ABSTRACT
Extracranial atherosclerotic cerebrovascular disease is a risk factor for myocardial infarction and stroke. Asymptomatic patients with evidence of disease may benefit from modification of risk factors for stroke (ie, hypertension, hyperlipidemia, diabetes mellitus, and cigarette smoking). Symptomatic patients with focal brain ischemia may benefit from antiplatelet therapy, anticoagulation, and surgery in addition to modification of risk factors.
Subject(s)
Arteriosclerosis/complications , Brain Ischemia/prevention & control , Arteriosclerosis/therapy , Brain Ischemia/diagnosis , Brain Ischemia/etiology , Humans , Risk FactorsABSTRACT
Hypertension is one of the most important risk factors for atherosclerosis, yet no morphologic evidence exists to explain it. This study is an attempt to identify lesions in the main pulmonary artery of rats in which pulmonary hypertension was induced by a single dose of monocrotaline. Pulmonary artery pressure was measured directly by catheterization or indirectly by measuring right ventricular thickness. Lesions were studied by both light and electron microscopy. As in previous studies in which monocrotaline was given chronically, we found thickening of the main pulmonary artery. We also found widening of subendothelial space, change in smooth-muscle cell polarity, shape, and organelle content (indicating change from contractile to secretory), focal areas of muscle necrosis and elastolysis. Interestingly, cardiac muscle was observed in adventitia of both controls and treated animals.
Subject(s)
Hypertension, Pulmonary/pathology , Pulmonary Artery/pathology , Pyrrolizidine Alkaloids , Animals , Hypertension, Pulmonary/chemically induced , Liver/pathology , Male , Microscopy, Electron , Monocrotaline , Muscle, Smooth, Vascular/pathology , Plants, Toxic , Pulmonary Wedge Pressure , Rats , Rats, Inbred Strains , Senecio , Time FactorsABSTRACT
Proton magnetic resonance imaging (MRI) using a 0.6- or 1.5-Tesla superconductive magnet was compared with high-resolution computed tomography (CT) in 60 patients with transient ischemic attacks (TIAs) or brain infarction. MRI showed focal parenchymal changes in 84% of patients with TIAs, whereas CT showed similar changes in 42%. The sensitivity of MRI was also greater in patients with infarcts, but the difference between CT and MRI was not as great. Infarcts were usually better delineated by MRI regardless of location. However, MRI failed to reveal cortical infarcts that were clearly seen on contrast-enhanced CT scans and was unable to clearly distinguish subacute from chronic hemorrhagic infarcts. MRI changes were best detected with T2-weighted images and usually appeared as multiple areas of increased signal intensity in the subcortical and periventricular white matter. MRI changes often could not be correlated with the clinical history and neurological findings; identical changes have been seen in patients with no history of cerebrovascular disease.
Subject(s)
Brain Ischemia/diagnosis , Brain/pathology , Acute Disease , Adult , Aged , Brain Ischemia/pathology , Cerebral Hemorrhage/diagnosis , Cerebral Infarction/diagnosis , Chronic Disease , Diagnosis, Differential , Female , Humans , Ischemic Attack, Transient/diagnosis , Magnetic Resonance Spectroscopy , Male , Middle Aged , Tomography, X-Ray ComputedABSTRACT
During 1968 consecutive percutaneous transluminal coronary angioplasty (PTCA) procedures, 4 patients (0.2%) suffered a focal central nervous system complication. Two patients had a hemisphere infarct, one a brainstem infarct and one a hemisphere transient ischemic attack. Embolism was the likely mechanism in 3 cases; in 1 air was injected through the guiding catheter, and in 2 post-coronary bypass cases the ascending aorta was "scraped" with the guiding catheter while searching for a graft ostium. In 1 case the event occurred after a successful PTCA during a period of hypotension. Neurologic complications are rare during PTCA but will occasionally occur as the procedure is performed more frequently.
Subject(s)
Angioplasty, Balloon/adverse effects , Cerebral Infarction/etiology , Ischemic Attack, Transient/etiology , Adult , Aged , Female , Humans , Male , Middle AgedABSTRACT
We performed double-blind crossover trials to assess the effects of thyrotropin-releasing hormone (TRH) on amyotrophic lateral sclerosis patients. For acute intravenous trials, 500 mg TRH or placebo with norepinephrine was given at 1-week intervals (16 patients). CSF TRH concentration increased, and clinical side effects appeared with TRH. For chronic studies, 25 mg TRH and a saline placebo were given subcutaneously every day for 3 months (25 patients). CSF TRH level increased 29-fold after a single TRH injection, and mild transient side effects occurred. Vital signs, respiratory function, semiquantitative and quantitative neurologic function, muscle strength by manual and dynamometer testing, and EMG were studied. With daily TRH, 10 patients noted subjective improvement without objective evidence, and 10 patients complained of worsening of the disease with objective decline after TRH was stopped. Statistical analysis, however, showed no beneficial effects from either acute or chronic TRH trials.
