Time, action and psychosis: using subjective time to investigate the effects of ketamine on sense of agency

Sense of agency refers to the experience of initiating and controlling actions in order to influence events in the outside world. A disturbed sense of agency is found in certain psychiatric and neurological disorders, most notably schizophrenia. Sense of agency is associated with a subjective compression of time: actions and their outcomes are perceived as bound together in time. This is known as ‘intentional binding’ and, in healthy adults, depends partly on advance prediction of action outcomes. Notably, this predictive contribution is disrupted in patients with schizophrenia. In the present study we aimed to characterise the psychotomimetic effect of ketamine, a drug model for psychosis, on the predictive contribution to intentional binding. It was shown that ketamine produced a disruption that closely resembled previous data from patients in the early, prodromal, stage of schizophrenic illness. These results are discussed in terms of established models of delusion formation in schizophrenia. The link between time and agency, more generally, is also considered

Temporal order assessment in patients with bipolar disorder

AbstractAlterations in temporal perception accompany dissociative symptoms. However, the extent and frequency of these temporal symptoms have not been extensively studied in Bipolar Disorder (BD). The study was a prospective, repeated measures design of 21 patients with BD, conducted at Barwon Health in Geelong, Australia. The study combined questionnaires of mood and dissociative symptoms with a novel psychophysical method of assessing altered sub-second temporal performance. Participants observed a series of two flashed visual stimuli (duration 20ms, inter stimulus interval 60ms) while making rapid (saccadic) eye movements. The experimental paradigm resulted in a proportion of observations (47%) in which the perceptual ordering of the flashes was inverted in time. Dissociative symptoms, as measured by the Dissociative Experiences Scale, were common in this patient cohort. The proportion of inverted temporal judgments correlated with both dissociative symptom scores (Clinician Administered Dissociative States Scale, unreality subscale) and with the Young Mania Rating Scale score (in linear model). This study shows that measures of temporal perception correlate with mood alterations in BD. This finding is the first to find such associations with a sub-second timing task. The linkage between the symptoms of BD and testable measures of time perception, supports the case for psychophysical measures of dissociation having utility as biomarkers of disease state

Factors predicting outcomes of microwave ablation of small hepatocellular carcinoma

Purpose: The aim of our study was to evaluate factors influencing effectiveness of percutaneous microwave ablation (MWA) in patients with small hepatocellular carcinoma (HCC) (3 cm from the capsule) (n = 22) and peripheral (<3 cm from the capsule) (n = 43). Imaging follow-up was performed at 1, 3, 6, and 12 months after treatment, then annually. Mean follow-up period was 18 months (range 1\u201355). Location of the lesion, age, sex, and underlying disease of the patients was analyzed and related with efficacy. Results: Technical success was obtained in all cases. Residual disease was registered in 21 lesions (32.3 %): 13 were peripheral and 8 were central. Twelve of them were retreated with percutaneous MWA. Local recurrence was recorded in 8 lesions (12.3 %): 5 were retreated with MWA. No significant difference in terms of effectiveness was observed in lesions located in a central position and those situated in the peripheral position. Age, sex, and underlying disease not influenced results. Only one major complication was observed. The rate of minor complications was 24.5 %. Mortality at 30 days was 0 %. Conclusions: Our results encourage the role of MWA in the treatment of small HCC. More numerous series and randomized studies are necessary to state the role of MWA and to select cases in which MWA may be more effective and safer than RFA

Microwave ablation of liver metastases to overcome the limitations of radiofrequency ablation

Purpose: The purpose of our study was to evaluate technical success, effectiveness and safety of microwave ablation (MWA) in patients with unresectable liver metastases, where radiofrequency ablation (RFA) presents some limits. Materials and methods: Twenty-five patients (17 men, 8 women) with 31 liver metastases >3 cm or located near vessels (>3 mm) were treated in a total of 29 sessions. Tumours were subdivided as follows: colorectal metastases (n=21) and no colorectal metastases (n=10). All procedures were performed percutaneously under ultrasound (US) guidance. Follow-up was performed with computed tomography (CT) scan at 1, 3, 6 and 12 months after treatment; mean follow-up period was 12.04 (range, 3-36) months. Technical success, mean disease-free survival, effectiveness and safety were evaluated. Results: Technical success was obtained in all cases. Mean disease-free survival was of 20.5 months. Local recurrence was recorded in 12.9% of metastases treated (4/31). No major complications were recorded. The rate of minor complications was 44.8% (13/29 sessions). Mortality at 30 days was 0%. Conclusions: Percutaneous MWA of liver metastases >3 cm or located near vessels (>3 mm) can be considered a valid and safe option, probably preferable to RFA. Further studies are required to confirm these encouraging initial results

Evaluation of tablet ultrasound for routine abdominal interventional procedures

Aim: The aim of the study was to establish if a novel tablet ultrasound (US) may replace a high-end US machine during routine interventional radiology activities. Materials and methods: Thirty consecutive patients were evaluated by two operators comparing the performance of the new US tablet system (VISIQ, Philips Healthcare) against a high-end US system (iU22, Philips Healthcare) using a curved probe (C5-2). A structured questionnaire was used to rank on a 4-point scale the ability of each system to locate a target as detected by previous examinations and visualize needles and path during an interventional procedure. Necessity for conversion from the tablet US to the high-end US system was registered; body mass index (BMI) was annotated for each patient. Results: Agreement between the operators was found for every patient. Mean patient BMI was 25 (range 17\u201334). Image quality of the tablet US was considered insufficient in 1 case to visualize the target and in another case to visualize the needle. Mean target image quality was superior with the high-end US system, while needle visibility scored higher with the tablet US. Conversion to the high-end system was registered in 40 % of cases: in most cases (66.6 %) the decision was due to the absence of a dedicated needle guide for the tablet US. Conclusions: The novel tablet US was found to provide sufficient image quality for the majority of routine interventional procedures. Dedicated accessories and additional experience with this new generation US device may be needed to replace bulky high-end US systems

Upper Urinary Tract Transitional Cell Tumors Diagnosis: Role of CT - Urography

Abstract Objective: The purpose of this study was to point out CT Urography (CTU) potentials and limitations for the diagnosis of Upper Urinary Tract Transitional Cell Carcinoma (UUT-TCC) and to suggest how and when to use invasive second-line investigations. Materials and Methods: 66 patients with a suspected UUT-TCC were examined with CTU; 52/66 patients underwent also Retrograde Pielography (RP). Reference standards were histopathology and the 24-month clinical and imaging follow-up. Moreover the T stage of 15 tumors, treated by surgery, was assessed. Results: 21/66 patients had a final diagnosis of UUT-TCC; CTU showed a sensitivity of 90.5%, a specificity of 84.4%, a Positive Predictive Value (PPV) of 73.1% and a Negative Predictive Value (NPV) of 95%. The overall accuracy of CTU in evaluation of T parameter was 80%. In the subgroup of 52 patients, CTU and RP showed both a sensitivity of 85.7%, a specificity respectively of 84.4% and 82.2%, a PPV of 46.2% and 42.8%, a NPV of 97.4% and 97.3%. In 7 cases, false positive both at CTU and RP, biopsy allowed a definitive diagnosis of tumor absence. Moreover in 1 case, false negative both at CTU and RP with positive urinary cytology, endoscopy and biopsy showed a small superficial tumor. Conclusion: CTU, complemented by urinary cytology and cystoscopy, is the technique of choice for UUT-TCC diagnosis and staging. In cases of positive CT findings, RP-guided biopsy is advisable to complete the diagnostic work-up; nevertheless, if CTU is negative and cytology is positive, endoscopy is indicated