Neuropsychometric changes in patients after carotid endarterectomy

BACKGROUND AND PURPOSE: One hundred twelve patients undergoing elective carotid endarterectomy for symptomatic and asymptomatic carotid artery stenosis were enrolled in a prospective study to evaluate the incidence of change in postoperative cerebral function. METHODS: Patients were evaluated preoperatively and postoperatively before hospital discharge and at follow-up 1 and 5 months later with a battery of neuropsychometric tests. The results were analyzed by both event-rate and group-rate analyses. For event-rate analysis, change was defined as either a decline or improvement in postoperative neuropsychometric performance by 25% or more compared with a preoperative baseline. RESULTS: Approximately 80% of patients showed decline in one or more test scores, and 60% had one or more improved test scores at the first follow-up examination. The percentage of declined test scores decreased and the percentage of improved test scores increased with subsequent follow-up examinations. Group-rate analysis was similar for group performance on individual tests. However, a decline in performance was seen most commonly on verbal memory tests, and improved performance was seen most commonly on executive and motor tests. CONCLUSIONS: Neuropsychometric evaluation of patients undergoing carotid endarterectomy for significant carotid artery stenosis demonstrates both declines and improvements in neuropsychometric performance. The test changes that showed decreased performance may be associated with ischemia from global hypoperfusion or embolic phenomena, and the improvement seen may be related to increased cerebral blood flow from removal of stenosis.     

Simultaneous determination of azathioprine and 6-mercaptopurine by high-performance liquid chromatography

We investigated whether linear whole-body acceleration along the interaural y-axis influenced the concurrent perception of visual motion direction as has been shown for angular accelerations. A sled running on air bearings along a 7.5-m track was used to accelerate 18 subjects at two different linear accelerations. These young, healthy volunteers, aged 25.50 +/- 7.38 years, used a joystick to indicate whether or not they perceived visual motion to the left within a random-dot kinematogram continuously presented on a monitor moving with them. The percentage of coherently leftward moving pixels presented for a 640-ms period during acceleration was adjusted according to a Modified Binary Search (MOBS) procedure. Six conditions were tested, two acceleration levels of 1 and 2 m/s2 to both left and right with, at the higher acceleration, two different times of visual motion presentation. Conditions were sequenced by means of a 6 x 6 Latin square balanced for order and carry over. A MANOVA did not show any statistically significant effects either for the independent variables acceleration, velocity, and direction of motion of the sled or for their interactions. The results obtained are in clear contrast to those obtained under rotatory stimulation. We conclude that the otolithic contribution to vestibular-visual motion processing is negligible.     

Growth of callosal terminal arbors in primary visual areas of the cat

In kittens ranging in age between postnatal day (P) 5 and P150, callosal axons originating near the 17/18 border were anterogradely labelled with biocytin and reconstructed from serial sections. At the end of the first postnatal week most of the axons begin to invade the cortex near the 17/18 border with multiple branches; some axons already span the grey matter up to layer 1. Branches tend to grow into the grey matter in loose bundles 相似文献   

Chronic demands and responsivity to challenge

Certain kinds of arousal in response to challenge situations reflect conditioning that makes one adaptive to task demands. A growing literature implicates chronic stress as a factor degenerating this conditioning. This study investigated the relation between objective occupational demands to which workers were classified for at least 2 years and various indicators of adaptive responsivity to challenge situations. There were consistently significant and negative relations between the occupational exposures and cardiovascular and skin temperature responsivity to the acute challenges administered in the laboratory, the corresponding speed of recovery to baseline after removal of the challenge stimulus, and peripheral catecholamine changes during a work shift.