Symptomatic compression of the optic nerve by the carotid artery: clinical profile of 18 patients with 24 affected eyes identified by magnetic resonance imaging.

OBJECTIVE: To characterize the clinical features and course of patients with magnetic resonance imaging (MRI)-defined optic nerve compression by the supraclinoid carotid artery. DESIGN: Retrospective, observational case series. PARTICIPANTS: Eighteen patients with 24 affected eyes were identified by reviewing case records from the author's referral-based neuro-ophthalmology practice. Predetermined inclusion and exclusion criteria were applied to potential participants. MAIN OUTCOME MEASURES: The following variables were abstracted from the medical record: age, gender, presenting symptoms, past medical problems, visual acuity, color vision, visual field, pupillary reactions, optic disc appearance, other neurologic signs, and previously documented and follow-up examinations. RESULTS: There were eight women and ten men ranging in age from 28 to 86 years (median age, 72 years) at the time of diagnosis. Ten (56%) of 18 patients had hypertension. Twelve patients had unilateral optic neuropathy, whereas 6 patients had bilateral optic neuropathy. One patient presented with subacute superior orbital fissure syndrome due to mass effect of a dolichoectatic carotid artery. Another patient had oculomotor nerve palsy with signs of aberrant regeneration due to intracavernous mass effect of a dolichoectatic carotid artery. One patient had a bitemporal hemianopia associated with bilateral compression of the immediate prechiasmatic optic nerves by dolichoectatic carotid arteries. The predominant pattern of visual field loss in most patients reflected nerve fiber bundle injury. A central scotoma or absolute central visual field loss was noted in only 6 (25%) of 24 affected eyes. Most patients demonstrated saucerlike excavation of the optic disc. Progression of visual acuity loss occurred at a relatively slow rate. CONCLUSIONS: Although uncommon, intracranial compression of the optic nerve by the carotid artery should be considered in a patient with unexplained or progressive unilateral or bilateral optic neuropathy. This entity can be diagnosed using clinical skills to exclude more common causes of optic nerve injury and coronal-oriented MRI to confirm anatomic compression of the symptomatic optic nerve. Although many affected patients have excavation of the optic disc and nerve fiber bundle visual field defects, most have additional signs atypical for glaucoma, minimizing the potential for diagnostic confusion between the two disorders.     

Reserpine as an uncoupler of oxidative phosphorylation and the relevance to its psychoactive properties

Many drugs differing widely in chemical structure uncouple mitochondrial oxidative phosphorylation in vitro. This observation has led to the hypothesis that in vivo uncoupling is the basis of their pharmacological activity. Serpasil, a parenteral preparation of reserpine, recently has been shown to uncouple oxidative phosphorylation in vervet monkey kidney mitochondria. Although the drug exhibits some properties of a "classical" uncoupler, our studies show that it has a dual effect on energy conservation. Reserpine released respiratory control in rat liver mitochondria only when dissolved in organic solvents (as in Serpasil) or when deprotonated. Reserpine also released the oligomycin-induced respiratory control in beef heart submitochondrial particles, and inhibited energized uptake of Ca2- by rat liver mitochondria. Reserpine had a dual effect on mitochondrial ATPase: It (a) enhanced ATP hydrolysis by intact liver mitochondria, and (b) inhibited ATP hydrolysis by submitochondrial particles of beef heart. On a molar basis, reserpine was less effective than carbonyl cyanide 3-chlorophenylhydrazone in all bioenergetic reactions examined. Homogenates and mitochondria isolated from brain and liver of rats stuporous from intraperitoneally injections of Serpasil exhibited no detectable abnormalities in respiratory states and responded to known uncouplers in the expected manner. There was no evidence of in vivo uncoupling of oxidative phosphorylation as a basis of the pharmacological activity of reserpine, although interference with energy transfer may be involved in toxic manifestations of the drug. The results indicate the need for caution in interpreting the action of drugs formulated in complex pharmaceutical preparations and based solely on in vitro experiments.     

Subtotal colectomy for obstructing carcinoma of the left colon

This retrospective review of seven patients with completely obstructing cancers of the left half of the colon, in addition to other reports in the literature, suggests that subtotal colectomy with primary ileal

1 Clinical data on seven patients who underwent subtotal colectomy for obstructing carcinoma of the left colon: 1975–1982.

Patient	Age (yr) and Sex	Tumor Location	Hospital Stay	Comments
1	68, F	Decending	10 days	A and W 40 mo postop1
2	71, F	Sigmoid	22 days	A and W 18 mo postop
3	73, F	Sigmoid	…	A and W 5 yr postop
4	66, F	Decending	8 mo	Dead from complications
5	72, M	Sigmoid	11 days	Incidental cecal cancer; A and W 3 mo postop
6	66, M	Sigmoid	28 days	Alive with metastasis 16 mo postop
7	78, M	Left transvers	34 days	Many other polyps; A and W 9 mo postop

1

A and W = alive and well.

proctostomy may be the treatment of choice for those lesions that are technically resectable and located high enough to permit an intraperitoneal ileal proctostomy. The morbidity and mortality is less than that seen with the staged approach and the length of hospitalization is shorter. By eliminating a second or third hospitalization and a temporary colostomy, palliation is better in those patients who ultimately die from recurrent cancer. Furthermore, those patients resected for cure may have increased rates of long-term survival.     

A comparison of digital subtraction angiography and noninvasive testing in the diagnosis of cerebrovascular disease

Among the 1,892 patients who underwent cerebrovascular digital subtraction angiography at our hospital over the past 18 months, there was a subgroup of 34 patients (65 carotid arteries) for whom noninvasive cerebrovascular test results and standard cerebral arteriograms were also available. These patients were reviewed retrospectively and the ability of both methods to detect hemodynamically significant lesions, defined as a greater than 50 percent reduction in the diameter of the carotid artery, was determined using the arteriograms as the "gold standard." Noninvasive cerebrovascular tests had a sensitivity of 81 percent, a specificity of 95 percent, a positive predictive value of 92 percent, a negative prediction value of 88 percent, and an overall accuracy of 89 percent. Digital subtraction angiography had a sensitivity of 84 percent, a specificity of 92 percent, a positive predictive value of 88 percent, a negative predictive value of 89 percent, and an overall accuracy of 89 percent. If the four cases of hemodynamically significant stenosis of the carotid siphon not detected by digital subtraction angiography had been considered as false-negatives, its sensitivity would have been reduced to 72 percent. In patients with hemispheric cerebral ischemia, we found noninvasive cerebrovascular tests neither necessary nor cost-effective. Digital subtraction angiography, on the other hand, often provided definitive diagnostic information in such patients if the intracranial circulation was well defined and the extracranial lesion corresponded to the patients' symptoms. Noninvasive cerebrovascular testing was the safest and most cost-effective technique for screening patients with asymptomatic bruits, atypical, nonhemispheric cerebral symptoms, and those who have undergone carotid endarterectomy. If the noninvasive cerebrovascular test result was positive or equivocal, digital subtraction angiography was performed to localize the responsible lesion and exclude carotid occlusion.     

Do bilineal pedigrees represent a problem for linkage analysis? basic principles and simulation results for single-gene diseases with no heterogeneity

Some investigators have expressed concern--especially for psychiatric disorders--that bilineal pedigrees should not be included in linkage studies. This study compares the "informativeness" of bilineal and unilineal families for a homogeneous single-gene disorder. Three approaches were used: (1) simulation studies of three-generation pedigrees, (2) calculation of expected lod scores (ELODs) in nuclear families, and (3) calculation of Fisher's information number I(theta) in nuclear families. The simulation studies in (1) permitted a realistic comparison between bilineal datasets and purely unilineal ones. The calculations in nuclear families in (2) and (3) then made it possible to analyze the sources of information loss in bilineal families. Overall, in datasets of five three-generation pedigrees each, the drop in mean maximum lod score was approximately 50% from purely unilineal datasets to extremely bilineal ones. In less-extreme bilineal datasets, which are closer to most real data than the extremely bilineal ones, the drops in lod score were very small--less than 10% in some, and practically zero in others. The details will vary, depending on size and structure of the pedigree, genetic model, true value of the recombination fraction, and informativeness of the marker. However, these results imply that the information loss due to bilineality is not necessarily very great. The nuclear-family calculations showed that for phase-known matings there is relatively little information loss in bilineal families, but for phase-unknown matings there the loss is much greater. In conclusion, for single-gene disorders with no genetic heterogeneity, whereas bilineal families can be less informative than comparable unilineal families, they are not so much less informative that they should automatically be discarded from linkage datasets. The implications of bilineal pedigrees for linkage studies of heterogeneous disorders are also discussed.     

Adenoid cystic carcinoma: factors influencing survival.

We have reviewed our experience with 264 patients treated for adenoid cystic carcinoma of salivary origin. This study updates a previous report from our hospital and includes all patients treated during a 30 year period who were eligible for a minimum follow-up of 10 years. The tumor arose in minor salivary (mucous) glands in two thirds of the patients; half had received treatment elsewhere, and both sexes were equally represented. Actuarial survival curves and "cure" rates calculated by the direct method confirm that clinical staging provides a reliable prognostic guide. We are unable to demonstrate that the microscopic appearance of the tumor exerts a predictable effect on treatment results. Although some patients lived for many years after resection despite local recurrence and distant metastases, prolonged survival was unusual in patients with stage 3 lesions, particularly in those with sinus or submaxillary gland primaries. Based on the site of origin of the tumor and its clinical stage, it is now possible to select which patients with adenoid cystic carcinoma have the most ominous prognosis and perhaps plan a more appropriate operation. More importantly, these data may help focus on the subpopulation at greatest risk, which is vital to the design of any prospective study to assess the value of adjunctive irradiation and chemotherapy.     

Duodenal and jejunal atresia with agenesis of the dorsal mesentery: "apple peel" small bowel.

Two newborn infants with duodenal and jejunal atresia and agenesis of the dorsal mesentery represent our surgical experience with "apple peel" small bowel or "christmas tree" demormity. The first patient had the typical appearance of this condition. The postoperative course was complicated by hyperbilirubinemia, septicemia, and disseminated intravascular coagulation. The infant is in satisfactory condition 1.5 years after operation. The second patient had agenesis of the dorsal mesentery without spiraling of the bowel around its vascular stalk. The child died after 1 month, with complete absence of extrahepatic bile ducts as seen at a second laparotomy. Neither child had been subjected to gastrostomy.     

Evaluation of the results of external choledochoduodenostomy for retained, recurrent, or primary common duct stones.

Twenty-five patients were treated for retained, recurrent, or primary common duct stones by permanent drainage of the biliary tract with external choledochoduodenostomy. Twenty-one patients had common duct stones which became evident two to fifty years after the initial biliary tract procedure and which may represent stones formed in the common duct. Three recent patients had a clinical history of primary common duct stones, had stones which were soluble in chloroform-methanol solution, and had hepatic bile which was lithogenic as determined by evaluating the molar percentage of cholesterol, phospholipid, and bile salt in bile samples obtained at the time of choledochoduodenostomy. These data suggest that further stone formation is possible and that permanent bypass of the sphincter of Oddi is indicated to prevent recurrent bile duct obstruction. Long-term evaluation of the results of external choledochoduodenostomy indicates that the procedure is safe and effective in the prevention of recurrent biliary tract calculi.     

Prosthetic arteriovenous fistula for vascular access in hemodialysis.

Vascular access through subcutaneous prosthetic arteriovenous fistulas was studied in eighteen dogs. Dacron velour and woven Dacron grafts (6 mm diameter) were constructed across the lower abdomen between the common femoral artery and the opposite common femoral vein. In heparinized animals 197 percutaneous punctures were made with a "14 guage hemodialysis cannula at weekly intervals. Over a period of one and a half years there was no instance of infection. One of the fourteen Dacron velous and all four woven Dacron fistulas thrombosed. These data suggested the feasibility of achieving repetitive blood access through Dacron velour vascular prostheses. Nineteen Dacron velour fistula bypasses between the brachial artery and median basilic vein were performed in fifteen selected patients for a total dialysis period of ninety-six months. Failed standard subcutaneous fistulas or absence of suitable vessels in the upper extremity were indications for the primary procedure. Of three looped forearm fistulas, two thrombosed at twenty-two and two months. Complications among sixteen straight bypasses in the arm included two graft infections and one cannula tract infection. There were no instances of thrombosis in this group. The advantages of single needle dialysis in these high risk patients have been emphasized. Eleven grafts are presently functioning two to nine months postoperatively. Our preliminary results suggest that a Dacron velour fistula merits consideration as an alternative for vascular access in maintenance hemodialysis.