Apneic oxygenation in apnea tests for brain death. A controlled trial.

We performed a prospective controlled study of apneic oxygenation on 15 patients undergoing apnea tests for brain death. All patients were preoxygenated with 100% oxygen at existing respirator settings. During the 10-minute apnea tests, nine patients were given continuous apneic oxygenation by tracheal cannula. The other six patients had tracheal tubes open to room air. The patients given apneic oxygenation had little or no hypoxia by the end of the test. The patients given room air during the test became hypoxic. Many neurologists perform apnea tests with no oxygenation or with preoxygenation alone. This is the first prospective controlled study (to our knowledge) of apneic oxygenation; it shows that preoxygenation alone does not prevent hypoxia during apnea tests for brain death. We recommend that all apnea tests be performed with apneic oxygenation.

Brachial plexopathy associated with human granulocytic ehrlichiosis.

Human granulocytic ehrlichiosis is a tick-borne disease of humans. Involvement of the peripheral nervous system is well known with Lyme disease and some rickettsioses but has yet to be described with this disease. We describe a man with bilateral brachial plexopathies associated with an acute febrile illness and clinical, laboratory, and serologic evidence diagnostic of human granulocytic ehrlichiosis. The clinical presentation suggests that the peripheral neuropathy was postinfectious. Human granulocytic ehrlichiosis should be considered in the differential diagnosis in patients with peripheral nervous system involvement, including brachial plexopathy, of individuals who live or recreate in areas known to harbor ticks.

Malignant melanoma in the resident population of Rochester, Minnesota.

The incidence of malignant melanoma in the population of Rochester, Minnesota, was studied through use of the countywide diagnostic indexing system at the Mayo Clinic. The average annual incidence of cutaneous melanoma (4.0/100,000 creude, 4.2 adjusted to the age structure of the US 1950 population) was similar to that reported by the Third National Cancer Survey for 1969 through 1971 for locations in the United States at the approximate latitude of Rochester. Unlike reports from other studies, no change in incidence rate during the 25 years 1950 through 1974 was detjected in Rochester. The crude annual incidence of malignant melanoma of the eye, also determined for the same period, was 1.3/100,000.

Acute posterior multifocal placoid pigment epitheliopathy with bilateral central retinal vein occlusion.

PURPOSE: We examined a patient with acute posterior multifocal placoid pigment epitheliopathy and bilateral central retinal vein occlusion. METHOD: Case report. A 28-year-old woman presented with the typical findings of acute posterior multifocal placoid pigment epitheliopathy. One month after presentation, the patient developed bilateral central retinal vein occlusion. RESULT: Four months after presentation, resolution of the bilateral central retinal vein occlusion resulted in a corrected visual acuity of RE, 20/25 and LE, 3/400. CONCLUSION: Vasculitis, sometimes associated with acute posterior multifocal placoid pigment epitheliopathy, can affect the ciliary vessels that supply the optic disk. This may result in axoplasmic stasis and compression of the central retinal vein, leading to impending or complete central retinal vein occlusion.

Body composition changes following laparoscopic gastric banding for morbid obesity.

Most reports of outcome following obesity surgery report weight and co-morbidity changes only. We studied body composition changes in 17 adult patients (15 F, 2 M, age 43+/-2 years, range 28-58 years), with morbid obesity (initial BMI 40.4+/-4.9 kg/m(2), range 34.7-48.8) who were managed surgically by laparoscopically inserting an adjustable gastric band. Body composition was studied before and after surgery (mean interval of 909+/-51 days, range 441-1155 days) using anthropometry (abdominal circumference, AC, sum of four skinfold thicknesses, SFSUM), whole-body potassium counting (TBK), in vivo neutron activation analysis total body nitrogen (TBProtein) and whole-body dual-energy ray absorptiometry (total body percent fat TBF%, and total body bone mineral density TBBMD). Weight loss over the study period was 23.4+/-2.5 kg. ( p<0.0003) with an AC reduction of 20.0+/-4.5 cm ( p<0.008). Both SFSUM and TBF% were significantly reduced ( p<0.02 and p<0.0005 respectively). Both TBK and TBProtein after normalization for sex and height, were significantly ( p<0.0054 and p<0.001 respectively) reduced, but the ratio of loss of fat mass to fat-free mass, at 4.4:1 was usual for weight loss, and there was no significant changes in the ratio of potassium to protein. TBBMD, after normalization relative to a young same sex adult, was not significantly changed. In this group of patients, most of the substantial weight loss over a 2- to 3-year period was due to loss of fat mass, with relatively less reduction in the components of fat-free mass. Adjustable laparoscopic gastric banding induces fat loss without significant other deleterious effects on body composition.

Ocular telemedicine between Nepal and the USA: prevalence of vitreoretinal disease in rural Nepal.

This study is aimed at reporting experiences with telemedicine between Nepal and the USA and at reporting the prevalence of age-related macular degeneration (AMD) and diabetic retinopathy (DR) in rural Nepal. AMD and DR are becoming more significant factors for non-reversible vision loss in rural Nepal due to increasing life expectancy and urbanisation. The prevalence of DM is low compared with the developed world, but the percentage of diabetics with DR is high, presumably due to limited access to healthcare. The higher prevalence of DM in Hetauda is explained as being due to a more urban lifestyle, dietary habits (more deep-fried food) and more advanced age.

Visual disturbance and carotid artery disease. 500 symptomatic patients studied by non-invasive carotid artery testing including B-mode ultrasonography.

Non-invasive carotid artery testing was performed on 500 consecutive patients with visual disturbances not related to local ophthalmic pathology to determine the extent of carotid artery disease, particularly in patients with symptoms not typical of amaurosis fugax. Three hundred eighty six patients (77.2%) had an abnormal study. However, the incidence of hemodynamically significant lesions was only 16%. The patients could be divided into three groups: Patients with symptoms that could be explained on an ocular basis, including amaurosis fugax, had a 79% incidence of ipsilateral carotid plaques. Patients with symptoms which could not be easily explained on an ocular basis, such as bilateral blurred vision, bilateral visual loss (both transient and permanent), and homonymous hemianopsia had an incidence of carotid artery plaques similar to patients with amaurosis fugax. Patients with unilateral blurred vision and bilateral scintillations had a lower incidence (57%) of carotid plaques than the other groups. Younger symptomatic patients had less carotid plaques than the overall series. Twenty-one percent of patients under age 50 had the Doppler finding of early systolic flutter turbulence, which is usually of mitral valve origin. Women predominated in the under 50 age group by about 2:1. In view of the prevalence of carotid plaques in the population of patients with visual symptoms other than amaurosis fugax, evaluation of these patients with non-invasive testing is indicated to determine which of these patients has hemodynamically significant obstruction to flow at the carotid artery bifurcation.

The metabolic effects of preferential reduction of visceral adipose tissue in abdominally obese men.

SETTING: This study was performed on free living subjects attending the body composition laboratory on a monthly basis for a total of six months. SUBJECTS/DESIGN: Thirty-one abdominally obese men (30 0.95) were enrolled in a placebo-controlled randomized double-blind study, using either dexfenfluramine (d-fen) or placebo, whilst also receiving food and fitness counselling. After a two week run-in period they were randomized to either d-fen or placebo for three months. This was followed by a further three months without medication, although food and fitness counselling continued. METHODS: Body composition assessment included anthropometry (weight, height and abdominal circumferences), dual-energy X-ray absorptiometry (DEXA) for total body fat, and intra-abdominal fat measured via magnetic resonance imaging (MRI) at the L3/L4 level. Biochemistry included serum lipids, insulin and glucose. All measurements including blood pressure were performed at baseline, three months and six months. STATISTICAL ANALYSIS: The change within each group in the three months on medication (d-fen or placebo) was assessed by paired t-tests, whilst the difference between the groups at baseline and at three months (measured by percentage change from baseline) was assessed by unpaired t-tests. An analysis of variance was performed over the six months for the d-fen group and the placebo group separately, to determine the overall effect of three months treatment with either d-fen or placebo, three months after medication had ceased. OUTCOMES AT THREE MONTHS: At three months, BMI decreased by -5.8+/-0.8% in the group on d-fen and by -2.7+/-0.8% in the placebo group (P<0.01 d-fen vs placebo). There was also a significant difference in the reduction of the visceral fat area between the groups (-21.0+/-4.0% in the d- fen group vs -6.7+/-2.2% in the placebo group, P<0.01) although there was no significant difference between groups with regard to reduction in subcutaneous fat area. The visceral:subcutaneous fat ratio (V/S ratio) was significantly reduced between groups at three months (-13.3+/-4.9% in the d-fen group vs -0.7+/-3.0% in the placebo group, P=0.03). At three months, the only metabolic parameters to show significant difference between the two groups were total cholesterol and LDL cholesterol. Total cholesterol reduced by -12.4+/-2.0% in the d-fen group compared with -2.3+/-2.1% in the placebo group (P<0.01). LDL cholesterol reduced by -15.6+/-2.6% in the d-fen group compared with -1.2+/-2.8% in the placebo group (P<0.01). OUTCOMES AT SIX MONTHS: In the d-fen group, the reductions in BMI, abdominal circumference and % total body fat (DEXA) were sustained after three months on no medication, whereas all changes in body composition seen in the group on placebo at three months, had reverted at the three month follow-up. Both groups sustained a reduction in the insulin to glucose (I/G) ratio and systolic and diastolic blood pressure for three months after medication was ceased, while those on d-fen initially also maintained a reduction in total and LDL cholesterol.

Problems associated with using in vivo proton (1H) magnetic resonance spectroscopy to quantify liver fat.

In-vivo 1H magnetic resonance (MR) spectra of the liver were obtained in 8 patients admitted for liver biopsy. These patients had abnormal liver function and the presumptive diagnosis of fatty liver prior to biopsy. Two patients with NIDDM were also studied but liver biopsies were not performed as liver function was normal. The MR spectra, obtained on a 60 cm clear-bore 1.9 tesla superconducting magnet showed two 1H resonances, one from water and the other from repeating methylene protons - (CH2)n - in triglyceride. The lipid: water signal ratio was used to characterize tissues as subcutaneous fat (high lipid:water ratio), normal liver (low lipid: water ratio) and fatty liver (intermediate lipid: water ratio). The spectra obtained at the greatest depth from the probe surface ~4.5 cm) was used as it was most likely to represent liver tissue. Although all 8 patients were expected to have fatty liver only 2 had evidence of significant fatty changes on microscopy. This was assessed by counting the vacuoles of fat over the area of the biopsy specimen and quantitated as 'fat vacuoles per high power field' (f/hpf). In the 2 patients with NIDDM, unusual stack plots suggested technical difficulties with 1H MR spectroscopy for in-vivo assessment of fatty liver. The first patient, PT had a significant increase in lipid:water ratio on the spectra thought to represent liver (lipid:water ~ 65% cf levels <3% in norma liver and 12.6% + 26.5% in those patients subsequently found to have fat on biopsy). This was later found on MR imaging to represent omental fat lying between the liver and muscle layer. The second patient, OM had a large amount of subcutaneous fat overlying the area assessed. As seen on the stack plot, the probe depth was not great enough to pass through the subcutaneous fat and muscle layer to penetrate liver tissue. There was a significant correlation between the lipid:water signal ratio and visible fat on biopsy in those patients who underwent liver biopsy. Difficulties experienced with probe depth suggests imaging would be necessary prior to spectroscopy to ensure liver tissue is actually assessed.

Selective deep peroneal nerve injury associated with arthroscopic knee surgery.

We report 3 cases of isolated deep peroneal nerve injury as a complication of arthroscopic knee surgery. At the level of the knee joint, the deep and superficial peroneal nerves are usually joined as the common peroneal nerve. However, because of the fascicular structure, a partial nerve injury can result in an isolated injury to the deep peroneal nerve fibers. Due to the intraneural topography of the peroneal nerve, electrodiagnostic studies in a partial nerve injury may erroneously indicate a more distal lesion.

Nosocomial stroke.

Nosocomial stroke occurs during hospitalization for unrelated problems. Increased understanding of this relatively ignored entity may provide the key to improved stroke prophylaxis for the hospitalized patient at risk and provide clues to the precipitants of stroke in the general population. We compared nosocomial stroke to stroke occurring outside the hospital in a mixed prospective and retrospective analysis of 372 consecutive strokes occurring over 2 years. We excluded nosocomial stroke associated with cardiac bypass surgery, carotid endarterectomy, and cerebral angiography for cerebrovascular disease because of the known associations of these procedures with stroke. Of our 372 strokes, 47 were nosocomial. There were no significant age and sex differences between nosocomial stroke and stroke admissions. Nosocomial stroke patients were significantly more likely than stroke admission patients to be normotensive (p = 0.001), diabetic (p = 0.01), and have cardiac disease (p = 0.03). Nosocomial stroke patients were significantly less likely to have brain hemorrhages (p = 0.001), lacunar infarcts (p = 0.03), or infarcts of undetermined cause (p = 0.047). Half of the nosocomial stroke patients died versus 11% of stroke admission patients. Nosocomial stroke differs in stroke type, associated diseases, and prognosis from stroke occurring outside the hospital.

Improvement in arterial stiffness during hypolipidaemic therapy is offset by weight gain.

Fourteen patients with familial hypercholesterolaemia were managed with dietary advice and simvastatin for 12 months. Either nicotinic acid or cholestyramine resin was added to the regimen if serum cholesterol was not less than 5.5 mmol/l within 18 weeks. After dietary advice but before commencing pharmacotherapy for hyperlipidaemia, arterial stiffness was measured in the common carotid and common femoral arteries. These studies were repeated after 12 months on pharmacotherapy. The primary objective of this study was to determine whether arterial stiffness could be altered with total cholesterol and low density lipoprotein (LDL) cholesterol lowering. Over the 12 month interval, serum total cholesterol, LDL cholesterol and triglycerides fell significantly, whereas high density lipoprotein (HDL) cholesterol and body mass index (BMI) rose significantly. Mean supine blood pressure did not change significantly. Arterial stiffness in the common carotid artery decreased from 1.04 +/- 0.21 x 10(5) N/m2 to 0.63 +/- 0.06 x 10(5) N/m2 (T = -2.67, P < 0.01) over the interval. Stiffness of the common femoral artery decreased from 2.10 +/- 0.57 x 10(5) N/m2 to 0.83 +/- 0.15 x 10(5) N/m2 (T = -2.73, P < 0.01). The change in arterial stiffness was not directly related to changes in circulating lipids or supine blood pressure. Increase in BMI, however, correlated with change in arterial stiffness in the common femoral artery (Rs = 0.53, P < 0.05) but not in the common carotid artery. An increase in BMI was associated with a smaller decrease in common femoral arterial stiffness. Aggressive hypolipidaemic therapy was therefore associated with a favourable effect on arterial wall stiffness.(ABSTRACT TRUNCATED AT 250 WORDS)

Atherosclerotic plaque at the carotid artery bifurcation. Correlation of ultrasonographic imaging with morphology.

Morphologic characteristics of atherosclerotic plaque at the carotid artery bifurcation were compared to the appearance of the plaque on real-time B-mode ultrasonography. Mural plaques propagating along the wall of the carotid sinus had a 72% frequency of recent organizing hemorrhage. Nodular plaques causing local narrowing of the vessel had only a 23% incidence of organizing hemorrhage. This difference was significant (P less than 0.01). The presence of recent organizing hemorrhage in mural plaques may account for the increased frequency of symptoms previously observed to occur ipsilateral to mural plaques compared to nodular plaques.

Reduction of visceral adipose tissue and improvement of metabolic indices: effect of dexfenfluramine in NIDDM.

Increased visceral adipose tissue is thought to contribute to impaired glucose tolerance. We studied 10 men with non-insulin dependent diabetes (NIDDM) before and after a 12-week intervention study using dexfenfluramine. Subjects had a mean body mass index (BMI) of 26.4 +/- 1.7 kg/m2 and had an abdominal distribution of body fatness (waist-to hip ratio > 0.9). Anthropometric indices, biochemistry, macronutrient intake from 7-day food records as well as a euglycaemic glucose clamp and magnetic resonance imaging (MRI) were performed at week 0 and week 12. Abdominal adipose tissue area measured by MRI was reduced from 854 +/- 270 cm2 to 666 +/- 231 cm2 (p = 0.003) due mainly to a selective 32% reduction in visceral fat area from 484 +/- 230 cm2 to 333 +/- 72 cm2 (p = 0.002). Insulin sensitivity improved from 0.29 +/- 0.13 [min-1 (mU/L)] to 0.54 +/- 0.21 [min-1 (mU/L)] (p = 0.01) and C-peptide levels reduced from 0.77 +/- 0.24 mumol/L to 0.58 +/- 0.15 mumol/L (p = 0.002). The reductions in fasting glucose and glycated haemoglobin failed to achieve significance. Fasting total cholesterol and triglyceride levels significantly reduced (p = < 0.001 and p = 0.021 respectively). There was a reduction in total energy intake (p = 0.005) due to a significant reduction in calories obtained from fat (p < 0.001). Thus dexfenfluramine was shown to be a useful adjunct therapy for the reduction of visceral fat in abdominally-obese men with NIDDM with an associated improvement in insulin sensitivity.

Atrial-septal-aneurysm-associated thrombus and stroke: Demonstration with transesophageal echocardiography.

Atrial septal aneurysm is an increasingly recognized cardiac abnormality. It represents a marked bulging of the interatrial septum into one atrium or the other. A consistent association between this structure and embolic stroke has been demonstrated. Because of the high prevalence of patent foramen ovale or atrial septal defect associated with this structure, paradoxical embolism has been suggested as a mechanism for embolic events. An alternate explanation is the local association of the aneurysm with thrombus. Few data have been found to support this mechanism, however. We report a young woman with multiple strokes during pregnancy in whom transesophageal echocardiography allowed the in vivo demonstration of atrial-septal-aneurysm-associated thrombus. This observation lends further support to the "local thrombus" mechanism of embolie events. It also underscores the potential utility of transesophageal echocardiography in evaluating patients with stroke of uncertain etiology.

Efficacy of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors for prevention of stroke.

OBJECTIVE: To determine if 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are effective in preventing fatal and nonfatal strokes in patients at increased risk of coronary artery disease. DESIGN: Meta-analysis of randomized controlled trials. Clinical trials were identified by a computerized search of MEDLINE (1983 to June 1996), by an assessment of the bibliographies of published studies, meta-analyses and reviews, and by contacting pharmaceutical companies that manufacture statins. Trials were included in the analysis if their patients were randomly allocated to a statin or placebo group, and reported data on stroke events. Thirteen of 28 clinical trials were selected for review. Data were extracted for details of study design, patient characteristics, interventions, duration of therapy, cholesterol measurements, and the number of fatal and nonfatal stroke events in each arm of therapy. Missing data on stroke events were obtained by contacting the investigators of the clinical trials. MAIN RESULTS: Among 19,921 randomized patients, the rate of total stroke in the placebo group was 2.38% (90% nonfatal and 10% fatal). In contrast, patients who received statins had a 1.67% stroke rate. Using an exact stratified analysis, the pooled odds ratio (OR) for total stroke was 0.70 (95% confidence interval [CI] 0.57, 0.86; p =.0005). The pooled OR for nonfatal stroke was 0.64 (95% CI 0.51, 0.79; p =.00001), and the pooled OR for fatal stroke was 1.25 (95% CI 0.71, 2.24; p =.4973). In separate analyses, reductions in total and nonfatal stroke risk were found to be significant only for trials of secondary coronary disease prevention. Regression analysis showed no statistical association between the magnitude of cholesterol reduction and the relative risk for any stroke outcome. CONCLUSIONS: The available evidence clearly shows that HMG-CoA reductase inhibitors reduce the morbidity associated with strokes in patients at increased risk of cardiac events. Data from 13 placebo-controlled trials suggest that on average one stroke is prevented for every 143 patients treated with statins over a 4-year period.

Measurement of liver fat by MRI and its reduction by dexfenfluramine in NIDDM.

OBJECTIVE: To validate a variation of a well-established magnetic resonance imaging (MRI) technique to detect liver fat and use it to monitor liver fat changes after treatment with dexfenfluramine in men with non-insulin dependent diabetes mellitus (NIDDM). DESIGN: (a) Simple correlation study of MRI Liver Fat Index with liver biopsy results; (b) Open Study of 10 men with NIDDM treated with dexfenfluramine for 12 weeks in addition to their 'usual' therapy. SUBJECTS: (a) 19 patients (3F; 16M) with abnormal liver function tests undergoing liver biopsy; (b) 10 men, Body Mass Index (BMI) < 30, Waist to hip ratio (WHR) > 0.90 with poorly controlled NIDDM despite oral sulphonylurea therapy. MEASUREMENTS: (a) MRI liver fat; standard liver biopsy; (b) MRI visceral fat, MRI liver fat, euglycaemic clamp, plasma lipids, fasting glucose and c-peptide levels. RESULTS: In the validation group, there was a strong relationship between the MRI Liver Fat Index and histopathological assessment of the liver biopsies (r = 0.87, < 0.0001). During treatment with dexfenfluramine the mean Liver Fat Index reduced from 10.6 +/- 3.4 to 6.6 +/- 2.8 (P = 0.05). The reduction in Liver Fat Index correlated with the reduction in visceral fat (r = 0.84, P = 0.001) as well as with the improvement in insulin sensitivity (r = 0.62, P = 0.05). Using partial correlation analysis, the relationship between the change in visceral adipose tissue and the improvement in insulin sensitivity was weaker if the Liver Fat Index was kept constant (r = 0.76 decreased to r = 0.56). CONCLUSIONS: In this group of subjects MRI Liver Fat Index correlated well with liver fat as seen on biopsy. The Liver Fat Index reduced after 12 weeks therapy with dexfenfluramine suggesting a role for hepatic steatosis in the complex interaction between visceral adipose tissue and insulin sensitivity.