The effect of cigarette smoking on extracranial carotid atherosclerosis was studies by obtaining cigarette smoking histories and information on other potential risk factors from consecutive patients undergoing carotid arteriography. At least on extracranial carotid artery was visualized in 752 patients in whom the extent of carotid atherosclerosis was assessed. The total years of cigarette smoking was the most significant independent predictor of the presence of severe carotid atherosclerosis. Other independent predictors, in order of significance, were age, hypertension, diabetes mellitus, male sex, and current systolic blood pressure. By age 60 years, the risk of having severe carotid atherosclerosis for a person who had smoked for 40 years was approximately 3.5 times that for a never smoker. The major benefit of smoking cessation is in limiting the accumulation of smoking years.
Abstract Myelography and myelography assisted with computed tomography have been the most commonly used radiographic methods in the study of syringomyelia. These studies have never been entirely reliable in demonstrating the syrinx cavity and its relationship to other intracranial structures. During the 1st year of operation of the magnetic resonance imaging facility, the syringomyelic cavity was demonstrated in 15 patients who all had typical clinical signs and symptoms associated with syringomyelia. Nine cases were syringomyelia with Chiari malformation. One case showed additional hydrocephalus. Four cases were idiopathic, and 1 case was remotely posttraumatic. Magnetic resonance imaging, although it is in its infancy, already promises to be the most important radiographic technique for syringomyelia because it provides an anatomically truthful visualization of the sagittal plane of the cervical cord and can demonstrate the syrinx cavity and its relationship with the cerebellar tonsils, the 4th ventricle, and other related structures.