Mental health markers and protective factors in students with symptoms of physical pain across WEIRD and non-WEIRD samples - a network analysis.

BACKGROUND: Studies conducted in Western societies have identified variables associated with chronic pain, but few have done so across cultures. Our study aimed to clarify the relationship between specific mental health markers (i.e., depression, anxiety, posttraumatic stress disorder [PTSD], perceived stress) as well as specific protective factors (i.e., social support and self-efficacy) related to physical pain among university students across non-WEIRD and WEIRD samples. METHOD: A total of 188 university students (131 women and 57 men) were included in the study. We used network analysis to ascertain mental health markers especially central to the experience of physical pain. RESULTS: No statistically significant difference was found between mental health markers (i.e., depression, anxiety, perceived stress, and PTSD) and protective factors (i.e., social support and self-efficacy) associated with physical pain symptoms for Swiss students versus Indian students (M = 0.325, p = .11). In addition, networks for Swiss versus Indian students did not differ in global strength (S = 0.29, p = .803). Anxiety was the most central mental health marker, and social support was the most important protective factor related to physical pain in both countries. However, for Swiss students, perceived stress, and for Indian students, PTSD symptoms were central mental health markers related to physical pain. CONCLUSION: Our results identify factors that may serve as important treatment targets for pain interventions among students of both countries before it becomes chronic.

Positive psychosocial factors and the development of symptoms of depression and posttraumatic stress symptoms following acute myocardial infarction.

Introduction: Acute myocardial infarction (MI) is a potentially fatal condition, leading to high psychological distress and possibly resulting in the development of depressive symptoms and posttraumatic stress symptoms (PTSS). The aim of this study was to investigate the association of clusters of positive psychosocial factors (resilience, task-oriented coping, positive affect and social support) with both MI-induced depressive symptoms and PTSS, independent of demographic factors. Methods: We investigated 154 consecutive patients with MI, 3 and 12 months after hospital discharge. All patients completed the short version of the German Resilience Scale, the Coping Inventory for Stressful Situations (CISS), the Enriched Social Support Inventory (ESSI) and the Global Mood Scale (GMS). The level of interviewer-rated MI-induced posttraumatic stress disorder (PTSD) symptoms at 3- and 12-months follow-up was evaluated through the Clinician-Administered PTSD Scale (CAPS). Depressive symptoms were assessed at 3- and 12-month follow-up with the Beck Depression Inventory (BDI-II). Results: Three different clusters were revealed: (1) lonely cluster: lowest social support, resilience and average task-oriented coping and positive affect; (2) low risk cluster: highest resilience, task-oriented coping, positive affect and social support; (3) avoidant cluster: lowest task-oriented coping, positive affect, average resilience and social support. The clusters differed in depressive symptoms at 3 months (F = 5.10; p < 0.01) and 12 months follow-up (F = 7.56; p < 0.01). Cluster differences in PTSS were significant at 3 months (F = 4.78, p < 0.05) and 12 months (F = 5.57, p < 0.01) follow-up. Differences in PTSS subscales were found for avoidance (F = 4.8, p < 0.05) and hyperarousal (F = 5.63, p < 0.05), but not re-experiencing, at 3 months follow-up. At 12 months follow-up, cluster differences were significant for re-experiencing (F = 6.44, p < 0.01) and avoidance (F = 4.02, p < 0.05) but not hyperarousal. Discussion: The present study contributes to a better understanding of the relationships among different positive psychosocial factors, depressive symptoms and PTSS following acute MI. Future interventions may benefit from taking into account positive psychosocial factors to potentially reduce patients' depressive symptoms and PTSS after MI.

Posttraumatic Stress Disorder as a Consequence of Acute Cardiovascular Disease.

PURPOSE OF REVIEW: To provide an update of the current evidence of cardiac disease-induced posttraumatic stress disorder (CDI-PTSD) with a focus on acute coronary events. RECENT FINDINGS: A cardiovascular disease, particularly a life-threatening cardiac event is often a highly stressful experience that can induce PTSD in patients and their caregivers, taking a chronic course if left untreated. There are several features distinguishing CDI-PTSD from "traditional" PTSD induced by external trauma, namely enduring somatic threat, inability to avoid trauma-related cues and hyperarousal with internal body sensations leading to constant fear of recurrent cardiac events. An increased risk of recurrent CVD events may be explained by pathophysiological changes, an unhealthy lifestyle and non-adherence to cardiac treatment. A trauma-focused approach might be useful to treat CDI-PTSD. Treatment options for patients and caregivers as well as long-term effects of trauma-focused interventions on physical and mental health outcomes should be future research directions.

Relationship between behavioral and mood responses to monetary rewards in a sample of Indian students with and without reported pain.

Physical pain has become a major health problem with many university students affected by it worldwide each year. Several studies have examined the prevalence of pain-related impairments in reward processing in Western, Educated, Industrialized, Rich, and Democratic (WEIRD) countries but none of the studies have replicated these findings in a non-western cultural setting. Here, we aimed to investigate the prevalence of physical pain symptoms in a sample of university students in India and replicate our previous study conducted on university students in Switzerland, which showed reduced mood and behavioral responses to reward in students with significant pain symptoms. We grouped students into a sub-clinical (N = 40) and a control group (N = 48) to test the association between pain symptoms and reward processes. We used the Fribourg reward task and the pain sub-scale of the Symptom Checklist (SCL-27-plus) to assess physical symptoms of pain. We found that 45% of the students reported high levels of physical symptoms of pain and interestingly, our ANOVA results did not show any significant interaction between reward and the groups either for mood scores or for outcomes related to performance. These results might yield the first insights that pain-related impairment is not a universal phenomenon and can vary across cultures.

Effect of Early Psychological Counseling for the Prevention of Posttraumatic Stress Induced by Acute Coronary Syndrome at Long-Term Follow-Up.

Objective: Psychological consequences of myocardial infarction (MI) are substantial, as 4% of all MI patients develop posttraumatic stress disorder (PTSD) and 12% clinically relevant posttraumatic stress symptoms (PTSS). The study investigated the course and development within 12 months of MI-induced PTSS to gain novel insights in potentially delayed response to early trauma-focused counseling aimed at preventing the incidence of MI-induced PTSS. Methods: In the MI-SPRINT two-group randomized controlled trial, 190 MI-patients were randomly allocated to receive a single-session intervention of either trauma-focused counseling or an active control intervention targeting the general role of stress in patients with heart disease. Blind interviewer-rated PTSS (primary outcome) and additional health outcomes were assessed at 12-month follow-up. Results: 12-month follow-up of outcomes were available for 106 (55.8%) of 190 participants: In the entire sample, one patient (0·5%, 1/190) who received trauma-focused counseling developed full PTSD. There was no significant difference between trauma-focused counseling and stress counseling regarding total score of interviewer-rated PTSS (p > 0.05). The only group difference emerged in terms of more severe hyperarousal symptoms in the trauma-focused counseling group in the ITT analysis, but not in the completer analysis. Conclusions: No benefits were found for trauma-focused counseling after 12 months when compared with an active control intervention. PTSD prevalence in the present study was low highlighting a potential beneficial effect of both interventions. Further studies are needed to determine the most accurate approach of counseling.

Mindfulness-oriented recovery enhancement improves negative emotion regulation among opioid-treated chronic pain patients by increasing interoceptive awareness.

OBJECTIVE: Long-term opioid therapy presents health risks for people with chronic pain. Some chronic pain patients escalate their opioid dose to regulate negative emotions. Therefore, emotion regulatory strategies like reappraisal are key treatment targets for this population. Mindfulness has been shown to enhance reappraisal, but the mechanisms of action are unknown. This study was a secondary analysis of data from a randomized, controlled trial of Mindfulness-Oriented Recovery Enhancement (MORE) to test a specific postulate of the Mindfulness-to-Meaning Theory: that mindfulness-based interventions promote reappraisal, via interoceptive self-regulation, as a means of decreasing emotional distress. METHODS: Ninety-five patients with opioid-treated chronic pain (age = 56.8 ±â€¯11.7, 66% female) were randomized to 8 weeks of MORE or Support Group (SG) psychotherapy. An interoceptive awareness latent variable was constructed from the Multidimensional Assessment of Interoceptive Awareness (MAIA). Next, interoceptive self-regulation was assessed as a mediator of the effect of MORE on post-treatment reappraisal, and then reappraisal was examined as a mediator of change in distress through 3-month follow-up. RESULTS: MORE participants had greater improvements in interoceptive awareness than the SG as measured by the interoceptive awareness latent variable (ß = 0.310, p = 0.008) and by the self-regulation MAIA subscale (ß = 0.335, p = 0.001). The effect of MORE on treatment-induced increases in reappraisal was mediated by increased interoceptive self-regulation (indirect effect: ß = 0.110, p = 0.030). In turn, decreases in distress through 3-month follow-up were mediated by increases in reappraisal (indirect: ß = -0.136, p = 0.031). CONCLUSION: MORE facilitated reappraisal of distress by enhancing interoceptive self-regulation, supporting a central mechanistic causal pathway specified by the Mindfulness-to-Meaning Theory.

An Ecological Monitoring and Management App (EMMA) for Older Adults With Chronic Pain: Protocol for a Design and Feasibility Study.

BACKGROUND: Chronic pain is a complex problem for many older adults that affects both physical functioning and psychological well-being. Mobile health (mHealth) technologies have shown promise in supporting older persons in managing chronic conditions. Cognitive behavior therapy is recommended for older people with chronic pain. However, web-based treatment programs for chronic pain are not aimed at the needs of older people and offer standard therapies without providing tailored treatment for this population. OBJECTIVE: To address this problem, we aim to develop a psychological web-based intervention for ecological monitoring of daily life experiences with chronic pain called EMMA to support self-management of chronic pain in older adults. METHODS: The key clinical and engagement features of the intervention were established through the integration of evidence-based material from cognitive behavioral therapy for the treatment of chronic pain in older adults. The development process uses a co-design approach and actively involves end-users in the design process by incorporating feedback from focus groups with older adults in order to inform a user-centered intervention design. For the co-design process, we will include 10 older adults with chronic pain, who will discuss the requirements for the app in workshops in order to ensure suitability of the app for older adults with chronic pain. In order to test the feasibility and acceptability of the intervention, we will include a sample of 30 older adults with chronic pain who will test all features of the intervention for a period of 8 consecutive weeks. After the trial period, validated instruments will be used to assess usability and acceptability, as well as influence on pain levels and associated physical and psychological symptoms. Participants will be invited to take part in a semistructured telephone interviews after the trial period to explore their experiences using the app. RESULTS: Digitalization of the pain diary and psychotherapeutic content has started. Recruitment of participants for the co-design workshops will start as soon as we have a functioning prototype of the electronic pain diary and EMMA intervention, which is expected to be in September 2021. The feasibility study will start as soon as the co-design process is finished and required changes have been implemented into the pain diary and the EMMA intervention. We expect to start the feasibility study early in 2022. CONCLUSIONS: Required changes to assure usability and acceptability will be directly implemented in the app. EMMA brings together a strong body of evidence using cognitive behavioral and self-management theory with contemporary mHealth principles, allowing for a cost-effective intervention that can be used to target chronic pain anywhere and anytime by older adults. Given the ubiquity of mHealth interventions for chronic conditions, the results of this study may serve to inform the development of tailored self-management interventions. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/26930.

Serum cortisol as a predictor for posttraumatic stress disorder symptoms in post-myocardial infarction patients.

BACKGROUND: After an acute myocardial infarction (MI2), patients may develop posttraumatic stress disorder (PTSD3). There is evidence for alterations in the hypothalamic-pituitary-adrenal axis in PTSD. An association between patients` cortisol level after experiencing an MI and subsequent PTSD symptoms has not been investigated yet. Therefore, the aim of this study was to examine whether serum cortisol measured in patients admitted to hospital for acute coronary care after MI is predictive of PTSD symptoms at three and 12 months post-MI, respectively. METHODS: Patients (N=106) with a verified MI and high risk for the development of MI-induced PTSD symptoms were included in the study within 48 hours of hospital admission for acute coronary intervention. Serum cortisol was measured from fasting venous blood samples the next morning. Hierarchical regression analysis was used to test for an independent contribution of cortisol levels from admission to the Clinician-Administered PTSD Scale sum score three and 12 months after discharge from the coronary care unit. RESULTS: Hierarchical regression analysis showed that lower serum cortisol levels were significantly associated with more severe PTSD symptoms three months (B=-0.002, p=0.042) and 12 months (B=-0.002, p=0.043) post-MI. LIMITATIONS: The generalizability of the findings is limited to patients with high acute peri-traumatic distress and without an acute severe depressive episode. The study does not provide any information about the diurnal cortisol pattern. CONCLUSION: Lower serum cortisol measured during MI hospitalization may predict more severe MI-induced PTSD symptoms three and 12 months after hospital discharge.

Course, Moderators, and Predictors of Acute Coronary Syndrome-Induced Post-traumatic Stress: A Secondary Analysis From the Myocardial Infarction-Stress Prevention Intervention Randomized Controlled Trial.

Acute coronary syndromes (ACS) induce post-traumatic stress symptoms (PTSS) in one out of eight patients. Effects of preventive interventions, the course and potential moderators of ACS-induced PTSS are vastly understudied. This study explored whether a preventive behavioral intervention leads to a decrease in myocardial infarction (MI)-induced PTSS between two follow-up assessments. Sociodemographic, clinical and psychological factors were additionally tested as both moderators of change over time in PTSS and predictors of PTSS across two follow-ups. Within 48 h after reaching stable circulatory conditions, 104 patients with MI were randomized to a 45-min one-session intervention of either trauma-focused counseling or stress counseling (active control). Sociodemographic, clinical, and psychological data were collected at baseline, and PTSS were assessed with the Clinician-Administered Post-traumatic Stress Disorder Scale 3 and 12 months post-MI. PTSS severity showed no change over time from 3 to 12 months post-MI, either in all patients or through the intervention [mean group difference for total PTSS = 1.6 (95% CI -1.8, 4.9), re-experiencing symptoms = 0.8 (95% CI -0.7, 2.2), avoidance/numbing symptoms = 0.1 (95% CI -1.6, 1.7) and hyperarousal symptoms = 0.6 (95% CI -0.9, 2.1)]. Patients receiving one preventive session of trauma-focused counseling showed a decrease from 3 to 12 months post-MI in avoidance symptoms with higher age (p = 0.011) and direct associations of clinical burden indices with total PTSS across both follow-ups (p's ≤ 0.043; interaction effects). Regardless of the intervention, decreases in re-experiencing, avoidance and hyperarousal symptoms from 3 to 12 months post-MI occurred, respectively, in men (p = 0.006), participants with low education (p = 0.014) and with more acute stress symptoms (p = 0.021). Peritraumatic distress (p = 0.004) and lifetime depression (p = 0.038) predicted total PTSS across both follow-ups. We conclude that PTSS were persistent in the first year after MI and not prevented by an early one-session intervention. A preventive one-session intervention of trauma-focused counseling may be inappropriate for certain subgroups of patients, although this observation needs confirmation. As predictors of the development and persistence of PTSS, sociodemographic and psychological factors could help to identify high-risk patients yet at hospital admission.

Body experience during post-acute rehabilitation in individuals after a traumatic spinal cord injury: a qualitative interview-based pilot study.

STUDY DESIGN: Qualitative interview-based pilot study. OBJECTIVES: A traumatic spinal cord injury (TSCI) profoundly disrupts the way individuals experience their body. Awareness of one's body is an important element in the psychological adjustment process after TSCI. This pilot study aimed to explore the body experience of individuals during post-acute rehabilitation following TSCI. SETTING: Specialized acute care and rehabilitation center in Switzerland. METHODS: Eight semi-structured face-to-face interviews were conducted with patients in the post-acute phase of their TSCI. Body experience was explored in relation to perceptive, cognitive, emotional, and behavioral aspects. The interviews were transcribed verbatim, and a structured content analysis was performed according to the Mayring method. RESULTS: The individuals verbalized body experience in all explored aspects. The two participants with tetraplegia described high body-related awareness, including dependence on other persons or aids, whereas individuals with paraplegia focused on their ability to regain activity and perceived autonomy, which was sustained by increasing injury- and self-related comprehension. They expressed uncertainty in their understanding of their paralyzed body while also verbalizing to see a continuity in their identity pre and post TSCI. Their emotions varied from anxiety and anger to hope and optimism. The interviewees confirmed that the growing ability to describe perceptions related to their body increased their active participation in the rehabilitation process and stimulated hope for the future. CONCLUSIONS: Exploration of individual body experience after a recent TSCI can strengthen patients' body awareness, communication and engagement in rehabilitation and help the interprofessional rehabilitation team individualize the rehabilitation process.

Myocardial infarction-induced acute stress and post-traumatic stress symptoms: the moderating role of an alexithymia trait - difficulties identifying feelings.

BACKGROUND: It has been acknowledged that medical life-threatening experiences such as an acute myocardial infarction (MI) often lead to acute stress disorder symptoms (ASS), which in turn can result in the development of post-traumatic stress symptoms (PTSS). Previous studies have suggested an association between various traumatic experiences and alexithymia. The association of alexithymia with ASS and PTSS in patients with MI is elusive. OBJECTIVES: The aim of this study was to examine the association of alexithymia with MI-induced ASS and PTSS in patients at high risk of developing PTSD. METHOD: Patients (N = 154) were examined twice, once within 48 hours, and then again three months after acute MI. All patients completed the self-rating Acute Stress Disorder Scale (ASDS) within 48 hours after the cardiac event. Three months after hospital discharge, all patients completed the Toronto Alexithymia Scale (TAS-20) and underwent the Clinician-Administered PTSD Scale (CAPS), a structured interview to assess the severity of PTSS. Descriptive statistics, correlations, multivariate linear regressions, and moderation analysis were conducted. RESULTS: The linear regression model explained 23% of the variance in MI-induced PTSS-symptoms (F(6.109) = 5.58, p < 0.001, R 2 = 0.23. ASS was significantly related to PTSS severity (r (152) = p < 0.001). The scores of the TAS-20 subscale difficulties identifying feelings (DIF) were found to significantly moderate this relationship (R2  = 0.03, p = 0.04). The scores of TAS-20 subscales DDF and EOT as well as the TAS-20 total score had no influence on the relationship between ASS and PTSS (p > 0.05). CONCLUSION: In MI patients with high levels of DIF, ASS predicted the development of PTSS. If replicated, the finding may inform emotion-oriented interventions to investigate whether increasing the capacity to identify feelings following acute MI could be beneficial in preventing the development of PTSS.

Antecedentes: Se ha reconocido que experiencias médicas en las que se pone en peligro la vida, tal y como el infarto agudo al miocardio (MI por sus siglas en inglés) frecuentemente pueden llevar a síntomas de Trastorno de estrés agudo (ASS por sus siglas en inglés), que pueden llevar a desarrollar síntomas de estrés postraumático (PTSS por sus siglas en inglés). Estudios previos han sugerido una asociación entre numerosas experiencias traumáticas y alexitimia. La asociación entre la alexitimia con los ASS y PTSS en pacientes con infarto agudo al miocardio es evasiva.Objetivos: Examinar la asociación entre la alexitimia y los ASS y PTSS inducidos por MI en pacientes con elevado riesgo de desarrollar un TEPT.Método: Pacientes (N=154) fueron examinados dos veces, una vez dentro de las primeras 48 horas y en otra ocasión tres meses después del infarto agudo al miocardio. Todos los pacientes completaron la Escala Del Trastorno de Estrés Agudo, que es auto-puntuada (ASDS por sus siglas en inglés) dentro de las primeras 48 horas posteriores al evento cardíaco. Tres meses posteriores al alta hospitalaria, todos los pacientes completaron la Escala de Toronto de Alexitimia (TAS-20) y fueron sometidos a una entrevista estructurada para evaluar la gravedad de los PTSS (CAPS). Se condujeron análisis de estadística descriptiva, correlaciones, regresiones lineares multivariadas y análisis de moderación.Resultados: El modelo linear de regresión explicó el 23% de la varianza en los PTSS inducidos por el MI. F (6.109) = 5.58, p < 0.001, R 2 =0.23. Los ASS estuvieron significativamente relacionados a la severidad de los PTSS (r (152) = 0.46, p < 0.001). Los puntajes de la subescala de dificultad de identificar sentimientos (DIF por sus siglas en inglés) dentro de las TAS-20 moderaba significativamente esta relación (R 2 = 0.03, p = 0.04). Los puntajes de las subescalas de TAS-20 DDF y EOT así como el puntaje total de la TAS-20 no tuvieron ninguna influencia en la relación entre ASS y PTSS (p > 0.05).Conclusión: en pacientes con MI y con altos niveles de DIF, los ASS predijeron el desarrollo de PTSS. Si se pudiesen replicar, estos hallazgos pueden apoyar intervenciones orientadas a las emociones para investigar si es que la capacidad de identificar sentimientos posteriormente a haber sufrido un infarto agudo al miocardio pudiese ser beneficioso en prevenir el desarrollo de PTSS.

5'UTR polymorphism in the serotonergic receptor HTR3A gene is differently associated with striatal Dopamine D2/D3 receptor availability in the right putamen in Fibromyalgia patients and healthy controls-Preliminary evidence.

BACKGROUND: Extensive literature has investigated the role of serotonin (5-HT) in the control of the central dopamine (DA) systems, and their dysfunction in the pathological conditions. 5-HT stimulates the local DA release in striatal regions via activation of various receptors including serotonin receptor-3 (5-HT3). Several studies have related polymorphisms (SNPs) in the serotonin receptor-3 (HTR3) genes to be associated with the pain modulation and endogenous pain suppression. A few studies suggested a functional role of 5'UTR SNP in the serotonergic receptor HTR3A gene (rs1062613) in the development of the chronic pain and Fibromyalgia syndrome (FMS) in particular. Here, we investigated the effect of a 5'UTR SNP in the serotonergic receptor HTR3A gene (rs1062613) on striatal dopamine D2/D3 receptor (DRD2) availability and reward-associated DA release in response to unpredictable monetary rewards in 23 women with FMS and 17 age-matched healthy female controls. Furthermore, we aimed to examine if SNP rs1062613 is associated with thermal pain and pain tolerance thresholds. METHODS: We used PET and [11 C]raclopride to assess the DRD2 availability. In the same participants we used the [11 C]raclopride PET bolus-plus-infusion method to measure the [11 C]raclopride receptor binding potential (ΔBP) between an unpredictable reward condition and a sensorimotor control condition. DRD2 availability and ΔBP were assessed in MRI-based striatal regions of interest. Thermal pain and pain tolerance thresholds were assessed outside the scanner. RESULTS: The frequency of SNP rs1062613 genotype differed significantly between groups, indicating that CC homozygotes were more frequent in FMS patients (82.6%) than in healthy controls (41.3%). Our results showed a significant main effect of SNP rs1062613 on [11 C]raclopride binding potential in the right caudate nucleus indicating a higher DRD2 receptor availability for CC-genotype of this SNP. Furthermore, we found a significant group × SNP interaction on [11 C]raclopride binding potential in the right putamen, indicating a higher DRD2 availability in T-carriers compared to CC genotype of SNP rs1062613 in FMS patients, whereas this effect was not present in healthy controls. However, we did not find an influence of SNP rs1062613 on reward-related DA release. In addition, there was no association between SNP rs1062613 and pain threshold or pain tolerance threshold in our data. CONCLUSION: These preliminary results indicate that SNP rs1062613 in the serotonergic receptor HTR3A gene possibly modulates the DRD2 receptor availability.

Effects of Cerebellothalamic Tractotomy on Cognitive and Emotional Functioning in Essential Tremor: A Preliminary Study in 5 Essential Tremor Patients.

Background: Subthalamic stereotactic interventions have recently caught renewed interest as a treatment for essential tremor (ET). However, it is not clear whether these interventions are associated with neurocognitive, mood or personality changes. Objective: To investigate neurocognition, neuropsychiatric functions and personality variables in patients with ET and to explore the neurocognitive and neuropsychiatric effects of cerebellothalamic tractotomy (CTT), a form of subthalamotomy. Methods: In our study, we investigated cognitive functions, frontal functions, mood and personality variables in 5 patients with intractable ET. Patients were tested before and 3 months after surgery using neuropsychological tests, clinical scales for depression, anxiety, anger regulation and a personality test. Results: Before surgery, ET patients showed normal neurocognitive function, a slightly elevated frontal lobe score in the dimensions mental control and memory, without being indicative of a frontal lesion, and no elevated depression or anxiety scores compared to norm values. After surgery, there was no change in neurocognitive function and no increase in depression or anxiety scores. Conclusion: In this exploratory study on 5 ET patients, CTT was not associated with alterations of mood or neurocognitive functions. © 2015 S. Karger AG, Basel.

Comparison of PET template-based and MRI-based image processing in the quantitative analysis of C11-raclopride PET.

BACKGROUND: Quantitative measures of 11C-raclopride receptor binding can be used as a correlate of postsynaptic D2 receptor density in the striatum, allowing 11C-raclopride positron emission tomography (PET) to be used for the differentiation of Parkinson's disease from atypical parkinsonian syndromes. Comparison with reference values is recommended to establish a reliable diagnosis. A PET template specific to raclopride may facilitate direct computation of parametric maps without the need for an additional MR scan, aiding automated image analysis. METHODS: Sixteen healthy volunteers underwent a dynamic 11C-raclopride PET and a high-resolution T1-weighted MR scan of the brain. PET data from eight healthy subjects was processed to generate a raclopride-specific PET template normalized to standard space. Subsequently, the data processing based on the PET template was validated against the standard magnetic resonance imaging (MRI)-based method in 8 healthy subjects and 20 patients with suspected parkinsonian syndrome. Semi-quantitative image analysis was performed in Montreal Neurological Institute (MNI) and in original image space (OIS) using VOIs derived from a probabilistic brain atlas previously validated by Hammers et al. (Hum Brain Mapp, 15:165-174, 2002). RESULTS: The striatal-to-cerebellar ratio (SCR) of 11C-raclopride uptake obtained using the PET template was in good agreement with the MRI-based image processing method, yielding a Lin's concordance coefficient of 0.87. Bland-Altman analysis showed that all measurements were within the ±1.96 standard deviation range. In all 20 patients, the PET template-based processing was successful and manual volume of interest optimization had no further impact on the diagnosis of PD in this patient group. A maximal difference of <5% was found between the measured SCR in MNI space and OIS. CONCLUSIONS: The PET template-based method for automated quantification of postsynaptic D2 receptor density is simple to implement and facilitates rapid, robust and reliable image analysis. There was no significant difference between the SCR values obtained with either PET- or MRI-based image processing. The method presented alleviates the clinical workflow and facilitates automated image analysis.