LCBF. LCGU decreased with reduced LCBF until LCBF fell to 38% of normal. Below this LCBF level LCGU increased, most likely implying anerobic glycolysis. Decline of tissue pH corresponds to the mismatch of LCBF and LCGU. These results suggest that brain tissue pH change cannot be predicted on the basis of LCBF or LCGU alone.
Reduction of neurologic deficit by 1,3-butanediol induced ketosis in levine rats.
Authors: Lundy E F , Dykstra J , Luyckx B , Zelenock G B , D'Alecy L G
Published: June 2011

The objective of this study was to determine if 1,3-butanediol would reduce a neurologic deficit in rats exposed to ischemic-hypoxia (Levine rats). Age and weight matched male Sprague-Dawley rats were anesthetized with 2% halothane. The right common carotid and external jugular vein were ligated and cannulated and EEG screws were implanted followed by a 2 hour recovery period. Thirty minutes prior to exposure the rats received either 1,3-butanediol (47 mmole/kg i.v.; n = 11) or an equal volume of saline (n = 10). The rats were then exposed to 4.5% O2 until mean arterial blood pressure fell to 70 mm Hg. The oxygen level was then increased to 8% for 30 minutes, after which the rats were returned to room air. Posture, hemiparesis, circling, shuffling, activity, and ability to hang on to a vertical screen were scored 1 (normal) to 5 (severe deficit) at 2 and 20 hours after insult. The time to 70 mm Hg was extended from 7.9 +/- 0.9 min for saline treated rats to 19.0 +/- 2.3 min for the 1,3-butanediol treated rats (p less than 0.001). All eleven 1,3-butanediol treated rats survived the hypoxic insult; 90% (9/10) saline treated rats died. In an attempt to reduce the insult, six additional saline treated rats were switched to 8% O2 at 75 mm Hg and still 4/6 died. The mean score at 20 hours for three surviving saline treated rats was 3.4. A significantly better (p less than 0.002) mean 20 hour score for the surviving 8/11 1,3-butanediol treated rats was 1.2. 1,3-butanediol increases survival and decreases the neurologic deficits associated with this ischemic-hypoxic insult.
Brain injury from marked hypoxia in cats: role of hypotension and hyperglycemia.
Authors: de Courten-Myers G M , Yamaguchi S , Wagner K R , Ting P , Myers R E
Published: June 2011

The present study identifies several factors that govern brain pathologic response to marked hypoxia. None of 13 cats exposed to 25 minutes of marked hypoxia (FiO2 = 3.4%; PaO2 = 17 +/- 3 mm Hg, S.D.) that maintained mean arterial blood pressure (MABP) greater than 65 mm Hg were brain injured after reoxygenation and long term survival. In contrast, 12 of 13 exposed to the same hypoxia but that experienced reductions in MABP less than 45 mm Hg for 4 +/- 1 minutes developed a pattern of brain injury closely resembling that of humans surviving in a persistent vegetative state after cardiorespiratory arrest. Higher serum glucose and lactate concentrations and lower blood pH values significantly correlated with development of hypotension during hypoxia. Four of 8 cats exposed to 21 minutes of marked hypoxia followed by 4 minutes of 100% N2 breathing that also led to hypotension similarly developed brain injury. Among the hypoxic/hypotensive cats the magnitude of the hyperglycemic response to hypoxia as modulated by 0, 1, or 2 days of preexposure fasting, strongly correlated with occurrence and extent of brain damage. Peak cisterna magna CSF lactate concentrations 10 to 30 minutes into recovery distinguished those animals that remained brain-intact (less than 13 mM) from those that developed brain damage (greater than 15 mM) with 100% accuracy. Seven cats developed delayed cardiogenic shock 3 to 12 hours into the recovery period. This outcome was predicted by blood pH values less than 6.70 shortly after resuscitation while all 27 surviving cats exhibited values greater than 6.80.
Spontaneous dissection of the extracranial vertebral arteries.
Authors: Caplan L R , Zarins C K , Hemmati M
Published: June 2011

Though the syndrome of carotid artery dissection is well known, "spontaneous" vertebral artery dissection is rarely recognized. We now report clinical and radiologic findings in five patients with presumed vertebral dissection, one pathologically confirmed. Mean age was 35.2 years (range 27-41). Two were men; three women. None had hypertension, vascular disease, or trauma. Headache and neck or occipital pain was prominent in all, often preceding other symptoms. Four of five patients had unilateral partial alteral medullary syndromes, in one accompanied by medial medullary signs. One patient had a cerebellar infarct. Angiography in four patients showed severe irregular stenosis of the distal extracranial vertebral artery (three bilaterally). A fifth patient with irregular stenosis above the vertebral origin had verified extensive dissection in the resected segment. No patient developed late ischemia. Repeat angiography in three showed healing. We conclude that spontaneous vertebral artery dissection, though rare, has recognizable clinical and radiologic features.
Vertebral artery injury and cerebellar stroke while swimming: case report.
Authors: Tramo M J , Hainline B , Petito F , Lee B , Caronna J
Published: June 2011

A twenty-five year old woman suffered the acute onset of dysequilibrium followed by headache, nausea, vomiting, vertigo, and slurred speech while swimming. Brain imaging revealed a right cerebellar infarct. Intravenous digital subtraction angiography showed a hypoplastic right vertebral artery and focal narrowing of the dominant left vertebral at the level of the C1-C2 junction. The patient was treated with aspirin and dipyridamole and immobilized for two weeks. She achieved almost complete recovery. Repeat angiography showed resolution of the left vertebral artery defect. Other cases of posterior circulation infarction associated with head turning during sports and ordinary activities are reviewed.
Internal carotid artery occlusion: clinical and therapeutic implications.
Authors: Fritz V U , Voll C L , Levien L J
Published: June 2011

Five hundred patients referred to the Cerebrovascular Clinic of the Johannesburg Hospital were examined by a battery of noninvasive tests and angiography. Thirty four occlusions of the internal carotid artery were found in 32 patients. These patients were prospectively evaluated, including clinical examination, analysis of risk factors and subsequent management. This group of patients was followed up for a mean period of 18 months, and the clinical and laboratory findings and follow up data of this group were compared to an age and sex matched group of patients with matched presenting symptoms, but with patent internal carotid arteries on angiography. Four clinical patterns emerged in the patients with occluded carotid arteries; asymptomatic (3), TIA's (17), initial fixed stroke (7), and TIA with subsequent stroke (5). Follow up of the occluded group revealed 19 patients (59%) with no further symptoms and no indication for surgical intervention. Nine patients required surgery; 4 external carotid endarterectomies (ipsilateral), 4 internal carotid endarterectomies (contralateral), and one extracranial to intracranial bypass. Two were lost to follow up and one died. After 18 months mean follow up 29 patients (91%) were well and asymptomatic. Follow up for a similar period of the non-occluded group revealed three deaths, three late strokes and three myocardial infarctions. None were lost to follow up. After 19 months mean follow up 26 patients (81%) were well with no new neurological symptoms. The prognosis of appropriately treated patients with total occlusion of the internal carotid artery does not appear to be worse than in patients with similar presenting features and patent carotid arteries.(ABSTRACT TRUNCATED AT 250 WORDS)
The value of noninvasive investigation in the diagnosis of total occlusion of the internal carotid artery.
Authors: Levien L J , Voll C L , Lithgow-Jolly P , Fritz V U
Published: June 2011

A battery of simple noninvasive tests consisting of directional Doppler ultrasound and carotid phonoangiography has been used to detect carotid stenosis in 700 patients Forty four carotid occlusions in 42 patients were confirmed on angiography, and this study examines the accuracy of this noninvasive battery in predicting the presence of an occluded internal carotid artery. Although the sensitivity of the battery described has been 70% for occlusion, with a specificity of 98% (only five false positives), this relatively low sensitivity and the uniform requirement for surgery in the false positive group have led us to conclude that this battery should not be used as a substitute for angiography when the diagnosis of internal carotid occlusion requires to be confirmed. Nevertheless, these noninvasive tests do have a role in alerting the physician to the presence of carotid occlusion and contralateral carotid artery stenosis, allowing more specific planning of any subsequent arteriography required.
Value of cardiac monitoring and echocardiography in TIA and stroke patients.
Authors: Rem J A , Hachinski V C , Boughner D R , Barnett H J
Published: June 2011

One hundred and eighty-four consecutive patients admitted to an Investigative Stroke Unit with transient ischemic attacks (TIA) and cerebral infarction (stroke) had 48-hour automated arrhythmia monitoring, 55 patients had additional Holter monitoring and 127 patients had 2-D echocardiography. One hundred and sixteen presented with stroke (63%) and 68 patients with TIA (37%). One hundred and twenty-two were men (66.3%) and 62 were women (33.7%), mean age 63.5 years, range 25-86. The monitoring identified twelve (6.5%) patients with significant arrhythmias undetected by history, examination and admission electrocardiogram: six with atrial fibrillation (AF), four with 2 degrees heart block type Mobitz II and one each with 3 degrees heart block and sick sinus syndrome. Two-D echocardiography showed a previously unknown potential source for cardiac emboli in 22 patients (17.3%): segmental ventricular disease in eleven, mitral valve prolapse in seven, left ventricular thrombus in six, left ventricular aneurysm in three and one each with mitral valve endocarditis and global myocardial dysfunction. Only the mitral valve findings were expected on the basis of a previous M-mode echocardiographic study carried out in our city on healthy elderly volunteers. From the clinical history and all cardiac investigations, we found 59 patients (32%) with a possible cardiac source for cerebral emboli. After cerebral angiography, 29 of these 59 patients also showed a vascular lesion in the appropriate carotid artery and we could not decide definitely which lesion was responsible for the cerebral embolus. In the remaining 30 patients (16.4%), the evidence implicated the heart as the most likely source.(ABSTRACT TRUNCATED AT 250 WORDS)
Detection of mitral valve abnormalities by carotid Doppler flow study: implications for the management of patients with cerebrovascular disease.
Authors: Weinberger J , Goldman M
Published: June 2011

Patients with symptoms of cerebral ischemia are often evaluated with non-invasive carotid artery testing. An abnormal carotid Doppler ultrasound frequency shift pattern of early systolic flutter (ESF) was demonstrated by auscultation and velocity wave form analysis in patients with normal carotid bifurcations. Ten of these patients were studied with echocardiography (echo) and eight had mitral valve prolapse (MVP). To evaluate the association between ESF and MVP, a prospective blinded study was performed, recording carotid Doppler frequency shift in 50 patients referred for routine echocardiography. A total of 18 patients had ESF: 9/12 patients with MVP by echocardiography had ESF. Nine additional patients without MVP had ESF (two with mitral regurgitation and two with redundant mitral valves). The association of ESF with MVP was significant (p less than 0.001). The findings of ESF with a normal carotid artery by non-invasive testing suggests a possible mitral valve origin for symptoms of cerebrovascular disease.
Altered membrane properties of cerebral vascular smooth muscle following subarachnoid hemorrhage: an electrophysiological study. I. Changes in resting membrane potential (Em) and effect on the electrogenic pump potential contribution to Em.
Authors: Waters A , Harder D R
Published: June 2011

Subarachnoid hemorrhage was produced experimentally in cats by intracisternal injection of non-heparinized autologous arterial blood obtained by cardiac puncture under ketamine and xylazine anesthesia. Cats were sacrificed at varying time intervals between 30 min and 7 days post ictus. Measurements of resting membrane potential were recorded from smooth muscle cells of the basilar artery. These measurements were obtained by impalement from the adventitial surface of isolated but otherwise intact segments of the artery using glass microelectrodes with tip sizes less than 0.1 micron. The resting membrane potential recorded in vitro from animals previously subjected to subarachnoid hemorrhage in vivo was consistently and significantly depolarized when compared to normal controls. This depolarization was present as early as 30 min post ictus. Addition of the cardiac glycoside, ouabain, in a concentration of 10(-5)M depolarized cells from both control and experimental animals. There is a significant electrogenic pump potential contribution to the resting membrane potential of vascular smooth muscle cells. Ouabain is a potent blocker of Na+, K+-ATPase, the enzyme responsible for maintaining the cation electrochemical gradients. The depolarization recorded in these cells following subarachnoid hemorrhage is not, therefore, due to impairment of the electrogenic pump. The significance and implications of these findings are discussed.