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Irle E, Lange C, Ruhleder M, Exner C, Siemerkus J, Weniger G. Hippocampal size in women but not men with schizophrenia relates to disorder duration. Psychiatry Res 2011; 192:133-9. [PMID: 21546218 DOI: 10.1016/j.pscychresns.2010.12.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 12/12/2010] [Accepted: 12/13/2010] [Indexed: 01/12/2023]
Abstract
Longitudinal studies have failed to find progressive hippocampal size reduction in schizophrenia. However, negative results may have been due to follow-up intervals at disease stages where no significant progressive brain changes occur. Furthermore, only male or mixed gender samples have been studied. Forty-six patients with schizophrenia (23 females) and 46 healthy controls (23 females) underwent three-dimensional structural magnetic resonance imaging of the hippocampus and a clinical investigation. Compared with controls, male but not female participants with schizophrenia displayed hippocampal size reduction. Hippocampal size of female but not male schizophrenia patients was related to disorder duration, indicating smaller hippocampal size in female patients with longer disorder duration. Female schizophrenia patients displayed normal hippocampal size at the onset of disorder, but similarly reduced hippocampal size as male schizophrenia patients after some years of illness had passed. Our results suggest preserved hippocampal size in women with schizophrenia during the first years of illness.
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Timpano KR, Exner C, Glaesmer H, Rief W, Keshaviah A, Brähler E, Wilhelm S. The epidemiology of the proposed DSM-5 hoarding disorder: exploration of the acquisition specifier, associated features, and distress. J Clin Psychiatry 2011; 72:780-6; quiz 878-9. [PMID: 21733479 DOI: 10.4088/jcp.10m06380] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 10/20/2010] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Compulsive hoarding, characterized by the acquisition of and failure to discard a large number of possessions, is increasingly recognized as a significant public health burden. Many facets of the phenomenology, including an understanding of the population prevalence and associated features, are not yet fully understood. There is growing evidence that hoarding may warrant its own diagnosis in DSM-5, and it is therefore imperative to investigate the proposed cardinal symptoms along with correlated features that may be diagnostically relevant. METHOD The present investigation examined the point prevalence of hoarding disorder in a nationally representative sample from the German population (N = 2,512). The hoarding definition considered in this study was derived from the Hoarding Rating Scale (HRS) and informed by 3 of the proposed DSM-5 criteria. Several hypothesized core components of hoarding disorder were also assessed using questions from the HRS and the UCLA Hoarding Severity Scale, including types of acquisition, perfectionism, indecision, procrastination, distress, and impairment. Data were collected from May 16, 2009, to June 19, 2009. RESULTS Analyses revealed a current population estimate of 5.8%. Hoarding prevalence did not differ between men and women. Hoarders were significantly more likely to buy items, acquire free things, and steal items they did not need, compared to nonhoarders (P < .001). Perfectionism, indecision, and procrastination were all uniquely and significantly associated with hoarding status (P < .001). Relationships between the proposed core features and distress/impairment are also detailed. CONCLUSIONS The current investigation identified the proposed hoarding disorder as a highly prevalent syndrome; however, it should be noted that we were not able to fully ascertain the DSM-5 criteria and that the current estimate may be higher than the actual population rate. Future research on the diagnostic criteria and associated features will be necessary to help clarify etiologic underpinnings, treatment efforts, and diagnostic nosology.
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Kikul J, Vetter J, Lincoln TM, Exner C. Effects of cognitive self-consciousness on visual memory in obsessive-compulsive disorder. J Anxiety Disord 2011; 25:490-7. [PMID: 21236631 DOI: 10.1016/j.janxdis.2010.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 12/10/2010] [Accepted: 12/11/2010] [Indexed: 11/30/2022]
Abstract
Previous research has documented high trait cognitive self-consciousness (CSC) in obsessive-compulsive disorder (OCD). It remains unclear whether elevated CSC levels can also explain cognitive performance deficits that have frequently been found in OCD. This study examined whether experimentally heightened CSC affects visual memory performance in OCD. OCD participants and healthy controls completed a complex figure test under three experimental conditions: simultaneously focusing on their thoughts (= CSC condition), simultaneously focusing on acoustic stimuli (= dual-task condition), and without a parallel task (= standard condition). In the OCD sample both the CSC condition and the dual-task condition reduced memory performance compared to the standard condition, whereas in controls only the dual-task condition led to reduced performance. Results indicate that raising CSC in OCD has a deteriorating effect on memory encoding that parallels the effect of a secondary task. High CSC and its effects on cognitive performance might be amenable to meta-cognitive treatment approaches.
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Karakas E, Steinfeldt T, Gockel A, Schlosshauer T, Dietz C, Jäger J, Westermann R, Sommer F, Richard HR, Exner C, Sesterhenn AM, Bartsch DK. Transoral thyroid and parathyroid surgery--development of a new transoral technique. Surgery 2011; 150:108-15. [PMID: 21458014 DOI: 10.1016/j.surg.2010.12.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Accepted: 12/24/2010] [Indexed: 12/26/2022]
Abstract
BACKGROUND Transluminal interventions via so-called natural orifices are gaining interest because they allow operative treatment without any skin incision. We previously described a transoral access for (para-)thyroid resection in pigs. To proceed with the first clinical trials, we evaluated the safety of the new technique. METHODS Transoral hemithyroidectomies were performed on 10 living pigs using a special cervicoscope and conventional laparoscopic instruments. Follow-up examinations were carried out for 14 days and followed by autopsy, which included macroscopic evaluation, microbiologic investigations, and blood testing. In addition, refinement of the new technique was achieved by developing the techniques in 10 human cadavers. Finally, transoral parathyroidectomies were performed in 2 patients with primary hyperparathyroidism and a preoperatively localized parathyroid adenoma. RESULTS All animal transoral hemithyroidectomies were performed without complications. Postoperatively, oral intake, weight gain, and white blood cell count remained normal. At autopsy, the access route, and operative field showed no signs of infection, and microbiologic swabs remained sterile. Based on these results, a transoral parathyroidectomy was performed successfully in 2 female patients with primary hyperparathyroidism; 1 patient experienced a transient palsy of the right hypoglossal nerve. CONCLUSION Transoral parathyroid and thyroid operation is feasible; however, additional controlled clinical studies are required to evaluate the safety and success rates of this new technique.
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Doering BK, Conrad N, Rief W, Exner C. Living with acquired brain injury: Self-concept as mediating variable in the adjustment process. Neuropsychol Rehabil 2011; 21:42-63. [DOI: 10.1080/09602011.2010.525947] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Mueller A, Mitchell JE, Crosby RD, Gefeller O, Faber RJ, Martin A, Bleich S, Glaesmer H, Exner C, de Zwaan M. Estimated prevalence of compulsive buying in Germany and its association with sociodemographic characteristics and depressive symptoms. Psychiatry Res 2010; 180:137-42. [PMID: 20494451 DOI: 10.1016/j.psychres.2009.12.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 12/07/2009] [Accepted: 12/09/2009] [Indexed: 10/19/2022]
Abstract
The aim of this study was to estimate the prevalence of compulsive buying and its association with sociodemographic characteristics and depressive symptoms in a nationally representative sample of the German population using the validated German version of the Compulsive Buying Scale (CBS; Faber and O'Guinn, 1992) in order to have a direct comparison with U.S. findings. The point prevalence of compulsive buying in the weighted representative sample (N=2,350) was estimated to be 6.9%. This was somewhat higher than the percentage in the American sample assessed in 2004 (5.8%). No significant difference was found between women and men (6.9% and 6.8%, respectively). Age was inversely related to the prevalence of compulsive buying. Individuals with compulsive buying reported more depressive symptoms assessed via the German version of the Brief Patient Health Questionnaire Mood Scale (PHQ-9). Further research on this topic is needed to establish a clearer delineation of when excessive buying is clinically significant and should be treated and how it could be prevented.
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Lincoln TM, Lange J, Burau J, Exner C, Moritz S. The effect of state anxiety on paranoid ideation and jumping to conclusions. An experimental investigation. Schizophr Bull 2010; 36:1140-8. [PMID: 19429844 PMCID: PMC2963045 DOI: 10.1093/schbul/sbp029] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Theoretical models of persecutory delusions have emphasized the impact of reasoning biases and negative emotion at the early stages of symptom formation. However, the causal mechanisms remain unclear. This study tests the hypothesis that state anxiety will increase paranoid ideation and that this increase will be moderated by the level of individual vulnerability and mediated by the tendency to jump to conclusions. Healthy participants (n = 90) with varying levels of vulnerability (psychosis symptoms assessed by the Community Assessment of Psychic Experiences) were randomly assigned to either an anxiety or a nonanxiety condition. Anxiety was induced by pictures from the International Affective Picture System and by in sensu exposure to individual anxiety-provoking situations. During each condition, symptoms of paranoia were assessed by a state-adapted version of the Paranoia Checklist. Jumping to conclusions (JTC) was assessed using a modified version of the beads task. Overall, participants in the anxiety condition reported significantly more paranoid thoughts and showed more JTC than participants in the neutral condition. Participants with higher baseline vulnerability were more likely to show an increase in paranoia as reaction to the anxiety manipulation. Moreover, the association of anxiety and paranoia was mediated by the increased tendency to jump to conclusions in the beads task. The results are in line with a threat anticipation conceptualization of paranoia and provide evidence for an interaction of anxiety and reasoning biases in the development of paranoid beliefs. A combination of meta-cognitive training directed at reasoning biases and promoting emotion regulation skills might prove beneficial in preventing symptoms.
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Braulke L, Heldmaier G, Berriel Diaz M, Rozman J, Exner C. Seasonal changes of myostatin expression and its relation to body Mass acclimation in the Djungarian hamster, Phodopus sungorus. ACTA ACUST UNITED AC 2010; 313:548-56. [DOI: 10.1002/jez.626] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Lincoln TM, Mehl S, Ziegler M, Kesting ML, Exner C, Rief W. Is fear of others linked to an uncertain sense of self? The relevance of self-worth, interpersonal self-concepts, and dysfunctional beliefs to paranoia. Behav Ther 2010; 41:187-97. [PMID: 20412884 DOI: 10.1016/j.beth.2009.02.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 02/25/2009] [Accepted: 02/28/2009] [Indexed: 11/24/2022]
Abstract
The assumption that a low sense of self-worth can give rise to paranoid delusions is relevant from a therapeutic perspective, but research has been inconsistent. The present study sought to investigate how interpersonal self-concepts and global self-worth relate to psychotic and depressive psychopathology in persons with psychosis. Participants with psychosis (n=83) and healthy controls (n=33) were assessed for global self-worth, interpersonal self-concepts, and dysfunctional beliefs using the Frankfurt Self-Concept Scale and the Dysfunctional Attitude Scale. Symptoms were assessed with the Positive and Negative Syndrome Scale, the Peters et al. Delusions Inventory, the Paranoia Checklist, and the Beck Depression Inventory. We hypothesized that perceived threat to self-worth, as expressed in dysfunctional acceptance beliefs and negative interpersonal self-concepts, would be uniquely associated with persecutory delusions. In contrast, low global self-worth would be strongly associated with symptoms of depression. Multiple regression analyses were used to investigate the association between symptoms and self-concepts. As expected, low global self-worth was associated with depression, whereas the more specific perception of not being accepted by relevant others was most clearly related to psychotic symptoms. Almost half of the variance in paranoia scores was explained by negative interpersonal self-concepts and the interaction between negative interpersonal self-concepts and dysfunctional acceptance beliefs. Thus, cognitive interventions for delusions might be improved by focusing more on interpersonal self-concepts.
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Conrad N, Doering BK, Rief W, Exner C. Looking beyond the importance of life goals. The personal goal model of subjective well-being in neuropsychological rehabilitation. Clin Rehabil 2010; 24:431-43. [DOI: 10.1177/0269215509358930] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Objective: To identify subjective importance, attainability and success of life goals and their predictive value for subjective well-being in patients with acquired brain injury. Design: Cross-sectional, descriptive. Setting: Two inpatient neurological rehabilitation centres. Participants: Patients with non-progressive neurological disorders. Interventions: Survey using questionnaires. Measures: Life goal characteristics were assessed using a life goal questionnaire (GOALS). Subjective well-being (composite score) was measured using the Center of the Epidemic Studies Depression Scale (CES-D), the Positive and Negative Affect Schedule (PANAS) and the Satisfaction With Life Scale (SWLS). Results: Fifty-nine patients participated in the study. The most important life goals are intimacy (4.59/5), achievement (3.96/5) and altruism (3.89/5). The intimacy goals are considered most attainable (4.19/5) and patients feel most successful in this domain (3.98/5). Two important predictions of the personal goal model of subjective well-being could be confirmed. First, goal attainability moderates the relation between goal importance and goal success. Second, the influence of goal importance on subjective well-being is mediated by experienced success. The most powerful predictors for subjective well-being are success in the achievement domain (β = 0.404) and discrepancy between importance and success in the intimacy domain (β = —0.276). Conclusions: The subjective well-being of neurological patients depends not only on the appraised importance of life goals but also on their attainability and success.
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Doering BK, Conrad N, Rief W, Exner C. Selbstkonzept nach erworbenen Hirnschädigungen: Veränderungen der Selbstwahrnehmung und Subjektives Wohlbefinden. ZEITSCHRIFT FUR NEUROPSYCHOLOGIE 2010. [DOI: 10.1024/1016-264x/a000001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Negative Selbstkonzepte stehen in Zusammenhang zu erhöhter depressiver Symptomatik, vermehrter psychosozialer Belastung und reduzierter Lebensqualität, was ihre Relevanz für Rehabilitationsprozesse begründet. Untersucht wurden Selbstkonzeptveränderungen nach erworbenen Hirnschädigungen bei PatientInnen der akuten (N = 59) und postakuten (N = 29) Rehabilitationsphase. Beide Stichproben bewerten aktuelle Selbstkonzepte verglichen mit prämorbiden Einschätzungen negativ. Faktorenanalytisch wurden 2 Selbstkonzeptbereiche ermittelt („Emotionales Erleben“, „Eigenschaften in sozialen Interaktionen“), die von der Erkrankung unterschiedlich stark betroffen sind. Negative aktuelle Selbstkonzepte stehen in engem Zusammenhang zu reduziertem Subjektivem Wohlbefinden und erklären regressionsanalytisch einen substantiellen Varianzanteil des Subjektiven Wohlbefindens. Soziodemographische und schädigungsbezogene Variablen spielen demgegenüber eine untergeordnete Rolle. Die Ergebnisse sprechen für die Berücksichtigung von Interventionen zur positiven Beeinflussung des Selbstkonzeptes in der psychotherapeutischen Behandlung von PatientInnen mit erworbenen Hirnschädigungen.
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Beblo T, Exner C. [Regarding the search for a specific neuropsychological profile in depression: limits and perspectives]. NEUROPSYCHIATRIE : KLINIK, DIAGNOSTIK, THERAPIE UND REHABILITATION : ORGAN DER GESELLSCHAFT OSTERREICHISCHER NERVENARZTE UND PSYCHIATER 2010; 24:234-242. [PMID: 21176704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
It has long been known that patients with depression show neuropsychological symptoms. A great number of studies aimed at an exact characterization of these symptoms. Scientifically, the knowledge about such a profile was thought to provide information about neurobiological dysfunctions. Clinically, this knowledge would be useful to differentiate depression from other psychiatric or neurological diseases. However, the neuropsychological profile of depression is still not well established. We discuss four perspectives that provide possible explanations for the current state of knowledge and may help to further develop our knowledge about neuropsychological dysfunctions in depression: first, because there is great variation in the aetiology and phenomenology of depression and even in different subtypes of affective disorders, unitary neuropsychological profiles can not be expected. Further research should focus on relevant factors that influence cognitive functioning of depressed patients. Second, neuropsychological tests administered should be specific for certain cognitive functions and, third, should provide emotionally relevant stimuli as well. Finally, future studies should systematically consider psychiatric control groups in addition to healthy participants. With the consideration of these factors, neuropsychological research in depression significantly contributes to our understanding and conceptualization of mental disorders.
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Exner C, Doering BK, Conrad N, Rief W. Integration von Verhaltenstherapie und Neuropsychologie. VERHALTENSTHERAPIE 2010. [DOI: 10.1159/000313848] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Exner C, Lange C, Irle E. Impaired implicit learning and reduced pre-supplementary motor cortex size in early-onset major depression with melancholic features. J Affect Disord 2009; 119:156-62. [PMID: 19345999 DOI: 10.1016/j.jad.2009.03.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 03/16/2009] [Accepted: 03/16/2009] [Indexed: 11/17/2022]
Abstract
BACKGROUND Major depression is a heterogeneous disorder. Biological markers and cognitive tasks have been employed to distinguish clinical subtypes but results have been inconclusive. METHODS The current study assessed implicit learning with the Serial Reaction Time Task (SRTT) known to be sensitive to frontostriatal dysfunctions and regional brain volumes of the anterior supplementary motor area (pre-SMA) in participants with early-onset major depression (MD) of either melancholic (n=26) or non-melancholic (n=9) subtype, and 26 matched controls. RESULTS Depressive subjects with melancholic features but not those with non-melancholic depression showed implicit learning deficits. This deficit could not be explained in terms of more severe depression or psychomotor retardation. Regional volumes of the right pre-SMA were reduced in depressive subjects with melancholic features. LIMITATIONS Medication effects in depressive subjects and the small size of the non-melancholic sample should be taken into consideration when reviewing the implications of these results. CONCLUSIONS Deficits in implicit motor sequence learning seem to be an additional characteristic of the melancholic subtype of depression. It might be linked to dysfunction within structural or functionally altered frontostriatal circuits. Use of implicit sequence learning tasks could offer useful diagnostic and aetiological cues for future research.
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Exner C, Kohl A, Zaudig M, Langs G, Lincoln TM, Rief W. Metacognition and episodic memory in obsessive-compulsive disorder. J Anxiety Disord 2009; 23:624-31. [PMID: 19233607 DOI: 10.1016/j.janxdis.2009.01.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 01/16/2009] [Accepted: 01/19/2009] [Indexed: 11/28/2022]
Abstract
Memory deficits in patients with obsessive-compulsive disorder (OCD) have been frequently reported but are not sufficiently accounted for by cognitive models of OCD. The aim of the study was to identify cognitive mechanisms that might be able to explain memory deficits in OCD. We hypothesized that a self-conscious meta-cognitive style might be responsible for reduced memory performance in OCD. Episodic verbal memory performance was assessed in 23 participants with OCD (DSM-IV criteria) and 22 matched controls. Cognitive self-consciousness was assessed with a self-report measure derived from the Meta-Cognitions Questionnaire (MCQ). Compared to controls, OCD participants showed reduced immediate and delayed recall of complex verbal material and increased self-reported levels of cognitive self-consciousness. Multiple regression analyses indicated that group differences in story recall were significantly mediated by self-reported trait cognitive self-consciousness. Results point to the deteriorating effects of a thought-focused cognitive style on effortful encoding processes in OCD.
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Exner C, Nehrkorn B, Martin V, Huber M, Shiratori K, Rief W. Sex-dependent hippocampal volume reductions in schizophrenia relate to episodic memory deficits. J Neuropsychiatry Clin Neurosci 2008; 20:227-30. [PMID: 18451195 DOI: 10.1176/jnp.2008.20.2.227] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Morphological abnormalities of the hippocampus might form the neurobiological basis of memory dysfunction in schizophrenia. Hippocampal volume was found to be bilaterally reduced in male, but not in female, subjects with schizophrenia. Right hippocampal volume was significantly related to impaired visual learning.
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Martin V, Huber M, Rief W, Exner C. Comparative cognitive profiles of obsessive-compulsive disorder and schizophrenia. Arch Clin Neuropsychol 2008; 23:487-500. [PMID: 18508232 DOI: 10.1016/j.acn.2008.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 12/09/2007] [Accepted: 03/28/2008] [Indexed: 11/28/2022] Open
Abstract
A body of neuropsychological research revealed cognitive impairments in patients suffering from obsessive-compulsive disorder (OCD). Only few investigations addressed the question of how specific these impairments are. The present study compared the performances of 19 subjects with OCD to 19 subjects with schizophrenia and 19 healthy controls on neuropsychological tasks across the main cognitive domains (memory, attention, visual spatial and executive functioning). For purposes of data-reduction, single test measures of the test battery applied were aggregated into eight cognitive domain scores. Contrary to our expectation we found comparable performance profiles of obsessive-compulsive (OC) and schizophrenia subjects across domains with impairments primarily affecting simple attentional skills and memory skills. However, deficits of subjects with schizophrenia were greater in magnitude than those of subjects with OCD on all domains assessed. Elevated depression scores exerted a relevant impact on performance deficits in the OC but not in the schizophrenia sample.
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Exner C, Martin V, Rief W. Self-Focused Ruminations and Memory Deficits in Obsessive–Compulsive Disorder. COGNITIVE THERAPY AND RESEARCH 2007. [DOI: 10.1007/s10608-007-9162-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Stumpf G, Hellmeyer L, Exner C, Folz B, Werner JA, Schmidt S, Litzke LF. Untersuchungen zur kongenitalen Zwerchfellhernie am Schafmodell nach fetalchirurgischer Therapie. Tierarztl Prax Ausg G Grosstiere Nutztiere 2007. [DOI: 10.1055/s-0037-1621510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Zusammenfassung
Gegenstand: Das Krankheitsbild der kongenitalen Zwerchfellhernie (CDH) ist aufgrund der damit häufig assoziierten Lungenhypoplasie mit einer Letalität von > 50% oder einer Langzeitmorbidität behaftet. Hieraus ergibt sich als einzige rationale Alternative zum Schwangerschaftsabbruch, bereits in utero durch minimal invasive fetalchirurgische Maßnahmen ein therapeutisches Vorgehen einzuleiten. Durch Okklusion der Trachea mithilfe eines Ballonkatheters erfolgt eine Retention des Trachealsekretes mit konsekutiver Ausdehnung des Lungengewebes, sodass hernierte Organe zurückgedrängt werden können und die Lungenentwicklung unbeeinträchtigt bleibt. Ziel: Die Untersuchung diente dazu, ein röntgenologisches Verfahren zu etablieren, mit dem nach der trachealen Okklusion beim ungeborenen Lamm der Therapieerfolg kontrolliert werden kann. Material und Methoden: Am etablierten Schafmodell für fetalchirurgische Operationen wurde am 105. Gestationstag bei Merinoschafen (Tragzeit 150 Tage) ein Brillant-Ballonkatheter aus dem Bereich der Neonatologie endoskopisch eingesetzt, der mit 1 ml Solutrast®-Kontrastmittel geblockt wurde. Am ersten postoperativen Tag erfolgte die Röntgenuntersuchung am stehenden Tier. Nach der Ermittlung des optimalen Verfahrens wurde mit konventioneller Röntgentechnologie durch Verlaufsuntersuchungen der Sitz des Katheters beim prämaturen Lamm kontrolliert. Ergebnis: Der minimal invasiv platzierte Katheter zeigte keine Deviation. Schlussfolgerung: Die Technik der trachealen Okklusion bei fetaler CDH kann interdisziplinär suffizient durchgeführt werden, wobei radiologische Untersuchungen des ungeborenen Schaffeten eine zusätzliche Möglichkeit bieten, den Therapieerfolg zu kontrollieren.
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Hellmeyer L, Exner C, Folz B, Hiller M, Sierra F, Lukasewitz P, Steinfeld T, Werner JA, Heldmaier G, Schmidt S. Telemetric monitoring of tracheal pressure after tracheal occlusion for treatment of severe congenital diaphragmatic hernia. Arch Gynecol Obstet 2006; 275:245-8. [PMID: 17021771 DOI: 10.1007/s00404-006-0252-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Accepted: 08/29/2006] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Prenatal tracheal occlusion using endoscopic techniques obstructs the normal egress of lung fluid during pulmonary development and stimulates lung growth in cases of congenital diaphragmatic hernia (CDH). Although FETO might be an effective strategy for treatment of CDH, the mechanism especially due to the supposed increasing transpulmonary pressure is unknown. OBJECTIVE The purpose of this study was to monitor the pressure below the attached balloon in the fetal lamb telemetrically. METHODS Four time-dated pregnant Merino ewes underwent fetal and maternal surgery. A special prepared silicone catheter was placed below the epiglottis by laryngoscopy on day 110 or 140 of gestation. The tracheal pressure below the fixed catheter could be monitored telemetrically using the Data Sciences TA11-PA-C40 pressure device. Hundred and twenty measurement points were recorded over a period of 2 min. RESULTS A maximum of lung pressure rate was found immediately after implantation (23.7 +/- 4.6 mm Hg). During the first hour, the pressure decreased to an average value of 16.9 mmHg. About 70 h after the block, this value decreased to a minimum level of 8.3 +/- 0.4 mmHg. CONCLUSION Decreasing pressure variation might indicate that lung growth has stopped and that the ideal point of time to remove the balloon is achieved. Increasing pressure has to be related to the morphometric analysis of the lung's structural development and maturation, comparing the efficacy of FETO in preventing or reversing pulmonary hypoplasia. Further investigation of continuous telemetric monitoring of tracheal pressure in the fetal lamb is required.
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Exner C, Weniger G, Schmidt-Samoa C, Irle E. Reduced size of the pre-supplementary motor cortex and impaired motor sequence learning in first-episode schizophrenia. Schizophr Res 2006; 84:386-96. [PMID: 16624528 DOI: 10.1016/j.schres.2006.03.013] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Revised: 03/01/2006] [Accepted: 03/05/2006] [Indexed: 11/29/2022]
Abstract
Increasing evidence suggests that schizophrenia is associated with various morphological and functional abnormalities of the frontal cortex. So far research has concentrated on the dorsolateral and orbitofrontal cortex. Behavioral evidence suggests however that regions responsible for higher motor control are compromised in schizophrenia as well. The current study assessed volumes of the anterior supplementary motor area (pre-SMA) and implicit motor sequence learning in 15 subjects with first-episode schizophrenia and 15 healthy matched controls. Pre-SMA volumes were assessed by three-dimensional structural magnetic resonance imaging (3D-MRI) and manual parcellation according to an established protocol. Implicit motor sequence learning was assessed using the Serial Reaction-Time Task (SRTT). Compared with control subjects, schizophrenia subjects had significantly smaller volumes of the left pre-SMA (16%). Subjects with schizophrenia were severely impaired on sequence-specific implicit motor learning. Size of the left pre-SMA of schizophrenia subjects was significantly related to impaired implicit learning. We conclude that subjects with first-episode schizophrenia have a morphological abnormality of the left pre-SMA that might predispose them to develop disturbances of higher motor control during acute episodes of psychosis. These structural and behavioral abnormalities might be conceptualized within a broader model that views schizophrenia as a disorder of disturbed coordination of thought and action.
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Helwig M, Khorooshi RMH, Tups A, Barrett P, Archer ZA, Exner C, Rozman J, Braulke LJ, Mercer JG, Klingenspor M. PC1/3 and PC2 gene expression and post-translational endoproteolytic pro-opiomelanocortin processing is regulated by photoperiod in the seasonal Siberian hamster (Phodopus sungorus). J Neuroendocrinol 2006; 18:413-25. [PMID: 16684131 DOI: 10.1111/j.1365-2826.2006.01431.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A remarkable feature of the seasonal adaptation displayed by the Siberian hamster (Phodopus sungorus) is the ability to decrease food intake and body weight (by up to 40%) in response to shortening photoperiod. The regulating neuroendocrine systems involved in this adaptation and their neuroanatomical and molecular bases are poorly understood. We investigated the effect of photoperiod on the expression of prohormone convertases 1 (PC1/3) and 2 (PC2) and the endoproteolytic processing of the neuropeptide precursor pro-opiomelanocortin (POMC) within key energy balance regulating centres of the hypothalamus. We compared mRNA levels and protein distribution of PC1/3, PC2, POMC, adrenocorticotrophic hormone (ACTH), alpha-melanocyte-stimulating hormone (MSH), beta-endorphin and orexin-A in selected hypothalamic areas of long day (LD, 16:8 h light:dark), short day (SD, 8:16 h light:dark) and natural-day (ND, photoperiod depending on time of the year) acclimated Siberian hamsters. The gene expression of PC2 was significantly higher within the arcuate nucleus (ARC, P < 0.01) in SD and in ND (versus LD), and is reflected in the day length profile between October and April in the latter. PC1/3 gene expression in the ARC and lateral hypothalamus was higher in ND but not in SD compared to the respective LD controls. The immunoreactivity of PC1/3 cleaved neuropeptide ACTH in the ARC and PC1/3-colocalised orexin-A in the lateral hypothalamus were not affected by photoperiod changes. However, increased levels of PC2 mRNA and protein were associated with higher abundance of the mature neuropeptides alpha-MSH and beta-endorphin (P < 0.01) in SD. This study provides a possible explanation for previous paradoxical findings showing lower food intake in SD associated with decreased POMC mRNA levels. Our results suggest that a major part of neuroendocrine body weight control in seasonal adaptation may be effected by post-translational processing mediated by the prohormone convertases PC1/3 and PC2, in addition to regulation of gene expression of neuropeptide precursors.
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Exner C, Boucsein K, Degner D, Irle E. State-dependent implicit learning deficit in schizophrenia: evidence from 20-month follow-up. Psychiatry Res 2006; 142:39-52. [PMID: 16580734 DOI: 10.1016/j.psychres.2005.09.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Revised: 09/22/2005] [Accepted: 09/29/2005] [Indexed: 11/30/2022]
Abstract
Previous research has confirmed stable explicit memory deficits in schizophrenia across disease states. However, little is known about the implicit learning capabilities of individuals with schizophrenia across the course of illness. The current study assessed procedural learning in 19 schizophrenia subjects (DSM-IV criteria) and 19 matched controls using the Serial Reaction-Time Task (SRTT). The severity of negative, positive and disorganized symptoms was assessed using the Scales for the Assessment of Positive and Negative Symptoms. A sub-sample of 11 schizophrenia subjects and 11 controls was reassessed 20 months later when symptoms in the schizophrenia subjects had largely remitted. Schizophrenia subjects were severely impaired on sequence-specific procedural learning during an acute episode. This deficit could not be explained by a general memory or processing speed impairment. Impaired implicit learning scores were significantly related to higher ratings of disorganized symptoms. However, 20 months later, when acute symptoms had remitted, the performance of the schizophrenia subjects on procedural learning had normalized. Our findings might share a conceptual overlap with previous reports of a reduced ability of schizophrenia subjects during an acute episode to adapt ongoing perceptual and behavioral programs to previously experienced regularities in their environment.
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Seebeck P, Bail HJ, Exner C, Schell H, Michel R, Amthauer H, Bragulla H, Duda GN. Do serological tissue turnover markers represent callus formation during fracture healing? Bone 2005; 37:669-77. [PMID: 16126014 DOI: 10.1016/j.bone.2005.06.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Revised: 06/06/2005] [Accepted: 06/13/2005] [Indexed: 10/25/2022]
Abstract
Serological parameters of bone and fibrous tissue turnover were demonstrated to monitor the course of fracture healing. The aim of this study was to evaluate the correlation between the serological parameter levels during fracture healing and callus development in a standardised ovine model of fracture healing. Two years old female sheep received a standardised 3 mm tibial bone defect stabilised by an external fixator. The serological levels of the C-terminal propeptide of procollagen type I (PICP), bone specific alkaline phosphatase (bALP), total alkaline phosphatase (tALP), osteocalcin, tartrate-resistant acid phosphatase (TRAP), calcium, phosphate and the N-terminal peptide of procollagen type III (PIIINP) were observed over a 9-week healing period. The course of fracture healing was monitored radiographically, and the callus composition was evaluated histologically at 2, 3, 6 and 9 weeks post-surgery. The serological results were compared with an untreated control group. Additionally, the maximum values during healing were compared with juvenile values to gauge the level of the serological response. The histological and radiographical results demonstrated callus formation without complications. All serological parameters showed broad inter-individual variations, and the response to the standardised fracture scenario was strongly individual. Maximum values during fracture healing did not reach the juvenile levels. The fractured as well as the control animals showed significant changes in the parameter levels. No correlations were observed between the histological course of healing and the course of bone formation markers whilst the TRAP level was reduced during bony callus formation. The PIIINP level increased when the amount of soft callus tissue decreased during healing. The observed bone formation markers were not suitable as general markers to detect the course of fracture healing, whilst PIIINP was able to reflect soft callus degradation.
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Abstract
The authors sought to clarify whether lesions in different parts of the cerebellum result in differential cognitive and affective impairment. Six subjects with cerebellar lesions due to posterior inferior cerebellar artery (PICA) infarction, five subjects with lesions in the SCA vascular territory, and 11 matched controls were administered a battery of standard neuropsychological tests. PICA lesions but not SCA lesions resulted in cognitive and affective deficits pointing to a dominant role of posterior cerebellar regions in cognitive and affective processing.
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Dinkel A, Berth H, Exner C, Rief W, Balck F. Deutsche Adaptation der Restraint Scale zur Erfassung gezügelten Essverhaltens. DIAGNOSTICA 2005. [DOI: 10.1026/0012-1924.51.2.67] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Zusammenfassung. Mit dem Konstrukt des gezügelten Essverhaltens wird die Kontrolle der Nahrungsaufnahme mit der Absicht, eine Gewichtsreduktion zu erreichen, bezeichnet. Diesem Essstil wird eine zentrale Rolle bei der Entstehung von Adipositas und Essstörungen zugeschrieben. Eines der international am weitesten verbreiteten Verfahren zur Erfassung gezügelten Essverhaltens ist die Restraint Scale (RS) von Herman und Polivy (1980) . In der vorliegenden Studie wurde die Reliabilität und Validität der deutschen Form der RS bei einer Stichprobe von N = 349 Studenten untersucht. Die zweifaktorielle Struktur der RS konnte exakt repliziert werden. Die Gesamtskala weist ein Cronbachs Alpha von .83 auf. Bezüglich der Kriteriumsvalidität der RS zeigten sich signifikante Unterschiede zwischen Männern und Frauen. Weiterhin hatten gezügelte Esser einen signifikant höheren BMI und sie berichteten ein höheres Maß an dysfunktionalen Einstellungen im EDI. Hinweise auf die Konstruktvalidität zeigten sich durch signifikante Korrelationen der RS mit Skalen des EDI und Maßen der psychischen Befindlichkeit (ADS, BAI, SCL-K-9).
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Ehrhardt N, Heldmaier G, Exner C. Adaptive mechanisms during food restriction in Acomys russatus: the use of torpor for desert survival. J Comp Physiol B 2005; 175:193-200. [PMID: 15742195 DOI: 10.1007/s00360-005-0475-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Revised: 12/10/2004] [Accepted: 01/21/2005] [Indexed: 11/28/2022]
Abstract
The golden spiny mouse (Acomys russatus) is an omnivorous desert rodent that does not store food, but can store large amounts of body fat. Thus, it provides a good animal model to study physiological and behavioural adaptations to changes in food availability. The aim of this study was to investigate the time course of metabolic and behavioural responses to prolonged food restriction. Spiny mice were kept at an ambient temperature of 27 degrees C and for 3 weeks their food was reduced individually to 30% of their previous ad libitum food intake. When fed ad libitum, their average metabolic rate was 82.77+/-3.72 ml O(2) h(-1) during the photophase and 111.19+/-4.30 ml O(2) h(-1) during the scotophase. During food restriction they displayed episodes of daily torpor when the minimal metabolic rate gradually decreased to 16.07+/-1.07 ml O(2) h(-1), i.e. a metabolic rate depression of approximately 83%. During the hypometabolic bouts the minimum average body temperature T(b), decreased gradually from 32.6+/-0.1 degrees C to 29.0+/-0.4 degrees C, with increasing duration of consecutive bouts. In parallel, the animals increased their activity during the remaining daytime. Torpor as well as hyperactivity was suppressed immediately by refeeding. Thus golden spiny mice used two simultaneous strategies to adapt to shortened food supply, namely energysaving torpor during their resting period and an increase in locomotor activity pattern during their activity period.
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Exner C, Boucsein K, Degner D, Irle E, Weniger G. Impaired emotional learning and reduced amygdala size in schizophrenia: a 3-month follow-up. Schizophr Res 2004; 71:493-503. [PMID: 15474920 DOI: 10.1016/j.schres.2004.02.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2004] [Revised: 02/23/2004] [Accepted: 02/27/2004] [Indexed: 11/15/2022]
Abstract
Individuals with schizophrenia have difficulties in emotional information processing. A relationship between behavioral variables of emotional processing and structural amygdala alterations in schizophrenia has been proposed but not shown, yet. Morphological studies of amygdala size in schizophrenia have yielded inconsistent results. The current study assessed paired associates learning of emotional and neutral faces in 16 subjects with schizophrenia during acute episode and in relative remission after 3 months. Sixteen matched controls were studied for comparison. Subjects also underwent structural magnetic resonance imaging (3D-MRI) at the first time of assessment. Subjects with schizophrenia showed a significant decrease (by 13%) in total size of the amygdala compared to controls, which was more pronounced on the right side. Subjects with schizophrenia improved associative learning of facial identities but not of emotional facial expressions after relative remission of psychotic symptoms. Volume of the right amygdala in subjects with schizophrenia and in controls was significantly related to emotional learning, indicating better learning in subjects with larger amygdala size. Our results indicate that subjects with schizophrenia have a deficit to form associations when emotionally loaded material is used. This deficit seems to be trait-like and independent of disease state. It seems to be linked to size reduction of the right amygdala in schizophrenia.
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Exner C, Wehrend A, Hospes R, Einspanier A, Hoffmann B, Heldmaier G. Hormonal and behavioural changes during the mating season and pregnancy in Alpine marmots (Marmota marmota). Reproduction 2003; 126:775-82. [PMID: 14748696 DOI: 10.1530/rep.0.1260775] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Under natural and artificial conditions, Alpine marmots (Marmota marmota) are true hibernators with a single breeding season starting immediately upon emergence from hibernation. Over three mating and breeding seasons, hormonal and mating patterns of colony-housed reproductive female marmots were investigated after exit from hibernation. Blood samples were taken for progesterone, oestrogen and relaxin assays with parallel ultrasound investigations. Copulations were observed from the first day after exit from hibernation until the end of pregnancy and reached a maximum number on day 37 before parturition. Mating behaviour was observed between the dominant animals as well as between dominant and subdominant group members. In the first week after exit from hibernation, plasma progesterone was detected in half of the animals. During the third week, progesterone concentrations were significantly higher in pregnant than in non-pregnant animals or animals that had aborted. Immediately after emerging from hibernation, all successfully mated females showed higher serum relaxin values than non-successfully mated animals and this increase in relaxin concentration lasted until the end of pregnancy. The total concentration of oestrogen did not differ between pregnant and non-pregnant animals. The results of this study indicate that progesterone and relaxin might be useful indicators of early pregnancy in Alpine marmots.
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Dinkel A, Berth H, Exner C, Rief W, Balck F. Psychische Symptome bei Studentinnen in Ost- und Westdeutschland: Eine Replikation nach 10 Jahren. VERHALTENSTHERAPIE 2003. [DOI: 10.1159/000074025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Nitsche M, Schauenburg A, Exner C, Lang N, Tergau F, Paulus W. Transkranielle Gleichstromstimulation des motorischen Kortex verbessert implizites motorisches Lernen. KLIN NEUROPHYSIOL 2003. [DOI: 10.1055/s-2003-816500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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82
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Hebebrand J, Exner C, Hebebrand K, Holtkamp C, Casper RC, Remschmidt H, Herpertz-Dahlmann B, Klingenspor M. Hyperactivity in patients with anorexia nervosa and in semistarved rats: evidence for a pivotal role of hypoleptinemia. Physiol Behav 2003; 79:25-37. [PMID: 12818707 DOI: 10.1016/s0031-9384(03)00102-1] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Patients with anorexia nervosa (AN) often show normal to elevated physical activity levels despite severe weight loss and emaciation. This is seemingly in contrast to the loss of energy and fatigue characteristic of other starvation states associated with weight loss. Despite the fact that historical accounts and clinical case studies of AN have regularly commented on the elevated activity levels, the behavior has become only recently the subject of systematic study. Because rodents and other species increase their activity upon food restriction leading to weight loss when given access to an activity wheel--a phenomenon referred to as activity-based anorexia or semi-starvation-induced hyperactivity (SIH)-it has been proposed that the hyperactivity in AN patients may reflect the mobilization of phylogenetically old pathways in individuals predisposed to AN. Exogeneous application of leptin in this animal model of AN has recently been shown to suppress completely the development of SIH. Hypoleptinemia, as a result of the food restriction, may represent the initial trigger for the increased activity levels in AN patients and in food-restricted rats. In the first and second parts of our review, we will summarize the relevant findings pertaining to hyperactivity in AN patients and in the rat model, respectively. We conclude with a synopsis and implications for future research.
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Nitsche MA, Schauenburg A, Lang N, Liebetanz D, Exner C, Paulus W, Tergau F. Facilitation of implicit motor learning by weak transcranial direct current stimulation of the primary motor cortex in the human. J Cogn Neurosci 2003; 15:619-26. [PMID: 12803972 DOI: 10.1162/089892903321662994] [Citation(s) in RCA: 677] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Transcranially applied weak direct currents are capable of modulating motor cortical excitability in the human. Anodal stimulation enhances excitability, cathodal stimulation diminishes it. Cortical excitability changes accompany motor learning. Here we show that weak direct currents are capable of improving implicit motor learning in the human. During performance of a serial reaction time task, the primary motor cortex, premotor, or prefrontal cortices were stimulated contralaterally to the performing hand. Anodal stimulation of the primary motor cortex resulted in increased performance, whereas stimulation of the remaining cortices had no effect. We conclude that the primary motor cortex is involved in the acquisition and early consolidation phase of implicit motor learning.
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Exner C, Koschack J, Irle E. The differential role of premotor frontal cortex and basal ganglia in motor sequence learning: evidence from focal basal ganglia lesions. Learn Mem 2002; 9:376-86. [PMID: 12464697 PMCID: PMC187585 DOI: 10.1101/lm.48402] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2002] [Accepted: 09/04/2002] [Indexed: 11/24/2022]
Abstract
There has been a growing interest in the differential role of various neural structures in implicit learning processes. The goal of our study was to clarify how focal lesions restricted to the basal ganglia interfere with different aspects of implicit visuo-motor sequence learning. A version of the Serial Reaction Time Task (SRTT) of Nissen and Bullemer using a 12-trial sequence was administered. A total of 20 subjects with focal basal ganglia lesions caused by ischemic or hemorrhagic infarction and 20 matched control subjects participated in this study. The results indicate that subjects with focal basal ganglia lesions showed unimpaired implicit learning of a 12-item motor sequence. Subjects with basal ganglia lesions, however, had more difficulties improving their general proficiency with the reaction-time task independent of sequence-specific learning. We observed a tendency toward smaller regional volumes in the cerebellum and left pre-supplementary motor area (pre-SMA) of subjects with basal ganglia lesions. Smaller cerebellar and pre-SMA volumes were related to lower implicit learning performance in the lesion group. The size of lesions in the basal ganglia was not related to sequence-specific implicit learning but had a significant influence on subjects' general proficiency for execution of the reaction-time task. We propose that implicit learning is achieved by a distributed network of cortical and subcortical structures. The basal ganglia seem to be responsible for adjusting to the general requirements of a task rather than for learning specific associations between stimuli that might be accomplished by premotor frontal areas and the cerebellum instead.
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Exner C, Boucsein K, Lange C, Winter H, Weniger G, Steinhoff BJ, Irle E. Neuropsychological performance in frontal lobe epilepsy. Seizure 2002; 11:20-32. [PMID: 11888256 DOI: 10.1053/seiz.2001.0572] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The search for a special neuropsychological profile of frontal lobe epilepsy subjects (FLE) has so far led to inconclusive results. In this paper we compared the preoperative neuropsychological performance of FLE and temporal lobe epilepsy (TLE) subjects. We further investigated whether frontal lobe lesions of epileptogenic cause produce the same type of cognitive dysfunction as do tumours of the frontal lobe. Sixteen FLE subjects were compared to 16 TLE subjects as well as to a group of 10 subjects after the removal of frontal lobe tumors (TUM) and a healthy control group. A set of neuropsychological test measures routinely used for presurgical evaluation, an emotional conceptualization task and two associative learning tasks were administered. We found that subjects with frontal lobe damage were significantly impaired relative to controls on a wide range of cognitive functions independent of neurological cause. FLE subjects could hardly be discriminated from TLE subjects as both groups showed a similarly reduced level of neuropsychological performance. Our results demonstrate the devastating effect that frontal lobe epilepsy can have on cognitive functioning. Routinely used neuropsychological test measures lack the specificity to distinguish between frontal and temporal lobe epilepsy. Highly specialized measures are necessary to reveal differences.
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Abstract
BACKGROUND Lesions of the thalamus interfere with cognitive functions mainly in the area of declarative learning and memory. Little is known about the role the thalamus plays in implicit learning. OBJECTIVE To study explicit and implicit learning and memory in subjects with thalamic lesions and to analyze the influence of lesion characteristics on cognitive performance. METHODS The authors studied the performance of 15 subjects with focal thalamic infarction or hemorrhage on a comprehensive neuropsychological test battery focusing on tests of explicit memory and learning of a nondeclarative motor skill. Subjects with thalamic lesions were compared to 15 healthy matched control subjects and to a clinical control group of 22 subjects who had sustained basal ganglia lesions. RESULTS Subjects with thalamic lesions showed well-preserved intellectual and executive functions but demonstrated deficits on measures of attention and psychomotor speed, explicit memory, and implicit visuomotor sequence learning. Lesion size in the thalamus was clearly related to subjects' long-term explicit memory performance. However, few of the neuropsychological deficits found seemed specific to the long-term neuropsychological outcome of focal thalamic infarctions. Subjects with lesions in the basal ganglia demonstrated similar deficits. CONCLUSIONS Focal subcortical lesions in the thalamus and the basal ganglia lead to a similar profile of neuropsychological deficits. Lesions in the thalamus not only affect declarative memory but also interfere with nondeclarative motor skill learning.
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Exner C, Hebebrand J, Remschmidt H, Wewetzer C, Ziegler A, Herpertz S, Schweiger U, Blum WF, Preibisch G, Heldmaier G, Klingenspor M. Leptin suppresses semi-starvation induced hyperactivity in rats: implications for anorexia nervosa. Mol Psychiatry 2000; 5:476-81. [PMID: 11032380 DOI: 10.1038/sj.mp.4000771] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Semi-starvation induced hyperactivity (SIH) occurs in rodents upon caloric restriction. We hypothesized that SIH is triggered by the decline in leptin secretion associated with food restriction. To test this hypothesis, rats, which had established a stable level of activity, were treated with leptin or vehicle via implanted minipumps concomitantly to initiation of food restriction for 7 days. In a second experiment treatment was initiated after SIH had already set in. In contrast to the vehicle-treated rats, which increased their baseline activity level by 300%, the development of SIH was suppressed by leptin. Furthermore, leptin was able to stop SIH, after it had set in. These results underscore the assumed major role of leptin in the adaptation to semi-starvation. Because SIH has been viewed as a model for anorexia nervosa, we also assessed subjective ratings of motor restlessness in 30 patients with this eating disorder in the emaciated state associated with hypoleptinemia and after increments in leptin secretion brought upon by therapeutically induced weight gain. Hypoleptinemic patients ranked their motor restlessness higher than upon attainment of their maximal leptin level during inpatient treatment. Thus, hypoleptinemia might also contribute to the hyperactivity frequently associated with anorexia nervosa.
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Irle E, Exner C, Thielen K, Weniger G, Rüther E. Obsessive-compulsive disorder and ventromedial frontal lesions: clinical and neuropsychological findings. Am J Psychiatry 1998; 155:255-63. [PMID: 9464207 DOI: 10.1176/ajp.155.2.255] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE The authors sought to determine the long-term outcome of subjects with severe and refractory obsessive-compulsive disorder (OCD) who had undergone ventromedial frontal leukotomy during the 1970s. Special emphasis was given to the analysis of specific lesion sites. METHOD Sixteen OCD subjects who had undergone ventromedial frontal leukotomy were evaluated clinically and neuropsychologically and compared to seven well comparison OCD subjects without leukotomy. The 16 leukotomized subjects were divided into three groups according to the main lesion sites as determined by current magnetic resonance imaging scans. RESULTS The leukotomized OCD subjects showed significant improvement of obsessive-compulsive symptoms; subjects with frontostriatal lesions tended to have improved most. The subjects with combined diagnoses of OCD and obsessive personality disorder (N = 3) had improved significantly less. Of 11 subjects with lesions of the ventral striatum, eight had developed substance dependence postoperatively. Intellectual functions were largely preserved in subjects with ventromedial frontal lesions only or frontostriatal lesions. However, all subjects showed subnormal performance on the Wisconsin Card Sorting Test. Subjects with lesions of the dorsolateral frontal convexity also showed memory problems, attentional slowing, and lower performance IQ. CONCLUSIONS Restricted ventromedial frontal leukotomy should be discussed as a last-resort treatment for severe and refractory OCD but not obsessive personality disorder. Lesions of the ventral striatum were significantly related to the occurrence of substance dependence, suggesting a role of this area in human addictive behavior.
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Exner C, Unshelm J. [Climatic condition and airborne microorganisms in wild cat housing]. ZENTRALBLATT FUR HYGIENE UND UMWELTMEDIZIN = INTERNATIONAL JOURNAL OF HYGIENE AND ENVIRONMENTAL MEDICINE 1997; 199:497-512. [PMID: 9376063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The aim of the present study was to obtain information to improve the environmental conditions in enclosures for cats of prey. There was a large variation in indoor temperature, relative humidity, concentration of airborne ammonia and microorganisms during the year. The ascertained concentrations of airborne microorganisms distinguished between the different housing systems and ranged between 7177 and 15,835 KBE/m3. The concentration correlated negatively with the temperature outside of the buildings, while the amount of each compound, especially the gram positive cocci and rods, was influenced by the microclimate of the stables. The gram negative germs covered only 4.5 to 7.5%. Therefore the gram positive microorganisms were predominant. Part of the primary pathogen germs was low and amounted below 1%. There was now risks for visitors to get an infectious disease caused by the zoo animals.
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Curry J, Exner C. Comparison of tactile preferences in children with and without cerebral palsy. Am J Occup Ther 1988; 42:371-7. [PMID: 3394788 DOI: 10.5014/ajot.42.6.371] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Fifteen normal preschool children and 15 preschool children with cerebral palsy were presented with 10 pairs of objects and asked to identify their preference for one of the objects in each of the pairs. Five objects of different textures were used. The children only handled the objects; they did not view them during testing. The children with cerebral palsy chose hard objects significantly more often than they chose soft objects; the normal children had no significant choice preferences. Eleven of the children with cerebral palsy had choice patterns significantly different from those of the normal children. The apparent preference of the children with cerebral palsy for hard objects and their avoidance of soft objects suggests that they may have decreased tactile awareness and need the greater proprioceptive input that hard objects provide. The findings of this study indicate that preschool children with cerebral palsy may be at high risk for somatosensory disorders, which could markedly affect their hand function.
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