Intracerebral venous hemorrhage in "high-risk" carotid-cavernous fistula

Intracerebral hematoma associated with carotid-cavernous fistula is a rare occurrence. Based on a review of the literature and on the analysis of personal observation, the authors define as "high-risk fistula" a carotid-cavernous fistula at risk of intracerebral hemorrhage. Characteristic features of these are computed tomography demonstration of parenchymal vermicular enhancement of brain vessels, and an angiographic pattern of dilated and tortuous cerebral veins. When an intracerebral hemorrhage occurs in a patient with carotid-cavernous fistula an early but phased and combined neuroradiological-neurosurgical approach is suggested as the best way to treat this life-threatening situation.     

Aging and the development of automaticity in conjunction search

In two experiments, younger and older observers carried out feature searches for targets defined by their luminance contrast and orientation. Additionally, they received consistent-mapping (CM) training in luminance contrast by orientation conjunction search, followed by a brief exposure to conjunction search under reversal conditions. In Experiment 1, display size effects on reaction time suggested that both younger and older observers were conducting a parallel search in all conditions and showed equivalent disruption at reversal. Experiment 2 was a substantive replication of the first using more difficult conjunction search displays. In addition to latency, we measured the number, duration, and feature-based selectivity of fixations made during conjunction search. Display size effects were larger than in Experiment 2 and were of equivalent magnitude in younger and older people. There were no age differences in improvement in conjunction search and minimal age differences in disruption following reversal. Both age groups demonstrated early in training that they could select items possessing target features (i.e., the color white), and both age groups demonstrated that they could not completely reverse this selectivity when these features no longer defined the target. These experiments have several implications for models of visual attention and age differences therein.     

Age, skill transfer, and conjunction search

Ten younger and ten older adults were provided with 16 sessions of conjunction search under consistent mapping, where target and distractors remain constant in identity. The target and one distractor were reversed after every fourth session. After the first four training sessions, on target-present trials, display size slopes were near zero for both age groups. However, on target-absent trials, older adults continued to show significantly larger display size effects than younger adults. There were no systematic age differences in either the probability of fixating objects that possess the target's features or in the amount of disruption at any reversal. Thus, although older adults exhibited more conservative criteria in visual search, they developed proficient and flexible search skill to the same degree as their younger counterparts. These data have implications for models of visual attention, skill acquisition, and cognitive aging.     

Adult age differences in the time course of inhibition of return

Inhibition of return (IOR) occurs when people are slower to detect a target that appeared at a previously cued location. Prior research has shown that younger and older adults display similar amounts of IOR, but this research has not examined the time course of the process. Because elderly people may be slower to engage or disengage spatially based attention, the present experiment examined age differences in IOR at stimulus-onset asynchronies ranging from 50 ms to 3,000 ms. The results show that the peak magnitude of IOR was similar for younger and older adults, but the onset of IOR occurred approximately 300 ms later in elderly persons. Older adults also showed a greater degree of facilitation at shorter stimulus-onset asynchronies. The results suggest that there is a change in the temporal dynamics of inhibition that occurs with age.     

The arteries of the roof of the fourth ventricle

Summary This is an anatomical and radiological study based on an examination, in the lateral and 4 frontal projections, of the brainstem and cerebellum in 70 subjects.     

The value of direct percutaneous puncture technique in vertebral angiography

Summary The authors perform vertebral angiography with three techniques: 1. percutaneous puncture of the vertebral artery; 2. percutaneous puncture of the brachial artery; 3. catheterization via the femoral artery. In both vascular and neoplastic lesions of the posterior fossa the best results are obtained with the first technique, which, in expert hands, gives the same percentage of successful examinations as the other two methods. In the great majority of cases direct percutaneous vertebral angiography must be performed on both sides.

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Der Wert der direkten percutanen Punktion bei der Vertebralisangiographie

Zusammenfassung Die Verfasser geben ihre Anschauung wieder, daß sowohl bei vasculären als auch bei raumfordernden Prozessen im Bereich der hinteren Schädelgrube die besten Untersuchungsresultate erzielt werden, wenn die A. vertebralis direkt punktiert wird. Sie vergleichen diese Untersuchungsmethode mit der percutanen Punktion der A. brachialis und der Kathetermethode über die A. femoralis.

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La valeur de la technique de ponction percutanée directe en angiographie vertébrale

Résumé Les auteurs pratiquent l'angiographie vertébrale selon trois techniques: 1. La ponction percutanée de l'artère vertébrale. 2. La ponction percutanée de l'artère brachiale; 3. La cathétérisation par l'artère fémorale.—Tant dans les lésions vasculaires que dans les lésions néoplasiques de la fosse postérieure, les meilleurs résultats furent obtenus à l'aide de la 1ère technique qui, pratiquée par des mains expertes, donne le même pourcentage de résultats satisfaisants que les deux autres méthodes. Dans la grande majorité de cas de ponctions percutanées, l'angiographie vertébrale dut être réalisée des deux côtés.

     

Lesions of the dorsomedial hypothalamic nucleus do not influence the daily profile of pineal metabolism in rats

The present study attempted to characterize the effects of electrolytic lesions of the hypothalamic dorsomedial nucleus on the daily profile of pineal metabolism as well as on the inhibition of pineal melatonin synthesis induced by acute light exposure during the night. Adult male Wistar rats (n = 107, 12:12 h light-dark cycle) were left intact (n = 47) or lesioned (n = 60). Lesioned rats and their respective controls were killed at six time points distributed throughout the light-dark cycle. At ZT (zeitgeber time) 18 the animals were killed either in the dark or after 15 min of light stimulation. Pineal glands were assayed using high-performance liquid chromatography with electrochemical detection (HPLC-ED). There was no difference in the amounts of pineal indoles between lesioned and control rats under any of the experimental situations tested. These results suggest that in rats, the hypothalamic dorsomedial nucleus does not participate in either the neural control of daily pineal metabolism or the nocturnal light-induced inhibition of the pineal metabolism.     

Age differences in Vistech near contrast sensitivity

Contrast sensitivity was measured at near using the Vistech 6000 Contrast Test System (VCTS) in 287 persons aged 4 to 87 years. Obtained data compared well with those previously reported for the Vistech charts. Results indicate an age-related loss in sensitivity to intermediate and higher spatial frequencies. This is consistent with the age trends observed using other methods for measuring contrast sensitivity functions (CSFs). However, the Vistech charts yield contrast sensitivity values which are lower than those obtained previously with the Nicolet system. These between-method differences are greatest at lower spatial frequencies, and are attributed to the small number of grating cycles in the Vistech charts. The data are used to develop provisional age norms for the Vistech charts which allow the assessment of an individual's performance relative to their age cohort. Recommendations for use and future development of the Vistech charts are also given.