Evidence on magnetic resonance (MR) images of disk degeneration and herniation, as well as of cord and root impingement, may be regarded either as normal, age-related changes or as causative of symptoms. Individuals referred for MR examinations of the larynx without symptoms referable to the cervical spine were studied retrospectively (35 patients) or prospectively (65 patients) over a 2-year period. With a solenoid surface coil, 5-mm-thick sections were acquired in sagittal, axial, and coronal planes with T1-weighted spin-echo pulsing sequences. Disk protrusion (herniation/bulge) was seen in five of 25 (20%) patients aged 45-54 and 24 of 42 (57%) patients older than 64 years of age. Posterolateral protrusions were seen in only nine of 100 patients and occurred with greatest frequency in patients over 64 years of age. In no patient was obliteration of the intraforaminal fat seen. Spinal cord impingement was observed in nine of 58 (16%) patients under 64 years of age, and in 11 of 42 (26%) patients over 64 years of age. Cord compression was observed in seven of 100 patients and occurred solely secondary to disk protrusion in all cases. The percentage of cord area reduction never exceeded 16% and averaged approximately 7%.
Angiographic and clinical data from 155 patients with carotid cavernous fistulae were retrospectively reviewed to determine angiographic features associated with increased risk of morbidity and mortality. These features included presence of a pseudoaneurysm, large varix of the cavernous sinus, venous drainage to cortical veins, and thrombosis of venous outflow pathways distant from the fistula. Clinical signs and symptoms that characterized a hazardous carotid cavernous fistula included increased intracranial pressure, rapidly progressive proptosis, diminished visual acuity, hemorrhage, and transient ischemic attacks. Cortical venous drainage from the carotid cavernous fistula is secondary to occlusion or absence of the normal venous outflow pathways and is associated with signs and symptoms of increased intracranial pressure and an increased risk of intraparenchymal hemorrhage. Angiographic demonstration of a cavernous sinus varix, with extension of the sinus into the subarachnoid space, is associated with an increased risk of fatal subarachnoid hemorrhage. Identification of these high-risk features provides a basis for making decisions about treatment.
Thirty symptomatic indirect carotid cavernous fistulas were treated between 1978 and 1986 with a variety of treatment modalities. Combined carotid artery and jugular vein compression resulted in a complete cure in seven of 23 patients (30%) and improvement in one additional patient. There were no complications from this treatment, which is performed by the patient on an outpatient basis. Patients in whom carotid jugular compression therapy failed or who demonstrated cortical venous drainage or visual decline were treated with intravascular embolization. Embolization resulted in complete cure in 17 of 22 (77%) and improvement in four of 22 (18%). One patient required surgical excision of the involved dura after embolization to achieve complete cure. There was one permanent complication (stroke), which resulted in mild weakness caused by clot formation on a catheter.
To associate the identical drug state with both a loeation and a flavor, rats were given intraperitoneal amphetamine injeetions and then eonfined for 20 min in one side of a shuttlebox with aecess to a flavored solution; on control trials without injections, they were confined for 20 min in the opposite side with a different flavor. In the first experiment, the rats were plaeed in the shuttlebox immediately after injections; in the second experiment, they were placed in the shuttlebox 20 min after injections. Subsequent free-choice tests in both experiments revealed an increased choice of the side of the shuttlebox associated with amphetamine but also an aversion to the flavored solution associated with the drug.In attempts to eharaeterize the reinforeing properties of abused drugs, a paradox has arisen. Cappell and l..e Blane (1973) found aversive taste eonditioning by intraperitoneal amphetamine within the range of doses which Pickens and Harris (1968) found rats would selfinjeet intravenously. Thus, a single pharmaeologieal stimulus may aet as both a positive and a negative reinforeer depending on the associated stimuli and responses.Wise, Yokel, and deWit (1976) pointed out, however, that these seemingly paradoxical effeets eould be explained by differenees in proeedural variables such as route of drug administration, extent of drug habituation, and delay of reinforeement. Wise et al. therefore attempted to eontrol for these faetors in demonstrating positive and negative reinforeement by intravenous amphetamine and apomorphine. Their first experiment circumvented habituation diffieulties by giving rats that had previously shown amphetamine self-administration a IO-min exposure to saccharin followed by an amphetamine injection. A subsequent test indicated moderate suppression of saccharin drinking. However, as the report aeknowledges, this does "not ... establish that a particular drug injection can be both reinforcing and aversive" (p. 1273). The difficulty is that positive reinforcement was demonstrated by self-adrninistered amphetamine immediately following leverpressing, while negative reinforcement was demonstrated by a single, experimenter-administered amphetamine injection given only after a IO-min drinking period. In the second experiment by Wise et al., rats previously trained to selfadminister amphetamine were given aceess to saccharin followed immediately by an apomorphine self-injection session. Some of the rats continued to leverpress for apomorphine, yet subsequently showed an aversion to the saccharin. As Wise et al. mentioned, however, there were still difficulties in this proeedure, including the difference in the delay of reinforcement for leverpressing and saccharin-drinking, as weIl as the possible ambiguity created by first training the rats to self-administer amphetamine and then suddenly switching to apomorphine.The present experiments avoided some of these problems by associating the same injections with a compound stimulus consisting of a distinctive flavor and a distinctive loeation...
Intraoperative digital subtraction angiography using commercially available equipment was employed to confirm the precision of the surgical result in 105 procedures for intracranial aneurysms or arteriovenous malformations (AVM's). Transfemoral selective arterial catheterization was performed in most of these cases. A radiolucent operating table was used in all cases, and a radiolucent head-holder in most. In five of the 57 aneurysm procedures, clip repositioning was required after intraoperative angiography demonstrated an inadequate result. In five of the 48 AVM procedures, intraoperative angiography demonstrated residual AVM nidus which was then located and resected. In two cases intraoperative angiography failed to identify residual filling of an aneurysm which was seen later on postoperative angiography, and in one case the intraoperative study failed to demonstrate a tiny residual fragment of AVM which was seen on conventional postoperative angiography. Two complications resulted from intraoperative angiography: one patient developed aphasia from cerebral embolization and one patient developed leg ischemia from femoral artery thrombosis. This technique appears to be of particular value in the treatment of complex intracranial aneurysms and vascular malformations.
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