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S W Lewis

Publications and source records attributed to S W Lewis.

At least 19 recordsLinked to original sources
PubMed1992

A controlled study of 99mTc-HMPAO single-photon emission imaging in chronic schizophrenia.

Regional cerebral blood flow (rCBF) during a word fluency task was compared in twenty-five male, right-handed, medicated schizophrenic patients and twenty-five age-matched male, right-handed healthy volunteers, using 99mtechnetium-HMPAO multidetector single-photon emission tomography. Increased rCBF in caudate and thalamus was found in patients, probably secondary to neuroleptic medication. Patients showed decreased rCBF in left frontal cortical regions and increased rCBF in left posterior cortical regions, compared to controls. Patterns of left-sided frontal rCBF dominance in controls were reversed in patients, as were normal patterns of right-sided parietal rCBF dominance. Negative symptom score correlated inversely with mesial frontal rCBF, particularly on the left.

Adult↗
PubMed1992

A neurodevelopmental approach to the classification of schizophrenia.

The conventional distinction between schizophrenia and manic depression has received little objective support from recent studies of phenomenology, outcome, or familial homotypy. Instead, much clinical, epidemiological, and morphological evidence suggests that within the broad range of Schneiderian schizophrenia there exists one form (congenital schizophrenia) that can be distinguished from other types, the manifestations of which are confined to adult life. We hypothesize that congenital schizophrenia is a consequence of aberrant brain development during fetal and neonatal life. Such patients show structural brain changes and cognitive impairment, and in their male predominance, early onset, and poor outcome, they reflect Kraepelin's original description of dementia praecox. We contend that adult-onset schizophrenia is itself heterogeneous. One important component is a relapsing and remitting disorder that is more frequent in females than in males, exhibits positive but not negative symptoms, and has much in common etiologically with affective psychosis. There also exists a very-late-onset group in which degenerative brain disorder is implicated.

Bipolar Disorder↗
PubMed1992

Ventricular size and regional cerebral blood flow in schizophrenia: an attempted replication.

We attempted to replicate the finding of Berman et al. (1987) that frontal cortical blood flow correlated inversely with ventricular size in schizophrenia. Computed tomography and high-resolution 99m-Tc-HMPAO single photon emission computed tomography were performed in 25 right-handed chronic schizophrenic men engaged in a word-fluency task. Weak, nonstatistically significant inverse correlations were found between the ventricle-brain ratio (VBR) and frontal cortical blood flow. The VBR was significantly inversely correlated with the ratio of left to right medial frontal blood flow.

Adult↗
PubMed1991

Obsessive-compulsive disorder and schizophrenia in three identical twin pairs.

Three monozygotic twin pairs are described who are concordant for DSM-III-R obsessive-compulsive disorder while being discordant for schizophrenia or schizoaffective disorder. Follow-up interview showed the non-psychotic co-twins to have schizotypal personality disorder. It is concluded that obsessive-compulsive and schizophrenia-spectrum disorders can truly co-exist, thus supporting diagnostic changes introduced into DSM-III-R, and may in some cases be inherited together.

Adult↗
PubMed1991

Assessing schizophrenia in adults with mental retardation. A comparative study.

Twenty-five patients with mild mental retardation were compared with 26 schizophrenic patients of normal intelligence. The patients with retardation had suffered an earlier onset and were less likely to have been married or employed. However, the clinical phenomena exhibited by the two groups, as elicited by a SADS-L interview, were very similar. Thus, standardised interviews and criteria for schizophrenia can be readily applied to those with an IQ between 50 and 70.

Adult↗
PubMed1990

The ventricular-brain ratio (VBR) in functional psychoses: the relationship of lateral ventricular and total intracranial area.

CT scans were performed on 72 consecutive patients with a functional psychosis, and compared with 50 community controls. There was a specific difference in lateral ventricular area between these two groups but it accounted for only 11% of the variance in this measure. In contrast, racial and sexual differences in the ventricular-brain ratio (VBR) related to differences in intracranial area. It is argued that analysis of variance, using lateral ventricular area and intra-cranial area, is more informative than VBR in examining these structural changes in functional psychoses.

Adolescent↗
PubMed1990

Can brain damage protect against schizophrenia? A case report of twins.

In a pair of male monozygotic twins discordant for schizophrenia, MRI revealed no abnormality in the ill proband, but extensive white-matter damage of likely congenital origin in the psychiatrically normal twin. These findings are difficult to reconcile with multifactorial models of schizophrenia, and raise the possibility that some forms of brain damage may preclude expression of the schizophrenia genotype.

Adult↗
PubMed1989

Hand preference in psychotic twins.

In an attempt to replicate the influential study of Boklage (1977), hand preference for writing was examined in a new series of 30 monozygotic (MZ) and 30 dizygotic (DZ) twin pairs in whom the proband had suffered a functional psychosis. In contrast to the original report, no increased rate of left-handedness was found in MZ compared to DZ twins, or psychotic compared with nonpsychotic twins. In particular, no relationship between within-pair left-handedness and discordance for psychosis emerged. Possible reasons for the disagreement between the two studies are examined.

Adult↗
PubMed1989

Absence of central functional cholinergic deficits in myasthenia gravis.

Sporadic reports have suggested central involvement in myasthenia gravis, a disorder in which there is an antibody-mediated loss of peripheral nicotinic acetylcholine receptors. Five patients with symptomatic myasthenia gravis performed an auditory vigilance test of ability to direct and sustain attention, presumed to reflect central cholinergic function. No deficits were found, either in comparison with the same subject's performance when muscle strength had improved after plasma exchange, or compared with that of healthy controls. The results thus failed to substantiate reports of functionally significant central cholinergic deficits in myasthenia gravis.

Adult↗
PubMed1989

Family history and cerebral ventricular enlargement in schizophrenia. A case control study.

Ventricular size was measured from CT scans in 48 patients meeting RDC for schizophrenia who had a first-degree relative with a history of treatment for major psychiatric disorder, in 48 age- and sex-matched schizophrenic patients with no such history in first- or second-degree relatives, and in 48 matched, healthy controls. There was no difference in ventricular size between those with and without a positive family history, although both groups showed ventricular enlargement with respect to normal controls. Ventricular enlargement was demonstrated in the subgroup of 23 patients with a family history of schizophrenia, but not in the subgroup of 18 patients with a family history of affective disorder. These observations provide further evidence that schizophrenics with a family history of affective disorder may constitute an aetiologically distinct subgroup.

Adult↗
PubMed1988

Obstetric complications and schizophrenia: a computed tomographic study.

All patients aged 16-50 years who had been discharged from the Maudsley Hospital over a 4-year period with a diagnosis of schizophrenia were ascertained retrospectively. Case records were rated blindly for a history of obstetric complications (OCs). Sixty-one patients who satisfied the RDC for schizophrenia had undergone CT scanning. Those with a definite history of OCs presented at an earlier age. In this group widening of cortical sulci and fissures was more strongly correlated with VBR than in subjects without OCs. Moreover, large VBRs when accompanied by widened cortical sulci and fissures occurred more commonly in subjects with OCs than in those without. These results support the hypothesis that OCs, or a factor associated with them, lead to brain damage of aetiological significance in some cases of schizophrenia.

Adolescent↗
PubMed1988

Agenesis of the corpus callosum and schizophrenia: a case report.

Clinical, radiological and neuropsychological findings in the first reported case of schizophrenia with complete agenesis of the corpus callosum are described. Although causal inferences were made difficult by the co-existence of a left frontotemporal cyst and a family history of affective disorder, some theories of the role of callosal dysfunction in schizophrenia require revision in the light of this case.

Agenesis of Corpus Callosum↗