Richard Janeway

Transient ischemic attacks A prospective study of 225 patients

Between the years 1964 and 1973, 225 patients with transient ischemic attacks (TIAs) due primarily to atherosclerosis were evaluated and treated. They have now been followed for from 3 to 14 years (average 5.5 years). As of 1976, 82 of the 225 patients were dead, 21 from cerebral infarction, 52 from heart disease and nine from other causes. Of the 56 untreated patients, 11 (19 percent) had cerebral infarctions, four (7 percent) of which were fatal; six (11 percent) were still having TIAs. Of the 45 patients medically treated, 10 (24 percent) had cerebral infarctions, three (7 percent) of which were fatal; 11 (25 percent) still experienced TIAs. In the surgical group of 124, 27 (21 percent) had postoperative. cerebral infarctions, seven (6 percent) of which were fatal; 23 (18 percent) had cerebral infarctions during follow-up, of which seven (6 percent) were fatal; and 15 (12 percent) were still having TIAs. No statistically significant differences (p · 0.05) related to cerebral infarction or TIAs developed among the three groups. The majority (23 percent) eventually succumbed to myocardial infarction, leading us to conclude that great emphasis must be placed upon TIAs as a warning for cardiac as well as cerebrovascular disease.

Value of the Routine Use of the Cerebral Dynamic Radioisotope Study

Abstract The results of 1,165 serial dynamic studies were reviewed. The routine addition of the dynamic study to the static image increased the detection of lesions by 33%. In patients with middle cerebral or carotid disease, the number of abnormal studies was doubled. Meningioma, arteriovenous malformation, and middle-cerebral-artery occlusion produced characteristic patterns on the dynamic study. Specific combinations of dynamic study and static image findings increased the certainty of diagnosis. Decreased perfusion was due to cerebrovascular disease eight times more often than to tumor. The combination of normal perfusion and a positive gamma camera image occurred three times as frequently with tumor as with cerebrovascular disease.

”Radioisotope Arteriography” as an Adjunct to the Brain Scan

The brain scan is now widely employed for the evaluation of patients with suspected intracranial lesions. It is a simple, safe, relatively accurate diagnostic procedure and may be used both to screen patients and to complement cerebral arteriography and air studies in the identification of intracranial lesions. Although not as accurate as the latter two procedures in the detection of intracranial pathology (1–3), the brain scan has the decided advantages of lower patient morbidity, better demonstration of the extent of the lesion, availability on an out-patient basis, and a simplicity that makes its repeated use practical in following the course of a disease. In spite of its value, the brain scan has two major disadvantages: (a) it fails to localize all intracranial lesions, particularly those related to occlusive vascular disease, and (b) a positive scan alone is not sufficient to accurately identify the etiology of the lesion (tumor vs. infarction, etc.). The introduction of the scintillation camera has...

Hemodynamics of the Upper Extremities in Subclavian Steal Syndrome

Digital flow, digital artery systolic pressure, resistance, pulse volume, pulse contour, and delay between right and left pulses were evaluated in the upper extremities of four patients with the subclavian steal syndrome. Studies were made preoperatively in all patients and following surgical reconstruction of the subclavian in three cases.Digital artery pressures were consistently lower on the side with the subclavian occlusion.Flow on the occluded side was equal to or higher than that in the opposite extremity except when a second, more distal occlusion was present.In each case there was a delay in the foot of the digital pulse on the occluded side and a more marked delay in the pulse peak. Distal to the occlusion the pulse amplitudes were decreased and the contours were abnormal.The amplitude of the digital pulse was markedly decreased with exercise of the affected extremity.The pulse delay and the disappearance of pulse in the radial artery during exercise previously described clinically has been confirmed by measurement.

Thermistor Recording of Forehead Skin Temperature as an Index of Carotid Artery Disease

Skin temperatures were recorded from the medial upper orbital area and above the nasal, mid and lateral portions of the brows in normal subjects and in patients with suspected cerebrovascular disease. Temperatures were reduced across the brow in patients with external carotid artery disease. Temperatures were lower than normal in the orbit in patients with internal carotid artery disease except when the internal carotid circulation was severely compromised. In such patients the supraorbital temperature was higher than normal, suggesting significant reversed flow via the supraorbital artery. With internal carotid occlusion, lateral brow temperatures suggested increases in external carotid flow. The interpretation of results was more reliable when temperatures were compared to normal values than when they were judged as differences between the two sides as is done in thermography.

Statistical Relationship of Brain Scans, Cervicocranial Dynamic Studies, and Cerebral Arteriograms

The authors compared rapid sequence cervicocranial camera images, scans, angiograms, and pneumograms in 146 cases of neurological disorder. It was found that use of imaging is justified as a screening procedure prior to performance of routine radionuclide brain scanning. Further information is offered in a significant number of cases, particularly when this single study is compared with information obtained by cerebral angiography and pneumography. Additionally, the rapid sequence images, when studied with the brain scans, may help establish such diagnoses as arteriovenous malformation, tumor, or infarction.

Cephalic blood flow: A study of the dynamics of vertebral artery reversed flow in the dog

BECAUSE LITTLE INFORMATION is available describing total cephalic blood flow values, this report details the results of its measurement under varying conditions in order to gain an understanding of the dynamics of the extracranial portions of the cerebral and cephalic circulation. Our measurements define the changes in cephalic blood flow after occlusion of the proximal portion of the right subclavian artery, the major result of which is the causation of reversed blood flow in the right vertebral artery.

Chronic reversal of vertebral artery flow: An experimental study in dogs

REVERSAL of vertebral artery flow, editorially dubbed the “subclavian steal”1 syndrome, was described in 1960.2 Its relation to vertebrobasilar insufficiency was made evident by Reivich and associates in 1961,3 and the remediable nature of the disease process was stressed. Factors influencing acute reversal of flow through the vertebral arteries of dogs have been documented,4 but studies in chronic animals have not heretofore been reported. This study was undertaken to determine the effects of chronic occlusion of the subclavian artery upon flow, pressure, and resistance in the extremity.

Report of the Joint Committee for Stroke Facilities VI. Special Procedures and Equipment in the Diagnosis and Management of Stroke

The use of special procedures and equipment has become an integral, progressively complex, and increasingly expensive part of diagnosis and management in cerebrovascular disease. However, tests have enhanced rather than replaced the role of precise neurological examination and sound clinical judgment in caring for the stroke patient. The physician is obligated to understand the nature, limitations, complications, costs, indications, contraindications, and values of the many available diagnostic modalities and to avoid their indiscriminate use; most, and in some cases all, of this information should be known as well by hospital administrators, nurses, allied health professionals, and even the patient and his family. This Section discusses the present status of radiological and other diagnostic studies in disorders of the cerebral circulation. Rapid changes are occurring in this field with the almost daily appearance of new procedures, modifications, and applications, thus increasing the responsibility of all concerned to keep current with these new developments.

The Effect of Body Position and Forelimb Exercise on Cephalic Blood Flow

Flow through both common carotid, vertebral, and subclavian arteries was measured with “C-core” probes and square wave electromagnetic flowmeters in mongrel dogs. Exercise of the neurally isolated forelimb was simulated by electrical stimulation to obtain first clonic and then tetanic muscle contraction. Exercise was performed in the horizontal supine, 30° head-up, and 30° head-down positions. Bilateral forelimb exercise induced abrupt increase in subclavian artery flow and conductance. Cephalic arterial flow and conductance decreased at the onset of exercise and showed gradual recovery. Left subclavian artery flow and conductance decreased during right forelimb exercise. Right subclavian and brachiocephalic artery flow decreased during left forelimb exercise. Head-up position induced general decreases in cephalic blood flow in spite of increased mean arterial blood pressure. Response patterns of flow and conductance during bilateral exercise did not differ significantly from those in the horizontal supine position. Administration of gallamine triethiodide before stimulation eliminated all hemodynamic responses. Femoral artery flow and conductance decreased on the side contralateral to the side of the exercising limb. The clinical implications of redistribution of blood are discussed.