bluuebunny/crossref_metadata_2025 huggingface dataset:
The Community Medicine of Cerebrovascular Disease
Authors: WYLIE CHARLES M.
Published: June 2011

We now know enough about the incidence rates of cerebrovascular disease in different age groups in the U.S.A. to estimate the number of new cases occurring in mainly white communities in the coming years. Our information on nonwhite incidence is less secure, although rough estimates are possible. Prevalence figures are also known, but give less help in planning future programs. Medical care and hospital programs have given figures which show many deficiencies in our current arrangements for care. A tentative list of risk factors should encourage wider efforts to show whether primary prevention is truly possible. More extensive diagnostic examinations, more specific methods of treatment, and earlier and wider attempts at rehabilitation will improve the fate and quality of existence of future stroke patients. Shorter-trained personnel will help extend good care to a greater proportion of all patients, but not without upsetting some cherished beliefs of health professionals. We should resist the temptation to concentrate on collecting more data, and act now to eradicate neglect from this large problem in community medicine.
Opacity Pulse Propagation Measurements in Humans: Atraumatic Screening for Carotid Arterial Occlusion
Authors: HECK ALBERT F. , PRICE THOMAS R.
Published: June 2011

Opacity pulse propagation times to areas of facial skin supplied by internal carotid (medial supraorbital area) and external carotid arteries (lateral supraorbital areas, cheeks, etc.) were carried out in 27 patients with cerebrovascular symptoms, 16 of whom had normal four-vessel angiographical studies and 11 of whom had unilateral carotid occlusion. In most persons with normal extracranial vessels, no significant difference is found between mean values of propagation time to internal carotid beds on the two sides of the face or between homologous areas of the face supplied by external carotid branches. With unilateral internal carotid occlusion, mean propagation time is prolonged to the medial supraorbital (internal carotid) area on the side of occlusion, while mean propagation times to external carotid beds do not differ significantly. Occlusion of the common carotid artery results in prolongation of mean propagation time to both internal
and
external carotid beds on the side of the arterial obstruction. Limitations of the technique and possible sources of error are discussed. The preliminary results reported suggest that this technique may be useful in atraumatic evaluation of patients for carotid arterial disease.
Hypoxyrrhachia in Association with Intracranial Hemorrhage
Authors: SUSSMAN BERNARD J. , LLOYD RAYMOND
Published: June 2011

Oxygen and carbon dioxide tensions in lumbar cerebrospinal fluid and arterial blood were determined in 15 patients. The results confirmed those reported in the literature with the exception of four patients with intracranial hemorrhage. Under this circumstance, oxygen tensions in the spinal fluid were considerably lower than those obtained in arterial blood. This hypoxyrrhachia, associated with cerebral hemorrhage, is probably related to oxygen uptake by cellular blood elements as demonstrated by in vitro studies. Cerebral arterial vasoconstriction may also play a role. Cerebrospinal fluid acidosis was also demonstrated. It is possible that these changes may significantly affect the operability of patients with intracranial hemorrhage.
Intravenous nitroglycerin in experimental cerebral vasospasm. A preliminary report.
Authors: Kistler J P , Lees R S , Candia G , Zervas N T , Crowell R M , Ojemann R G
Published: June 2011

Cerebral arteriospasm is a common complication of subarachnoid hemorrhage and is responsible for much of the brain damage which accompanies it. No pharmacologic agent has been found which regularly alleviates arteriospasm. We have evaluated the effect of continuous intravenous nitroglycerin infusion on the diameter of the basilar artery in dogs with cerebral vasospasm experimentally induced by subarachnoid blood injection. In 6 consecutive dogs, 10 minutes after beginning intravenous nitroglycerin at 100 microgram/min and at other times during 120 minutes of infusion, the diameter of the basilar artery had increased from 75 +/- 2% of control value to 114 +/- 2% of control value (p less than 0.001). In all 6 dogs, the basilar artery diameter during infusion was greater than the control value prior to creating subarachnoid hemorrhage. Intravenous nitroglycerin caused only a moderate (8%) decrease in blood pressure. Further investigation of the effects of nitroglycerin on cerebral vasospasm is warranted.
Serial measurement of cerebral blood flow using external counting of microspheres.
Authors: McCalden T A
Published: June 2011

Described is a modified method of measuring organ blood flow which combines the serial injection of a standard dose of microspheres and the external counting of their gamma activity when they are distributed to the tissues. The method produces similar results to measurements of grey matter blood flow by the clearance of 133xenon.
Total cerebral ischemia: a new model system for the study of post-cardiac arrest brain damage.
Authors: Jackson D L , Dole W P
Published: June 2011

The pathophysiology of post-cardiac arrest brain damage is not well understood. Many of the model systems presently used to study global ischemia have serious limitations. A new model system for total cerebral ischemia (TCI), using aortic and inferior vena caval occlusion balloons, is described. This model system produces verifiable TCI and avoids surgical invasion of the thorax or the use of vasoactive drugs. It does not impede cerebral venous return and protects the cardiopulmonary system from damage. This model system can be used to study the efficacy of various therapeutic interventions following a standardized CNS global ischemic insult.
Adenine compounds: cerebrovascular effects in vitro with reference to their possible involvement in migraine.
Authors: Hardebo J E , Edvinsson L
Published: June 2011

Adenosine and adenine compounds (AMP, cyclic AMP, ADP and ATP) markedly dilated feline and human pial arteries in vitro, the effect being more prominent with increasing tone of the vessel (active tonic contraction induced by prostaglandin F 2 alpha or serotonin). In contrast, the various adenine compounds were unable to produce any dilation of extracranial arteries tested (branches of lingual, external maxillary, and superficial temporal arteries). The degree of dilatation depended upon the perivascular potassium concentration, so that low potassium increased Emax and reduced ED50 values. Possible involvement of adenine compounds in the vasodilatory phase of the migraine attack is discussed.
Ischemic brain edema following middle cerebral artery occlusion in baboons: relationship between regional cerebral water content and blood flow at 1 to 2 hours.
Authors: Symon L , Branston N M , Chikovani O
Published: June 2011

The relationship between increase in water content in ischemic brain and levels of regional blood flow has been studied in 11 primates. Flows were recorded using the method of hydrogen (2-minute) clearance, from a total of 128 electrodes in cortex and white matter, and a gradation of ischemia was produced by middle cerebral occlusion transorbitally. The flows were reduced in the area of densest ischemia from control levels of 12.0 +/- 12.0 ml/100g/min to 7.0 +/- 5.4 ml/100g/min, with lesser decreases over the remainder of the ischemic hemisphere. Water content was measured in cortex and white matter, in regions topographically related to those of flow measurements, by densitometric assessment using precalibrated kerosene/bromobenzine columns. The average water content of cortex in regions remote from ischemia was 797.4 +/- 5.8 mg/gm and in white matter 708.5 +/- 8.2 mg/gm. Significant increases in water content (comparing corresponding regions of the two hemispheres) of up to 11.4 +/- 7.5 mg/gm were demonstrated in the most ischemic cortical areas. A gradient of water increase was evident in the ischemic hemisphere, increases water content being greatest in the opercular zone and least in the parasagittal area. Significant differences in white matter water content between the 2 hemispheres were demonstrated only in the most densely ischemic areas in the current experiments where ischemia was limited to 93 +/- 20 mins in the 11 animals without reperfusion. The relationship between ischemic density and water content increase showed that significant increases in water content occurred in regions where terminal flows had been below 20 ml/100g/min, indicating that accumulation of water in ischemic brain begins at flow values comparable to those associated with the failure of synaptic transmission, higher than those associated with failure of the ionic pump of the cell. Possible pathophysiological mechanisms are discussed.
Platelet thrombi in experimental cerebral infarction.
Authors: Petito C K
Published: June 2011

Cerebral infarction was produced in paralyzed, ventilated rats by a 30 min period of right common carotid artery occlusion combined with systemic hypoxia (Pao2 21-25 mm Hg). After 30 min the arterial clamp was removed and the animals were reoxygenated and allowed to survive for 1 min (6 animals), 30 min (12 animals), or 1 1/2 to 2 h (6 animals). The animals were reanesthetized and sacrificed by perfusion-fixation with paraformaldehyde-glutaraldehyde. Light and electron microscopy revealed ischemic cell change in neurons in the ipsilateral cerebral cortex, striatum and hippocampus. These changes were mild to moderate in the early post-ischemic period and severe in the post-ischemic period. Cerebral infarction was present in one of the 30 min survivors and in all of the 1 1/2 to 2 h survivors. Electron microscopy showed platelet thrombi in the infarcted brain in 3 of the 7 animals with infarcts, and in an area of very severe ischemic cell change in a fourth animal. They were not present in areas of brain showing only mild to moderate ischemic cell change. These findings showed that platelet thrombi form in association with cerebral infarcts and suggested that they are induced by tissue necrosis rather than by neuronal ischemic cell change alone.
The carotid bifurcation plaque: pathologic findings associated with cerebral ischemia.
Authors: Imparato A M , Riles T S , Gorstein F
Published: June 2011

Embolization from or decreased flow through cervical carotid and vertebral arteries causes ischemic stroke syndromes. Specific pathologic findings were studied in 50 symptomatic patients who underwent 69 carotid endarterectomies. Detailed analyses of their carotid plaques included correlations between photographs of gross specimens, microscopic findings, angiograms, preoperative symptoms and long-term postoperative follow up. Carotid plaques were primarily fibrous with significant (greater than 70%) stenoses encountered in 70% of the arteries. Stenoses were due to simple fibrous thickening in only 20%; the remainder due to intraplaque hemorrhage, atheromatous debris and, least often, luminal thrombus with or without ulceration. Intramural hemorrhage was frequent in plaques associated with focal neurologic symptoms and may have preceded localized collections of atheromatous debris. Ulceration occurred in 1/3 of all plaques, symptomatic or not. It is concluded that the carotid plaques start as fibrointimal thickening evolving to symptomatic stages by the occurrence of one or more of a number of pathologic changes, intraplaque hemorrhage being prominent. A single rational therapeutic regimen seems impossible until patients can be classified according to their pathologic changes diagnosed non-invasively.
EEG monitoring for induced hypotension for surgery of intracranial aneurysms.
Authors: Jones T H , Chiappa K H , Young R R , Ojemann R G , Crowell R M
Published: June 2011

EEG was monitored at bilateral scalp sites outside the operative field during hypotensive aneurysm surgery in 21 patients. Mean arterial blood pressure at axillary level was 50-60 mm Hg (average 55 mm) for 1.9-5.3 hours (average 3.6). Four new deficits were noted immediately post-operatively, all related to the operated site: these were attributable to intra-operative rupture with forced vascular clipping, vasospasm, or edema. In no instance was hypotension solely responsible for a new deficit. EEG showed persistent slowing in relation to surgery in only 1 patient, where aneurysmal rupture led to severe hypotension, forced clipping of 1 posterior cerebral artery, and subsequent brain stem infarction. In the 3 other patients with fresh focal postoperative deficits, no persistent intraoperative EEG changes were observed. EEG monitoring did not detect ischemia in these 3 patients because 1) hypotension was moderate and did not per se cause new deficit, and 2) EEG electrodes did not survey the area at maximal risk, namely the operative field. EEG scalp electrodes near but outside the operative site do not seem useful for monitoring cerebral function in the region of aneurysm surgery. Epidural or cortical electrodes in the operative field may prove to be more useful.
Quantitation of carotid stenosis with continuous-wave (C-W) Doppler ultrasound.
Authors: Spencer M P , Reid J M
Published: June 2011

Two methods for determining the degree of stenoses developing on the origin of the internal carotid were tested using non-invasive Doppler ultrasonic imaging (DOPSCAN) of the carotid bifurcations. Spectral analysis of Doppler audio recordings was utilized in determining the maximum frequencies found within the stenosis, as well as the ratio of the frequency downstream to the stenosis, to the frequency within the stenosis. The theoretical relationships between blood flow, velocity, and pressure drop are defined for all grades of stenosis and they predict that carotid flow will not be reduced unless the lumen diameter is less than 1.5 mm. At critical diameter reductions, below 1 mm, the frequencies in human carotids do not exceed 16 KHz because turbulence limits peak velocities. If the maximum systolic frequency exceeds 5 KHZ, when 5 MHZ probes are directed at a 30 degree angle from the body axis, there is always present stenosis up to diameters of less than 3.5 mm by x-ray angiographic measurements. Frequency ratio studies confirm that plaque growth is not symmetrical but they did not improve x-ray angiography correlations because of the limitations of x-ray in measuring cross sectional areas from projection films and limitations of the spot size of x-ray tubes.
Effect of STA-MCA anastomosis on the course of experimental acute MCA embolic occlusion.
Authors: Levinthal R , Moseley J I , Brown W J , Stern W E
Published: June 2011

The experiments in this report were designed to evaluate the effect of superficial temporal-middle cerebral artery (STA-MCA) anastomosis on the course of middle cerebral artery (MCA) occlusion by emboli while avoiding a vessel clipping technique as well as the use of long-acting barbiturate anesthesia. Dogs were divided into 3 general groups: A) embolus placement 1 h following anastomosis; B) embolus placement 5 h prior to anastomosis; C) control group without anastomosis. Anastomosis prior to MCA occlusion has a favorable clinical effect and reduces the size of an infarction. Anastomosis 5 h after embolus placement is deleterious unless other therapeutic modalities can be shown to delay the course of infarction.
Role of adrenergic nerves in blood-induced cerebral vasospasm.
Authors: Simeone F A , Vinall P E , Alderman J L , Irvin J D
Published: June 2011

Cerebral arteries have an abundant supply of adrenergic nerve fibers which are believed to release vasoactive substances responsible for the induction of cerebral vasospasm. To assess the importance of adrenergic nerves in this phenomenon, high doses (600 microgram/ml) of 6-hydroxydopamine (6-OHDA) were used to produce in vitro chemical sympathectomy in bovine middle cerebral artery. 6-OHDA reduced catecholamine fluorescence to undectable limits. H3-norepinephrine re-uptake was reduced to 1.5% of intact controls. Arterial norepinephrine content was reduced by 92%. Contractile responses to norepinephrine, serotonin, and fresh human whole blood were modestly reduced after denervation. This reduction was probably due to alpha receptor inactivation by 6-OHDA, because after protection of the alpha receptors with phentolamine the vessel response was the same as in untreated controls. Contractions in response to aged human whole blood were not affected by denervation. The results suggest that the endogenous release of catecholamines does not play a major role in the initiation or spread of blood-induced vasospasm in large cerebral arteries.
Results of electroencephalographic monitoring during 367 carotid endarterectomies. Use of a dedicated minicomputer.
Authors: Chiappa K H , Burke S R , Young R R
Published: June 2011

Three hundred sixty-seven carotid endarterectomies were monitored using routine electroencephalographic (EEG) techniques. In 9.8%, changes in the EEG followed clamping of the internal carotid artery and could roughly be grouped into 6 patterns. The most common (47%) was rapid unilateral or bilateral attenuation of background anesthetic-induced fast EEG activity. Conclusions drawn from studies of the 9 patients who had immediate postoperative neurological deficits of varying degrees are presented as they illustrate monitoring techniques that are useful for early recognition of cerebral ischemia. Thirty-five patients were monitored with both routine and computerized techniques--the latter proved more useful than the former on all counts.
Modification of cerebrovascular CO2 reactivity by inhibition of dopamine beta-hydroxylase.
Authors: Oishi M , Gotoh F , Toyoda M , Seki T , Takeoka T , Takagi S , Niimi T
Published: June 2011

The influence of sympathetic nervous activity on cerebral circulation and cerebrovascular CO2 reactivity was investigated through inhibition of dopamine beta-hydroxylase (DBH). A PO2 electrode, a PCO2 electrode and a plate-type thermocouple-flowmeter were placed on the pial surface of the cat brain. Cerebrocortical PO2, PCO2, cerebrocortical blood flow and arterial blood pressure were continuously recorded before, during and after intracarotid infusion of 10 mg/kg of fusaric acid, a potent DBH inhibitor. The effects of 5% CO2 inhalation and hyperventilation were measured before and after the inhibition of DBH. Following the intracarotid infusion of fusaric acid, cerebrocortical PO2 and cerebrocortical blood flow increased significantly. After the inhibition of DBH, the degree of the increase in cerebrocortical PO2 during 5% CO2 inhalation was enhanced while the degree of the decrease in cerebrocortical PO2 during hyperventilation did not show any significant change. The cerebral vasodilatation caused by fusaric acid suggests that the sympathetic nervous system takes part in the resting tone of cerebral blood vessels. The increase in the cerebrovascular CO2 reactivity produced by the inhibition of DBH suggests that the sympathetic nervous system modifies cerebrovascular CO2 reactivity.
External carotid artery in internal carotid artery occlusion. Angiographic, therapeutic, and prognostic considerations.
Authors: Countee R W , Vijayanathan T
Published: June 2011

Twenty-three instances of internal carotid artery occlusion occurring with minimal neurological deficit in 22 patients are described. Although each of these patients was referred to the neurosurgical service for evaluation for an extracranial-intracranial microvascular bypass procedure, complete arteriographic evaluations of their cerebrovasculature suggested that alternative methods should be the treatment of choice. For each patient reported the ipsilateral external carotid artery was demonstrated by angiography to be an important source of collateral blood supply to the cerebral hemispheres or retinae distal to the occluded internal carotid arteries. Ten patients with no significant atherosclerotic narrowing or ulceration of the external carotid artery have remained free of symptoms of cerebral ischemia for 6 to 40 months. In twelve patients who developed delayed recurrent cerebral or retinal ischemia ipsilateral to their internal carotid artery occlusion, there were found obstructive and/or ulcerative plaques involving the common and/or external carotid arteries. Thromboendarterectomy in 11 of these patients gave complete relief of ischemic symptoms during the 4 to 36 months of postoperative follow up. One of these 12 patients refused operation and went on to develop a major cerebral infarction. Angiographic identification of a functionally important external carotid artery ipsilateral to an internal carotid artery occlusion carries considerable prognostic and therapeutic significance.
Frequency of focal cerebral transient ischemic attacks during a 12 month period. The Copenhagen city heart study.
Authors: Boysen G , Jensen G , Schnohr P
Published: June 2011

As an offshoot of a larger prospective cardiovascular population study, the present study aimed to determine the 12 months frequency of focal cerebral transient ischemic attacks (TIAs) in persons randomly selected after age stratification from the Copenhagen city population register. A questionnaire of 5 questions pertaining to cerebrovascular attacks sustained within the last 12 months was distributed to 2,357 persons. The TIA-questionnaire was returned by 88%, of whom 22% responded affirmatively to one or more questions. The positive responders were interviewed by phone, and when suspected of having TIAs they were examined by a neurologist. A total of 11 persons proved to have had TIAs, which for the age group of 60 years and over gives o 12 months frequency of 8/1000. Dizziness, ophthalmologic problems and migraine were the most frequent causes of a "false" positive response.
Effect of intravenous ethanol on cerebral vasospasm produced by subarachnoid blood.
Authors: Barry K J , Scott R M
Published: June 2011

The cat basilar artery was exposed using the transclival approach. After administration of 5% ethanol via intravenous infusion, vasospasm was produced by applying the animal's fresh arterial blood to the exposed artery. The resultant vasospasm was of markedly reduced intensity and duration as compared to vasospasm in control animals. In ethanol-treated animals with spasm induced from non-autogenous fresh arterial bloof free of ethanol, a reduction in the duration of vasospasm was noted although the initial intensity of spasm was similar to control animals. There was no anti-spasm effect if the ethanol infusion followed the production of vasospasm.
Brain edema during ischemia and after restoration of blood flow. Measurement of water, sodium, potassium content and plasma protein permeability.
Authors: Ito U , Ohno K , Nakamura R , Suganuma F , Inaba Y
Published: June 2011

The left cerebral hemisphere of Mongolian gerbils was used to elucidate the mechanisms of brain edema which develop during cerebral ischemia and after restoration of cerebral blood flow following temporary ischemia. Water content was measured by the tissue-drying method. Sodium and potssium ion concentration was measured by flame photometry. Passage of 131I-albumin (RISA) from blood to the cerebral parenchyma was measured on a gamma scintillation counter. Our findings indicate that pure cytotoxic edema develops during ischemia and during a short period after restoration of cerebral blood flow. Vasogenic edema, which is accelerated by the leakage of plasma constitutents from blood due to blood-brain barrier damage, developed after restoration of the cerebral blood flow. After less than 1 hr of ischemia, restoration of the cerebral blood flow drastically reduced the degree of brain edema. However, restoration of the cerebral blood flow greatly worsened the brain edema following more than 3 hr of ischemia.
Body fluid oxygen tension and prognosis in patients with ruptured aneurysm.
Authors: Kishikawa H , Iwatsuki K , Fujimoto S , Umeda A
Published: June 2011

Body fluid gas pressure and electrolytes of patients with ruptured aneurysm were continuously analyzed. Intracranial pressure (ICP) was regulated at the level of 120-100 mm H2O by cerebral ventricular drainage. There was no significant change in the pH, PCO2, HCO3-, Na+, K+, Ca++ in the cerebrospinal fluid (CSF) of patients with slight or moderate disturbance of consciousness (lethargic-drowsy state). The PcsfO2 of the patients with marked disturbances of consciousness (semicoma-coma) was significantly low. PcsfO2 of the patients with cerebral vasospasm was significantly lower than for those without vasospasms. PcsfO2/PaO2 was 0.27 +/- 0.01 in the patients with vasospasm and 0.50 +/- 0.01 in those with vasospasm. PcsfO2 tended to decrease in patients with markedly bloody CSF. When the bloody CSF was cleared by ventricular drainage, PcsfO2 increased. PcsfO2 did not return to a normal value in the patients with marked disturbances of consciousness despite sufficient arterial oxygen tension. This suggests that PcsfO2 and PcsfO2/PaO2 should provide a convenient index for the prognosis of patients with ruptured aneurysm.
Brain metabolism following bilateral carotid occlusion in 2 different models of experimental hypertensive rats.
Authors: Fujishima M , Morotomi Y , Kumamoto K , Noda Y , Ogata J , Omae T
Published: June 2011

Brain metabolites and arterial acid-base measurements were made one hr after bilateral carotid artery occlusion in 2 different models of hypertensive rats. Animals used included renovascular hypertensive rats (RHR) with an altered renin-angiotensin system and desoxycorticosterone hypertensive rats (DHR) with low plasma renin activity (PRA). The mean value for supratentorial lactate of 7.41 mM/kg in RHR was significantly higher than in DHR (3.90 MM/kg) or in control normotensive rats (3.10 - 2.56 mM/kg). Concomitantly, the lactate/pyruvate ratio tended to increase and ATP to decrease in RHR only. In these same rats (RHR) infratentorial lactate was also increased. The results suggest that bilateral carotid occlusion leads to anaerobic metabolism of the brain in RHR but not in DHR, suggesting that the renin-angiotensin system may play some role in the susceptibility to cerebral ischemia following carotid occlusion in the hypertensive rats.
Arterial air embolism in the cat brain.
Authors: Fritz H , Hossmann K A
Published: June 2011

In cats air embolism of the brain was produced by injecting 0.6 ml blood foam into the innominate artery proximal to the origin of both common carotid arteries. Air embolism caused transient ischemia of the brain, reaching a maximum within 1 min after injection. Resolution of the air embolism began a few minutes later and was completed within 15 min in the center and within 30 min in the border zone of the main supplying arteries. During this phase tissue perfusion was inhomogenous with reduced flow rates in some areas and reactive hyperemia up to 300% in others. This resulted in venous hyperoxia and a decrease of arteriovenous oxygen difference to as low as 2 ml/100 ml blood. Reactive hyperemia was accompanied by brain swelling and an increase in intracranial pressure from 3.6 +/- 1.2 to 12.3 +/- 2.0 mm Hg. The reason for hyperemia was a decrease of cortical pH which fell from 7.33 +/- 0.03 to 7.03 +/- 0.05, and which caused a dilation of pial arteries up to 260%. Immediately after embolism, the EEG flattened and oxygen consumption decreased. After normalization of flow, oxygen consumption returned to normal, but EEG only partially recovered. Air embolism had little effect on the water and electrolyte content of the brain, and produced very little damage to the blood-brain barrier.
Fusiform basilar aneurysm simulating carotid transient ischemic attacks.
Authors: Hirsh L F , Gonzalez C F
Published: June 2011

Fusiform aneurysms of the basilar artery are extremely unusual. Most show signs of a posterior fossa mass. One case is reported which presented with recurrent transient ischemic attacks suggesting carotid vascular disease. Failure of an appropriate endarterectomy to relieve the symptoms, and later brain stem infarction, led to the correct diagnosis. Whenever recurrent or new symptoms appear following carotid vascular surgery, other diagnoses must be considered.
Recovery in treated aphasia in the first year post-stroke.
Authors: Sarno M T , Levita E
Published: June 2011

During a one year post-stroke period of observation, the recovery trend in treated aphasic patients was characterized by general progression in communication skill. The most notable improvement occurred on a measure of everyday function with changes worthy of note on tasks of auditory comprehension and spontaneous word production. In the first 6 months post-stroke, the greatest gain occurred in aphasic patients classified as Fluent, and the least gain in Global aphasics. On the auditory comprehension task, however, improvement was noted in all aphasics regardless of type. In contrast, during the latter half of the first year post-stroke, Fluent aphasics showed least and Global aphasics the greatest improvement. In spite of their progress, Global aphasic patients remained considerably more impaired than the other groups. That the Global aphasics remained so impaired was expected, but the extent and temporal characteristics of their progress in communicating was unexpected.
Intracranial venous thrombosis in young women.
Authors: Estanol B , Rodriguez A , Conte G , Aleman J M , Loyo M , Pizzuto J
Published: June 2011

Twenty women of child-bearing age with intracranial venous thrombosis are reported. Thirteen developed thrombosis post-partum; 6 while on oral contraceptives. In one patient no cause was found. All diagnoses were confirmed by carotid angiography and in 10 out of 14 patients laboratory data indicated a hypercoagulable state. Coagulation studies were performed in 14 normal puerperal women, matched by age, who served as controls. No statistical differences was found between thrombotic and control groups. Radiologic signs of sino-venous occlusion are reviewed. Conservative treatment with anti-edematous agents, anticonvulsants and antiplatelet aggregants is advocated.
Measurement of regional brain glucose utilization in vivo using [2(-14)C] glucose.
Authors: Hawkins R , Hass W K , Ransohoff J
Published: June 2011

A new technique is described for the autoradiographic determination of regional brain glucose metabolism employing 14C labeled glucose as substrate and measurement principles previously described for whole brain. Regional glucose values correlate closely with those reported for the 14C-deoxyglucose technique. The method has the advantages of 1) a much shorter experimental period, 2) a relatively simple mathematical treatment, and 3) the utilization of the actual, fully metabolizable substance itself, glucose, as the label. In addition to normal rats, regional values are reported for 20 individual brain areas of rats in bicuculline induced status epilepticus, rats intoxicated with ammonium and rats anesthetized with pentobarbital sodium or ketamine.
Comparison of Doppler sonography and plate thermography for detection of carotid artery stenosis.
Authors: Hofferberth B , Gottschaldt M , Dykan S
Published: June 2011

Foils coated with specific cholesterol esters indicate differences in temperature by changes in color. When these foils are placed on the skin, the skin temperature measured is related to the perfusion provided by the vessels supplying this area of the skin. A group of 300 patients were examined simultaneously with plate thermography and directional Doppler sonography in order to detect obstruction or occlusions of the carotid artery. Abnormalities were found in 42 patients. In 31, the positive findings obtained by the 2 methods were in agreement. In 8 only plate thermography gave a positive result, and in 3 only Doppler sonography yielded a relevant finding. Plate thermography as a method for the detection of a stenosis or an occlusion of the carotid artery is suggested as useful for an initial screening method.
Reduction in regional cerebral blood flow during normal aging in man.
Authors: Melamed E , Lavy S , Bentin S , Cooper G , Rinot Y
Published: June 2011

Regional cerebral blood flow (rCBF) was measured by the 133Xenon inhalation method in a selected group of 44 normal non-hospitalized, normotensive subjects aged 19 to 79 years. rCBF was computed as the initial slope index value (ISI). Advancing age was associated with significant reductions in the mean brain and mean hemispheric ISI as well as in individual ISI levels measured from all areas in both hemispheres. Our findings suggest that decline of rCBF is not limited to normal elderly subjects but that it is a progressive phenomenon which begins at an earlier age.
Extrancranial occlusive vascular disease: does size matter?
Authors: Caplan L R , Baker R
Published: June 2011

A 47-year-old patient had lesser development of her left limbs and face, smaller left vascular structures, and severe occlusive disease of the left internal carotid, left subclavian, left vertebral and left iliac arteries. In 12 examples of occlusion of a carotid artery, 10/11 with unequal vascular luminal size had the occlusion on the smaller side. Of 20 patients with severe asymmetrical carotid stenosis, 13/17 with unequal size had more stenosis on the smaller side. These preliminary observations suggest that a small vessel may be more likely to occlude than its larger counterpart.
Integrity of blood-brain barrier during ethanol intoxication and withdrawal in the rat: normal glucose transfer and permeability to Na+ and Cl-.
Authors: Hemmingsen R , Hertz M M , Bolwig T G
Published: June 2011

The unidirectional brain uptake of 14-C-D-glucose, 24Na+ and 36Cl- was measured by the Oldendorf tissue uptake method in order to test whether severe ethanol intoxication or withdrawal affected the glucose transfer across the blood-brain barrier (BBB) or the integrity of the BBB to small ions. The Oldendorf technique rests upon the assumption that water is freely diffusible across the BBB, but in the present study a correction was applied, which takes into account the fact that the water extraction actually depends upon the different cerebral blood flow (CBF) in the groups. The 24Na+ and 36Cl- extraction values were about 1% as reported in other studies and this suggests that there was no major effect on the BBB reaction to small ions during severe ethanol intoxication or during withdrawal. The permeability surface area product did not deviate significantly from control values in any group and thus there was no indication that glucose transfer across the BBB differed during ethanol intoxication or withdrawal.
Embolization from a fusiform middle cerebral artery aneurysm.
Authors: Cohen M M , Hemalatha C P , D'Addario R T , Goldman H W
Published: June 2011

A 34-year-old man had a transient ischemic attack and subsequently a completed stroke. Arteriography revealed a large fusiform aneurysm of the left middle cerebral artery with intraluminal thrombus. At surgery, the thrombus was seen within the lumen of the aneurysm. Absolute evidence for embolization is lacking as no examination for this could be done. Embolization from intracranial aneurysms seems to occur exclusively in large or giant aneurysms. Turbulent flow and a "stagnant zone" probably promotes thrombus formation. The reasons for the relative rarity of subsequent embolization are discussed. Because embolization from intracranial aneurysm is so uncommon and because aneurysms usually produce focal deficit by other mechanisms, 4 criteria are presented to determine whether embolization is likely.
Cardiovascular mortality in transient ischemic attacks.
Authors: Heyden S , Heiss G , Heyman A , Tyroler A H , Hames C G , Patzschke U , Manegold C
Published: June 2011

Statistical analyses were made of the mortality of persons diagnosed as having definite TIA in an epidemiologic survey of a biracial Southern community. None of the usual risk factors associated with this illness such as heart disease, hypertension or diabetes appears to account for the excess deaths observed in a 10 year period of follow up.
Effects of gamma-hydroxybutrate and gamma-butyrolactone on cerebral energy metabolism during exposure and recovery from hypoxemia-oligemia.
Authors: MacMillan V
Published: June 2011

Cerebral hypoxia-oligemia was produced by lowering of the arterial PO2 to 30 mm Hg and by right common carotid artery occlusion in rats who were pretreated with intravenous Krebs' solution, gamma-hydroxybutyrate (GHB) (500 mg/kg) or gamma-butyrolactone (GBL) (300 mg/kg). At 0.5 h exposure the right cerebral hemisphere of animals receiving Krebs', GHB or GBL showed equivalent decreases of ATP and phosphocreatine and increase of ADP, AMP and lactate which indicated that these depressant drugs had no beneficial effect on the energy metabolism of the acutely hypoxic-oligemic brain. In a second series of rats in which Krebs' solution, GHB or GBL were administered to animals during the early recovery period from 0.5 h hypoxic-oligemic exposure, the brain metabolic patterns of the right hemisphere indicated that GHB retarded the restitution of energy phosphates and the oxidation of the accumulated lactate; whereas, GBL led to a delayed metabolic deterioration. It is concluded that GHB and GBL do not beneficially alter cerebral energy metabolism during acute hypoxia-oligemia and that their administration during restitution may result in metabolic alterations which suggest an unfavorable effect.
Deleterious effect of glucose pretreatment on recovery from diffuse cerebral ischemia in the cat. I. Local cerebral blood flow and glucose utilization.
Authors: Ginsberg M D , Welsh F A , Budd W W
Published: June 2011

Diffuse cerebral ischemia was created in pentobarbital-anesthetized cats by basilar and bilateral carotid artery occlusions and hypotension. Local cerebral blood flow (ICBF) was assessed autoradiographically with 14C-antipyrine, and local cerebral glucose utilization with 14C-2-deoxyglucose. In animals without glucose pretreatment, 15 min of ischemia led to a homogeneous reduction of post-ischemic cerebral perfusion to 31% of control; ischemia of 30 min produced post-ischemic perfusion heterogeneities in the cerebral cortex and deep gray structures. In animals pretreated with dextrose, 1.5 gm/kg intravenously, heterogeneous cerebral perfusion was observed following only 15 min of ischemia, and a severe global impairment of cerebral reperfusion occurred after the 30 min insult. Deoxyglucose autoradiograms in the latter animals were remarkable for a complete suppression of tracer uptake in the cerebral cortex and a paradoxically increased tracer concentration in the cerebral white matter. Mean plasma glucose in the treated animals exceeded 1000 mg/100 ml. Large glucose loads prior to ischemia dramatically impair post-ischemic cerebral perfusion.
Effects of surrounding tissue on the sound spectrum of arterial bruits in vivo.
Authors: Miller A , Lees R S , Kistler J P , Abbott W M
Published: June 2011

Turbulent flow distal to arterial stenoses producers bruits with a characteristic sound spectrum, analysis of which has permitted accurate non-invasive assessment of the residual lumen diameter of the stenosis in the case of the human carotid artery. In contrast, investigators working with in vitro elastic models of arteries or with excised vessels have reported finding mainly resonant spectra of bruits recorded distal to stenoses. We have studied the effects of turbulent flow on the sound spectrum produced at the arterial wall and the influence of surrounding tissue on this spectrum. Aortic, carotid, and femoral stenoses were produced in dogs by external banding of the arteries with 5mm wide Teflon bands. Recordings of bruits made directly on the vessel wall had a sound spectrum made up of 2 components, one due to turbulent flow, and the second to a superimposed resonant spectrum from arterial wall vibration. This was true of 3 kinds of vessels studied. The effects of surrounding tissue on the sound spectrum of arterial bruits was shown by comparing the spectra o bruits recorded directly on the vessel wall, on the freshly closed wound and on the healed wound. The sound properties of the artery in situ are very different from those of exposed or excised vessels or elastic tubes. Although intravascular turbulence may be accurately appreciated at the skin surface, arterial wall resonance in the intact animal is extensively damped by the normal coupling of the artery to its surrounding tissue.
Lipohyalinosis and miliary microaneurysms causing cerebral hemorrhage in a patient with moyamoya. A clinicopathological study.
Authors: Mauro A J , Johnson E S , Chikos P M , Alvord E C
Published: June 2011

Moyamoya is an intriguing and controversial syndrome. This patient study serves to align the pathophysiology of intracranial hemorrhage in moyamoya with the cerebral vascular disease seen with hypertension, or aging. The historical evidence linking lipohyalinosis and microaneurysms to cerebral hemorrhage is reviewed, the pathogenesis of this angiopathy is discussed, and explanations considered for its association with the vascular pattern of moyamoya. We propose that hemodynamics, genetics or both are among the primary operant etiologic factors.
Management of cerebral embolism of cardiac origin.
Authors: Easton J D , Sherman D G
Published: June 2011

The cardiac conditions most commonly associated with cerebral embolism are rheumatic heart disease (RHD), atherosclerotic heart disease (myocardial infarction and atrial arrhythmias) and other kinds of nonvalvular atrial fibillation (AF). The natural history of cerebral embolism from these cardiac sources is reviewed. Virtually all rheumatic hearts producing emboli have mitral stenosis, but not all of them are in AF. Of patients with RHD, 10--20% will experience a systemic embolus, and approximately half will have a recurrence, usually early. Of patients with a myocardial infarction, 5--12% will have a clinically apparent systemic embolus, and one-third to one-half have a recurrence, usually early. As many as 10--20% of patients with nonrheumatic AF have a systemic embolus. Anticoagulation reduces systemic embolism to 10--20% of the natural incidence in RHD, and it reduces embolic recurrences to 10--20% of the natural recurrence rate. Anticoagulation diminishes the incidence of emboli in myocardial infarction to 25% of the natural incidence. It is not known what effect anticoagulation has on the incidence of embolism in nonrheumatic AF. The data regarding the effect of valvulotomy and prosthetic valve placement in RHD are briefly reviewed. Recommendations are made for the use and timing of anticoagulation based on the available data.
Subdural hematoma of the spinal cord and widespread subarachnoid hemorrhage complicating anticoagulant therapy.
Authors: Vinters H V , Barnett H J , Kaufmann J C
Published: June 2011

A patient developed paraparesis and signs of meningeal irritation spontaneously while on anticoagulant therapy. At autopsy, a subdural hematoma of the thoracic cord and evidence of widespread subarachnoid hemorrhage were found. The possible mechanism for these combined hemorrhages is discussed.
Experimental brain infarcts in cats. I. Pathophysiological observations.
Authors: Hossmann K A , Schuier F J
Published: June 2011

In 48 cases the left middle cerebral artery was occluded under light barbiturate anaesthesia using a transorbital approach. The animals were kept alive for 1, 2, and 4 hours after vascular occlusion. Regional cerebral blood flow was measured by the intracardiac microsphere injection technique before ischemia, 15 min after the onset of ischemia, and at the end of experiments. The density of regional ischemia was correlated with EEG changes and with the electrolyte, water and metabolite content of the same tissue samples in which blood flow was assessed. In the territory of the occluded middle cerebral artery, cortical blood flow decreased from 41.4 +/- 3.8 to 21.3 +/- 4.0 ml/100 g/min (means +/- SE), the actual flow rate depending on the individual efficacy of collateral blood supply. At flow rates below 10--15 ml/100 g/min, ischemia involved more than 50% of the middle cerebral artery territory, water and electrolyte homeostasis was severely disturbed and ischemic brain edema developed. Adenosine triphosphate decreased to about 60% of the control value at flow rates below 40 ml/100 g/min, but it remained at this level down to flow rates as low as 5 ml/100 g/min. EEG intensity -- but not EEG frequency -- decreased in parallel with blood flow, indicating that with increasing density of ischemia an increasing portion of the excitable neuropil was inhibited. The development of ischemic brain edema determined the further progression of ischemia. When blood flow decreased below the threshold for water and ion disturbance, ischemia was progressive (critical ischemia), but an amelioration of flow occurred in animals in which flow remained above this level (non-critical ischemia). In the contralateral hemisphere the EEG, blood flow, water and electrolyte content did not change significantly during the initial few hours of ischemia. Diaschisis, in consequence, was not a prominent feature during the early phase of infarct development.
Central conduction time in primate brain ischemia -- a study in baboons.
Authors: Hargadine J R , Branston N M , Symon L
Published: June 2011

The relationship between central conduction time (CCT) and levels of regional blood flow were studied in 9 primates. Flows were recorded in both hemispheres using the method of hydrogen (2 min) clearance. The somatosensory evoked potentials were recorded over the contralateral cortex and the dorsal columns, following median nerve stimulation. The CCT, a measure of the brain's electrical conduction, was determined by the difference in latencies between N10, (the arrival of the afferent volley at the sensory cortex) and N7 (its arrival at the dorsal column). Ischemia was produced by transorbital occlusion of the right middle cerebral artery. In the acute ischemic phase within 5 minute of occlusion, there was a significant correlation between the change in CCT and the decrease in flow. In the later occlusive phase, the CCT was unaltered with flows above 15 ml/100g/min. Below that level smaller decreases in flow resulted in progressively larger changes in CCT until a flow was reached where the N10 disappeared or the entire cortex was electrically silent. Focal ischemia had no effect on the first positive deflection recorded from the cortex (P8) or the first negative peak response from the cervical region (N7). However, the latency of P8 was increased or it was absent with the introduction of hypotension, while N8 was unaltered. From our measurements, it appears that prolongation of CCT can be related to developing ischemia, and that the thresholds for change are not dissimilar to those already recorded for somatosensory evoked responses to the basis of amplitude alterations in the cortex. Below these levels, prolongation of CCT appears to bear a parametric relationship to alteration in blood flow. While the measurement displays only one of the many alterations which are induced by ischemia in the brain, its attraction lies in its simplicity and in the fact that it may be applied with relative ease in the clinical situation. Under these circumstances, it appears to be an adequately sensitive monitor of developing brain ischemia, and deserves further study.