A short review of game theory for neurosurgeons.

Neurosurgery and medicine in general are increasingly dominated by economic factors and considerations. Physicians themselves have partially adopted economic terminology, although they rarely have a profound knowledge of economics. Today game theory is one of the most important factors driving microeconomics, which is the competition for limited resources within a small group of individuals. The purpose of this article is to give a short introduction to game theory and its application to the healthcare system. The Prisoner's Dilemma considers strategies between two persons. In the classic version two burglars are caught. Each could confess and be released from jail if the other does not confess--who will then get a long term in prison. If both confess, both get an intermediate time in jail, and if no one confesses, both get a mild sentence. Wanting to be released from jail, they both confess and get the intermediate term in prison. This remarkable result, initially described by John von Neumann in 1928 and showing that individually rational actions can result in both persons becoming worse off, had a great impact on modern social science. Other scenarios are more complex. The Nash Equilibrium is a wider concept. If there is a set of strategies with the property that no player can benefit by changing his strategy while the other players keep their strategies unchanged, then that set of strategies and the corresponding payoffs constitute the Nash Equilibrium. Another concept particularly important in sociology is the Pareto criterion. If no one can be made better off without making somebody else worse off, then that outcome is Pareto optimal. Respecting these basic principles is a necessary precondition for successful deals and cooperative projects.

[Global risk score and subclinical coronary atherosclerosis]. / Globalrisiko und subklinische Koronarsklerose. Beobachtungen an 50 konsekutiven, ambulanten Patienten.

In fifty healthy patients without signs of coronary heart disease but elevated global risk score subclinical coronary atherosclerosis could be demonstrated in 45 patients by electron-beam computed tomography (CT). Two patients with hight risk (>20%) and 3 patients with intermediate risk (10-20%) showed a negative CT. Because of subclinical atherosclerosis 29/32 patients with intermediate risk have to be newly classified as high risk. So calculation of global risk and careful evaluation of patients with intermediate risk may add to better risk stratification.

[Anticoagulatin in atrial fibrillation--status of therapy in a network of physicians]. / Antikoagulation bei Vorhofflimmern--Stand der Therapie in einem Arztenetzwerk.

Despite of sound evidence, that oral anticoagulation reduces substantially the incidence of stroke-events in patients with atrial fibrillation and concomitant risk factors, in daily practice only a part of these patients is in fact treated with anticoagulation. The aim of this cross-sectional study was to evaluate to which extent existing guidelines for the treatment of patients with atrial fibrillation are transformed in the "real world" context of a Swiss urban network of primary care providers. The greatest part (88.4%) of the included patients with atrial fibrillation had a high risk for thromboembolism and herewith the indication for anticoagulation was given. For a primary care collective the amount of patients with anticoagulation was high: 74.1% did receive this kind of preventive therapy. 89% had robust International normalized ratio (INR) values within the recommended range (INR 2.5-3.5). The most common reasons not to prescribe oral anticoagulation were: old age (17.5%; mostly in combination with other reasons), risk of falls (16.5%), medical indication not given (16.5%). Thus the recommendations of the guidelines have been transformed into practice for a bigger part of the included patients. Given these results a broadly implemented quality-improvement-project to bring up the anticoagulation rate even higher hardly seems to be efficacious and is presently not of top priority in this network of primary care providers.

Severe potential consequences of delayed diagnosis in patients with hip claudication.

Delayed diagnosis in patients with hip claudication can lead to severe consequences. We report on patients with ischaemic hip claudication which had primarily been attributed to coxarthrosis. One patient went through a variety of treatments including hip arthroplasty. The second patient had a life-threatening abdominal aortic aneurysm (AAA) which remained undiagnosed. Orthopaedic surgeons should maintain a high degree of suspicion for vascular disease. Moreover, we strongly advocate that all men over 60 years old who seek medical advice for whatever reason should be screened once for AAA by ultrasonography.

Takayasu disease with predominant pulmonary involvement.

We report a case of Takayasu's arteritis with predominant pulmonary involvement, which led eventually to complete obliteration of the right pulmonary artery. Subsequently, cavitation and chronic inflammation developed in the nonperfused right lung. A right pneumonectomy was performed to control the infectious process, leading to functional improvement and better control of the underlying immunologic disorder.

Infection of a hip prosthesis by Actinomyces naeslundii.

We present the case of a 77-year-old woman who developed an Actinomyces naeslundii infection of a hip prosthesis. The isolate grew well aerobically with 5% CO(2). Possible diagnostic problems may arise in the microbiological laboratory because aerobic growth is not sufficiently accounted for in some of the traditional identification schemes and commercial test kits. Therefore, besides presenting an unusual pathogen in this setting, this report focuses on possible diagnostic problems in the microbiological laboratory.

[A patient with cryoglobulinemia and hepatitis C]. / Eine Patientin mit Kryoglobulinämie und Hepatitis-C.

We describe a 73-year-old woman who presented with purpura, recurrent ulcerations of both lower limbs as well as worsening of her condition. Laboratory tests revealed a mixed cryoglobulinemia (type-II). Two years after diagnosis, an amputation of the right femur had been performed due to extensive necrotizing ulcerations. Further complications such as membranoproliferative glomerulonephritis, cirrhosis of the liver with portal hypertension and ultimately, hepatocellular carcinoma developed. A chronic hepatitis C infection was diagnosed rather late, mainly because of the false negative results of the first generation EIA. This case report illustrates the various complications-hepatic and extrahepatic-of chronic hepatitis C infection. The pathogenesis of mixed cryoglobulinemia remains unclear. However, a current literature review suggests a strong association with chronic hepatitic C. Diagnosis, clinical features and course of hepatitis C infection are discussed.

Body composition and fuel metabolism after kidney grafting.

Kidney transplant patients display decreased muscle mass and increased fat mass. Whether this altered body composition is due to glucocorticoid induced altered fuel metabolism is unclear. To answer this question, 16 kidney transplant patients were examined immediately after kidney transplantation (12 +/- 4 days, mean +/- SEM) and then during months 2, 5, 11 and 16, respectively, by whole body dual energy X-ray absorptiometry (Hologic QDR 1000W) and indirect calorimetry. Results were compared with those of 16 age, sex and body mass index matched healthy volunteers examined only once. All patients received dietary counselling with a step 1 diet of the American Heart Association and were advised to restrict their caloric intake to the resting energy expenditure plus 30%. Immediately after transplantation, lean mass of the trunk was higher by 7 +/- 1% (P < 0.05) and that of the limbs was lower by more than 10% (P < 0.01) in patients than in controls. In contrast, no difference in fat mass and resting energy expenditure could be detected between patients and controls. During the 16 months of observation, total fat mass increased in male (+4.9 +/- 1.5 kg), but not in female patients (0.1 +/- 0.8 kg). The change in fat mass observed in men was due to an increase in all subregions of the body analysed (trunk, arms+legs as well as head+neck), whereas in women only an increase in head+neck by 9 +/- 2% (P = 0.05) was detected. Body fat distribution remained unchanged in both sexes over the 16 months of observation. Lean mass of the trunk mainly decreased between days 11 and 42 (P < 0.01) and remained stable thereafter. After day 42, lean mass of arms and legs (mostly striated muscle) and head+neck progressively increased over the 14 months of observation by 1.6 +/- 0.6 kg (P < 0.05) and 0.4 +/- 0.1 kg (P < 0.01), respectively. Resting energy expenditure was similar in controls and patients at 42 days (30.0 +/- 0.7 vs. 31.0 +/- 0.9 kcal kg-1 lean mass) and did not change during the following 15 months of observation. However, composition of fuel used to sustain resting energy expenditure in the fasting state was altered in patients when compared with normal subjects, i.e. glucose oxidation was higher by more than 45% in patients (P < 0.01) during the second month after grafting, but gradually declined (P < 0.01) over the following 15 months to values similar to those observed in controls. Protein oxidation was elevated in renal transplant patients on prednisone at first measurement, a difference which tended to decline over the study period. In contrast to glucose and protein oxidation, fat oxidation was lower in patients 42 days after grafting (P < 0.01), but increased by more than 100% reaching values similar to those observed in controls after 16 months of study. Mean daily dose of prednisone per kg body weight correlated with the three components of fuel oxidation (r > 0.93, P < 0.01), i.e. protein, glucose and fat oxidation. These results indicate that in prednisone treated renal transplant patients fuel metabolism is regulated in a dose-dependent manner. Moreover, dietary measures, such as caloric and fat intake restriction as well as increase of protein intake, can prevent muscle wasting as well as part of the usually observed fat accumulation. Furthermore, the concept of preferential upper body fat accumulation as consequence of prednisone therapy in renal transplant patients has to be revised.

Central nervous system lupus: concomitant occurrence of myelopathy and cognitive dysfunction.

Reported are two cases of patients with central nervous system systemic lupus erythematosus (SLE) with clinical features of a myelopathy confirmed by magnetic resonance imaging (MRI). In one case, further evaluation including Single Photon Emission Computerized Tomography (SPECT) and neuropsychological testing, indicated higher cortical deficits which improved after treatment with monthly pulse intravenous cyclophosphamide. Subsequent cessation of cyclophosphamide was associated with further progression of the neurological disease in this patient.

Changes in bone mass early after kidney transplantation.

Renal transplant patients exhibit increased rates of trabecular bone fractures, probably due to glucocorticoid-induced osteopenia, which is known to occur within 6 months after kidney grafting. This mineral loss at a mostly trabecular site (lumbar spine) contrasts with a gain at the radius, which consists mainly of cortical bone. However, the early effects of kidney transplantation on the other parts of the human skeleton and the time course of these changes during the first 5 months after transplantation remain unknown. Therefore, 34 kidney transplant recipients were prospectively followed immediately after kidney grafting (12 +/- 1 days, mean +/- SEM, and then on a monthly basis up to 152 +/- 3 days) and compared with 34 normal healthy volunteers matched for age, sex, and body mass index. Bone mineral measurements of whole body (n = 34), lumbar spine (n = 32), and upper femur (n = 23) were performed using dual-energy x-ray absorptiometry (Hologic QDR 1000W). At time of transplantation, lumbar bone mineral density (BMD) and BMD of the upper femur were lower (p < 0.01) in female but not male patients compared with controls. Lumbar BMD decreased by 1.6 +/- 0.2% per month in both sexes (p < 0.01), whereas BMD of upper femur further decreased in males (p < 0.01) but only tended to decrease in females. At time of transplantation, whole-body bone area (BA), bone mineral content (BMC), and BMD were decreased by about 8, 15, and 9%, respectively, in patients compared with controls (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[Ocular manifestations of rheumatic diseases. Cooperation between internist/ophthalmologist]. / Okuläre Manifestationen bei rheumatischen Krankheiten. Zusammenarbeit Internist/Ophthalmologe.

A red or painful eye may be the clue to a systemic condition, many of which are of a rheumatological or immunological nature. Conjunctivitis may occur in Sjögren's Syndrome, Reiter's Syndrome (and other sero negative spondyloarthropathies) and with infections such as chlamydia and viruses. 70% of cases of episcleritis are idiopathic, the other 30% being associated with rheumatoid arthritis or other connective tissue diseases or herpes zoster infection. Scleritis may be seen with connective tissue diseases or auto immune conditions (rheumatoid arthritis, Wegener granulomatosis, polyarteritis nodosa, relapsing polychondritis, SLE), infections (herpes, tuberculosis, syphilis, aspergillosis) or metabolic (gout, porphyria, cystinosis). Retinal vasculitis is seen in SLE, Behçet's Disease, sarcoidosis, polyarteritis nodosa, Whipple's disease and Crohn's disease among others. However, uveitis presents perhaps the greatest diagnostic challenge and interface between ophthalmology and rheumatology. Some syndromes are purely ophthalmological (eg: Fuch's heterochromic cyclitis) but others may lead to the diagnosis of a rheumatic disorder (eg: recurrent unilateral acute anterior uveitis and ankylosing spondylitis). Systemic syndromes most likely to be associated with uveitis are Reiter's disease, ankylosing spondylitis, sarcoidosis, juvenile arthritis, interstitial nephritis, inflammatory bowel disease, syphilis. The patterns are different, eg: acute painful unilateral anterior uveitis with ankylosing spondylitis and chronic asymptomatic bilateral uveitis in juvenile arthritis (ANA positive, pauci-articular) or bilateral symptomatic uveitis in sarcoidosis. An illustrative case will be presented and an algorithm for the evaluation of uveitis discussed.

["Psychogenic" bulbar paralysis]. / "Psychogene" Bulbärparalyse.

This 58-year-old female presented with a history of difficulties in swallowing for 30 years. No diagnosis was made in spite of repeated investigations including barium-contrast radiography. A probative strumectomy and psychotherapy were unsuccessful. After an episode of major depression the swallowing disturbances increased. In addition the patient complained of mastication difficulties and was dysarthric. Finally, neurological examination and neurophysiological studies established the diagnosis of progressive bulbar palsy.

[Rare form of uveitis with neurological symptoms: the Vogt-Koyanagi-Harada uveomeningoencephalitic syndrome]. / Seltene Uveitis mit neurologischem Krankheitsbild: das uveo-meningo-enzephale Syndrom nach Vogt-Koyanagi-Harada.

A 51-year-old Italian woman developed migraine-like headaches with increasing frequency 5 years after menopause. The simultaneous onset of severe bilateral uveitis, neurological signs such as vertigo, hearing loss, small sensomotor hemisyndrome, cognitive brain dysfunction and lymphocyte liquor pleocytosis confirmed the diagnosis of Vogt-Koyanagi-Harada syndrome, a rare disease of probably autoimmune origin with destruction of pigment containing neuroepithelium. Other vasculitic diseases, especially those of infectious or rheumatologic origin, were excluded. Systemic corticoid treatment suppressed the activity of the illness but on dose reduction relapses occurred. Additional immunosuppressive medication prevented uveitic relapses and made it possible to reduce the corticoid dose.

[Aplastic anemia combined with an autoimmune disease (eosinophilic fasciitis or glomerulonephritis)]. / Aplastische Anämie kombiniert mit einer Autoimmunkrankheit (eosinophile Fasciitis beziehungsweise Glomerulonephritis).

We describe 3 patients with aplastic anemia and an autoimmune disease. Two had eosinophilic fasciitis and 1 glomerulonephritis. In all patients both diseases were successfully treated by immunosuppressive therapy. Pathophysiological aspects of this association are discussed.

Recurrence rate after discontinuation of long-term mebendazole therapy in alveolar echinococcosis (preliminary results).

The recurrence rate was investigated in 19 patients with non-resectable alveolar echinococcosis after discontinuation of a long-term therapy with mebendazole (average treatment 4.3 years). A control group consisted of 14 patients who underwent radical surgery and finished a course of prophylactic postoperative mebendazole treatment of 2 years. In the controls, no recurrence was observed after a post-therapy period averaging 3.5 years. In contrast, recurrence occurred in 7/19 patients (37%) with non-resectable alveolar echinococcosis an average of 1.6 years after discontinuation of the long-term mebendazole therapy. The absence of clinically detectable recurrence in the remaining 12 patients seems to be due either to spontaneous inactivation of alveolar echinococcosis preceding chemotherapy or too short post-therapy surveillance. The patients with recurrence responded favorably to reintroduction of chemotherapy. The data indicate that mebendazole therapy is parasitostatic rather than parasiticidal.