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Biomedical subjects

P Fossati

Publications and source records attributed to P Fossati.

At least 19 recordsLinked to original sources

[Episodic autobiographical memory in depression: a review].

INTRODUCTION: Autobiographical memory and personal identity (self) are linked by a reciprocal relationship. Autobiographical memory is critical for both grounding and changing the self. Individuals' current self-views, beliefs, and goals influence their recollections of the past. According to Tulving, episodic memory is characterized by autonoetic consciousness, which is associated with a sense of the self in the past (emotions and goals) and mental reliving of an experience. Its close relationship with self and emotion strongly involves episodic autobiographical memory in the psychopathology of depression. However, due to methodological and conceptual issues, little attention has been paid to episodic autobiographical memory in depression. Since the seminal work of Williams et al. 15 years ago, there is now growing interest around this issue. LITERATURE FINDINGS: We reviewed the evidence for three major features of autobiographical memory functioning in depression: an increase in general memory retrieval (overgenerality), a mood-congruent memory effect and the high occurrence of intrusive memories of stressful events. Although it was first observed among suicidal patients, overgenerality is actually associated with both depression and post-traumatic stress disorder. Overgenerality is not associated with anxious disorders other than post-traumatic stress disorder, obsessive-compulsive disorder, or borderline personality disorder. Most of controlled studies carried out on autobiographical memory in depression rely on the Williams' Autobiographical Memory Test (AMT). When presented with positive and negative cue words and asked to retrieve specific personal events, depressed patients (unlike matched controls) are less specific in their memories. They tend to recall repeated events (categorical overgeneral memories) rather than single episodes (specific memories). Overgenerality in depression is: 1) more evident with positive than with negative events (mood-congruent memory effect); 2) related to avoidance of intrusive memories; 3) quite stable over time, ie, remaining after remission; and 4) related to short-term prognosis in depression. Although it is not clear whether overgenerality is a cause or an effect of depression, there is some evidence to suggest that overgenerality is a trait marker indicating vulnerability to persistent depression. Mood-congruent effect, a well-known effect in depression, has been addressed in both autobio-graphical and non-autobiographical memory. Depressed patients spontaneously recall more negative than positive memories. With the AMT, depressed patients take longer to respond to positive than to negative cues, whereas controls do the opposite. Depression is also associated with a high occurrence of spontaneous intrusive memories of stressful life events. Studies found intrusions and related avoidance, as measured by the Impact of Event Scale, to be positively correlated with overgenerality, whereas there was no direct link between performance on the Autobiographical Memory Test and stressful life events per se. Both Williams' mnemonic interlock model and Conway's self-memory system are useful models to address the complexity of findings regarding autobiographical memory and depression. DISCUSSION: According to Williams, repeated avoidance of stressful memories leads depressed patients to have an autobiographical memory functioning characterized by iterative retrievals of categorical overgeneral memories, producing an enduring overgeneral retrieval style. According to Conway, the recollection of autobiographical memories requires a retrieval process that provides access to sensory/perceptual event-specific knowledge (ie perceptions and feelings) via a personal semantic knowledge base (ie lifetime periods and generic events). This retrieval process (generative retrieval mode) relies on both executive functioning and current self-view, namely the working-self. Spontaneous memories, usually vivid, result from a direct retrieval mode in which event-specific knowledge is directly triggered. In line with this model, episodic autobiographical memory impairment in state depression may arise from the working self rather than from autobiographical knowledge. The mood-congruent effect may be explained by the current (depressed) self. The high occurrence of intrusive memories may be explained by lack of executive control during direct retrieval. Overgenerality may rely on the interaction of both executive dysfunction and current (depressed) self, within the working-self, during generative retrieval. Our review suggests that further evidence is needed to address the relationship between executive functioning, self and autobiographical memory in depression.

Attention↗

[Utility of electroconvulsive therapy for severe depression in subjects aged over 65].

The management of depression in subjects aged over 65 is based on the isolated or combined use of antidepressant chemotherapy, psychotherapy and electroconvulsive therapy. Electroconvulsive therapy, under general anaesthesia and use of curare, consists in producing a generalised seizure using a short, pulsed, electrical current administered via the transcranial route. There is renewed interest in electroconvulsive therapy with the development of specific rules and conditions for its use, together with the recruitment of depressed patients resistant to classical treatments in hospital settings. The efficacy of electroconvulsive therapy has been demonstrated in the elderly. The immediate side effects, related to the electrical stimulation and the seizure, such as headaches, nausea, confusion, and transient amnesia, regress within a few minutes or hours after the session. The limits of electroconvulsive therapy are the high risk of relapse on suspension of the sessions, relapse basically related to the severity of the depression. Consolidation electroconvulsive therapy provides new hope for better control of such relapses.

Age Factors↗

The neural system that bridges reward and cognition in humans: an fMRI study.

We test the hypothesis that motivational and cognitive processes are linked by a specific neural system to reach maximal efficiency. We studied six normal subjects performing a working memory paradigm (n-back tasks) associated with different levels of monetary reward during an fMRI session. The study showed specific brain activation in relation with changes in both the cognitive loading and the reward associated with task performance. First, the working memory tasks activated a network including the dorsolateral prefrontal cortex [Brodmann area (BA) 9/46] and, in addition, in the lateral frontopolar areas (BA 10), but only in the more demanding condition (3-back task). This result suggests that lateral prefrontal areas are organized in a caudo-rostral continuum in relation with the increase in executive requirement. Second, reward induces an increased activation in the areas already activated by working memory processing and in a supplementary region, the medial frontal pole (BA 10), regardless of the level of cognitive processing. It is postulated that the latter region plays a specific role in monitoring the reward value of ongoing cognitive processes. Third, we detected areas where the signal decreases (ventral-BA 11/47 and subgenual prefrontal cortices) in relation with both the increase of cognitive demand and the reward. The deactivation may represent an emotional gating aimed at inhibiting adverse emotional signals to maximize the level of performance. Taken together, these results suggest a balance between increasing activity in cortical cognitive areas and decreasing activity in the limbic and paralimbic structures during ongoing higher cognitive processing.

Adolescent↗

Antenatal diagnosis and management of a vallecular cyst.

Vallecular cysts are rare. It is important to be aware of their presence as they can cause upper airway obstruction. We describe a case of congenital vallecular cyst diagnosed at 28 weeks of gestation. This early diagnosis enabled us to plan careful perinatal management. We believe that, in cases of suspected oropharyngeal tumors, elective delivery should be carried out in a tertiary referral center in which emergency ventilation and tracheostomy are possible.

Adult↗

[Prenatal diagnosis at 25 weeks gestation and neonatal management of a vallecular cyst].

Due to the anatomical location, vallecular cyst is a rare but well-recognized cause of upper airway obstruction and death in newborn. This cyst can be accurately diagnosed by echography in utero and by MR imaging. Prenatal diagnosis allows for early consultation with surgical specialist, so that the time and place of the delivery can be addressed for neonatal preoperative planning. We report the first prenatal diagnosis of a vallecular cyst at 25 weeks of gestation. At birth, the cyst was drained and then marsupialized. We believed that, in cases of oropharyngeal tumors discovered in utero, elective delivery should be realised in a tertiary referral center in which emergency ventilation and tracheostomy are possible.

Adult↗

Problem-solving abilities in unipolar depressed patients: comparison of performance on the modified version of the Wisconsin and the California sorting tests.

Problem solving relies on such abilities as decision-making, planning, initiation and hypothesis testing. Although problem-solving deficits have been consistently reported in depression, the specific nature of these deficits is not fully elucidated. In order to assess and isolate cognitive processes underlying problem-solving impairments in depression, depressed patients and normal controls were evaluated with the modified version of the Wisconsin Card Sorting Test (WCST) and the California Card Sorting Test (CCST). The California Card Sorting Test, unlike the modified WCST, provides several different measures of concept generation, concept identification and concept execution. Compared with controls, depressed patients did not show any deficits on all the measures of the modified WCST. In contrast, depressed patients evidenced mild impairment on the CCST with a specific deficit on concept generation but no major problems in concept identification and concept execution. The deficit in concept generation may be rooted in multiple factors such as hypothesis-testing deficits, a loss of cognitive flexibility and a conservative style of response. Since a positive relation between problem-solving deficits and the mean duration of the depressive episode was observed, problem-solving abilities might be predictive of poorer outcome in patients with unipolar affective disorders.

Adult↗

Absence of cognitive impairment at long-term follow-up in adolescents treated with ECT for severe mood disorder.

OBJECTIVE: Cognitive functions of adolescents treated with ECT for mood disorder were evaluated at long-term follow-up. METHOD: At an average of 3.5 years (SD=1.7) after the last ECT, 10 subjects treated during adolescence with bilateral ECT for severe mood disorder completed a clinical and cognitive evaluation, including the California Verbal Learning Test and Squire's Subjective Memory Questionnaire. The same assessments were given to 10 psychiatric comparison subjects matched for sex, age, and diagnosis. RESULTS: All cognitive test scores of the patients treated with ECT were similar to those of the comparison subjects and did not differ from norms from the community. Six of the 10 ECT-treated patients reported having had memory losses immediately after the ECT course, but only one complained of subjective memory impairment at follow-up. CONCLUSIONS: The results suggest that adolescents given ECT for severe mood disorder do not suffer measurable cognitive impairment at long-term follow-up.

Adolescent↗

Executive functioning and verbal memory in young patients with unipolar depression and schizophrenia.

Although neuropsychological studies have consistently reported executive deficits in schizophrenia, studies of executive functions in depression have produced equivocal results. The aim of this study was to examine the profile and the specificity of the executive impairment and its association with memory performance in young patients with unipolar depression. We compared patients with depression to normal control subjects and schizophrenics. Twenty young inpatients with unipolar depression, 14 schizophrenics and 20 age-, education- and IQ-matched control subjects were assessed with a neuropsychological battery including: (1) verbal memory task; (2) frontal tasks (WCST, Cognitive Estimate, Verbal fluency, verbal and visuo-spatial span) and a new complex sorting test (Delis test). Depressed patients and schizophrenics exhibited executive deficits. Unlike schizophrenics, depressed patients did not show memory impairment. Deficits in several 'higher-level' functions combined to produce executive impairments in patients with depression including complex integration for concept formation, spontaneous cognitive flexibility and initiation ability. Impaired functions in schizophrenia and in depressed patients were similar but were differently related to clinical variables. The pattern of memory failure in our schizophrenics is believed to reflect retrieval and encoding deficits. Our findings highlight the heterogeneity of skills grouped under the term 'executive functions' that are vulnerable in depression or schizophrenia.

Adolescent↗

[Pituitary radiotherapy. Current data and future prospects].

Some technical improvements have allowed to minimize the frequency of severe complications following fractionated pituitary conventional radiotherapy, without altering its efficiency. "Conformational" radiotherapy is currently under development, aiming at the best fitting of the tumor borders to the irradiation zone, by the means of stereotactic imaging. More recently, radiosurgery has been proposed for pituitary adenomas. It consists in a single high radiation dose to the tumor, by the means of either cobalt minibeams (Gamma Unit) or photon beams from a linear particle accelerator. These techniques require the use of a stereotactic frame and precise 3D imaging in order to tightly superimpose the target volume to the reference isodose. They must not be viewed as an alternative to conventional radiotherapy. They can be applied only to small lesions (less than 20 mm in their maximal axis) which are distant (> 5 mm) from the optic chiasma and nerves. Their efficiency is similar to the one of fractionated conventional radiotherapy, with a shorter response time. In conclusion, radiotherapy can be used safely for pituitary adenomas. It remains however a second line treatment, when surgery has been incomplete and when a simple, effective and inexpensive medical treatment is not possible.

Adenoma↗

[Gonadotropic adenomas].

Since the advent of immunohistochemical and cell culture techniques, the role of gonadotroph adenomas in hypophyseal disorders appears more important than formerly. A large part of "nonfunctional" adenomas in fact correspond to gonadotroph adenomas in vitro. These adenomas raise many clinical and biological questions since their presentation is not univocal. In addition, diagnosis of these adenomas is important since their spontaneous development leads to neuro-opthalmological complications, which presently are still too often the revealing manifestations of these adenomas.

Adenoma↗

[Results of sub-inguinal revascularization in the treatment of diabetic ischemic foot].

From January 1993 to August 1995, we performed 60 revascularizations of the lower limb using 65 bypasses in 55 patients (32 men, 23 women, mean age 66.6 yars) with diabetes. Trophic lesions of the foot existed in 57 of the revascularizations, and in 3 cases pain was provoked by the supine position. Supra-articular femoropopliteal bypass was performed in 8 cases, subarticular femoropopliteal bypasses in 25, femorotibial bypasses in 14 and paramalleolar bypasses in 18. There were 6 post-operative deaths. Six major amputations were required including 2 despite patent bypasses. Twenty-nine minor amputations were required for trophic disorders. There were 5 deaths after the postoperative period in which 4 major amputations were required despite patent bypasses in 2 cases. Retarded cicatrization was seen in 13 of the amputation stumps of areas of atrophism. Actuarial survival at 2 years was 77 +/- 6% with primary patency of 53 +/- 9.5% and secondary patency of 74 +/- 7%. The rate of success in saving the lower limb was 80.5 +/- 5.6%. Bypass revascularization has been effective in the treatment of the diabetic ischemic foot. Operative mortality was high, resulting from associated cerebral vascular events and coronary heart disease.

Aged↗