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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We designed this study to test the hypothesis that in acute mitral regurgitation the mitral regurgitant area (MRA) is a dynamic quantity which varies with the time variation of ventricular volume. Mitral insufficiency was created in five open-chest dogs in which a portion of the anterior leaflet was excised. Phasic aortic and mitral flows were measured electromagnetically, along with left atrial and ventricular pressures. Filling, regurgitant, and stroke volumes, and systolic pressure gradient were determined by digital methods. MRA was calculated from the fluid dynamic equation of motion to give the temporal mean and the instantaneous value at three instants of time and at the time of peak flow (when inertia is negligible). Mean regurgitant fraction was 42 +/- 12% with no indication of left ventricular failure due to volume overload. MRA decreased monotonically with time to 59% of its initial value and closely paralleled the decrease in ventricular volume during systole. In a control study using a tilting-disc prosthesis with a hole 5 mm in diameter in the occluder, the calculated MRA was time invariant and equal to the measured area for regurgitation. We conclude that in acute mitral regurgitation the MRA is a function of ventricular volume.
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PMID:Dynamic changes in the canine mitral regurgitant orifice area during ventricular ejection. 48 30

End-to-side anastomosis between the maxillary artery and a branch of the middle cerebral artery was performed in the dog. The technique was devised as a new experimental model for extracranial-intracranial arterial shunt operation. The middle cerebral artery was ligated at the origin through a subtemporal small burr hole under the operating microscope in 13 dogs. Then, the shunt operation was carried out in 8 dogs 4 hours after the ligation(acute state), and in 5 dogs 3 weeks after(chronic stage). The patency of the anastomotic site was evaluated by the selective external carotid angiography 2 weeks after the shunt operation. In the acute stage of 8 dogs, 7 cases showed patency of anastomosis (88%), and in the chronic stage of 5 dogs, arteriogram revealed 4 patent anastomosis (80%). In successful cases, arteriogram showed excellent filling of the entire territory of the middle cerebral artery through the shunts (Fig. 4, 5). Various types of experimental shunt operation were attempted in our review of the literature. Among them, the anastomosis between the superficial temporal artery and a branch of the middle cerebral artery by Yasargil (1967) is rather popular and this procedure has been used by some investigators including us to investigate the effect of the extracranial-intracranial shunt on experimental acute stroke. So far as dog's experiment is concerned, the superficial temporal artery appeared to be not suitable for a donor artery, because the superficial temporal artery runs far from the middle cerebral artery and its distal part is extremely small in caliber. Therefore, the superficial temporal artery was often obstructed by compression, kinking or narrowing by surrounding tissues and by adhesion to the bone edge of the burr hole. On the other hand, the maxillary artery of the dog, which is the largest terminal branch of the external carotid artery, has plenty of blood flow and suitable size for end-to-side anastomosis to the middle cerebral artery. In addition, maxillary artery is located very close to the proximal part of the middle cerebral artery. These anatomical and spatial advantage of the maxillary artery seemed to be favorable donor artery to the middle cerebral artery and have brought hight patency rate in our series of anastomosis than that of the other previous experimental extracranial-intracranial shunts. To our knowledge, this is the first report on successful patent shunt formation after long-term occlusion of the middle cerebral artery in animals. Now, it is in our mind that progress of the study can be expected in the field of extracranial-intracranial shunt operation for cerebral infarction by this experimental procedure.
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PMID:[Maxillary artery to middle cerebral artery anastomosis in dog-- a new experimental model (author's transl)]. 103 86

The prognosis of hemiplegic hand function may reflect intrinsic recovery. Applying the variables of initial neurological loss in the hemiplegic upper extremity to predict the prognosis of hand function will enable therapists to establish the ultimate goals of rehabilitation and to select the appropriate treatment programs. Pinch and grip strength tests, Frenchay arm function test and the nine-hole peg test were used to determine the relationship between the initial Brunnstrom motor stage of the hemiplegic upper extremity and the prognosis of hand function after six months. Forty stroke patients were divided into three groups. Group I was subjects with a motor stage below the Brunnstrom motor stage III in both proximal and distal parts of the hemiplegic upper extremity. Group II was subjects with motor stage below Brunnstrom motor stage III in the proximal part and above stage III in the distal part or vice versa. Group III was subjects with a motor stage above Brunnstrom motor stage III both in the proximal and the distal parts. The results of this study indicated that the prognosis of the Brunnstrom motor stage of the hemiplegic upper extremity generally improved about one or two stages. According to the results of the grip and pinch strength tests, the Frenchay arm function test or the nine-hole peg test, group I patients could hardly use their affected hand functionally. The grip strength and the pinch strength deficits of group I were 93.8% and 91.4% respectively. The grip strength and the pinch strength deficits of group II were 72.1% and 68.5% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The relationship between early motor stage and hand function recovery six months after stroke]. 235 11

The stereotactic aqua-stream and aspirator (SAS & A) was a modification of the aqua-stream and aspirator (AS & A) in order to remove hypertensive intracerebral hematoma. The newly designed needles were held with an adaptor to any kind of Leksell's, Patil's, UT's, Sugita's, or Komai's stereotactic equipment. The needles were stereotactically inserted into the center of the hematoma cavity through a burr-hole. The needles were composed of an outer tube and two inner tubes. The inner tubes were arranged parallel with each other. One was an irrigation tube of 0.1 mm in inner diameter, the other was a suction tube of 2 mm in outer diameter. The blood clot was sucked through a window of the outer tube by the aspirator and incarcerated there soon after. The incarcerated blood clot was crushed by a small streak of saline solution from the nozzle of the irrigation tube. Crushed clot and fluid were sucked through the suction tube. The extent of evacuation of the hematoma was evaluated by CT scans during stereotactic surgery. In all 10 cases of hypertensive intracerebral hematoma, 73-98% of hematoma content was removed. Disturbances of consciousness recovered soon after the surgery. Aphasia and hemiparesis improved later. Hard clot could be removed completely and safely by this new instrument, SAS & A, at an early stage after a stroke, because of the crushing and washing action.
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PMID:[Removal of hypertensive intracerebral hematoma with stereotactic aqua-stream and aspirator (SAS & A)]. 268 34

The stereotactic aqua stream and aspirator (SAS & A) is a modification of the aqua stream and aspirator (AS & A) designed for stereotactic evacuation of intracerebral hematoma. The needle of the new instrument is inserted into the brain through a burr hole by a conventional stereotactic technique and its tip is directed to the center of the hematoma. The hematoma is broken up with a stream of saline solution from a nozzle. Fragments of clot and fluid can then be aspirated piecemeal through the suction tube. The postoperative CT images show successful evacuation of the hematoma, and the clinical evaluation also showed satisfactory results. This instrument can be used safely, without any complications, early after the stroke.
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PMID:Stereotactic aqua stream and aspirator for hypertensive intracerebral hematoma. 269 65

An air-powder abrasive system, the Prophy-Jet model C-100, is now available for use by the dental community. However, its use has been restricted to cleaning enamel surfaces of stain and dental plaque. The purpose of this investigation was to ascertain the effects of this air-powder abrasive system on root surfaces of extracted human teeth. Thus, root surfaces of 20 teeth were covered with a template consisting of a metal band with a centrally located 2-mm diameter hole. The banded root surfaces, under controlled conditions, were exposed to the air-powder abrasive for 30 seconds. The resulting defects were measured by using a light microscope equipped with a graduated focus knob. Three teeth were randomly selected for examination by scanning electron microscopy and one was selected for histologic evaluation by light microscopy. Untreated extracted teeth were used as controls. In addition, one untreated tooth root was exposed to the air-powder abrasive without use of the template. In this instance, a brush stroke was used for approximately 1 minute, as might be done in a clinical situation. This tooth root was also examined by scanning electron microscopy. The Prophy-Jet air-powder abrasive system removed an average of 636.6 micrometers of root structure in 30 seconds of exposure time. The resulting surface was smooth, free of connective tissue fibers and debris, and all cementum was removed. Few open dentin tubules were observed since most appeared to have been obliterated. The powder crystals, as viewed by scanning electron microscopy, were sharp-pointed, somewhat elongated and of varying lengths. The Prophy-Jet air-powder abrasive system appears to have considerable potential for treatment of periodontally diseased root surfaces. However, its use should be tempered by the results of this and future research and sound clinical judgment.
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PMID:The effect of an air-powder abrasive system on in vitro root surfaces. 631 58

Right ventricular function was assessed in 15 patients using right ventricular pressure-volume loops. Right ventricular pressure using a micromanometer-tipped catheter, thermodilution cardiac output and gated blood pool scintigrams were simultaneously obtained. To help isolate the right ventricle, a slant hole collimator was used. The measurements were repeated during dobutamine infusion, which was titrated so there was minimal change in systemic pressure and heart rate. The right ventricular pressure-volume loop resembles the usual left ventricular loop except that the isovolumic contraction phase is often not as distinct, and right-sided ejection may continue well beyond right ventricular peak systolic pressure. Systolic but not diastolic function improved with dobutamine administration. There was no significant difference in right ventricular systolic function (ejection fraction, stroke work index, stroke volume index and cardiac index) or in end-diastolic volume index between patients without (Group I) and with (Group II) significant right coronary artery stenosis. However, there was a small but significant difference in right ventricular end-diastolic pressure (5.3 +/- 2.5 and 8.1 +/- 1.8 mm Hg [p less than 0.05]) for Group I and II, respectively. Thus, the right ventricular pressure-volume loop can be used to graphically display right ventricular function and improvement in contractility with dobutamine. The right ventricular isovolumic contraction phase and ejection phase differ from those in the usual left ventricular loop. Although there was a small difference in right ventricular end-diastolic pressure in patients with and without right coronary artery stenosis, the right ventricular pressure-volume loop did not provide additional discriminatory information between these two groups of patients.
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PMID:Characterization of the human right ventricular pressure-volume relation: effect of dobutamine and right coronary artery stenosis. 649 Oct 90

This investigation describes a surgical approach for ligation of the middle cerebral artery (MCA) in the young rat and evaluates consequences of the occlusion with a neurologic exam for motor deficits, Evans blue test for blood-brain barrier leaks, and light microscopy for histologic changes after 3 days. Evans blue extravasation and the lesion were limited to cortex at the burr hole site in occluded and sham operated rats. MCA occlusion beyond the point of origin of the striate branches in the young rat results in neither neurological deficits, dye markings, nor histologic changes in the distal vascular field to indicate an infarct. Apparently, the young rodent collateral supply maintains the tissue in a viable state.
Stroke
PMID:Middle cerebral artery occlusion in the young rat. 714 5

The ventricular stroke volume ratio or VSVR (left/right) was measured by gated radionuclide angiography in 33 normal subjects, using a 30 degree caudal slant-hole collimator and computer-generated functional images to aid in definition of the right ventricle. The mean ratio was found to be 1.06 +/- 0.05, compared to the normal value of 1.00. Comparative studies indicated that definition of the right ventricle based on the end-diastolic frame alone or standard collimation without caudal angulation commonly causes overestimation of the VSVR and considerably greater variance between measurements. Such errors are the result of inadequate atrioventricular separation and/or underestimation of the right-ventricular region.
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PMID:Measurement of the ventricular stroke volume ratio by gated radionuclide angiography. 745 79

A longitudinal study was performed on 118 first-ever stroke patients to evaluate neurophysiological measurements of central motor conduction time (CMCT) in the period immediately following stroke as predictors of functional outcome and mortality at 12 months. Measurements of CMCT were made as described in the accompanying article (Heald et al., 1993, Brain, 116, 1355-1370), in which the following three groups of patients were recognized within 12-72 h after the onset of symptoms: normal response group, delayed response group and no response group. Neurophysiological and clinical investigations were commenced 12-72 h (designated as day 1) after the onset of symptoms and repeated at set time intervals up to 12 months. The subjects were examined neurologically and assessed using the Motricity Index for muscle strength, the Nine-hole Peg Test to measure manual dexterity, the Barthel Score for activities of daily living and the modified Rankin Scale for functional outcome. The duration of stay in hospital and the occurrence of stroke-related death were noted. During the first week following stroke, absence of responses correlated closely with the patient's symptoms and neurological observations of abnormal muscle tone and tendon reflexes. Correlations were made in the three groups of patients of functional scores at day 1 and at 12 months. Patients with normal CMCT had consistently higher scores throughout the 12 month period and achieved significantly better functional recovery. Patients with no responses showed poor performance in neurological and functional tests throughout the 12 month period. Patients with delayed CMCT had neurological and functional scores intermediate between those of the other two groups, but outcome at 12 months was similar to those in the normal response group. Where the threshold to cortical stimulation was abnormally high, functional outcome was generally poor. Mortality was highest in the group with absent responses and the survivors spent the longest period in hospital. In conclusion, the observation of normal or delayed CMCT at day 1 identifies a group of patients with a high probability of survival and functional recovery. The absence of responses to cortical stimulation at day 1 identifies a group of patients who are at high risk of poor functional recovery at 12 months and greater probability of stroke-related death during this period.
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PMID:Longitudinal study of central motor conduction time following stroke. 2. Central motor conduction measured within 72 h after stroke as a predictor of functional outcome at 12 months. 829 76


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