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Mismatch Negativity in Schizophrenia from the prodrome to chronicity: relationships with functional status, generator sources and grey matter loss| old_uid | 7319 |
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| title | Mismatch Negativity in Schizophrenia from the prodrome to chronicity: relationships with functional status, generator sources and grey matter loss |
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| start_date | 2009/07/20 |
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| schedule | 11h30 |
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| online | no |
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| summary | In this talk, I will report on three separate studies which examine whether mismatch negativity (MMN) is reduced in prodromal schizophrenia, and the relationship of MMN in schizophrenia patients to functional status, grey matter loss and generator sources.
Study 1: MMN to duration deviants was recorded from 72 individuals at ultra-high risk (UHR) of developing schizophrenia (13 met criteria for first episode psychosis at baseline - FEP, 6 made a subsequent transition within one year) and 20 healthy subjects. Study 2: MMN was recorded in response to duration, frequency and intensity deviants in 18 schizophrenia patients with an established illness and 18 healthy subjects. Functional status was assessed using the SOFAS. High-resolution structural magnetic resonance scans were acquired to generate average cerebral cortex models using cortical pattern matching and provided grey matter estimates. Study 3: Cortically constrained LORETA source analysis of duration MMN was conducted in 16 recent-onset patients, 19 chronic patients and 35 matched controls.
Study 1: duration MMN was significantly reduced in both FEP and UHR groups, and a non-significant reduction in MMN in 6 UHR individuals making a subsequent transition to schizophrenia compared to 19 UHR individuals who did not.
Study 2: MMN amplitude to all deviants was reduced in schizophrenia patients but only frequency and duration MMN correlated with SOFAS. However, only frequency MMN in patients was correlated with fronto-temporal grey matter reduction.
Study 3; LORETA analysis revealed strong duration MMN sources in temporal cortex and weak sources in frontal regions. Both sources were reduced in schizophrenia but more marked in recent-onset patients.
Our findings suggest a close association between frequency MMN with cerebral pathology and daily functioning in established schizophrenia while reduced MMN to duration deviants appears to be associated with the prodrome and first-episode phase of the disorder. |
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| responsibles | <not specified> |
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