Does sex influence the relation between symptoms and neurocognitive functions in schizophrenia?

Objective: A secondary analysis of our data to investigate if sex influences the specificity of the relationship between each of the 3 clinical syndromes (i.e., reality distortion, disorganization and psychomotor poverty) in schizophrenia and the neurocognitive functions that are thought to represent regional brain functions.

EEG coherence and syndromes in schizophrenia.

Background: Frith et al (1995) and others have hypothesised that disruptions in the connection between left frontal and temporal areas of the brain are a central deficit in schizophrenia. In this paper we examine whether such connectivity as assessed by EEG coherence is related to level of symptoms in patients with schizophrenia.

Method: For 73 patients with schizophrenia, assessment of the EEG coherence between frontal and temporal regions were carried out under conditions of activation by a mathematical task, and between frontal and occipital regions when performing a visuo-spatial task.

Neuropsychological correlates of syndromes in schizophrenia.

Background: On the basis of Liddle's three-syndrome model of schizophrenia, it was predicted that: (1) symptoms of psychomotor poverty would be particularly correlated with impaired performance on neuropsychological tests likely to reflect functioning of the dorsolateral prefrontal cortex; (2) disorganisation would be particularly correlated with impaired performance on tests sensitive to medio-basal prefrontal functioning; and (3) reality distortion would be particularly correlated with measures sensitive to temporal lobe functioning.

Method: The above hypotheses were tested on 87 subjects with a confirmed diagnosis of schizophrenia. Patients' symptoms were scored for each of the three syndromes.

Aberrant interhemispheric alpha coherence on electroencephalography in schizophrenic patients during activation tasks.

Thirty schizophrenic patients (20 medicated, 10 off medication) were compared with 30 normal controls subjects matched for age, sex, handedness and intelligence. During the performance of a frontal activation task, normal subjects showed increased interhemispheric coherence between anterior brain regions. Schizophrenic patients did not show the same amount of bilateral anterior activation.

Membrane phospholipid metabolism and schizophrenia: an in vivo 31P-MR spectroscopy study.

Membrane phospholipid metabolism was studied with 31P magnetic resonance spectroscopy in the left dorsal prefrontal cortex of 19 male, medicated, schizophrenic patients and compared to 18 normal male controls matched in age, education and parental education level. The schizophrenic patients had significantly decreased phosphomonoester levels (PMEs, metabolites predominantly involved in the synthesis of membrane phospholipids). Phosphodiester levels (PDEs, breakdown products of membrane phospholipids) were not statistically different in schizophrenic patients compared to controls.