Cerebral ventricular enlargement in chronic schizophrenia: consistencies and contradictions

Cerebral investigation of healthy siblings of schizophrenics

Computed tomography (CT) studies have demonstrated that lateral ventricular size measured by ventricular brain ratio (VBR), as well as third ventricle width, is statistically enlarged in schizophrenics. Moreover, these cerebral abnormalities differ according to symptomatology evaluated with a positive and negative symptom scale. The aim of this study was to investigate, using CT scans, healthy siblings of schizophrenics, and relate the results to their ill siblings. Nineteen healthy siblings of 12 previously studied schizophrenics underwent CT scans, which were compared to those of their related schizophrenic sibling and to 17 unrelated control subjects. The results showed that in ten of 12 families, schizophrenics have larger ventricles (lateral and third ventricles) than their healthy siblings. Ventricular enlargement of healthy siblings was correlated with severity of negative symptoms of their ill sibling. Implications of a familial contribution for ventricular size and negative symptoms are discussed.

CT and MRI Abnormalities in Schizophrenia: The New Developmental Biology of Psychosis?

Despite more than a decade of studies, biological psychiatry has yet to satisfactorily resolve the issue of whether new brain imaging technologies reliably indicate the presence of abnormal cerebral morphology in schizophrenia. The present Perspective offers an alternative view on this topic, as a counter-point to one previously offered in the Journal. It addresses several of the methodological problems inherent to such studies, and evaluates some of the more recent aspects of the literature. Those structural abnormalities which have been reported in schizophrenia appear most readily explicable as a consequence of neurodevelopmental anomalies.

Obstetric complications and age-related changes in brain morphology in schizophrenia

Birth problems can lead to changes in brain morphology in the general population and an increased prevalence of both birth problems and altered brain morphology are found in patients with schizophrenia. The purpose of this study was to test the hypothesis that these two findings are related. Birth history and the size of ventricular and sulcal spaces from nine regions of the brain were assessed in 80 male subjects with schizophrenia. No differences were found between patients with and those without a history of birth problems for the size of any brain space; however, ventricular size increased significantly with age in patients who had no birth complications but not in patients with a history of birth problems. The size of cortical sulci increased with age in patients with and those without a history of birth problems. These results suggest that region-specific rates of change in size may identify clinically meaningful patients subgroups.

VBR in schizophrenia: relationship to family history of psychosis and season of birth

Ventricular enlargement has been consistently demonstrated in schizophrenia using both CT and MRI. Despite this, the structural changes that underlie increased ventricle-brain ratio (VBR) and its relationship to environmental factors (intrauterine viral exposure, obstetric complications, etc.) and family history of schizophrenia remain poorly defined. Increased VBR has been shown in some studies to correlate with an absence of family history of schizophrenia and with Winter-Spring birth. In an attempt to obtain a clearer picture of the contribution of environmental and genetic factors to VBR, we studied 54 patients with DSM III-R schizophrenia. VBR was determined from head CT scans via computerized planimetry. Family history of psychosis and non-psychotic mood disorder was determined with the family informant method. Season of birth was encoded in several ways, including season, trimester and dichotomously. Patients without a family history of psychosis had significantly larger VBR than patients with such a history; family history of mood disorder was not related to VBR. Season of birth was not predictive of VBR. Family history of psychosis and season of birth were not related to each other. These results are in line with prior work demonstrating an association between increased VBR and sporadic (non-familial) schizophrenia. We did not find a relationship between VBR and season of birth, which suggests that risk of perinatal viral exposure and other seasonal environmental factors may not account for the ventricular enlargement in non-familial schizophrenia observed in our sample.

Structural abnormalities of the brain in schizophrenia: sex differences in the Cantabria First Episode of Schizophrenia Study

This paper examines structural brain abnormalities, as evaluated by the CT scan, in first episodes of schizophrenia and their association with sociodemographic, diagnostic and clinical variables. The investigation included all patients with a first episode of schizophrenia who, over a 2-year period, made contact with any of the public mental health services of the Autonomous Region of Cantabria in Northern Spain. Diagnostic and clinical characteristics were evaluated through the use of the Spanish version of the Present State Examination (PSE-9) and the Scales for the Assessment of Positive and Negative Symptoms (SANS and SAPS respectively). The study demonstrated the presence of structural brain abnormalities in this sample of first episode schizophrenics. These abnormalities were mainly expressed in the presence of larger VBR for schizophrenic patients than in the controls, these findings being more marked in women than in men. We failed to reveal, however, any evidence of an association of these brain abnormalities with diagnostic or clinical characteristics.

Systematic search for major genes in schizophrenia: methodological issues and results from chromosome 12

We describe a method of systematically searching for major genes in disorders of unknown mode of inheritance, using linkage analysis. Our method is designed to minimize the probability of missing linkage due to inadequate exploration of data. We illustrate this method with the results of a search for a locus for schizophrenia on chromosome 12 using 22 highly polymorphic markers in 23 high density pedigrees. The markers span approximately 85-90% of the chromosome and are on average 9.35 cM apart. We have analysed the data using the most plausible current genetic models and allowing for the presence of genetic heterogeneity. None of the markers was supportive of linkage and the distribution of the heterogeneity statistics was in accordance with the null hypothesis.

Cerebral ventricle dimensions as risk factors for schizophrenia and affective psychosis: an epidemiological approach to analysis

A case-control study was undertaken of volumetric computerized tomographic scan measures in 216 consecutive admissions for functional psychosis and 67 healthy community controls. Odds ratio analysis demonstrated significant linear trends in the association between increasing lateral and third ventricle volumes, and both RDC schizophrenia (N = 121) and schizo-affective disorder (N = 41); cases were consistently associated with larger volumes than controls. There was an association between larger third, but not lateral, ventricle size in affective psychoses (N = 54). These associations were statistically independent of intracranial volume, sex, social class and ethnicity, factors which were significantly associated with ventricular measures in the controls. There was no evidence of a threshold corresponding to the notion of normal versus enlarged ventricles. Within the schizophrenia group, there were no large or significant associations between ventricle dimensions and age at onset, duration of illness or pre-morbid social functioning. Neither obstetric complications nor a family history of schizophrenia or other psychiatric illness was associated with large ventricles in these cases.

A reconsideration of the relationship between cerebral structural abnormalities and family history of schizophrenia

In a study of 229 schizophrenic patients for whom reliable family history information was available, ventricular size and incidence of ventricular enlargement were found to be greater in male cases without a family history of schizophrenia. A significant sex by family history interaction on cerebral ventricular dimension was detected. The age-corrected morbid risk for schizophrenia was lower among first degree relatives of male probands with ventricular enlargement vs. those with normal ventricles, but similar in relatives of females with and without ventricular enlargement. On the other hand, no association was found between family history and degree of cortical atrophy. A meta-analysis of published studies on the issue revealed 20% larger ventricles in patients without any known genetic predisposition for schizophrenia.

Magnetic resonance imaging in schizophrenia: relationship with clinical measures

Relationships were examined between clinical features of schizophrenia and cerebrospinal fluid (CSF) volume in brain obtained by magnetic resonance imaging (MRI) in a sample of 59 patients. The volumes of the cerebral hemispheres and CSF were measured with a computer program designed to separate reliably neural tissue from CSF. The CSF to cranial volume ratios were related to history, symptom profile and outcome functioning. Earlier age of onset was associated with higher sulcal CSF ratio, r = -0.40. The anatomic measures were unrelated to symptom severity. However, patient subtypes differed in the laterality of measures. Higher left hemispheric ratios were seen in patients with severe negative symptoms, and left predominance of ventricular relative to sulcal ratios was associated with the presence of hallucinations and delusions. The results suggest that while higher CSF is related to earlier age of onset, the clinical symptoms are more related to its lateralization. This is consistent with the hypothesis that schizophrenia is a lateralized brain disease.

Ventricular enlargement, neuropsychological status, and premorbid function in schizophrenia

Ventricular enlargement is one of the most consistently documented neurobiological abnormalities in schizophrenia. The timing of the development of this abnormality in the course of schizophrenic illness and its relationship to neuropsychological dysfunction and premorbid adjustment is, however, unclear. To address these questions, we examined the relationship between ventricle-brain ratio (VBR), premorbid adjustment, and neuropsychological function, in 23 acutely exacerbated chronic schizophrenic inpatients. We observed that larger ventricles were associated with better current neuropsychological test performance, better premorbid cognitive ability, greater cognitive deterioration, better childhood premorbid social function, and greater decline in social function from premorbid levels. These data suggest that at least two developmental processes may operate in the genesis of cognitive and social dysfunction in schizophrenia: (1) childhood onset associated with poor premorbid childhood function, low educational achievement, lower intelligence quotient (IQ) and variably with VBR; and (2) adolescent onset associated with relatively normal childhood social function, higher academic achievement and IQ and increased VBR. Ventricular enlargement may reflect a late developmental or degenerative pathological process in schizophrenia.

Multidiagnostic evaluation of prolactin response to haloperidol challenge in schizophrenia: maximal blunting in Kraepelinian patients

We have previously reported that prolactin (PRL) responses to haloperidol 0.5 mg IV were blunted in subjects characterized by several diagnostic systems of schizophrenia compared to controls (Keks et al 1990). However, an attempt to find a diagnostic system most different from controls was unsuccessful due to inherent difficulties in the statistical analysis of multidiagnostic data. In this paper we present new methodologies. A test for differences in dependent correlations demonstrated that most of the variance in stimulated PRL was accounted for by Kraepelinian, and least by Schneiderian and M. Bleulerian, schizophrenias (p < 0.001). The main symptomatic difference between nonKraepelinian and Kraepelinian patients was the presence of association disturbance and feelings of passivity. Patients with both symptoms had a lower stimulated PRL than controls. Further findings and possible implications are discussed.

Ventricular enlargement in schizophrenia. A meta-analysis of studies of the ventricle:brain ratio (VBR)

Multivariate meta-analysis was performed on 39 studies of ventricular size in schizophrenia which used the ventricle:brain ratio (VBR). The size of the VBR was dependent both upon the date when studies were carried out (more recent studies showing a reduction in the difference between schizophrenics and controls), and upon the diagnostic criterion used in the studies. Methodological factors in study design seemed more important than the characteristics of the schizophrenic subjects, in determining the VBR. Our analysis suggests that there is a difference in VBR between schizophrenics and controls which would seem to be an indisputable characteristic of schizophrenia. However, the difference is smaller than has previously been thought, so that, although of undoubted theoretical interest in accounting for the aetiology of schizophrenia, it is probably too small to be of practical significance in diagnosis, or in the differentiation of subtypes.

Ventricular enlargement, clinical correlates and treatment outcome in chronic schizophrenic inpatients

The ventricle-brain ratio (VBR) of 42 chronic schizophrenic patients was compared with that of 42 age-matched medical controls. For the schizophrenics, the relationship of various clinical parameters to the VBR was assessed, and the outcome of 12 weeks of double-blind treatment with either risperidone or haloperidol. The results confirm that schizophrenic patients have slightly enlarged lateral ventricles compared with medical controls. Only for schizophrenics, an effect of age, but not of duration of illness, was noticed. This study does not support the validity of a clinical subdivision of chronic schizophrenic patients on the basis of the VBR. Neither negative, positive nor general psychopathological symptoms, as measured by the Positive and Negative Syndrome Scale for Schizophrenia (PANSS), were related to the VBR, nor were abnormal involuntary movements or extrapyramidal symptoms. No association between season of birth or a family history of major mental disorder and VBR could be demonstrated. Treatment response was predicted by the total PANSS score and the PANSS general psychopathology subscale score at baseline. There was a trend for patients with higher VBR to have a more or haloperidol). or haloperidol).

Lack of a bimodal distribution of ventricular size in schizophrenia: a Gaussian mixture analysis of 1056 cases and controls

The finding of clinical and laboratory differences between schizophrenic patients with large and small cerebral ventricles has led to the widespread assumption that large ventricles are a marker that characterizes a subgroup of patients with schizophrenia. We reviewed all published English language ventricle-to-brain ratio (VBR) studies in which individual data points were available (schizophrenics: n = 691, medical controls; n = 205, normal volunteers: n = 160). Using a univariate normal mixture model to examine the distribution of ventricular size in each group, we found no evidence of a mixture of Gaussian distributions (i.e., "bimodality") within any of the three groups. The same analysis was then performed on the combined sample of schizophrenic patients and normal and medical controls, respectively. In each case the improvement in fit of a mixture of normal distributions compared to a single component normal distribution was significant. The data do not support the notion that ventricular enlargement is a discontinuous marker of a subtype of schizophrenia.

Family history and brain morphology in schizophrenia: an MRI study

This study examined neuroanatomical differences between male schizophrenic patients with a family history of psychosis (n = 16) and those without such a history (n = 15). Intracranial area, cerebral area, ventricular size, and cortical atrophy were assessed using magnetic resonance imaging (MRI). Third ventricular enlargement was more prevalent in patients than controls (n = 15). Familial and nonfamilial patients differed significantly. Reduced cranial and cerebral areas without ventricular enlargement characterized familial patients, whereas nonfamilial patients showed marked lateral ventricular enlargement without a reduction in cranial/cerebral size.

Comparison of CATEGO-derived ICD-8 and DSM-III classifications using the composite international diagnostic interview in severely ill subjects

Two classifications, DSM-III and CATEGO4-derived ICD-8, included in the CIDI, are compared in 63 in-patients and out-patients with a broad range of psychiatric illness. Agreement for main diagnosis between these classifications was statistically significant for two time frames, the present state and lifetime. However, while diagnostic assignment by CATEGO4 remained fairly constant between time frames, there was a marked shift in DSM-III-assigned diagnosis, with cases changing from anxiety state diagnosis (present state) to affective disorder (lifetime). Thirty-nine subjects were assigned a DSM-III diagnosis of affective disorder for lifetime illness compared with 21 assigned to this diagnostic group by CATEGO4.

A magnetic resonance imaging study of schizophrenia: brain structure and clinical symptoms

Thirty-one patients with schizophrenia and 33 normal control subjects underwent MRI. The BPRS was used to rate clinical symptoms and the NART to estimate pre-morbid IQ. All were right handed. The temporal lobe was significantly smaller on the left than the right in both the control and schizophrenic groups. The amygdala was smaller on the left than the right in controls but not in schizophrenics. The parahippocampal gyrus was smaller on the left side in the schizophrenic group but not in controls. In the schizophrenic group, ventricular enlargement and cerebral atrophy were significantly related to severity of symptoms. Patients with marked negative symptoms had a bilateral reduction in the size of the head of caudate and the two measures were significantly correlated. Patients with marked positive symptoms had larger VBRs and again the clinical and morphometric changes were significantly correlated. There were no morphometric differences between patients with short duration (two years or less) and chronic symptoms.

Schizophrenia: a neuropathological perspective

It is probable that all schizophrenics have abnormalities in the medial temporal lobe, which differ in degree but not in kind. The structures of the medial temporal lobe are believed to have a crucial role in the integration and processing of the output from the association cortex. Dysfunction of this system could result in the clinical symptoms that form the core of the schizophrenia syndrome. The structural differences appear to fit the profile of a disturbance in the normal pattern of brain development. The asymmetrical patterns of normal brain development explain how such a disturbance simultaneously affecting both hemispheres could, disproportionately, affect the left (dominant) hemisphere. Epidemiological and pathological evidence points to aberrant genetic mechanisms as being the cause of the developmental anomaly in the majority of cases; environmental factors probably play a minor role. Despite the great progress made in solving the enigma of the structural changes in the brains of schizophrenics, the cause(s) of the changes--the aberrant genetic mechanism controlling brain development--may prove difficult to define.

History of obstetric complications, family history, and CT scan findings in schizophrenic patients

It has been proposed that obstetric complications (OCs) are more common in patients with nonfamilial schizophrenia, and associated with lateral ventricular enlargement in such patients. We examined the relations among OCs, family history of schizophrenia or bipolar mood disorder, and lateral ventricular size and cortical sulcal prominence in 44 schizophrenic patients. A history of OCs was not related to an absence of a family history of schizophrenia, ventricle-brain ratio, or cortical sulcal prominence. None of the CT findings was related to family history.

Structure and function in neurology and psychiatry

In the 19th century the triumphs of neuropathology and the clinico-anatomical method led to the evolution of neurology as a separate 'organically' based discipline associated with the concept of functional localisation. At the same time the growth of psychodynamic psychiatry contributed to the progressive separation of the two disciplines, with neuropsychiatry sitting uneasily in the middle. Psychiatrists are now showing increasing interest in the structure and function of the nervous system, but are having difficulty in integrating their findings into 'functional' diseases. This may be because disorder of function in the nervous system is much more complex than previously envisaged. The function of the nervous system is profoundly affected by psychological and social factors. The view that neurology is wholly 'organic' and synonymous with structural disease of the nervous system is fallacious. Neurological patients have complex dynamic disorders of function in the nervous system whether or not structural disease is present.

Aetiological heterogeneity of schizophrenia: the problem and the evidence

When Kraepelin formulated the concept of dementia praecox, he lumped together a number of diagnostic categories. One of his reasons for doing so was that he had seen many patients who ended up in the same kind of demented state, even though their initial symptoms might have been quite different. He noted that even some cases presenting with mania, or melancholia, took the same downhill course as did the more classic cases of dementia praecox. Kraepelin, aware of the striking paradigm of general paresis, stated that “a single morbid process” explained the downhill course (Kraepelin, 1983, p. 68).

Schizophrenia: the cellular biology of a functional psychosis

Structural abnormalities are found in the brains of schizophrenics. They affect preferentially, but not exclusively, medial temporal lobe structures (parahippocampal gyrus, hippocampus and amygdala), and can be found in all sub-types of schizophrenia. The structures of the medial temporal lobe are believed to have a crucial role in the integration and processing of the output from association cortex. It is probable that all schizophrenics have abnormalities in the medial temporal lobe that differ in degree but not in kind. Dysfunction of this system could result in the clinical symptoms that form the core of the schizophrenia syndrome. The changes in brain structure are not the result of neurodegenerative processes or destructive lesions but suggest a disturbance in the normal pattern of brain development.

The ventricle-brain ratio (VBR) in functional psychoses: an admixture analysis

An admixture analysis of the ventricle-brain ratio (VBR) on the computed tomographic (CT) scans of 72 patients with functional psychosis and 50 healthy controls was made, to determine whether two distinct distributions could be demonstrated. The patients showed a more positively skewed distribution, and a significantly higher mean VBR, but there was no evidence of more than one underlying normal distribution of values. The use of VBR alone to define a biologically separate subgroup of patients is not supported.

Notes from the graveyard: neuropathology and schizophrenia

Schizophrenia is commonly regarded as a 'functional' psychosis, the implication being that the delusions, hallucinations and cognitive impairment characteristic of the disease have no organic basis. This view is due in no small way to the failure of pathologists to find convincing pathological changes associated with the disease in the first seven decades of the century. Over the last 10 years things have changed considerably. Recent CT and MRI scan studies have provided convincing evidence of significant ventricular enlargement in the brains of schizophrenics and post-mortem studies have shown that schizophrenic brains are about 6% lighter than controls and have a reduced volume and reduced antero-posterior length. Planimetric studies on post-mortem material and a recent MRI study show that medial temporal lobe structures (parahippocampal gyrus, hippocampus and amygdala) are preferentially affected. Although other brain regions (e.g. cingulate gyrus, frontal cortex) also show alterations they appear to be 'downstream' from the regions primarily affected. Morphological studies show that there is a loss of neurons from medial temporal lobe structures and indicate irregularities in their cytoarchitectonic arrangement. The alterations in structure are not associated with degenerative, inflammatory, or abnormal vascular processes. There has been much debate as to the possible causes of the structural changes and whether they are limited to particular 'types' or sub-groups of schizophrenics. At present it seems simpler to suppose that all schizophrenics have a degree of structural abnormality which may differ in degree but not in kind. It has been proposed that the changes in brain structure in schizophrenia are the result of an anomaly of brain development. In the last year CT and MRI studies have shown that ventricular enlargement precedes clinical symptoms and is not progressive. These studies support the developmental interpretation. Future studies will need to focus on (a) the mechanisms (probably genetic) which can cause such developmental anomalies, (b) the neurochemical perturbations occurring as a result of such anomalies and (c) how both relate to clinical symptoms.

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.

Tomografia cerebral computadorizada e esquizofrenia: revisão crítica da literatura

Vários estudos sobre tomografia cerebral computadorizada (CT) relatam alteração da estrutura cerebral em esquizofrenia. A grande variação da prevalência e da localização das anomalias pode estar relacionada à heterogenidade da amostra estudada, à escolha das medidas de CT ou ao uso de diferentes critérios diagnósticos. Apesar de alguns achados contraditórios, parece estabelecido que um subgrupo de pacientes esquizofrênicos apresenta atrofia cerebral discreta ou moderada; esse subgrupo se caracterizaria por apresentar cronicidade da doença, pior resposta ao tratamento neuroléptico e pela presença de outros sinais de disfunção cerebral difusa, como distúrbios neuropsicológicos, anormalidades no EEG e «soft signs» neurológicos. Sinais de atrofia na CT foram observados em pacientes esquizofrênicos jovens, no primeiro surto psicótico, indicando que o desenvolvimento das anomalias estruturais não é conseqüência do tratamento ou da cronicidade da doença. Nos diferentes estudos, pacientes com atrofia apresentaram menor carga genética (história familiar para a esquizofrenia) e se observou com maior freqüência história de complicações na gestação, no parto e trauma craniano nos primeiros anos do desenvolvimento. Em face da possibilidade de que doentes esquizofrênicos com atrofia cerebral formem um subgrupo homogêneo quanto à clínica e à etiopatologia da doença, é importante identificar e estudar as alterações da CT e caracterizar esse subgrupo de pacientes.

Prevalence of familiality, obstetric complications, and structural brain damage in schizophrenic patients

Schizophrenic in-patients with and without a family history were identified prospectively. The two groups did not differ with respect to clinical variables, ventricular enlargement, prevalence of cortical sulcal widening, or a history of obstetric complications, even when a variety of definitions of familiality were used.

Is there really a split in schizophrenia? The genetic evidence

Although the clinical presentation and course of schizophrenia is highly variable, it is unclear whether this reflects heterogeneity at an aetiological level. The genetic evidence is reviewed concerning 'traditional' clinical subtypes as more novel categories derived from multivariate statistical methods and Crow's type I-type II classification. Recent data based on a twin series and re-analysis of older published family material suggest that attempts to divide up schizophrenia have resulted in splits between two or more categories of disorder which occupy different positions on the same continuum of liability. Thus, apparent heterogeneity is more likely to be due to quantitative difference in familial-genetic loading rather than qualitative differences. Similarly, the hypothesis that schizophrenia can be broadly divided into two groups, one genetic and the other non-genetic has little to support it. It seems improbable that any further useful and genetically relevant subdivision of schizophrenia can be effected on purely clinical grounds. Further progress awaits developments in the discovery of endophenotypes and the application of molecular genetic marker strategies.