Flaviu C. A. Romanul

Spinal cord infarction occurring during insertion of aortic graft.

ZULCH~ FIRST recognized a predilection for cerebral infarction to occur in the border zones between the territories of supply of the cerebral arteries in cases in which a diminution in the cerebral blood flow was produced by a fall in blood pressure or by stenosis of large cerebral vessels. Romanul and Abramowicz2 studied in detail the localizing features of this pattern of cerebral infarction in 13 patients, some of whom had occlusion of large arteries in the neck, and defined the resulting clinical picture. They also found that morphological changes in small pial vessels in such patients are secondary to the hemodynamic disturbance and are not indicative of a different disease. A topographic vulnerability within the spinal cord related to such “critical zones” of vascular supply has been emphasized by Ziilchs since his earliest report. However, spinal cord infarction is relatively infrequent, and due to the difficulties in investigating completely the extravertebral arterial supply, the few cases studied pathologically have not resulted in a clear understanding of all the hemodynamic factors involved. The present authors had the opportunity to study clinically and pathoIogicalIy an instance of paraplegia following resection of a ruptured arteriosclerotic aneurysm of the abdominal aorta with survival of three weeks. A thorough pathological study was performed including examination of the intercostal, lumbar, radicular, and spinal arteries. The aim of this com-

State resembling akinetic mutism in basilar artery occlusion

AKINETIC AIUTISM is the name given by Cairns and associates’ to a clinical state described in a patient with epidermoid cyst of the third ventricle. The patient showed almost complete absence of speech, voluntary movement, and emotional expression. However, having retained optic fixation and following movements of the eyes in response to visual and auditory stimuli, the patient had an appearance of alertness which contrasted strikingly with her silence and general immobility. The authors emphasized that the disturbance of movement was not caused by paralysis in the ordinary sense of the word. They concluded that in their patient the disorder was produced by pressure exerted by the cyst on structures situated in the walls of the third ventricle, possibly on hypothalamic-thalaniic connections. Denny-Brown2 pointed out that akinetic mutism associated with dystonia occurs characteristically in patients with severe bilateral lesions of the globus pallidus. He found the lesions affecting the inner segments of these nuclei to produce severe akinesia and only mild rigidity. Akinetic mutism without dystonia but with loss of visual fixation was described by Denny-Brown3 as a result of damage to the superior colliculi. A clinical state resembling akinetic mutism has been observed in a few patients with occlusion of the basilar artery.4-1‘’ The disorder has been attributed by some authors5.7 to infarc tion of the long-descending motor tracts, but they did not attempt to explain the preservation of the eye movements. Other investigatorss believed the clinical picture to be clue to infarction of the reticular substance. The anatomical basis for the disorder is difficult to analyze in many of these cases, since some patients survived for too short a period of time,

Localization of theta alloantigens in mouse brain by immunofluorescence and cytotoxic inhibition

Summary The indirect fluorescent antibody and the cytotoxic inhibition techniques were used to localize theta alloantigens in adult mouse brain. The procedure was validated critically by genetic specification of brain tissue and antiserum, as well as by the standard immunologic blocking and deletion tests. Reactive sites were demonstrated in white matter tracts such as corpus callosum, internal capsule, penetrating tracts of the caudate/putamen, fimbria of the hippocampal formation and central white matter at the cerebellar folia. In addition reactive sites were demonstrated in cells of various sizes from the cerebral gray matter. Both the white and gray matter localizations were confirmed by cytotoxic inhibition tests.

Reversal of Enzymatic Profiles and Capillary Supply of Muscle Fibers in Fast and Slow Muscles After Cross Innervation

During the past decade histochemical studies have contributed much to our understanding of skeletal muscle. As a result of these investigations it has become possible to bring together in a meaningful way some very basic observations from anatomy, physiology, and biochemistry. It is weil known by now that the marimialian skeletal muscles are composed of a number of fiber types which differ in enzymatic activity. In every type of fiber the activities of the enzymes of glycolysis are inversely proportional to the activities of the enzymes of oxidative and lipid metabolism1,2,3. These differences indicate that some muscle fibers derive their energy of contraction mostly by anaerobic glycolysis while others obtain it chiefly by oxidative breakdown of lipids and other compounds.