Investigations on maladaptive plasticity in the sensorimotor cortex of unilateral upper limb CRPS I patients.

BACKGROUND: Patients with a complex regional pain syndrome (CRPS) in the upper limb show a sensory and motor impairment of the hand. Decreased intra-cortical-inhibition (ICI) of the motor representation of the affected hand muscle and decreased somatosensory hand representation size were related to maladaptive plasticity. OBJECTIVE: To achieve new insights about CRPS we examined whether these alterations were present in a single cohort. METHODS: We used a multi-modal approach comprising behavioral testing, transcranial magnetic stimulation, and high resolution fMRI combined with a new analysis technique for improved neuronal specificity. RESULTS: We found a decreased pinch-grip performance, two-point discrimination on the fingertips, ICI in the motor cortex, and representation size of the hand in Brodmann Area 3b (BA3b) in the somatosensory cortex. Our analysis further showed that correlations with ICI on the non-affected side were absent on the affected side. CONCLUSIONS: This study is the first to gather behavioral, neurophysiologic and imaging measurements for one patient cohort and it therefore enables a comprehensive view of collapsed associations of function and representation focused on the hemisphere contralateral to the affected hand.

Estimating the prevalence of Parkinson's disease (PD) and proportions of patients with associated dementia and depression among the older adults based on secondary claims data.

OBJECTIVES: While the epidemiology of Parkinson's disease (PD) has been extensively studied, data on the prevalence of PD among the older adults in Germany are scarce, based on small samples, and limited to primary data designs. This study estimated the PD prevalence among the older adults in Germany in 2006 using secondary data. METHODS: We included 815,573 health insurance members aged ≥65 years from all regions in Germany. PD was identified in case of at least one inpatient or outpatient diagnosis. An outpatient diagnosis had to be confirmed by either a subsequent diagnosis or an antiparkinsonian drug within 12 months. PD was also assumed if a first prescription was confirmed by a diagnosis within 12 months. Cases were checked for a diagnosis of dementia or depression. RESULTS: The standardized prevalence of PD was 1680 (95% confidence interval (CI): 1644-1716) cases per 100,000 persons. The prevalence increased with age and peaked in the age group of ≥90 years (4633 cases; 95% CI: 4227-5068) with higher rates in men (1729; 95% CI: 1684-1776) than in women (1644; 95% CI: 1593-1697). Dementia and depression occurred in 26.6% (95% CI: 25.8-27.5) and 32.6 (95% CI: 31.7-33.5) of PD cases, respectively. CONCLUSIONS: The age-related increase of PD prevalence and the age-specific prevalence estimates are in line with other European studies, stressing the public health relevance related to PD. In addition to the minimization of biases that might occur in primary data studies, further strengths of our findings are the large underlying sample size and the coverage of Germany.

Cine MRI: a new approach to the diagnosis of scapholunate dissociation.

OBJECTIVE: To evaluate the feasibility of cine MRI for the detection of scapholunate dissociation (SLD) and to compare the sensitivity and specificity of cine MRI with those of cineradiography and arthroscopy. MATERIALS AND METHODS: To evaluate feasibility, healthy subjects underwent cine MRI of the wrist. To evaluate sensitivity and specificity, patients with clinically suspected scapholunate ligament (SLL) injury after trauma to the wrist were prospectively included and underwent radiographic examination, cineradiography, and cine MRI. In 25 out of 38 patients, subsequent arthroscopy was performed. Results of cineradiography and cine MRI correlated with those of arthroscopy. RESULTS: Cine MRI was of diagnostic quality in all healthy subjects and patients with good interrater agreement. There was excellent correlation between cineradiography and cine MRI. Scapholunate distance differed significantly between healthy subjects and patients with scapholunate dissociation (p < 0.001), but not between imaging modalities in the patient group. Cine MRI had 85% sensitivity and 90% specificity for the detection of SLD. CONCLUSION: Cine MRI of the wrist is a fast and reliable technique for the detection of SLD with diagnostic accuracy comparable to cineradiography. It can be easily implemented as a routine clinical MRI examination, facilitating diagnostic workup of patients with suspected SLD while avoiding radiation exposure.

Usage of the middle finger shapes reorganization of the primary somatosensory cortex in patients with index finger amputation.

PURPOSE: The primary somatosensory cortex (S1) is somatotopically reorganized after limb amputation. The duration of the amputation, the intensity of phantom limb pain but also a multifactoral model of altered cerebral input have been discussed to be associated with cortical changes. Patients with finger amputation rarely show phantom limb pain, the deafferented cortical area is small but other fingers might well overtake function. METHOD: We selected a group of index finger amputated patients and performed a high resolution (in plane: 1.5 mm2) S1-mapping during tactile stimulation of finger tips. RESULT: We found an interhemispheric imbalance of the distance between the thumb and middle finger only for the patient-group. When patients used their middle finger more they showed less interhemispheric imbalance, increased spatial tactile discrimination and increased fMRI-activation in response to stimulation. Phantom limb pain was not associated with somatotopic representation parameters in S1. CONCLUSIONS: Overall, our fMRI-data point to a usage dependent plasticity of Brodmann's area 3b in man.

MR microscopy of the human finger and correlation with histology--a proof-of-principle study.

Magnetic resonance imaging (MRI) with small surface coils is a well established method for the diagnostic evaluation of finger masses. Until now, histological examination has been required to reliably assess tumor extent and infiltration of surrounding structures. Ultra-high-field MR microscopy (MRM) allows evaluation of anatomical structures and pathologies with submillimeter resolution. This study describes the diagnostic prospects and potential of MRM based on the ex-vivo examination of different finger pathologies. Ten human digits were examined by ex-vivo MRM at 7.1 Tesla (ClinScan, Bruker BioScan) using a T2-weighted turbo spin echo (TSE) sequence. Imaging parameters were: TE 48 ms; TR 8370 ms; slice thickness 700 µm; matrix size 1024 × 1024 pixels; FOV 37 × 37 mm; in-plane resolution 36 × 36 µm/voxel. Afterwards specimens were examined histologically. Histology and MRM were correlated. MRM allowed evaluation of the anatomy of the nail, the tendon insertions, the distal interphalangeal joint, and the neurovascular bundles. Finger abnormalities evaluated by MRM included osteomyelitis and metastatic disease. Subsequent histological examination confirmed MRM findings regarding origin, internal makeup, and extent of the structures visualized. This study demonstrates the potential of MRM for imaging small anatomical structures and pathologies of the human finger. Our ex-vivo findings correlate strongly with histology, suggesting that MRM may gain a central role in assessing anatomical structures and pathology in terms of morphology, extent, and infiltration of surrounding structures. Therefore, with increasing availability, MRM is expected to become an essential tool not only in experimental studies but also for daily routine.

Ganglions of the wrist and associated triangular fibrocartilage lesions: a prospective study in arthroscopically-treated patients.

PURPOSE: Wrist ganglions are the most common soft tissue tumors of the hand and wrist and can occur at any age. Their etiology remains controversial. A high prevalence of associated intrinsic ligamentous lesions has been described. We hypothesized that painful wrist ganglions are an indicator of an underlying joint abnormality, particularly of lesions of the triangular fibrocartilage complex (TFCC). The aim of our study was to prospectively determine the prevalence of associated TFCC lesions in patients with painful wrist ganglions. METHODS: Forty-six patients (35 women, 11 men; mean age, 36 ± 11 y; range, 18-57 y) with painful wrist ganglions (20 radiopalmar and 26 dorsal) had surgery from January 2008 to June 2010. There were 18 primary and 28 recurrent ganglions. Clinical examinations, pain score evaluations, disabilities in daily life evaluations, plain radiographs, and magnetic resonance imaging were obtained before arthroscopic resection. Concomitant intrinsic lesions of the wrist were assessed with magnetic resonance imaging and re-evaluated by arthroscopy. RESULTS: All ganglions were successfully resected. Overall, arthroscopy identified 22 TFCC lesions (48%) and 2 intracarpal ligament lesions. The TFCC perforations were more commonly associated with radiopalmar ganglions with a positive ulnocarpal stress test result and with recurrent radiopalmar ganglions. At 1-year follow-up, all patients were meaningfully improved in terms of pain and disabilities in daily life. CONCLUSIONS: Arthroscopy allows for the simultaneous treatment of ganglions and other pathologies. Therefore, arthroscopy should be contemplated as the primary treatment option for patients with painful ganglions of the wrist if they are in a radiopalmar location with a positive ulnocarpal stress test and for patients with recurrent radiopalmar ganglions, which are also highly associated with TFCC abnormalities. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Local cluster of germ cell cancer in a cohort of male automotive workers in Germany not explained by previous or concurrent activities and exposures in farming and forestry.

OBJECTIVE: To examine whether exposures or activities in farming, forestry and related occupations explain the excess incidence of germ cell cancer (GCC) observed among male employees in one of the six car-manufacturing plants that is located in a geographic area where farming is frequent. METHODS: A cohort based case-control study was conducted among workers in six car-manufacturing plants located in areas with different industrial structure. The study involved 188 cases of germ cell cancer identified through active retrieval in 38 hospitals and 1000 controls, drawn from administrative accounting files, individually matched by year of birth (± 2 years). Information regarding tasks and exposures and potential confounding variables were obtained by face-to-face or telephone interviews. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using a conditional logistic regression model adjusted for cryptorchidism and other potential confounders. RESULTS: In this case-control study 5.3% of cases and 6.3% of controls ever worked in agriculture or livestock farming. No increased risks were observed for working in agriculture (OR=0.8 95% CI: 0.4-1.6), livestock farming (OR=0.8 95% CI: 0.4-1.6) or for exposure to pesticides (OR=0.7 95% CI: 0.3-1.7), for exposure to fertilizers (OR=0.8 95% CI: 0.4-1.8) and disinfectants (OR=1.0 95% CI: 0.3-2.8). There were no statistically significant increases in risk associated with ever exposure to salt based wood protection agents (OR=2.3 95% CI: 0.6-9.1), working with plywood (OR=1.4 95% CI: 0.6-3.2), coated wood (OR=1.4 95% CI: 0.5-3.9) or working in forestry (OR=1.7 95% CI: 0.5-6.4). Lagging of exposures did not alter the results. CONCLUSIONS: The observed excess incidence in the cohort of automotive workers can be hardly explained by previous or concurrent work in farming or forestry. Because of the small numbers of subjects ever employed in farming the statistical power in assessing associations between agricultural work and agricultural exposures was limited and does not allow final conclusions about the association of farming related exposures and GCC risk.

Acute upper gastrointestinal hemorrhage: is a radiological interventional approach an alternative to emergency surgery?

The aim of our study was to discuss the option of endovascular treatment compared to surgery for patients with endoscopically unmanageable nonvariceal hemorrhage of the upper gastrointestinal tract. From 2000 to 2006, 23 patients (male, 15 male; female, 8; mean age, 69 years) who failed endoscopic therapy for upper gastrointestinal hemorrhage were retrospectively evaluated. Twelve patients were operated on (SG), whereas 11 patients had an endovascular intervention (IG). Technical and primary clinical success rates and complications rates were calculated. Clinical parameters and comorbidities were related to outcome. The surgical group suffered less frequently from pre-existing pulmonary diseases (SG, 17%; IG, 55%; p = 0.05) and had a higher incidence of shock requiring catecholamines (p < 0.01) or plasma expander therapy (p < 0.01). There was no significant difference in the incidence of recurrent bleeding episodes (SG, 17%; IG, 27%; p = 0.35) and mortality rates (SG, 17%; IG, 27%, p = 0.35). Deaths in the IG were due to recurrent bleeding. In patients with unsuccessful endoscopic control of nonvariceal bleeding of the upper GI tract, surgery remains a very effective treatment. However, in patients with a high surgical risk due to unknown bleeding sources and/or severe pre-existing diseases/comorbidities, endovascular therapy offers an excellent treatment option. These patients should then be operated on as early as possible to minimize the risk of recurrent bleeding episodes, which are associated with high morbidity and mortality.

Cosmic radiation and cancer mortality among airline pilots: results from a European cohort study (ESCAPE).

Cosmic radiation is an occupational risk factor for commercial aircrews. In this large European cohort study (ESCAPE) its association with cancer mortality was investigated on the basis of individual effective dose estimates for 19,184 male pilots. Mean annual doses were in the range of 2-5 mSv and cumulative lifetime doses did not exceed 80 mSv. All-cause and all-cancer mortality was low for all exposure categories. A significant negative risk trend for all-cause mortality was seen with increasing dose. Neither external and internal comparisons nor nested case-control analyses showed any substantially increased risks for cancer mortality due to ionizing radiation. However, the number of deaths for specific types of cancer was low and the confidence intervals of the risk estimates were rather wide. Difficulties in interpreting mortality risk estimates for time-dependent exposures are discussed.

Cardiovascular mortality of cockpit crew in Germany: cohort study.

Pilots and other cockpit crew in civil aviation are regularly screened for medical problems that could influence their work performance. Fitness particularly in terms of cardiovascular health is of major importance for this group. While previous studies had shown a low cardiovascular mortality risk of pilots, there is conflicting evidence concerning the prevalence of cardiovascular risk factors in this group. We investigated the cardiovascular mortality of German cockpit crew in a retrospective cohort study. A cohort that included all cockpit crew employed for two German airlines (n=6061) from 1960-1997 was compiled. We calculated the Standardised Mortality Ratio (SMR) and 95% confidence intervals as the ratio of observed and expected numbers of cardiovascular deaths with the German general population as comparison. The influence of age, age at hire and employment duration were analysed in stratified and regression analyses. Overall mortality from cardiovascular causes among cockpit crew was reduced. For mortality from all cardiovascular causes we found an SMR of 0.5(95% CI 0.3-0.6), for acute myocardial infarction the SMR was 0.4 (95% CI 0.3-0.7). Cockpit crew taking up employment at age 30 or later had a more than twofold cardiovascular mortality risk compared with those beginning employment earlier, but there was no risk gradient with duration of employment. Overall, cockpit crew has a relatively low cardiovascular mortality to which a low smoking prevalence and an early detection of cardiovascular health problems are likely to contribute. Cockpit crew employed before age 30 has the lowest cardiovascular mortality risk.

Mortality among pilots and cabin crew in Greece, 1960-1997.

BACKGROUND: Specific health hazards, among them radiation of cosmic origin, have caused some concern among aircrew in civil aviation in recent years. Several cohort studies in Northern countries have investigated mortality and cancer incidence among aircrew. Our goal was to study the pattern of mortality among Greek commercial airline cockpit and cabin crew. METHODS: We performed a retrospective cohort study including 843 Olympic Airways cockpit crew and 1835 cabin attendants. Standardized mortality ratios (SMR) were calculated based on death rates of the Greek population. Duration of employment as a proxy for occupational exposure was used to stratify the cohort. RESULTS: For cockpit crew, the overall SMR was 0.7 (n = 65, 95% CI: 0.5-0.9). The SMR for all cancers was also significantly decreased (n = 17; SMR = 0.6; 95% CI: 0.3-0.9). Most of this reduction was due to a large deficit in lung cancer deaths (SMR = 0.1; 95% CI: 0.0-0.5). Slight but non-significant increases were noted for brain and liver cancer. The SMR for cardiovascular death was close to unity. Among female cabin attendants the SMR for all causes was 0.8 (95% CI: 0.4-1.3). The SMR for all cancers was 0.8 (95% CI: 0.3-1.7). Mortality from breast cancer was not increased. Among male cabin crew, SMR for all causes was 0.5 (95% CI: 0.3-0.9). Analyses according to duration of employment showed no pattern. CONCLUSIONS: In this first-ever occupational cohort study in Greece, Greek aircrew had a low overall and cancer mortality. Due to the small number of events, the strength of our study is limited. The Greek data will be included in a pooled analysis of European studies.

The influence of guiding equipment and stents on the beta dose distribution in the brachytherapy of in-stent restenosis.

BACKGROUND: Intracoronary devices such as stents or guide wires may disturb the dose distribution of beta sources in cardiovascular brachytherapy. As clinical observations indicate that underdosage increases the risk of restenosis, accurate measurements are mandatory to investigate these effects. METHODS AND RESULTS: Dose perturbation effects of different interventional equipment were systematically determined. Dose distributions of 90Sr-beta line sources were measured by means of a special set-up employing plastic scintillator dosimeters in a water phantom. Shielding effects were found to be 2-5% for single stents and 5-10% for graft stents, stent-in-stent geometries, and guiding catheters. Guide wires close to the source reduced the dose by 25-30%. CONCLUSIONS: Beta dose perturbation effects of typical stent types are almost negligible and can be corrected by an increased source dwell time if necessary. Guide wires produce effects which are clinically much more important and should therefore be retracted from the irradiation area.