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Abstract Background The aim was to carry out the first voxel-based morphometry study of grey matter changes in the whole brain in schizophrenia associated with a history of seriously and violently offending. Methods Structural cerebral magnetic resonance imaging scans of 26 patients with schizophrenia were analyzed using voxel-based morphometry: 13 of the patients had seriously and violently offended directly as a result of schizophrenia prior to admission, the offences consisting of homicide, attempted murder or wounding with intent to cause grievous bodily harm; the other 13 patients did not have a history of violence. There was no history of comorbid psychoactive substance misuse disorder in any of the patients. Voxelwise generalized linear modelling was applied to the processed magnetic resonance data using permutation-based non-parametric testing, forming clusters at t > 2.3 and testing clusters for significance at p < 0.05, corrected for multiple comparisons across space. Results The two groups of patients were matched with respect to age, gender and duration of illness, but the group with a history of serious violence was on average receiving a higher dose of antipsychotic medication than the group without a history of violence. There were local regions of reduced grey matter volume in the schizophrenia patient group with a history of serious and violent offending, compared with the schizophrenia patient group without such a history. Significant voxels (p < 0.05, corrected for multiple comparisons) were noted bilaterally in the cerebellum and in BA 39 and 40. Conclusion These regions are important in verbal working memory. The cerebellum may integrate inputs from ventrolateral prefrontal cortex and parietal regions, providing a corrective signal that refines the process of rehearing the contents of the phonological store. A strong connection has been hypothesized between the supramarginal region corresponding to BA 39/40 and Broca's area, which may correspond largely to the arcuate fasciculus, with the connectional pattern of the language regions of this model fitting the network of parietotemporal-prefrontal connections that participate in working memory. Therefore our results point to the possibility of an abnormality in neural circuits involved in verbal working memory in this group of patients.

Abstract Background The range of the fatty acids has been largely investigated in the plasma and erythrocytes of patients suffering from neuropsychiatric disorders. In this paper we investigate, for the first time, whether the study of the platelet fatty acids from such patients may be facilitated by means of artificial neural networks. Methods Venous blood samples were taken from 84 patients with a DSM-IV-TR diagnosis of major depressive disorder and from 60 normal control subjects without a history of clinical depression. Platelet levels of the following 11 fatty acids were analyzed using one-way analysis of variance: C14:0, C16:0, C16:1, C18:0, C18:1 n-9, C18:1 n-7, C18:2 n-6, C18:3 n-3, C20:3 n-3, C20:4 n-6 and C22:6 n-3. The results were then entered into a wide variety of different artificial neural networks. Results All the artificial neural networks tested gave essentially the same result. However, one type of artificial neural network, the self-organizing map, gave superior information by allowing the results to be described in a two-dimensional plane with potentially informative border areas. A series of repeated and independent self-organizing map simulations, with the input parameters being changed each time, led to the finding that the best discriminant map was that obtained by inclusion of just three fatty acids. Conclusion Our results confirm that artificial neural networks may be used to analyze platelet fatty acids in neuropsychiatric disorder. Furthermore, they show that the self-organizing map, an unsupervised competitive-learning network algorithm which forms a nonlinear projection of a high-dimensional data manifold on a regular, low-dimensional grid, is an optimal type of artificial neural network to use for this task.

Abstract Background The aim of this study was to bring together all the results of in vivo studies of ethane excretion and cerebral spectroscopy in patients with schizophrenia who have dangerously seriously violently offended in order to determine the extent to which they shed light on the degree to which the membrane phospholipid hypothesis and the actions of free radicals and other reactive species are associated with cerebral pathophysiological mechanisms in this group of patients. Methods The patients investigated were inpatients from a medium secure unit with a DSM-IV-TR diagnosis of schizophrenia. There was no history of alcohol dependency or any other comorbid psychoactive substance misuse disorder. Expert psychiatric opinion, accepted in court, was that all these patients had violently offended directly as a result of schizophrenia prior to admission. These offences consisted of homicide, attempted murder or wounding with intent to cause grievous bodily harm. Excreted ethane was analyzed and quantified by gas chromatography and mass spectrometry (m/z = 30). 31-phosphorus magnetic resonance spectroscopy data were obtained at a magnetic field strength of 1.5 T using an image-selected in vivo spectroscopy sequence (TR = 10 s; 64 signal averages localized on a 70 × 70 × 70 mm3 voxel). Results Compared with age- and sex-matched controls, in the patient group the mean alveolar ethane level was higher (p < 0.0005), the mean cerebral beta-nucleotide triphosphate was lower (p < 0.04) and the mean gamma-nucleotide triphosphate was higher (p < 0.04). There was no significant difference between the two groups in respect of phosphomonoesters, phosphodiesters or broad resonances. Conclusion Our results are not necessarily inconsistent with the membrane phospholipid hypothesis, given that the patients studied suffered predominantly from positive symptoms of schizophrenia. The results suggest that there is increased cerebral mitochondrial oxidative phosphorylation in patients with schizophrenia who have dangerously and seriously violently offended, with an associated increase in oxygen flux and subsequent electron 'leakage' from the electron transport chain leading to the formation of superoxide radicals and other reactive oxygen species. In turn, these reactive species might cause increased lipid peroxidation in neuroglial membranes, thereby accounting for the observation of increased ethane excretion.