The two-syndrome concept postulates two "dimensions of pathology" underlying schizophrenia--a reversible (and potentially neuroleptic-responsive) component and a sometimes progressive and relatively irreversible component associated with the deficit state and poor long-term outcome. Negative symptoms (narrowly defined) appear to be more closely associated with the latter component (the type II syndrome), as also are cognitive impairments, abnormal involuntary movements, and behavioral deterioration. This syndrome is assumed to be more closely related than the type I syndrome of positive symptoms to the structural brain changes inferred from pneumoencephalograms, computed tomography scans, and recent post-mortem studies. However, since both syndromes often occur in the same patient--sometimes at the same point in time--they presumably have the same etiology.

The Two-syndrome Concept: Origins and Current Status

The authors explored the clinical correlates of ventricular enlargement in schizophrenia by comparing 16 patients with "large" ventricles (ventricles more than I SD above the control mean) with 16 patients with the smallest ventricles from a sample of 52 schizophrenic patients Patients with ventricular enlargement showed some impairment in the sensorium and had a preponderance of "negative" symptoms (eg, alogia, affective flattening, avolition, anhedonia), while those with small ventricles were characterized by "positive" symptoms (eg, delusions, hallucinations, positive formal thought disorder, bizarre behavior) These findings suggest that combining a measure of brain structure with the clinical picture may provide a useful new approach to the classification of schizophrenia

Ventricular Enlargement in Schizophrenia: Relationship to Positive and Negative Symptoms

Schizophrenia and brain dysfunction: an integration of recent neurodiagnostic findings

Discussion of the positive vs. negative distinction often fails to address whether this distinction refers to symptoms, syndromes, or diseases. Symptoms and syndromes are etiologically nonspecific, while diseases have a specific identifiable pathophysiology or etiology. The positive vs. negative distinction is sometimes discussed as a hypothesis for identifying discrete subtypes of disease within the schizophrenic syndrome. In this overview, the evidence supporting this approach to subtyping is critically reviewed, and modifications of the original form of the hypothesis are proposed.

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Positive vs. Negative Schizophrenia: A Critical Evaluation

• Using two standardized recording techniques (the Abnormal Involuntary Movement Scale [AIMS] and the Rockland Scale), spontaneous involuntary movement disorder was assessed in a sample of 411 hospitalized patients with chronic schizophrenia, 47 of whom apparently had never been exposed to neuroleptic medication. Prevalence of abnormality clearly depended on the criteria of severity adopted, but overall it was high, with half of the sample on the AIMS and two thirds on the Rockland Scale rating 3 (moderate) or more on one item or more. Comparison of those with a history of treatment with neuroleptics and those with no such history showed few significant differences with regard to prevalence, severity, and distribution of abnormal involuntary movements. We concluded that spontaneous involuntary disorders of movement can be a feature of severe, chronic schizophrenia unmodified by neuroleptic drugs.

Spontaneous involuntary disorders of movement: their prevalence, severity, and distribution in chronic schizophrenics with and without treatment with neuroleptics.

The relationship between size of cerebral ventricles in chronic schizophrenics and performance on a comprehensive neuropsychological battery, the Standardized Luria-Nebraska Neuropsychological Battery, was investigated. Ventricular size was determined by using a planimeter to measure the size of the lateral ventricles and the ventricular body, if present, on the computerized tomographic (CT) scan image that showed the largest lateral ventricles. This number was divided by the size of the brain as a whole on the same image of the CT scan to yield a ventricular brain ratio. This ratio was then correlated with the scores on the Luria-Nebraska Neuropsychological Battery. Eight of the 14 scales of the Luria-Nebraska Neuropsychological Battery correlated significantly at the .05 level with the ventricular brain ratio in a sample of 42 chronic schizophrenics with an average age of 32.3 years. Overall, there was a multiple correlation of .72 between the ventricular brain ratio and Luria scores. The overall ventricular brain ratio for the schizophrenics was significantly above that found in normal populations. Changes in the size of the ventricles in schizophrenics appear to have significant correlates with measures of neuropsychological performance.

Cerebral Ventricular Size and Neuropsychological Impairment in Young Chronic Schizophrenics: Measurement by the Standardized Luria-Nebraska Neuropsychological Battery

Robert Zelazowski

Papers

Cerebral Ventricular Size and Neuropsychological Impairment in Young Chronic Schizophrenics: Measurement by the Standardized Luria-Nebraska Neuropsychological Battery