[P300 in mild cognitive impairment and in dementia]. / P300 enyhe kognitív zavarban és demenciában.

OBJECTIVES: The late component of the event-related potential (ERP), P300 is a marker for cognitive brain functions. The objective of this study was to examine P300 parameters in dementia and in mild cognitive impairment (MCI), to examine whether there is a correlation between the changes in P300 parameters and the type and severity of dementia, and to determine P300 abnormalities in MCI in relation to the presence/absence of CT/MRI abnormalities. METHOD: Auditory event-related potentials, P300 were recorded in 28 MCI patients (14 of them with normal CT/MRI findings and 10 subjects with mild ventricular enlargement). In another group of patients, 31 demented patients were examined, of whom 17 patients were diagnosed with Alzheimer's dementia (AD), and 14 patients with vascular dementia (VD). Forty healthy volunteers served as the control group. RESULTS: Mean P300 latency was significantly increased for both demented patient-groups. We found that prolongation of P300 latency was correlated with the severity of dementia. Mean P300 amplitude was significantly decreased in both groups of demented patients. In MCI, the mean latency of P300 was significantly longer among patients with mild cerebral atrophy compared to control volunteers and no significant changes were found for MCI patients with normal CT/MRI findings. Mean P300 amplitude was decreased only in demented patients. CONCLUSIONS: The prolongation of P300 latency was significant among patients with both vascular and Alzheimer's dementia, and also among MCI patients with mild cerebral atrophy. The severity of dementia is positively correlated with P300 latency; however, this prolongation is independent of the type of dementia. The structural brain changes in MCI are related to P300 latency prolongation and thus may indicate an increased risk for developing dementia in MCI patients.

Clinical Decision Making and Mental Health Service Use Among Persons With Severe Mental Illness Across Europe.

OBJECTIVE: The study explored relationships between preferences for and experiences of clinical decision making (CDM) with service use among persons with severe mental illness. METHODS: Data from a prospective observational study in six European countries were examined. Associations of baseline staff-rated (N=213) and patient-rated (N=588) preferred and experienced decision making with service use were examined at baseline by using binomial regressions and at 12-month follow-up by using multilevel models. RESULTS: A preference by patients and staff for active patient involvement in decision making, rather than shared or passive decision making, was associated with longer hospital admissions and higher costs at baseline and with increases in admissions over 12 months (p=.043). Low patient-rated satisfaction with an experienced clinical decision was also related to increased costs over the study period (p=.005). CONCLUSIONS: A preference for shared decision making may reduce health care costs by reducing inpatient admissions. Patient satisfaction with decisions was a predictor of costs, and clinicians should maximize patient satisfaction with CDM.

Cognitive functions in prepsychotic patients.

OBJECTIVE: Cognitive dysfunctions are now widely understood as an essential feature of schizophrenia. A great number of cognitive disturbances have been described in drug-naive first-episode patients as well. The full-blown psychotic symptoms are usually preceded by a longer prodromal period, in which non-specific psychological disturbances are already present. The late prodromal phase is also coined as the prepsychotic state, with attenuated, isolated psychotic symptoms. The aim of the present study was to detect cognitive dysfunctions among young adults at the prepsychotic stage with the use of a standardized computer based cognitive test battery. METHOD: Eleven (9 men, 2 women) young Hungarian adults referred to the Outpatient Clinic of the Department of Psychiatry at the University of Debrecen were studied. The patients were re-evaluated for psychotic symptoms after 12 months. The patients had no history of psychiatric disorders or psychotic episodes and were referred by general practitioners on account of non-specific emotional or behavioural abnormalities. The subjects were asked to perform a series of 13 computerized neuropsychological tests of the Cambridge Neuropsychological Test. The performance of the patients were compared to that of the standardized database of the Cambridge Neuropsychological Test. RESULTS AND DISCUSSION: The performance of the prepsychotic patients was significantly lower compared to the healthy individuals in the paired associate learning (PAL, p<0.001), Spatial recognition memory (SRM, p<0.05), Rapid visual processing (RVP, p<0.05), and Spatial working memory (SWM, p<0.05) tests. CONCLUSION: Cognitive deficits were found mainly in attentional, frontal and prefrontal cognitive functions. These impairments may be present at the early stages of the development of psychosis and the standardized cognitive test battery (CANTAB) might be a useful tool for the detection of early cognitive impairments and provide a rationale for early intervention in individuals at risk of developing psychosis.