Neural correlates of regional EEG power change

To clarify the physiological significance of task-related change of the regional electroencephalogram (EEG) rhythm, we quantitatively evaluated the correlation between regional cerebral blood flow (rCBF) and EEG power. Eight subjects underwent H2 15O positron emission tomography scans simultaneously with EEG recording during the following tasks: rest condition with eyes closed and open, self-paced movements of the right and left thumb and right ankle. EEG signals were recorded from the occipital and bilateral sensorimotor areas. Cortical activation associated with EEG rhythm generation was studied by the correlation between rCBF and EEG power. There were significant negative correlations between the sensorimotor EEG rhythm at 10-20 Hz on each side and the ipsilateral sensorimotor rCBF and between the occipital EEG rhythm at 10-20 Hz and the occipital rCBF. The occipital EEG rhythm showed a positive correlation with the bilateral medial prefrontal rCBF, while the right sensorimotor EEG rhythm showed a positive correlation with the left prefrontal rCBF. In conclusion, decrease in the regional EEG rhythm at 10-20 Hz might represent the neuronal activation of the cortex underlying the electrodes, at least for the visual and sensorimotor areas. The neural network including the prefrontal cortex could play an important role to generate the EEG rhythm.     

Systemic sulpiride modulates striatal blood flow: relationships to spatial working memory and planning

The dopamine D2 receptor antagonist sulpiride can produce a range of cognitive deficits in normal volunteers, consistent with those seen in Parkinson's disease (PD). This, together with studies in experimental animals, implies sulpiride might be acting in the striatum. However, subtle changes in prefrontal cortex (PFC) activity are seen following L-Dopa withdrawal in PD during working memory tasks, suggesting that this may be a further site of action for dopamine D2 receptor antagonists. We have investigated the effects of sulpiride within the PFC and striatum in normal male volunteers. In two separate experiments, using identical PET regional cerebral blood flow (rCBF) methods, a combined drug and psychological challenge was performed, utilising working memory and planning tasks, and oral sulpiride 400 mg and placebo. Data were analysed using SPM99. Sulpiride increased striatal rCBF bilaterally and the working memory and planning tasks activated discrete frontoparietal networks in keeping with previous studies. However, for the working memory tasks, no changes in performance or task-induced rCBF were observed after sulpiride. For the planning task, improved performance was seen on sulpiride. Also, sulpiride attenuated striatal activity during planning (as assessed using a small volume correction, P<0.05 corrected), and this attenuation was related to performance changes. These findings suggest that (1) sulpiride produces clear increases in striatal rCBF, (2) in contrast to previous studies no effects of sulpiride on performance of the working memory tasks or the associated neural networks were observed, and (3) sulpiride may modulate performance of more complex cognitive tasks via alterations in striatal neural activity.     

Incremental value of CT in PET/CT of patients with colorectal carcinoma

Background: We assessed the contribution of dedicated computed tomographic (CT) interpretation to the accuracy of positron emission tomography (PET) plus CT in imaging patients with suspected primary or metastatic colorectal carcinoma.Methods: One hundred PET/CT scans in 90 consecutive patients were evaluated retrospectively. Imaging was performed on a GE Discovery LS PET/CT scanner. PET images were obtained from the skull base through the midthigh after intravenous administration of 15 to 20 mCi of [¹⁸F] fluorine-18-fluoro-2-deoxyglucose. Noncontrast axial CT images were obtained at the same anatomic locations, with 140 kV, 80 mA, 0.8 s/CT rotation, a pitch of 6, and a table speed of 22.5 mm/s. The CT component of the PET/CT study was reviewed independently by consensus of two blinded readers. Scans were evaluated for the presence of primary disease, local recurrence, and distant metastases. Results were compared with the PET/CT report. The gold standard was clinical and imaging follow-up for at least 6 months, surgery, or biopsy.Results: The study included 40 males and 50 females, with a mean age of 63 years (range, 31–92 years). The indications for the examination were to evaluate for recurrence of colorectal cancer in 83 cases, determine disease spread in 15 cases, and evaluate for possible primary malignancy in two cases with rising carcinoembryonic antigen. Sensitivity, specificity, and accuracy of the PET/CT report and of the combined PET/CT with dedicated CT interpretation were 0.914, 0.633, and 0.830 and 0.986, 1.000, and 0.980, respectively. The difference between PET/CT and the combined PET/CT with dedicated CT interpretation with respect to accuracy was statistically significant (p < 0.05).Conclusion: The CT portion of PET/CT provides valuable anatomic and pathologic information to the functional information provided by PET and helps improve the overall accuracy of the combined study.     

Feeding-induced dopamine release in dorsal striatum correlates with meal pleasantness ratings in healthy human volunteers

Seven healthy subjects underwent two [(11)C]raclopride positron emission tomography (PET) scans, one following a 16-h fast and the other after consumption of a favorite meal (following a 16-h fast) in counterbalanced fashion. Before and after each scan subjects gave ratings of hunger/fullness and desire to eat. In addition, meal pleasantness ratings were collected immediately after consumption of the favorite meal. PET data were analyzed using brain parametric maps to generate regions of statistically significant change, as well as regions of interest manually drawn on each individual's coregistered anatomical image. [(11)C]Raclopride binding potential was compared across the two states (hungry and full). A significant reduction in binding potential was observed in the full compared to the hungry state in the dorsal putamen and caudate nucleus, indicative of dopamine release. There were no changes elsewhere in the striatum. A correlation was observed between the reduction in [(11)C]raclopride binding and meal pleasantness ratings, but not with desire to eat (hunger) or satiety after eating. These results suggest that feeding is associated with dopamine release in the dorsal, but not the ventral striatum, and that the amount of dopamine released correlates with the degree of experienced pleasure.     

Neural correlates of memory confidence

The present study aimed to shed light on the neural underpinnings of high vs. low memory confidence. To dissociate memory confidence from accuracy, the Deese-Roediger McDermott (DRM) paradigm was employed, which - compared to other memory paradigms - elicits a rather evenly distributed number of high-confident responses across all possible combinations of memory response types (i.e., hits, false alarms, correct rejections, and misses). In the standard DRM procedure, subjects are first presented with thematically interrelated word lists at encoding, which at recognition are intermixed with related and unrelated distractor items. The signature of a false memory or DRM effect is an increased number of high-confident false memories, particularly for strongly related lure items. For the present study, 17 female subjects were administered a verbal DRM task, whereas neural activation was indexed by fMRI. The behavioral analyses confirmed the expected false memory effect: subjects made more high-confident old responses (both hits and false alarms) the closer the items were related to the central list theme. Across all four memory response types, an increase in confidence at recognition was associated with bilateral activation in the anterior and posterior cingulate cortex along with medial temporal regions. In contrast, increments in doubt were solely related to activation in the superior posterior parietal cortex. To conclude, the study provides some evidence for dissociable systems for confidence and doubt.     

脑梗塞患者缺血半暗带的PET检查

对正电子发射计算机断层显像 (Positronemissiontomography ,PET)在缺血性脑血管病早期缺血半暗带判定中的作用进行了综述。PET不但能早期发现半暗带的部位及大小 ,而且可以判定其中存活组织的生存状态 ,并能预测其转归 ,为缺血性脑血管病早期治疗对象的筛选及缺血半暗带的研究提供了一种新的、有效的检查手段。     

Neural correlates of feigned memory impairment

While initial neuroimaging studies have provisionally identified activation in the prefrontal (including the anterior cingulate) and parietal regions during lying, the robustness of this neuroanatomical pattern of activation across forms of stimuli, genders, and mother tongues remains to be demonstrated. In this paper we report the results of three studies designed to test the reproducibility of the brain activation previously observed during feigned memory impairment. A total of twenty-nine right-handed participants, divided into three cohorts, participated in three different studies of feigned memory impairment. Findings indicate that bilateral activation of prefrontal and parietal regions was invariant across stimulus types, genders, and mother tongues, suggesting the general importance of these regions during malingering and possibly deception in general. In conjunction with earlier imaging findings, these three studies suggest that the prefrontal parietal network provides a robust neuroanatomical foundation upon which future dissimulation research may build.     

Neural correlates of relational and item-specific encoding during working and long-term memory in schizophrenia

Successful long-term memory (LTM) depends upon effective control of information in working memory (WM), and there is evidence that both WM and LTM are impaired by schizophrenia. This study tests the hypothesis that LTM deficits in schizophrenia may result from impaired control of relational processing in WM due to dorsolateral prefrontal cortex (DLPFC) dysfunction. fMRI was performed on 19 healthy controls and 20 patients with schizophrenia during WM tasks emphasizing relational (reorder trials) versus item-specific (rehearse trials) processing. WM activity was also examined with respect to LTM recognition on a task administered outside the scanner. Receiver operator characteristic analysis assessed familiarity and recollection components of LTM. Patients showed a disproportionate familiarity deficit for reorder versus rehearse trials against a background of generalized LTM impairments. Relational processing during WM led to DLPFC activation in both groups. However, this activation was less focal in patients than in controls, and patients with more severe negative symptoms showed less of a DLPFC increase. fMRI analysis of subsequent recognition performance revealed a group by condition interaction. High LTM for reorder versus rehearse trials was associated with bilateral DLPFC activation in controls, but not in patients who activated the left middle temporal and inferior occipital gyrus. Results indicate that although patients can activate the DLPFC on a structured relational WM task, this activation is less focal and does not translate to high retrieval success, suggesting a disruption in the interaction between WM and LTM processes in schizophrenia.     

新生儿缺血缺氧性脑病行18F-FOG PET的护理

目的 探讨新生儿缺血缺氧性脑病行18F-FDG PET/CT检查的护理要点,以协助检查顺利进行.方法 对2012年核医学科行18F-FDG PET/CT检查的58例新生儿缺血缺氧性脑病患儿的护理特点和重点操作内容进行分析和总结.结果 3例患儿在检查时因发生病情变化而停止,其余55例患儿在精心护理下均顺利完成检查,取得满意结果.结论 对进行18F-FDG PET/CT检测缺血缺氧性脑病的新生儿进行有针对性的护理,可以使检查顺利进行,提高检查的准确性和检查结果的满意度.在实际临床工作中具有很好的应用价值.     

Impact of 2-Deoxy-2[F-18]Fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-Glucose Positron Emission Tomography on the Management of Patients with Advanced Melanoma

Objectives Accurate staging of patients with melanoma is vital to guide appropriate treatment. 2-Deoxy-2-[F-18]fluoro-d-glucose (FDG)-positron emission tomography (PET) has been reported to be a sensitive and specific technique for the staging of advanced melanoma, however, few studies provide information regarding its impact on patient management. Methods We retrospectively reviewed the FDG-PET scan results of 92 patients with melanoma who had 126 scans performed over a six-year period. These patients were seen at the specialist melanoma clinic at our Institution, and 84 patients (92%) had stage III or IV disease. FDG-PET scan results were correlated with computed tomography (CT) scans and other imaging when available, and with clinical follow-up of a minimum of three to six months. The impact of FDG-PET scans on patient management was also assessed. Results On a lesion-by-lesion analysis, FDG-PET had a sensitivity of 92%, a specificity of 88%, and an accuracy of 91%. FDG-PET correctly affected the clinical decision-making process in 40 of 126 patient studies (32%), particularly assisting in the selection of patients for surgery. Conclusion FDG-PET has an important role in guiding the management of patients with advanced melanoma, particularly when surgery is contemplated.     

Twelve-month safety,tolerability and susceptibility to adverse events of prophylactic migraine therapy with erenumab: a retrospective real-world study

BackgroundErenumab is a monoclonal antibody (mAb) against the calcitonin gene related peptide (CGRP) receptor and is commonly used in migraine prophylaxis. Pivotal and open-label studies show a good safety and tolerability. However, little is known about possible predictors, dose dependence and time course of development of adverse events (AEs) during the treatment under real-world conditions.MethodsClinical routine data of 128 patients with migraine treated in the West German Headache Center Essen were analyzed regarding AEs during a treatment interval of up to 12 months (3mo n = 128, 6mo n = 105, 9mo n = 74, 12mo n = 54). Patients obtained subcutaneous erenumab injections with either 70 mg or 140 mg per month. The occurrence and alterations of AEs were evaluated. All reported AEs, regardless of their severity, were included. AEs were graded using the common terminology criteria for adverse events (CTCAE). Possible parameters that could influence the occurrence of AEs (sex, episodic or chronic migraine, medication overuse headache, aura and the dosage of erenumab) were analyzed using the Chi-squared test, alpha adjustment was done using the Bonferroni’s correction (6 tests, adjusted alpha = 0.0083).ResultsThe proportion of patients who reported at least one AE were stable over the course of 12 months (after 3mo = 37%, 6mo = 36%, 9mo = 32%, 12mo = 35%). All reported AEs were grade 1 according to CTCAE with one exception (grade 2). Throughout the interval, five AEs were mostly reported: constipation, skin reactions, fatigue, sleep disturbances and nausea/emesis. Discontinuation of erenumab therapy was rarely caused by AEs (5/49). Increasing the dosage from 70 mg to 140 mg per month caused no higher frequency of AEs (Chi-squared test, p = 0.57). Significant more AEs were reported by females and by patients with aura (Chi-squared test, p < 0.001, respectively).ConclusionIn general, erenumab is well tolerated up to a treatment interval of 12 months and reported AEs rarely lead to discontinuation of therapy. A higher dosage does not increase the patient reported AEs. Furthermore, no habituation of AEs is observed. Nevertheless, females and patients with aura seem to be more prone to have AEs.Trial registrationNo registration, retrospective analysis.     

正电子发射型计算机断层显像检查患者的护理

目的:探讨正电子发射计算机断层显像检查中的护理方法。方法:对201例患者在进行正电子发射计算机断层显像检查的全过程,实施耐心、细致、周到的护理服务。结果:所有患者均顺利完成正电子发射计算机断层显像检查,所得正电子发射计算机断层显像图像全部达到了临床诊断要求。结论:全程、细致、耐心、周到的护理服务是正电子发射计算机断层显像检查中的一个重要环节。     

正电子发射计算机断层显像引导X刀治疗癫癎的护理

总结210例顽固性癫癎患者在正电子发射计算机断层显像引导下行X刀治疗的护理体会。认为及时、正确、完整的围手术期护理是保证治疗成功的重要环节,正电子发射计算机断层显像检查前控制血糖;检查中准确注射药物;检查后多饮水加速药物的排泄。X刀治疗过程中,护士全程陪护,治疗前遵医嘱预防性用药,防止术中癫癎发作,术后密切观察病情变化,做好病人的康复护理。     

18F-FDG PET显像探查原发肿瘤灶的价值

目的：探讨^18F-氟脱氧葡萄糖(^18F-FDG)PET显像在原发肿瘤不明患者中的诊断价值以及对治疗方案的影响。方法：采用临床随访、分析活组织检查和病理结果对PET检查的32例原发肿瘤不明转移癌的患者进行回顾性分析。结果：32例患者中^18F-FDG PET发现可疑原发灶16例，其中6例经手术病理证实；经随访，5例临床证实为原发灶；5例临床排除原发灶的诊断。另有2例PET显像未找到原发灶的患者经随访排除转移性癌的诊断。^18F-FDG PET对原发灶的检出率为36．7％(11／30)。PET共提示了35处转移病灶，CT／MR只提示了27处转移病灶。结论：①^18F-FDG PET显像对探查转移性肿瘤的原发灶和制定治疗方案具有很好的临床价值；②建议在CT／MR未能找到原发灶时，应进行^18F-FDG PET显像。     

PET在神经外科的应用

复习有关正电子发射断层显像术(PET)文献资料,分析归纳PET对脑瘤、癫痫、帕金森氏病等的放射学特点和诊疗效果,提倡临床积极应用PET。     

The Utility of 2-Deoxy-2-[F-18]fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose Positron Emission Tomography in the Investigation of Patients with Disseminated Carcinoma of Unknown Primary Origin

Purpose A retrospective analysis of the use of 2-deoxy-2-[F-18]fluoro-d-glucose (FDG) positron emission tomography (PET) was performed in patients with histologically proven disseminated carcinoma of unknown primary tumor (CUP).Procedures The records of 31 patients with CUP, excluding patients with isolated neck metastases, were reviewed to identify the ability of PET to detect the putative primary site (PPS) and/or to change therapeutic management.Results In eight out of 31 cases (26%), a PPS was confirmed, either definitively (one pathologically, one radiologically) (true positive) or clinically (six cases). For three cases (10%), histological evidence of a primary tumor distant from the PPS was found (false positive). In a further seven cases (23%), the PPS remained unconfirmed, whereas for 13 cases (42%) no PPS was identified. In five out of seven patients in whom the PET suggested a high probability of having identified the primary site, the PPS was confirmed definitively or clinically. PET altered clinical management in at least 12 cases (38%).Conclusions PET contributed to the management of previously extensively investigated patients with CUP. Identification of a PPS and/or change in management was documented in 38% of cases, the majority of which were lung or pancreatic cancer. These findings are worthy of evaluation in a prospective study.