Hydrocarbon exposure and Parkinson's disease.

BACKGROUND: Single cases of parkinsonism have been associated with hydrocarbon solvents. OBJECTIVE: To determine whether exposure to hydrocarbon solvents is related to PD. METHODS: Cohort study of 990 patients with PD according to Core Assessment Program for Intracerebral Transplantations (CAPIT) criteria, selected from 1455 consecutive subjects presenting at a referral center; case-control study assessing Unified PD Rating Scale scores (motor score as primary endpoint) in all subjects with positive history of hydrocarbon solvent exposure (n = 188), matched for duration of disease and gender to 188 subjects selected from the remaining 802 with a negative history. Two subgroups in the case-control study included the following: 1) response to apomorphine (n = 26); 2) brain MRI (n = 15). PET imaging (n = 9) was compared with that of historic controls. RESULTS: Exposed patients were younger (61.0 +/- 9.4 versus 64.7 +/- 9.4 years, p = 0.002), predominantly male (76.4% versus 45.2%, p = 0.0001), less educated (8.4 +/- 4.2 versus 10.1 +/- 4.4 years, p = 0.0001), and younger at onset of disease (55.2 +/- 9.8 versus 58.6 +/- 10 years, p = 0.014). Exposure to hydrocarbon solvents directly correlated to disease severity (r = 0. 311) and inversely correlated to latency period (r = -0.252). Nine blue-collar occupations accounted for 91.1% of exposures. CONCLUSIONS: Occupations involving the use of hydrocarbon solvents are a risk factor for earlier onset of symptoms of PD and more severe disease throughout its course. Hydrocarbon solvents may be involved in the etiopathogenesis of PD, which does not have a major genetic component.

Cerebral ventricular enlargement as a generalized feature of schizophrenia: a distribution analysis on 502 subjects.

Enlargement of cerebral ventricles is one of the most replicated biological features, and the one quantitatively most deviant in schizophrenia. It occurs in the early phases of the disease and may have pathogenetic relevance. Whether this abnormality is limited to a specific subgroup of patients or is a common feature to most or all patients affected by schizophrenia, however, is still a matter of debate. The answer to this question would improve our comprehension of the nature of this abnormality and contribute to the debate between the competing hypotheses of biological homogeneity vs heterogeneity of schizophrenia.We performed a distribution analysis of lateral ventricular dimensions of 340 schizophrenic patients and 162 non-psychiatric controls. All subjects underwent cerebral computerized tomographic scan, and ventricular dimensions were expressed as ventricular brain ratio (VBR). After removing the effect of confounding variables (age, sex and type of scanner) on individual VBR, data were power-transformed and different distribution hypotheses were tested by means of the maximum log-likelihood ratio method. Our findings indicate that, in the mixed sample of patients and controls, a mixture of two gaussian curves represents the distribution better than a single gaussian curve, but no evidence emerged leading to rejection of the normality hypothesis in the schizophrenic patients sample. Lateral ventricular enlargement in schizophrenia is not a marker of a discrete subgroup of schizophrenia, but occurs in most, if not all, schizophrenic patients. This supports the hypothesis of biological homogeneity of the disease, at least relative to its major brain morphological abnormality.

Epithalamus calcifications in schizophrenia.

We evaluated the prevalence and the size of epithalamus calcifications (EC) and choroid plexus calcifications (CPC) on computed tomography (CT) scans in a group of 64 schizophrenic patients and in a group of 31 healthy controls. The associations between cerebral calcifications, demographic variables, and other brain morphological characteristics (particularly cerebral ventricular size and cortical atrophy) in both, patients and controls, were also considered. A significant increase in size of the epithalamic-region calcifications in schizophrenic patients was found, whereas there was no evidence of increase in both, dimension and prevalence, of choroid plexus calcification. Such dimensional increase was unrelated to the duration of illness and therefore did not seem to be iatrogenic or secondary to the disease. A correlation was found between epithalamus calcifications and cortical atrophy and third-ventricle enlargement, suggesting that calcifications of this cerebral region may be associated with lesions of third-periventricular areas and of circuitries hypothesized to be involved in the pathophysiology of schizophrenia.

Non-selective impairment of Wisconsin Card Sorting Test performance in patients with schizophrenia.

Sixty-two schizophrenic patients and 26 healthy volunteers were administered the Wisconsin Card Sorting Test (WCST) a task putatively specific for frontal functions and the Wechsler Adult Intelligence Scale (WAIS). The purpose of this study was to evaluate the presence of specific frontal lobe deficits in the course of schizophrenia and the capacity of these tasks to discriminate between patients and controls. Schizophrenic patients showed a poorer performance than control subjects in both tests. No evidence emerged to support a higher discriminant power for the WCST in identifying schizophrenic subjects from healthy controls compared with the WAIS. Our data suggest that the deficit in WCST performance is not selective, but rather part of a more generalized neuropsychological impairment in schizophrenic patients.

Time course of cerebral ventricular enlargement in schizophrenia supports the hypothesis of its neurodevelopmental nature.

In the absence of direct and conclusive data demonstrating the 'neurodevelopmental hypothesis' of schizophrenia, several neuromorphological findings provide relevant clues in support of it. In this paper, we review a number of results obtained by our group in this area of research. In particular, the demonstration of stability of cerebral ventricular dimensions both in chronic schizophrenia and around the onset of the disease, and that of an identical effect of ageing on this morphological feature in large samples of patients and controls, strongly support the neurodevelopmental nature of brain pathomorphology in schizophrenia.

Language and thought disorder in schizophrenia: brain morphological correlates.

In this magnetic resonance imaging study, the authors analyzed the relationships between frontal and temporal lobe volumes, volumes of ventricular system subdivisions and clinical and neuropsychological aspects of language and thought disorder in a group of 19 young schizophrenic patients. Schizophrenics showed enlargement of lateral ventricles, especially of the central and occipital segments compared with 15 age and sex matched healthy controls but no differences were present in prefrontal, temporal lobe and superior temporal gyrus volumes. Prefrontal volume was inversely correlated with Thought, Language and Communication (TLC) scale total scores; left superior temporal gyral (STG) volume was positively correlated with verbal fluency test performance; higher total ventricular volume was significantly correlated with poor performance to a sentence generation test; STG laterality index was correlated with global TLC scores, the more severe the thought and language disorders, the relatively smaller the left and larger the right STG. These results suggest a complex neuroanatomical substrate for thought and language disorders in schizophrenia.

Influence of side chain configuration on anti-inflammatory analgesic and anti-pyretic properties of 4-biphenylyl alkanoic acids.

A study on the influence of the number of carbon atoms in the side chain as well as side chain configuration on some pharmacologic properties of 4-biphenylyl alkanoic acids is presented. Unlike the chemical structure dependent anti-inflammatory properties, mild analgesic and anti-pyretic properties were neither dependent upon number of carbon atoms nor side chain configuration.