Über die Validität von Persönlichkeitsprofilen in der nervenärztlichen Begutachtung

Although symptom validity tests have become available to German test users during the last few years, there is very little research into measures of negative response bias in personality assessment. The present study investigates the effects of negative response bias as measured by the Word Memory Test (WMT) and the Structured Inventory of Malingered Symptomatology (SIMS) on self-report personality scales. A retrospective analysis was performed on data from 93 patients who had undergone neuropsychiatric assessment in the context of independent medical examination. Complete data sets were available for the WMT, the SIMS, and the Freiburg Personality Inventory-Revised (FPI-R). Significant differences were found for a number of personality scales, depending on WMT and SIMS classification. The FPI-R validity scale (Openness) was linked to neither WMT nor SIMS, whereas the results in the latter two instruments showed a significant overlap of classification results (φ=0.44). A principal axis analysis yielded corresponding results. It is concluded that self-report personality measures may be considerably distorted by negative response bias. FPI-R Openness scale scores do not allow any interpretation in terms of negative response bias. More effort should be directed in German-speaking countries towards the development and validation of appropriate validity scales.     

Tissue engineering of bone for mandibular augmentation in immunocompetent minipigs: preliminary study.

Large mandibular defects caused by trauma, infection or resection of a tumour are still a major problem for plastic and maxillofacial surgeons. The modern concept of tissue engineering combines the osteoinductive effects of osteogenic cells with a suitable scaffold structure to promote differentiation of osteoblasts and optimal matrix production. Critical size mandibular bone defects were therefore made to investigate the osteogenic potential of periosteal cells and a bioabsorbable polymer fleece (Ethisorb 510) in minipigs. Periosteal cells were isolated from four minipigs, expanded in vitro and seeded with fibrin glue into Ethisorb 510 fleeces. Tissue constructs were used to repair critical size mandibular defects and compared with two minipigs with untreated bone defects. Bone healing was evaluated after 90 and 180 days by radiographs and a histological scoring system. The radiographs showed increased radiodensity of defects filled with the cell-fibrin-fleece-constructs compared with the untreated control group after 90 and 180 days in vivo. The defects repaired by the cell-fibrin-scaffolds (180 days in vivo) obtained the highest histological mean score 2.9 (range 2-3), while defects filled by cell-fibrin-scaffolds (90 days in vivo) achieved a mean score of 2.1 (range 2-3). In contrast, the control group (n = 2) scored 1 and 2. The results show that a combination of periosteal cells and polymer fleeces may be a promising approach for clinical mandibular augmentation.     

Fibrinogen promotes monocyte adhesion via a protein kinase C dependent mechanism

The accumulation of blood monocytes at sites of predilection of the vessel wall is an early cellular event of atherogenesis. Proteins of the vessel wall may facilitate monocyte adhesion and thus promote their recruitment. It has been shown that the relative content of extracellular fibrinogen increases during lesion development, and this study investigated the contribution of immobilized fibrinogen to monocyte adhesion and the underlying mechanism. Freshly isolated human blood monocytes were cultivated in serum-free RPMI 1640 in tissue culture wells precoated with albumin, fibrinogen, or fibrin. After 16 h the plates were washed and adherent cells enumcrated. Immobilized fibrinogen enhanced monocyte adhesion more than 1.9-fold compared to immobilized albumin or fibrin (P<0.05). Concomitant addition of the protein kinase C (PKC) inhibitors staurosporine or H7 suppressed monocyte adherence to immobilized fibrinogen but exerted no significant effect upon adhesion to any other surface tested. Stimulation of monocytes using phorbol myristate acetate resulted in increased binding of monocytes on fibrinogen but not on bovine serum albumin. When PKC activity was reduced through prolonged incubation with PMA for 16h, a significant reduction of monocyte adhesion on fibrinogen was observed. Peptides containing RGD sequences, which have been demonstrated to be ligands for certain integrins, did not inhibit monocyte adhesion. The data suggest that fibrinogen promotes monocyte adhesion in vitro by a PKC-dependent mechanism. PKC appears to be important not only for the initial cell adhesion but also for sustained binding of monocytes to fibrinogen.Abbreviations BSA Bovine serum albumin - ECM Extracellular matrix - PKC Protein kinase C - PMA Phorbol myristate acetate     

Performance of children on symptom validity tests: TOMM, MSVT, and FIT

Symptom validity testing is a major topic in the field of neuropsychological research, but until now, few studies focus on effort testing in children. Three symptom validity tests (SVTs), the Medical Symptom Validity Test, the Test of Memory Malingering, and the Fifteen Item Test plus several standard neuropsychological tests were administered to 73 German-language school children from 6 to 11 years.Participants were either instructed to give full effort or to follow a malingering scenario. It could be demonstrated that, except for one child, all participants with a basic reading level of grade 2 were able to pass all administered SVTs according to established cutoffs for poor effort (i.e., earned a score higher than the cutoff). For the experimental malingerers, however, it was fairly difficult to act according to the scenario throughout the session. While they scored worse in the neuropsychological tests, all but one of them failed at least one SVT. The results support the use of SVTs in childhood age. More elaborate experimental designs and studies with bona-fide patients and suspected malingerers are needed in order to evaluate both the appropriateness of available effort tests and the capabilities of children to fake poor performance.     

Analog validation of German-language symptom validity tests and the influence of coaching.

Although symptom validity testing is an integral part of the repertory of neuropsychologists in a number of countries, this is not yet true for Germany. The German adaptations of two effort tests, the Medical Symptom Validity Test (MSVT) by Green and the Amsterdam Short-Term Memory Test (ASTM) by Schmand et al., were investigated with a German-language sample. An analog study was performed with 18 healthy experimental malingerers and 18 controls with a mean age of 25.4 years. The scenario contained detailed information about mild post-traumatic cognitive impairment, as well as an explicit warning against symptom exaggeration. In addition to MSVT and ASTM, the Trail Making Test (TMT), the Complex Figure Test (CFT), and Digit Span were performed. Half of the sample were also given Rey's 15-Item-Test (FIT). Both groups were significantly different in all effort and performance measures, with the exception of the ratio TMT-B:TMT-A. With MSVT and ASTM, correct classification of group membership was between 97 and 100%. For the ratio TMT-B:TMT-A, there was a considerable overlap in the test scores for the two groups and the sensitivity of the FIT was too low. Although the ASTM and the MSVT were identified by a number of subjects as possible effort measures, both tests obtained very good results within this analog design.     

Distraktionsosteogenese der Mandibula bei kraniofazialen Fehlbildungen

In recent years, lengthening the human mandible by distraction osteogenesis has become an accepted treatment to correct severe mandibular hypoplasia. Using intraoral unidirectional and extraoral bidirectional distraction devices we report about our experiences and results in the application of the bone distraction technique in four selected cases of syndromal disease, including various forms of mandibular hypoplastic malformations. The patients involved were a boy with Pierre Robin syndrome, a girl with unilateral facial hypoplasia in Goldenhar's syndrome, a case with Nager's syndrome, and a rare case of midline deficiency caused by partial deletion of chromosome 18 (18p-syndrome). The distraction period lasted from 6 to 30 days and new bone formation, ranging from 6 to 28 mm, was achieved.     

An analysis of the Hooper Visual Organization Test with neurological patients

An item analysis of the Hooper Visual Organization Test (VOT) was performed using the test protocols of 320 German-speaking neurological patients with a mean age of 51.3 years. All patients presented some form of cerebral pathology. The sample yielded a mean test score of 18.8 (SD = 6.2). Estimates of internal consistency of the total scale yielded acceptable results (>.88). Although the VOT was judged to be a useful instrument for assessing visuoperceptual and visuospatial-organizational dysfunction, item characteristics of the test are not satisfactory. In particular, the item ranking does not correspond to the order of difficulty. Moreover, in their current form, scoring rules of a number of items seem to be arbitrary and not founded on empirical data. A revision of the VOT is proposed to improve its psychometric properties.     

Neuropsychologie des Normaldruckhydrozephalus

Although dementia is described as one of the constituent characteristics of normal pressure hydrocephalus (NPH), alongside gait disturbances and urinary incontinence, there is a rather limited number of controlled studies concerning neuropsychological deficits in the disease. A wide range of psychopathologically relevant symptoms have been described, but the common features of most cases include mental and motor slowing, apathy, emotional indifference, anosognosia, memory and attentional impairment. A number of other functional deficits such as dyslexia, dysgraphia, acalculia, apraxia can also frequently be found. Some emphasis is put on the work of J. de Mol (Brussels) which appears to be most important for the study of neuropsychological symptoms in NPH patients. The methodological standard of a number of studies has been found to be rather low, and yet a sound neuropsychological investigation may be of utmost importance for the diagnosis and neurosurgical outcome assessment. Concerning morphological correlates of the functional deficits in NPH, various hypotheses have been formulated, but it is argued that symptoms can neither be described as predominantly "diffuse" in nature, nor can they be reduced to unilocular dysfunctions. Recommendations for future research strategies are formulated.