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Biomedical subjects

S A Cross

Publications and source records attributed to S A Cross.

At least 19 recordsLinked to original sources
PubMed2001

A randomized trial of intravenous immunoglobulin in inflammatory demyelinating optic neuritis.

OBJECTIVE: To determine whether IV immunoglobulin (IVIg) reverses chronic visual impairment in MS patients with optic neuritis (ON). METHODS: In this double-blind, placebo-controlled Phase II trial, 55 patients with persistent acuity loss after ON were randomized to receive either IVIg 0.4 g/kg daily for 5 days followed by three single infusions monthly for 3 months, or placebo. RESULTS: The trial was terminated by the National Eye Institute because of negative results when 55 of the planned 60 patients had been enrolled. Fifty-two patients completed the scheduled infusions, and 53 patients completed 12 months of follow-up. Analysis of this data indicated that a difference between treatment groups was not observed for the primary outcome measure, improvement in logMAR visual scores at 6 months (p = 0.766). Exploratory secondary analyses suggested that IVIg treatment was associated with improvement in visual function (including logMAR visual scores at 6 months and visual fields at 6 and 12 months) in patients with clinically stable MS during the trial. CONCLUSIONS: IVIg administration does not reverse persistent visual loss from ON to a degree that merits general use.

Adult↗
PubMed1997

Sarcoid masquerading as optic nerve sheath meningioma.

Sarcoid manifesting as an optic nerve tumor without evidence of systemic disease is uncommon. Throughout a 2-year period, a 22-year-old white woman had progressive monocular loss of vision to the level of no light perception. Optic atrophy but no uveitis was noted in the affected eye. Magnetic resonance imaging revealed thickening and enhancement of the apical optic nerve, with "tram-tracking." The presumptive diagnosis was optic nerve sheath meningioma; however, a biopsy specimen from the optic nerve revealed sarcoid. Extensive postoperative investigations revealed no systemic sarcoidosis. To our knowledge, 17 cases similar to ours, with the diagnosis proved by optic nerve biopsy, have been previously reported in the English-language literature. Most of these were mistaken preoperatively for optic nerve sheath meningioma. None of the patients had evidence of systemic sarcoidosis on initial postoperative testing. Neuroimaging, serum level of angiotensin-converting enzyme, and clinical characteristics such as age, race, sex, and optochoroidal collaterals do not distinguish optic nerve sheath meningioma from sarcoid of the optic nerve. In the absence of uveitis or systemic involvement, optic nerve sarcoid manifesting as an orbital tumor is virtually impossible to diagnose without results of biopsy.

Adult↗
PubMed1995

Optic neuritis: a population-based study in Olmsted County, Minnesota.

We reviewed the records of all patients with optic neuritis (ON) in Olmsted County, Minnesota, identified through the comprehensive records-linkage system at the Mayo Clinic, and identified 156 ON patients from 1935 to 1991 who had onset of the disease while residing in Olmsted County (incidence cases). Poisson regression analysis revealed that age, gender, and calendar year were associated with incidence. The annual age- and sex-adjusted incidence rate was 5.1 per 100,000 person-years from 1985 to 1991. On December 1, 1991, 128 patients with a documented history of ON resided in Olmsted County (prevalence cohort). The age- and sex-adjusted prevalence rate per 100,000 was 115. The average length of follow-up for the incidence cohort was 13.2 years. Life table analysis showed that 39% of the 95 patients with isolated ON in the incidence cohort had progressed to clinically definite multiple sclerosis (MS) by 10 years of follow-up, that 49% had by 20 years, 54% by 30 years, and 60% by 40 years. There was no difference in the risk of developing MS between men and women. The presence of venous sheathing (p = 0.044) and evidence for recurrent ON (p < 0.0001) were associated with an increased likelihood of developing MS. The estimated 25-year survival rate was 88.3% +/- 5.8% for the incidence cohort with isolated ON, compared with 83.9% for the general US population of similar age and sex.

Adolescent↗
PubMed1994

Pathophysiology of pain.

OBJECTIVE: To review the pain pathways in the central and peripheral nervous system and the actions of drugs used to treat pain. DESIGN: An overview of pain pathways is presented, beginning in the periphery and progressing centrally, and the ascending and descending pathways are described in detail. RESULTS: The nociceptive pathway, consisting of the classic three-neuron chain, is now understood to be a dual system at each level, and the sensation of pain is thought to arrive in the central nervous system with the discriminative component of pain ("first pain") carried separately from the affective-motivational component of pain ("second pain"). In addition to spinal control mechanisms of nociceptive transmission, descending pathways that originate in three major areas--the cortex, thalamus, and brain stem--can modify functions at the spinal level. At every level of the nervous system, a close relationship prevails between somatic pain pathways and visceral pathways. This relationship likely accounts for the transmission of visceral pain and also for autonomic responses to somatic pain and somatic responses to visceral pain. CONCLUSION: By understanding the pathways of pain and the transmitters involved, prevention and treatment of pain will be improved.

Afferent Pathways↗
PubMed1993

Idiopathic intracranial hypertension (pseudotumor cerebri). Descriptive epidemiology in Rochester, Minn, 1976 to 1990.

The medical records-linkage system of the Mayo Clinic was used to identify cases of idiopathic intracranial hypertension in the 15-year period, 1976 through 1990, among the population of Rochester, Minn. Nine patients (eight women and one man) were identified, corresponding to an average annual age-adjusted incidence rate per 100,000 of 0.9 for the total and 1.6 for the female population. In females aged 15 to 44 years, idiopathic intracranial hypertension occurred at a rate of 3.3 per 100,000 per year; for those defined as obese (body mass index > 26), the rate rose to 7.9. Median follow-up was 2.7 years (range, 5 months to 15 years). Three of 18 eyes developed visual impairment; this was mild in all cases.

Adolescent↗
PubMed1993

Incidence and clinical significance of anaerobic bacteremia in a community hospital.

The importance of performing anaerobic blood cultures on a routine basis has been questioned in recent reports; this prompted us to review data on episodes of anaerobic bacteremia that have occurred in our 350-bed community hospital. In 1991, 771 of 7,397 blood cultures yielded bacteria or fungi; 569 (7.7%) were true positive cultures, 35 (6.2%) of which yielded 48 anaerobic isolates from 20 patients. The charts of these patients were reviewed, and it was determined that 16 of the patients had significant anaerobic bacteremia. The outcome was fatal for seven (44%) of these 16 patients, including two who died before results were reported. The results of blood culture led to a change of antimicrobial therapy for nine (56%) of the 16 patients. The source of infection was obvious for 11 of the 16 patients, and 50% of patients were receiving antimicrobial agents active against anaerobes before culture results were obtained. Although anaerobic bacteremia is uncommon in our hospital, positive culture results often resulted in a change in antimicrobial therapy.

Adult↗
PubMed1991

Ischemic injury to the spinal cord or lumbosacral plexus after aorto-iliac reconstruction.

Between January 1, 1980, and June 30, 1989, 9 patients (6 males and 3 females) developed ischemic injury to the spinal cord or lumbosacral plexus following 3,320 operations on the abdominal aorta (0.3%). The incidence of this complication was 0.1% (2 of 1,901) after elective and 1.4% (3 of 210) after emergency abdominal aortic aneurysm repair, and 0.3% (4 of 1,209) after repair for occlusive disease. Three of the latter had prior clinical evidence of distal embolization. Eight grafts were bifurcated (aorto-iliac:four, aorto-femoral: three, aorto-ilio-femoral:one). One patient underwent extra-anatomic revascularization. Only two patients had supraceliac aortic cross-clamping and one patient underwent exclusion of both internal iliac arteries. Four patients had hypotension. Early mortality was 22% (two of nine). Severe perioperative complications, mostly due to associated visceral and somatic ischemia and sepsis, were present in seven of the nine patients. The extent and type of the neurologic injury correlated with long-term outcome. Patients with ischemic injury of the lumbosacral roots or plexus had better recovery. Attention to the pelvic circulation and the collateral blood supply is important. Use of gentle technique to prevent embolization, avoidance of hypotension and prolonged supraceliac cross-clamping, revascularization of at least one internal iliac artery, and the use of heparin may decrease but not eliminate paraplegia. Once this unexpected complication occurs, careful neurologic evaluation should be done to localize the lesion and aid prognosis.

Aged↗
PubMed1986

Therapeutic embolization angiography for extra-axial lesions in the head.

Percutaneous transcatheter arterial embolization has played an increasingly important role in the management of vascular lesions in the head. Embolization can promote thrombosis within vascular tumors and malformations, reduce bleeding and decrease the need for transfusion intraoperatively, and facilitate surgical approaches to otherwise unresectable lesions. It is important for the clinician to be aware of this interventional technique because many of the patients who are considered for embolization are triaged through several different clinical areas, and much can be gained from the collaboration of the clinician, the surgeon, and the angiographer. We performed 31 therapeutic particulate embolization procedures for extra-axial head lesions in 23 patients by using flow-directed techniques. Of these procedures, 11 resulted in vascular occlusion and 15 resulted in 80 to 95% obstruction, as demonstrated by angiography. In 14 patients, embolization was performed preoperatively both to decrease blood loss and to occlude inaccessible or unresectable portions of a lesion. In nine patients, embolization was the sole means of treatment for occluding an abnormal vascular shunt. Two patients (9%) experienced a minor transient neurologic change after the procedure.

Adolescent↗
PubMed1983

Occipital lobe infarction after open heart surgery.

The most common permanent neuro-ophthalmologic complication of cardiopulmonary bypass surgery is visual loss. Bilateral lower altitudinal visual field defects were documented in a patient who noted blurred vision following open heart surgery. A difference of opinion existed as to whether the field defects were due to retina-optic nerve or occipital lobe lesions. Two points are emphasized in this report: 1) the field defects were much easier to define on the tangent screen than on Goldman perimetry, and 2) occipital coronal high resolution CT scan confirmed bilateral upper bank calcarine cortex infarctions in this patient. Occipital coronal, thin-section, high-resolution computed tomographic scans are helpful in studying patients with occipital lobe visual field defects.

Blindness↗
PubMed1982

Crossed-quadrant homonymous hemianopsia. The "checkerboard" field defect.

A 70-year-old man with a history of hypertension and coronary artery disease suffered an abrupt loss of vision in June 1980. Neuro-ophthalmologic examination in August 1981 revealed 20/20+ acuity in both eyes, but quantitative perimetry disclosed a classic crossed-quadrant homonymous hemianopsia. This is known as the "checkerboard" visual field defect; a right upper quadrantanopsia as well as a left lower quadrantanopsia. A review of the eight previously reported cases is presented. A trial with "checkerboard" Fresnel prisms gave only a slight improvement in ambient field in this patient. The significance of that point is discussed. To our knowledge, this is the first patient with a "checkerboard" occipital lobe infarction pattern documented by computed tomography.

Aged↗
PubMed1982

Periodic alternating nystagmus clearing after vitrectomy.

Periodic alternating nystagmus 1) may be related to vestibulocerebellar system disease, 2) may occur with loss of vision, and 3) may be congenital in origin. We report the case of a patient with acquired periodic alternating nystagmus in whom the nystagmus followed bilateral vitreous hemorrhages. Upbeating nystagmus was interposed between the right beating and left beating phases. Bilateral vitrectomy resulted in the prompt disappearance of the nystagmus. The importance of visual function in relation to periodic alternating nystagmus and associated motility disturbances is emphasized.

Aged↗
PubMed1977

Localization of histamine and histamine H2-receptor antagonists in the gastric mucosa.

Histamine stimulates acid secretion by the parietal cell and this secretion is inhibited by the histamine H2-receptor antagonists. Whole body autoradiography showed that radioactivity from 14C-histamine was localized in the artery walls of the stomach and in the muscularis mucosae, but that the level in the fundic mucosa was the same as the blood. When the H2-receptor antagonists burimamide, metiamide and cimetidine were labelled with 35S, 14C or 3H and dosed to rats, whole body autoradiography showed that the stomach was predominantly labelled in the glandular mucosa from 5 to 120 min after administration. Microautoradiography in the rat and dog after intravenous injection of [3H]metiamide or [3H]cimetidine demonstrated an uptake of tritium in the parietal cell cytoplasm that was 3- to 4-times greater than that found in adjacent peptic cells or areas of muscularis mucosa. The preferential labelling persisted at a low level up to 6h after injection in the rat. The localization of radioactivity from the H2-antagonists in the parietal cell cytoplasm correlates well with their pharmacological activity in preventing acid secretion from this cell.

Animals↗