Setting boundaries: brain dynamics of modal and amodal illusory shape completion in humans.

Normal visual perception requires differentiating foreground from background objects. Differences in physical attributes sometimes determine this relationship. Often such differences must instead be inferred, as when two objects or their parts have the same luminance. Modal completion refers to such perceptual "filling-in" of object borders that are accompanied by concurrent brightness enhancement, in turn termed illusory contours (ICs). Amodal completion is filling-in without concurrent brightness enhancement. Presently there are controversies regarding whether both completion processes use a common neural mechanism and whether perceptual filling-in is a bottom-up, feedforward process initiating at the lowest levels of the cortical visual pathway or commences at higher-tier regions. We previously examined modal completion (Murray et al., 2002) and provided evidence that the earliest modal IC sensitivity occurs within higher-tier object recognition areas of the lateral occipital complex (LOC). We further proposed that previous observations of IC sensitivity in lower-tier regions likely reflect feedback modulation from the LOC. The present study tested these proposals, examining the commonality between modal and amodal completion mechanisms with high-density electrical mapping, spatiotemporal topographic analyses, and the local autoregressive average distributed linear inverse source estimation. A common initial mechanism for both types of completion processes (140 msec) that manifested as a modulation in response strength within higher-tier visual areas, including the LOC and parietal structures, is demonstrated, whereas differential mechanisms were evident only at a subsequent time period (240 msec), with amodal completion relying on continued strong responses in these structures.

Substance use and suicidal conduct: a study of adolescents hospitalized for suicide attempt and ideation.

AIM: To study the prevalence of psychoactive substance use disorder (PSUD) among suicidal adolescents, psychoactive substance intoxication at the moment of the attempt, and the association between PSUD at baseline and either occurrence of suicide or repetition of suicide attempt(s). METHODS: 186 adolescents aged 16 to 21 y hospitalized for suicide attempt or overwhelming suicidal ideation were included (T0); 148 of them were traced again for evaluations after 6 mo (T1) and/or 18 mo (T2). DSM-IV diagnoses were assessed each time using the Mini International Neuropsychiatric Interview. RESULTS: At T0, 39.2% of the subjects were found to have a PSUD. Among them, a significantly higher proportion was intoxicated at the time of the attempt than those without PSUD (44.3% vs 25.4%). Among the 148 adolescents who could be traced at either T1 or T2, two died from suicide and 30 repeated suicide attempts once or more times. A marginally significant association was found between death by suicide/repetition of suicide attempt and alcohol abuse/dependence at baseline (OR=3.3, 95% CI 0.7-15.0; OR=2.6, 95% CI 0.7-9.3). More than one suicide attempt before admission to hospital at T0 (OR=3.2, 95% CI 1.1-10.0) and age over 19 y at T0 (OR=3.2, 95% CI 1.1-9.2) were independently associated with the likelihood of death by suicide or repetition of suicide attempt. CONCLUSION: Among adolescents hospitalized for suicide attempt or overwhelming suicidal ideation, the risk of death or repetition of attempt is high and is associated with previous suicide attempts--especially among older adolescents--and also marginally associated with PSUD; these adolescents should be carefully evaluated for such risks and followed up once discharged from the hospital.

Safety and feasibility of NeuroFlo use in eight- to 24-hour ischemic stroke patients.

BACKGROUND: Acute treatment of ischemic stroke patients presenting more than eight-hours after symptom onset remains limited and largely unproven. Partial aortic occlusion using the NeuroFlo catheter can augment cerebral perfusion in animals. We investigated the safety and feasibility of employing this novel catheter to treat ischemic stroke patients eight-hours to 24 h following symptom onset. METHODS: A multicenter, single-arm trial enrolled ischemic stroke patients at nine international academic medical centers. Eligibility included age 18-85 years old, National Institutes of Health stroke scale (NIHSS) score between four and 20, within eight-hours to 24 h after symptom onset, and perfusion-diffusion mismatch confirmed by magnetic resonance imaging. The primary outcome was all adverse events occurring from baseline to 30 days posttreatment. Secondary outcomes included stroke severity on neurological indices through 90 days. This study is registered with ClinicalTrials.gov, number NCT00436592. RESULTS: A total of 26 patients were enrolled. Of these, 25 received treatment (one excluded due to aortic morphology); five (20%) died. Favorable neurological outcome at 90 days (modified Rankin score 0-2 vs. 3-6) was associated with lower baseline NIHSS (P < 0·001) and with longer duration from symptom discovery to treatment. There were no symptomatic intracranial hemorrhages or parenchymal hematomas. Asymptomatic intracranial hemorrhage was visible on computed tomography in 32% and only on microbleed in another 20%. CONCLUSIONS: Partial aortic occlusion using the NeuroFlo catheter, a novel collateral therapeutic strategy, appears safe and feasible in stroke patients eight-hours to 24 h after symptom onset.

Substance use and suicidal conducts : a study of adolescents hospitalized for suicide attempt and ideation

RESUME Objectifs: Etudier la prévalence des troubles liés à l'utilisation de substances psychoatives parmi des adolescents suicidaires; évaluer l'influence de la prise de substances psychoactives sur le geste suicidaire; analyser l'association entre les troubles liés à l'utilisation de substances psychoactives et le risque de récidive de la conduite suicidaire. Méthode: 186 adolescents, âgés de 16 à 21 ans, hospitalisés pour tentative de suicide ou idées suicidaires envahissantes, ont été inclus. Parmi eux, 148 ont été revus pour évaluation à 6 et/ou 18 mois. Des diagnostics psychiatriques, basés sur les critères du DSM-IV, ont été posés à l'aide d'un questionnaire, le MINI (Mini International Neuropsychiatric Interview). Résultats: A l'inclusion, 39.2% des sujets avaient un trouble lié à l'utilisation de substances psychoactives. Parmi eux, une proportion significativement plus élevée était sous l'influence d'alcool ou drogue au moment de la tentative de suicide (44.3% versus 25.4%). Des 148 adolescents suivis et revus à 6 ou 18 mois, 2 sont décédés par suicide et il y a eu 30 récidives de tentative de suicide durant l'étude. Une association significative a été trouvée entre les récidives de suicide et un diagnostic d'abus/dépendance à l'alcool à l'inclusion (OR=3.3; CI 0.7-15.0; 0R=2.6, CI 0.7-9.3). Des antécédents de plusieurs tentatives de suicide (OR=3.2; CI 1.1-10.0) et un âge supérieur à 19 ans (OR=3.2; CI 1.1-9.2) à l'inclusion étaient associés à la probabilité de mort par suicide ou de récidive de tentative de suicide. Conclusion: Parmi les adolescents hospitalisés pour tentative de suicide ou idées suicidaires envahissantes, le risque de décès ou de récidive est important. Ce risque est associé, entre autres, à des antécédents suicidaires et au diagnostic de trouble lié à l'utilisation de substances psychoactives. Le risque suicidaire ainsi que la consommation de substances psychoactives devrait être évalué chez les adolescents. De plus, les sujets jugés à risque devraient être suivis systématiquement après une hospitalisation pour conduite suicidaire. ABSTRACT Aim: To study the prevalence of psychoactive substance use disorder (PSUD) among suicidal adolescents, psychoactive substance intoxication at the moment of the attempt and the association between PSUD at baseline and either occurrence of suicide or repetition of suicide attempt(s). Methods: 186 adolescents aged 16 to 21 hospitalised for suicide attempt or overwhelming suicidal ideation were included (TO); 148 of them were traced again for evaluations after 6 months and/or 18 months. DSM-IV diagnoses were assessed each time using the Mini International Neuropsychiatric Interview. Results: At TO, 39.2% of the subjects were found to have a PSUD. Among them, a significantly higher proportion was intoxicated at the time of the attempt than those without PSUD (44-.3% vs. 25.4%). Among the 148 adolescents who could be traced at either Ti or T2, two died from suicide and 30 repeated suicide attempt once or more time. A marginally significant association was found between death by suicide/repetition of suicide attempt and alcohol abuse/dependence at baseline (0R=3.3; CI 0.7-15.0; 0R=2.6, CI 0.7-9.3). More than one suicide attempt before admission to hospital at TO (OR=3.2; CI 1.1-10.0) and age over 19 at TO (0R=3.2; CI 1.1-9.2) were independently associated with the likelihood of death by suicide or repetition of suicide attempt. Conclusion: Among adolescents hospitalised for suicide attempt or overwhelming suicidal ideation, the risk of death or repetition of attempt is high and is associated with previous suicide attempts - especially among older adolescents - and also marginally associated with PSUD; these adolescents should be carefully evaluated for such risks and followed up once discharged from the hospital.

Patients who attend a private practice vs a university outpatient clinic: how do they differ?

Although interpersonal continuity is commonly assumed to be essential for care, some patients prefer to attend a university outpatient clinic where physicians change regularly and interpersonal continuity of care is not ensured. The aim of this exploratory study was to evaluate the differences between patients attending a university outpatient clinic and patients frequenting a private practice, explore their patterns of care-seeking and their understanding of continued care. We conducted a cross-sectional study of patients attending the university medical outpatient clinic (OC) in Lausanne, Switzerland and ten randomly selected private general practices (PP). Eligible patients were >30 years, Swiss nationals or long term residents, with one or more chronic conditions and attending the same practice for >3 years. They were asked to complete a questionnaire on sociodemographic data, use of medical resources and reasons for choosing and remaining at the same practice. Semi-structured interviews were conducted with a randomly selected subset of 26 patients to further explore their preferences. 329 patient questionnaires were completed, 219 by PP and 110 by OC patients. OC patients tended to be of lower socioeconomic status than PP patients. The main reason for choosing a PP were personal recommendation, while a higher percentage of patients chose the OC because they could obtain a first appointment quickly. A higher percentage of PP patients accorded importance to physician communication skills and trust, whereas a higher percentage of OC patients favoured investigation facilities. Qualitative data suggested that although OC and PP patients reported different reasons for consulting, their expectations on the medical and relationship level were similar. Our study suggests that the two groups of patients belong to different social backgrounds, have different patterns of care-seeking and attach importance to different aspects of care continuity. However, patients' expectations and perceptions of the physician-patient relationship are similar.