Ssri-related toxic serotonin syndrome: improvement by discontinuation of treatment and propranolol

We report three cases in which toxic serotonin syndrome developed in relation to three different selective serotonin reuptake inhibitors (SSRI) (ie, fluoxetine, sertraline, paroxetine), and which all responded to the discontinuation of the SSRI and also to an additional propranolol treatment.

Abnormal prediction error is associated with negative and depressive symptoms in schizophrenia

Prediction error in learning is where learning occurs to the degree to which an outcome consequent to a stimulus is surprising. It has been suggested that abnormal use of prediction error in schizophrenia may underlie the formation of inappropriate associations giving rise to psychotic symptoms. Kamin blocking is a phenomenon that demonstrates prediction error. Kamin blocking is shown where prior learning about a stimulus A paired with an outcome retards learning about a stimulus B when presented subsequently as part of a stimulus compound AB paired with the same outcome. Prior studies have indicated reduced Kamin blocking in schizophrenia specifically in non-paranoid patients. It is however unclear how reduced Kamin blocking is associated with specific symptoms in schizophrenia. The present study examined Kamin blocking performance in a high functioning community-based sample of 34 people with schizophrenia and 48 controls closely matched for pre-morbid IQ. In these patients we measured Kamin blocking and symptoms using positive and negative symptom scales (PANSS) and Scale for the Assessment of Negative Symptoms (SANS) and Scale for the Assessment of Positive Symptoms (SAPS). Results confirmed that people with schizophrenia had significantly reduced Kamin blocking. Kamin blocking performance was associated with negative and depressive symptoms. These associations with symptoms were crucially not found with baseline associative learning or unblocking measures, confirming specificity to the Kamin blocking effect. These data demonstrate first that abnormal prediction error as assessed in the Kamin blocking task is associated with negative and depressive symptoms rather than positive symptoms in high functioning schizophrenia patients. Second this strongly suggests that reduced Kamin blocking may be useful as an animal model of specific relevance to negative and depressive symptoms in schizophrenia.

Measuring memory impairment in community-based patients with schizophrenia. Case-control study

BACKGROUND

The majority of memory impairment studies in schizophrenia are cohort studies using laboratory-based tests, which make it difficult to estimate the true extent and relevance of memory impairment in patients with schizophrenia in the community.

AIMS

To examine the extent of memory impairment in community-based patients with schizophrenia using a clinically relevant test.

METHOD

All patients with schizophrenia (n=190) in one catchment area were identified, of whom 133 were potentially eligible for the study; 73 patients volunteered to take part. They were assessed using the Rivermead Behavioural Memory Test (RBMT), the National Adult Reading Test, the Positive and Negative Syndrome Scale, the Health of the Nation Outcome Scales and the Scales and the Office for National Statistics Classification of Occupation. Their performance on the memory test was compared with that of matched controls (n=71).

RESULTS

Patients as a group performed significantly worse (P<0.001) than controls on the RBMT. Using the RBMT normative scores, 81% of patients were found to have impaired memory compared with 28% of controls.

CONCLUSIONS

Using a clinically relevant test, the majority of community-based patients with schizophrenia may have memory impairment.

Reduced Kamin blocking in non paranoid schizophrenia: associations with schizotypy

Kamin blocking (KB) is an attentional phenomenon whereby prior learning about a stimulus (A) retards learning about a new stimulus (B) when later presented in compound (AB) with the original stimulus A. KB has been shown to be reduced in patients with schizophrenia. Using Oades' KB paradigm it has been suggested that drug treatment may influence the expression of KB abnormalities in patients. It is therefore unclear whether Reduced KB are due to drug treatment or to the illness itself. One experimental approach that circumvents drug treatment confounds is to study schizotypal traits in healthy volunteers. In the present study we investigated KB using the Oades paradigm in 27 healthy volunteers and 21 schizophrenic patients. We additionally investigated the relationship between KB performance and measures of schizotypal traits and a number of factors relevant to the experience of schizophrenia using the O-LIFE questionnaire. Our results indicate first a clear negative relationship between general schizotypy and more specifically, Unusual experiences (UNEX) and cognitive disorganisation (COGDIS) and KB performance. This relationship was qualitatively and quantitatively similar in both healthy volunteers and schizophrenic patients. Second we have independently replicated reduced KB in non-paranoid patients and no change in KB in paranoid patients using the Oades KB task. This study also confirms that reduced KB in non-paranoid patients is confined to early test trials (3-4) while the negative relationships with schizotypy scales UNEX and COGDIS that we have found are also confined to these early test trials confirming the psychological relevance of this specificity.

Improved antisaccade performance with risperidone in schizophrenia

OBJECTIVE

Antisaccade errors are consistently increased in schizophrenia. As they have been demonstrated only in cross sectional studies, it is unclear how they vary longitudinally or with different medications. In a previous cross sectional study, we reported a trend towards a reduction in error rates in a patient group treated with risperidone, compared with clozapine and sulpiride treated groups.

METHODS

Gap random and antisaccade paradigms were performed on two occasions in the same sample of DSM-IV schizophrenic patients (n=12) in transition between conventional antipsychotic drugs and risperidone. A cross over design was used with six patients switching from risperidone to conventional (group I) and six in the opposite direction (group II). A control sample (n=12) was also tested on two occasions and their performance compared. The effects of practice between first and second testing and of switching between conventional antipsychotic drugs and risperidone and vice versa was also evaluated.

RESULTS

A significant reduction in error rate was demonstrated during risperidone treatment (n=12), compared with conventional APD treatment. Switching from conventional to risperidone produced a reduction in errors, and vice versa.

CONCLUSIONS

Treatment with risperidone was associated with improvement in antisaccade errors.

Effects of antidepressant treatments on first-ECT seizure duration in depression

1. Current guidelines on the practice of Electroconvulsive Therapy (ECT) suggest that antidepressant medications should be discontinued prior to the course of therapy. However, the practice of withholding potentially helpful medication is debatable because the effects of these medications on seizure duration remain unclear. In particular, there is a lack of empirical knowledge about the effects of Selective Serotonin Reuptake Inhibitors (SSRIs) on ECT treatment. 2. Therefore, we investigated and compared the effects of SSRIs and tricyclic antidepressants (TCAs) on seizure duration after the first bilateral ECT treatment. 3. The diagnosis of major depressive disorder was made using the DSM-IV criteria. Both patient groups were age- and sex-matched. ECT was indicated for acute suicidal acts or refractoriness to medications. All patients had received antidepressant treatment for at least eight weeks and were receiving at least the recommended dose of medication. All patients were ECT treatment-naïve and we measured the seizure duration after the first bilateral ECT treatment. 4. There was no significant difference between electrical charge applied to either group. Between the TCA and SSRI group the seizure duration was not significantly different: 33.2 seconds and 31.4 seconds respectively.

An exploratory approach to the serotonin syndrome: an update of clinical phenomenology and revised diagnostic criteria

Serotonin-related adverse side-effects of psychotropic drugs were first recorded in humans in 1960. However, since 1991, these related cases have been diagnosed as 'serotonin syndrome (SS)' according to the criteria reported by Sternbach. In this article, we have reviewed and further explored the validity of these criteria. The clinical profile of 24 cases of the SS published between 1991 and 1995 has been analysed in detail and compared with the symptomatology of 38 previous cases which were also further analysed. Mainly Medline and references from other reports were used to review these cases. The general concept put forward by Sternbach has been approved. On the basis of the severity of overall clinical presentation, it appeared that there is a need to further classify SS into three main groups as: (1) mild state of serotonin-related symptoms; (2) serotonin syndrome (full-blown form); (3) toxic states. Furthermore, the detailed analysis of the SS cases published so far suggests that 'the diagnostic criteria for SS' also require further revision, and these are presented here. We also review, present and discuss the guidelines for the management and treatment of SS.

Effects of clozapine and typical antipsychotic drugs on plasma 5-HT turnover and impulsivity in patients with schizophrenia: a cross-sectional study

OBJECTIVE

To compare the efficacy of clozapine with typical antipsychotic drugs in controlling impulsivity and to explore the possible correlation of impulsivity with plasma 5-hydroxytryptamine (5-HT) levels, plasma 5-hydroxyindoleacetic acid (5-HIAA) levels and plasma 5-HT turnover.

DESIGN

Prospective, cross-sectional study open to medication and blinded to biochemical analyses.

PARTICIPANTS

Healthy control subjects (n = 24) and 46 inpatients and outpatients meeting the DSM-IV criteria for schizophrenia; 20 were being treated with clozapine and 26 were taking typical antipsychotic drugs.

INTERVENTIONS

All psychotropic drugs other than clozapine or typical antipsychotic drugs were discontinued for at least 5 days and subjects fasted overnight before they were assessed.

OUTCOME MEASURES

Coccaro Impulsivity Scale scores, plasma 5-HT levels, 5-HIAA levels and 5-HT turnover.

RESULTS

Patients treated with clozapine and those treated with typical antipsychotics had significantly higher impulsivity scores than the control group, and the mean impulsivity score of the typical antipsychotic group was significantly higher than that of patients treated with clozapine. The mean concentration of 5-HT of the typical antipsychotic group was significantly lower than that of the control group and patients treated with clozapine; however, mean plasma levels of 5-HIAA were significantly higher for the clozapine group than the other 2 groups. 5-HT turnover was significantly higher for the 2 drug-treatment groups than for the control group.

CONCLUSIONS

These results suggest that treatment with clozapine should be considered for patients with schizophrenia who are impulsive and aggressive.

The effects of antipsychotic medication on saccadic eye movement abnormalities in Huntington's disease

1. The study was a prospective open trial done to determine the effect of antipsychotic medication on saccadic eye movements in patients with Huntington's disease (HD). The authors tested 16 outpatients with HD, 8 of whom were drug free and 8 of whom were on antipsychotic medication. We also tested 24 healthy control subjects. 2. The antisaccade task was used to investigate the voluntary control of saccadic eye movements. Antisaccade latencies and error rates were used as outcome measures. Both HD patient groups showed significantly more antisaccade abnormalities than controls and the rate of abnormalities was very similar between the drug-free and medicated patient groups. 3. The results suggest that these abnormalities are related to underlying neuropathology rather than effects of medication. Either specific dysfunction of the dorsolateral prefrontal cortex or of the subcortical circuit connecting this cortical area to the superior colliculus via the striatum are likely to be responsible for the generation of such antisaccade eye movement abnormalities.

Antisaccade eye movement abnormalities in Tourette syndrome: evidence for cortico-striatal network dysfunction?

Saccadic eye movements are rapid eye movements which act to redirect the eyes from one object of interest to another. Accurately and objectively measurable, their underlying neuroanatomical mechanisms have been extensively studied. The antisaccade task allows the study of the frontocortico-striatal network involved in the voluntary control of saccadic eye movements. In this task, the subject is instructed to inhibit a reflex eye movement towards a peripheral target light and, instead, to generate a movement in the equal and opposite direction. An error occurs when the subject fails to suppress reflexive saccades towards the target. Significantly high error rates and increased latencies in the antisaccade task have been reported in disorders associated with dysfunction of the frontocortico-striatal network. Increased saccadic eye movement latencies and error rates have been reported in Tourette syndrome patients (n = 4) who were receiving antipsychotic medication. To investigate this further, we tested the antisaccade task on six male Tourette syndrome patients. The results were compared with 18 age- and sex-matched mentally and physically healthy, medication/alcohol-free controls. Antisaccade latencies were (mean +/- SD; ms) 751.2+/-186.7 for the Tourette syndrome group and 417+/-75.3 for controls, and error rates were 59+/-14.3 for the Tourette syndrome group and 11.9+/-6.4 for controls, respectively. These significant results may further support dysfunction of the frontocortico-striatal network in Tourette syndrome.

The effects of clozapine on levels of total cholesterol and related lipids in serum of patients with schizophrenia: a prospective study

OBJECTIVE

To investigate the effects of 12 weeks of clozapine treatment on levels of cholesterol and related lipids in patients with schizophrenia.

DESIGN

Prospective study.

SETTING

University department associated with a teaching hospital.

PARTICIPANTS

Eight patients (6 women and 2 men) with a clinical diagnosis of schizophrenia consistent with DSM-IV criteria. The patients were classified as treatment-resistant and had not responded to treatment with at least 2 conventional antipsychotics.

INTERVENTIONS

Current antipsychotic medications were tapered and treatment with clozapine was initiated.

OUTCOME MEASURES

Cholesterol and serum lipid levels, as well as Brief Psychiatric Rating Scale (BPRS) scores were measured before and after 12 weeks of treatment with clozapine.

RESULTS

Clozapine treatment significantly improved the BPRS scores but did not significantly alter serum lipid levels, except triglyceride levels, which increased.

CONCLUSION

The previously reported lower levels of cholesterol in treatment-resistant patients with schizophrenia cannot be attributed to the effects of clozapine administration. Further research is required to support and clarify the effects of antipsychotic drugs on lipid levels.

Refractory symptomatic schizophrenia resulting from frontal lobe lesion: response to clozapine

A 34-year-old man with a 10-year history of persistent auditory hallucinations and passivity delusions had failed to respond to a variety of conventional antipsychotic medications. He had a history of head trauma 8 years before the onset of psychiatric symptoms. Recent investigations revealed a post-traumatic infarct, situated in the left frontal lobe, on a magnetic resonance imaging scan. Treatment with clozapine for more than 2 years resulted in a marked improvement in his psychotic symptoms. The localization of the brain lesion may be related to the etiology of his symptoms and to the clinical response to clozapine.

Effects of amphetamine on saccadic eye movements in man: possible relevance to schizophrenia?

The antisaccade task can be used to test the voluntary control of saccadic eye movements (SEMs). In many disorders with postulated hyperdopaminergic neurotransmission, there are reports of abnormalities in SEMs. To further investigate this, the role of dopamine in SEMs, performance on an antisaccade task was examined in subjects with a history of amphetamine use (a dopamine releaser and reuptake inhibitor). A prospective design was employed in a teaching hospital setting. Six subjects (five males) with a history of amphetamine use were compared to 24 normal controls. None of the subjects were using any other substances, except alcohol and nicotine, as determined by urine screening, which we believe limited the sample size. For subjects who used amphetamine before the task, the presence of amphetamine was confirmed by urinalysis. All subjects completed the antisaccade task. Both error rates and latency rates during the antisaccade task were compared between the amphetamine users and controls. The amphetamine users had significantly increased error rates and latencies. These results may suggest that increased error rates and latencies during antisaccade tasks may be due to increased dopamine transmission, which is similar to the findings in schizophrenia.

Effects of typical antipsychotic drugs and risperidone on the quality of sleep in patients with schizophrenia: a pilot study

OBJECTIVE

To investigate the effects of a newer antipsychotic drug, risperidone (a potent serotonin 5-HT2A/2C and dopamine D2-receptor blocker), on the quantity and quality of sleep in patients with schizophrenia.

DESIGN

Prospective pilot study.

SETTING

Outpatient treatment at a mental health hospital.

PATIENTS

Two groups of age- and sex-matched patients with schizophrenia receiving either risperidone (n = 8) or a typical antipsychotic drug (n = 8), and a group of age- and sex-matched controls (n = 8).

OUTCOME MEASURES

Sleep quality, measured by a visual analogue scale, and sleep continuity, measured using a movement index calculated from actigraph data.

RESULTS

Patients with schizophrenia had more disturbed sleep than controls. Compared with patients treated with typical antipsychotic drugs, patients treated with risperidone reported significantly better sleep quantity and quality as well as general functioning.

CONCLUSION

Improvement by risperidone may be related to 5-HT2A/2C receptor blockade; however, further controlled studies are required to confirm these results.

Differential effects of transdermal nicotine on microstructured analyses of tics in Tourette's syndrome: an open study

BACKGROUND

The treatment of Tourette's syndrome (TS) is often unsatisfactory. However, there is some evidence that transdermal nicotine patch (TNP) application may improve tics of nonsmoking TS patients who are refractory to haloperidol treatment.

METHODS

In this open study we applied two 10 mg TNP for 2 consecutive days to four TS patients whose symptoms were not controlled by haloperidol and to a never-medicated TS patient, all of whom are non-smokers. The Yale Global Tic Severity Scale (YGTSS) and a quantified video-taped micro-structured analysis of tics (head-shake tics, eye-blinks, vocal tics, facial grimace and other body tics) were both carried out to assess the change after the application of TNP.

RESULTS

TNP application significantly reduced the YGTSS by an average of 50%, with no reported side-effects, for up to 4 weeks but not 16 weeks, as compared with TNP-free period. Consistent with these results, the total counts of tics also showed a significant decrease for up to 4 weeks after the TNP application.

CONCLUSION

TNP application differentially affected individually quantified tics, which may suggest a differential role of nicotinic receptors in the generation of different tics.

Cholesterol and mental disorder

BACKGROUND

Cholesterol plays an important part in cellular structure and function and changes in serum levels may affect neurotransmission in the central nervous system.

METHOD

A MEDLINE literature search was made covering the period 1990-95 with systematic searching of citations from the articles identified. Representative articles were selected, focusing on those aspects which had not been thoroughly reviewed elsewhere, namely suicidal ideation, depression, personality and schizophrenia.

RESULTS

Lowering cholesterol levels have been associated with an increase in violent deaths in cardiovascular primary prevention studies. However, altered cholesterol levels have also been reported in relation to other psychiatric disorders.

CONCLUSION

There is substantial evidence that serum cholesterol levels may be associated with variations in mental state or personality. Further work is needed to clarify this and to elucidate the mechanisms involved.

A comparative trial use of sulpiride and risperidone in Huntington's disease: a pilot study

Sulpiride and risperidone treatment significantly improved the abnormal involuntary movements of two patients with Huntington's disease on both actometer and clinical assessments. However, treatment with risperidone, but not sulpiride, significantly improved the functional activities as assessed by the Functional Disability Scale. To the best of our knowledge this is the first report of the successful treatment of Huntington's disease with risperidone.

Successful treatment of urinary incontinence with clozapine in a schizophrenic patient

There is evidence that urinary incontinence (UI) can develop without any organic aetiology as a direct side effect of typical antipsychotic medication. Clozapine was administered to a chronic schizophrenic patient with UI who was refractory to typical antipsychotic medication. After various laboratory and functional tests, UI was demonstrated to be unrelated to any organic aetiology. UI was monitored throughout the study as frequency (wetting the bed) per day and night. The Brief Psychiatric Rating Scale (BPRS) was also rated. Clozapine (dose-dependently) reduced both the BPRS score and frequency of UI, which were refractory to trifluoperazine and sulpiride. This is the first report of a dramatic resolution of UI in a schizophrenic patient after clozapine treatment. It is suggested that preference should be given to clozapine in such cases, since various other antipsychotic medications were ineffective and in some cases worsened the existing UI.

Saccadic abnormalities in psychotic patients. I. Neuroleptic-free psychotic patients

Most of the previous research reporting abnormalities of rapid re-fixation eye movements (saccades) in patients with schizophrenia has used patients receiving neuroleptic medication. In this study non-neuroleptically medicated schizophrenics were compared with other psychiatric patients using a variety of saccadic paradigms to determine the specificity of saccadic dysfunction. The patient groups consisted of schizophrenics (N = 18), bipolar affectives (N = 18), anxiety neurotics (N = 10) and normal controls (N = 31), none of whom had received neuroleptic medication for the preceding 6 months. Four behavioural paradigms, reflexive, predictive, remembered and ANTI were used to elicit saccades. The primary abnormality in the schizophrenic group was a significantly increased rate of distractibility in the ANTI (saccades made towards the target rather than in an opposite direction) and REM (saccades made prior to the imperative cue) paradigms. The major neuropsychological variable predictive of these errors was Wisconsin card sort perseverative errors. These data, in conjunction with findings from previous neurological research, would seem to provide converging evidence towards dysfunction of prefrontal cortex in schizophrenia.

Saccadic abnormalities in psychotic patients. II. The role of neuroleptic treatment

The effects of dopamine-antagonistic neuroleptic (NL) medication on saccadic eye movements were compared in matched groups of 40 NL-treated and 18 NL-free schizophrenic patients and in 18 NL-treated and 14 NL-free bipolar affective patients. Manipulation of the saccadic paradigm yielded data on four types of saccade: those reflexively elicited by novel stimuli (REFLEX saccades), those directed towards the remembered location of a target now extinguished (REM) or towards the location where a predictably alternating target is expected to appear (PRED), or ANTI saccades, directed away from the stimulus to the mirror image location. Extensive psychiatric, neurological and neuropsychological assessments were also carried out on all subjects. The saccades of NL-treated patients, regardless of diagnosis, were less spatially accurate than those of NL-free patients, with a greater tendency to fall short of the target when generated towards the locus of a mentally represented target. This effect was greatest with a predictably alternating target, especially during periods when target visibility was withdrawn, only a temporal cue remaining. This pattern of impairment which is also found in early stages of Parkinson's disease is likely to be due to deficiency of striatal dopamine. Its best clinical predictors were disease duration, and Webster-Parkinsonism scores. Failure to suppress reflexive saccades to the stimulus in the REM and ANTI paradigms were more closely associated with schizophrenia than with NL treatment and were best predicted by negative symptoms and Wisconsin perseverative errors, both of which are widely regarded as indicators of frontal lobe dysfunction.

Serotonin hypothesis of psychiatric disorders during HIV infection

We are presenting a hypothesis which provides a neurobiological explanation for the aetiology of psychiatric disorders which are very common during the human immunodeficiency virus infection (HIV). Understanding the neurobiological basis, and therefore providing an effective treatment for these psychiatric disorders, is very important since disturbed behaviours may facilitate the behaviour and risk factors which are crucially involved in spreading this infection.

Pimozide treatment of a male case with de Clerambault's syndrome and schizophrenia

Effective treatment with pimozide of a male patient with secondary de Clérambault's syndrome (DCS) and schizophrenia is reported. There was no evidence of relapse at 24-month follow-up. Pimozide is suggested to be the drug of choice in DCS and may be in other disorders in which symptoms of erotomania are prominent. The unique anti-erotomanic activity of pimozide may be due to its calcium channel antagonist activity, a property which is not shared by the other antipsychotic drugs.

Improvement of abnormal saccadic eye movements in Huntington's disease by sulpiride: a case study

Sulpiride treatment improved both the abnormal asymmetric saccadic eye movements (SEM) and the abnormal involuntary movements (AIMs) in a patient with Huntington's disease (HD). However, sulpiride corrected the abnormalities of SEM in the right, but not the left, hemi-field and the degeneration of the left striatal tissue was greater as visualised by the magnetic resonance imaging (MRI) scan.

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.

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.

The familial/sporadic distinction as a strategy in schizophrenia research

The rationale and limitations of discriminating between cases of schizophrenia with and without a family history are reviewed. It is concluded from the evidence available that, by identifying subgroups of greater aetiological homogeneity, the strategy can be a useful starting point for research into likely causes.

Left cerebral hemisphere hypodensity in discordant schizophrenic twins. A controlled study

Eleven identical (monozygotic) twin pairs discordant for schizophrenia and 18 unselected control monozygotic twin pairs received a computed tomographic scan. Brain absorption density was determined on quadrants at five slice levels using a fully automatic program that eliminated cerebrospinal fluid spaces from analysis. There was no difference in brain density among schizophrenics, co-twins, and controls. There was a significant difference in right vs left hemisphere asymmetry of density across diagnostic groups. Overall, the left hemisphere was less dense than the right in the schizophrenics, while the reverse was found for the co-twins and controls. These results support the hypothesis of left hemisphere dysfunction in schizophrenia and suggest that it is an environmentally acquired, rather than genetic trait.

Increased CSF amino acids and ventricular enlargement in schizophrenia: a preliminary study

We found significantly higher levels of cerebrospinal fluid alanine, glycine, leucine, and phenylalanine in schizophrenic patients compared to healthy controls. Ventricular enlargement was present in 4 of 11 schizophrenics, and elevated CSF alanine was highly correlated with ventricular enlargement. The implications of these findings are discussed.

The relationship of twinning to the familial-sporadic distinction in schizophrenia

Cerebral ventricular enlargement in schizophrenia may occur more often in the absence of a family history of the disorder, suggesting that it is related to some non-genetic component of aetiology. This paper shows the finding to be much more apparent in a group of twins than in a similar group of singletons. Previous studies have shown twins in general to have larger cerebral ventricles than non-twins; we suggest that it is the greater susceptibility of twins to obstetric complications that is responsible for both the larger cerebral ventricles found in normal twins, and the very marked increase in ventricular size found in family history negative schizophrenic twins. We go on to consider evidence relating to a possible increased susceptibility of twins to develop schizophrenia.

A fully-automated computer-assisted method of CT brain scan analysis for the measurement of cerebrospinal fluid spaces and brain absorption density

Computer-assisted methods of CT brain scan analysis offer considerable advantages over visual inspection, particularly in research; and several semi-automated methods are currently available. A new computer-assisted program is presented which provides fully automated processing of CT brain scans, depending on "anatomical knowledge" of where cerebrospinal fluid (CSF)-containing spaces are likely to lie. After identifying these regions of interest quantitative estimates are then provided of CSF content in each slice in cisterns, ventricles, Sylvian fissure and interhemispheric fissure. Separate measures are also provided of mean brain density in each slice. These estimates can be summated to provide total ventricular and total brain volumes. The program shows a high correlation with measures derived from mechanical planimetry and visual grading procedures, also when tested against a phantom brain of known ventricular volume. The advantages and limitations of the present program are discussed.

Tardive dyskinesia in schizophrenics under 60 years of age

Ninety-one schizophrenics (mean age 34 years) were examined for tardive dyskinesia (TD) during chronic neuroleptic treatment. Dyskinesia was found in 23 (25.3%). The only variable that showed an association with TD was the current doses of neuroleptics: in none of the TD patients did the dose of fluphenazine decanoate (or equivalent) exceed 45 mg/week, whereas it was higher in 23 of the 68 without TD (p less than 0.01). When these 23 "high-dose" patients were disregarded, the TD group differed significantly from the 45 dose-matched non-TD subjects in that it had more common anticholinergic drugs, more common parkinsonian symptoms, and less instances of good remission (p less than 0.05 in each case). There was no association between TD and other considered variables (drug history, age, sex, clinical characteristics, size of the lateral brain ventricles, neurological "soft" signs, cognitive impairment). The results illustrate a relationship between TD prevalence and current doses of neuroleptics and indicate that differences in doses between the groups with and without TD may obscure associations between dyskinesia and other factors.

Ventricular enlargement in schizophrenia. The validity of computerised tomographic findings

There has been a considerable range in both the prevalence of ventricular enlargement and values for ventricular size of both schizophrenics and controls, in studies using computerised tomography (CT). The CT scans of 19 unrelated chronic schizophrenics, all of monozygotic (MZ) twin birth, and 36 age-and-sex-matched normal twins from 18 MZ pairs were examined by linear, planimetric, and semi-automated computerised methods. All methods distinguished schizophrenics from controls at approximately the same level of significance, but partial volume artefact led to a greater than two-fold variation in apparent ventricular size, and significantly reduced the validity and reliability of mechanical planimetric and linear measures. Measurement error may be an important source of artefact in uncontrolled studies using those techniques, and when comparing absolute values across studies, but the use of computerised methods should significantly reduce this source of artefact and allow more meaningful comparison.

Cytomegalovirus and schizophrenia. A test of a viral hypothesis

Cerebrospinal fluid (CSF) from 20 chronically hospitalised male schizophrenics and from 12 patients admitted with acute schizophrenia were examined for antibodies against cytomegalovirus. A sensitive and specific enzyme-immunoassay was used to detect IgG or IgM classes of antibodies in the CSF of the schizophrenic patients and of ten orthopaedic patients, who served as controls. No significant amounts of IgM antibody were found in the CSF of either group. A significant titre of IgG was found in only one of the 32 schizophrenics, an acute patient, but in four of the orthopaedic patients. The results do not support an association of cytomegalovirus infection with schizophrenia; if such an association occurs, it must be unusual.

CT scans in schizophrenia

The term ‘dementia praecox’ was used by Kraepelin to emphasise the tendency towards deterioration to a state of impairment resembling a dementia. Early studies looked for structural brain lesions post mortem, and later using pneumoencephalography; there were positive findings (Haug, 1962), but they were not always replicated (Storey, 1966). The risks and limitations of pneumoencephalography gradually led to its being abandoned. However, studies showing minor neurological abnormalities (Rochford et al, 1970) and cognitive impairment (Malec, 1978) continued to suggest an organic component to schizophrenia.