Staging of cytoskeletal and beta-amyloid changes in human isocortex reveals biphasic synaptic protein response during progression of Alzheimer's disease

We have examined the relationships between dementia, loss of synaptic proteins, changes in the cytoskeleton, and deposition of beta-amyloid plaques in the neocortex in a clinicopathologically staged epidemiological cohort using a combination of biochemical and morphometric techniques. We report that loss of synaptic proteins is a late-stage phenomenon, occurring only at Braak stages 5 and 6, or at moderate to severe clinical grades of dementia. Loss of synaptic proteins was seen only after the emergence of the full spectrum of tau and beta-amyloid pathology in the neocortex at stage 4, but not in the presence of beta-amyloid plaques alone. Contrary to previous studies, we report increases in the levels of synaptophysin, syntaxin, and SNAP-25 at stage 3 and of alpha-synuclein and MAP2 at stage 4. Minimal and mild clinical grades of dementia were associated with either unchanged or elevated levels of synaptic proteins in the neocortex. Progressive aggregation of paired helical filament (PHF)-tau protein could be detected biochemically from stage 2 onwards, and this was earliest change relative to the normal aging background defined by Braak stage 1 that we were able to detect in the neocortex. These results are consistent with the possibility that failure of axonal transport associated with early aggregation of tau protein elicits a transient adaptive synaptic response to partial de-afferentation that may be mediated by trophic factors. This early abnormality in cytoskeletal function may contribute directly to the earliest clinically detectable stages of dementia.

A qualitative and quantitative study of grumose degeneration in progressive supranuclear palsy

Grumose degeneration (GD) of the dentate nucleus is a common feature in progressive supranuclear palsy (PSP), but its pathogenesis has not been well studied, and its clinical significance remains unknown. This report describes a quantitative study of GD in 9 cases of PSP using image analysis with single- and double-immunolabeling, as well as histochemical stains for myelin and axons. GD was associated with demyelination, axonal loss, glial tau pathology, and microgliosis in regions juxtaposed to the dentate nucleus (DN). Specifically, demyelination and microgliosis were prominent in the superior cerebellar peduncle (SCP), dentate hilus, and cerebellar hemispheric white matter. Tau pathology and microgliosis were less prominent in the DN itself. The degree of myelin loss correlated with the tau burden in the SCP. GAP-43, which is a phosphoprotein known to be involved in axonal growth and sprouting, was decreased in the DN of PSP, and the degree of GAP-43 loss correlated with severity of GD. These results suggest that GD may be related to progressive pathology in the dentatorubrothalamic tract as well as the cerebellar hemispheric white matter, and that GD may be a consequence of concurrent degeneration in both output from and input to the DN. The results further suggest a possible role for oligodendroglial and myelin pathology in the pathogenesis of PSP.

Entorhinal cortex pre-alpha cell clusters in schizophrenia: quantitative evidence of a developmental abnormality

BACKGROUND

Previous studies using semiquantitative or qualitative techniques demonstrated abnormalities of positioning of clusters of neurons (pre-alpha cells) in the entorhinal cortex in schizophrenia, suggesting a developmental mechanism could contribute to the illness. Recent quantitative studies of laminar thickness and laminar cell counts have been less consistent, and several failed to replicate the finding. However, none of the quantitative studies focused on the position of the pre-alpha cell clusters.

METHODS

To study pre-alpha cell position in detail, we examined the entorhinal cortex in serial sections from 21 control and 19 schizophrenic brains. Cluster position relative to the gray-white matter junction and cluster size were measured.

RESULTS

Quantitative assessment of 1991 clusters indicated clusters were positioned relatively closer to the gray-white matter junction in the anterior half of schizophrenic entorhinal cortices. In addition, the size of clusters in males with schizophrenia was reduced.

CONCLUSIONS

These results support the model of schizophrenia as an illness in which brain development is impaired. The findings in males with schizophrenia may indicate the presence of more severe pathology, or an additional pathogenic mechanism.

Alpha-synuclein inclusions in Alzheimer and Lewy body diseases

Alpha-synuclein has assumed particular neuropathological interest in the light both of its identification as a non-beta-amyloid plaque constituent in Alzheimer disease (AD), and the recent association between dominant inheritance of Parkinson disease (PD) and 2 missense mutations at positions 30 and 53 of the synuclein protein. We report a systematic study of alpha-synuclein, tau, and ubiquitin immunoreactivity in representative neurodegenerative disorders of late life. The alpha-synuclein association with Lewy bodies is variable, peripheral, and is not stable with respect to proteases or acid treatment, whereas there is no association with Pick bodies. Stable patterns of immunoreactivity included neurites and a novel inclusion body. Although there is an overlap between the presence of Lewy bodies and stable alpha-synuclein immunoreactivity, this is seen only in the presence of concomitant neuropathological features of AD. The novel alpha-synuclein inclusion body identified in pyramidal cells of the medial temporal lobe in particular was found in AD and in the Lewy body variant of AD, and was associated neither with ubiquitin nor tau protein. The inclusion is therefore neither a Lewy body nor a PHF-core body, but may be confused with the Lewy body, particularly in the Lewy body variant of AD. Abnormal processing of alpha-synuclein leading to its deposition in the form of proteolytically stable deposits is a particular feature of the intermediate stages of AD.

Location of a major susceptibility locus for familial schizophrenia on chromosome 1q21-q22

Schizophrenia is a complex disorder, and there is substantial evidence supporting a genetic etiology. Despite this, prior attempts to localize susceptibility loci have produced predominantly suggestive findings. A genome-wide scan for schizophrenia susceptibility loci in 22 extended families with high rates of schizophrenia provided highly significant evidence of linkage to chromosome 1 (1q21-q22), with a maximum heterogeneity logarithm of the likelihood of linkage (lod) score of 6.50. This linkage result should provide sufficient power to allow the positional cloning of the underlying susceptibility gene.

Cortical cholinergic denervation elicits vascular A beta deposition

Selective destruction of the cholinergic nucleus basalis magnocellularis (nbm) in the rabbit by the p75 neurotrophin receptor (NTR) immunoglobulin G (IgG) complexed to the toxin saporin leads to the deposition of amyloid-beta (A beta) in and around cerebral blood vessels. In some instances, the perivascular A beta resemble the diffuse deposits observed in Alzheimer's disease (AD). We propose that cortical cholinergic deprivation results, among other perturbations, in the loss of vasodilation mediated by acetylcholine. In addition to a dysfunctional cerebral blood flow, alterations in vascular chemistry affecting endothelial and smooth muscle cells may result in cerebral hypoperfusion and a breached blood-brain barrier (BBB). The selective removal of the rabbit nbm and A beta accumulation may serve as an important nontransgenic, and more physiological, model for the testing of pharmacological and immunological agents designed to control the deposition and the deleterious effects of A beta in AD.

Disturbed gyrification of the prefrontal region in male schizophrenic patients: A morphometric postmortem study

OBJECTIVE

The goal was to test the hypothesis that abnormalities of gyrification are present in the prefrontal region of postmortem brains from schizophrenic patients.

METHOD

The authors compared the prefrontal regions in brains from 24 schizophrenic patients and 24 normal comparison subjects. The gyrification index, the ratio of inner and outer surface contours, was measured bilaterally in three different slices from each brain. Area measurements of gray and white matter were studied separately by planimetric analysis in the same sections. In addition, a gray-to-white-matter ratio and an asymmetry coefficient were computed.

RESULTS

The mean gyrification index on the right side was significantly higher in the male schizophrenic patients than in the comparison men. The gyrification index of the female patients was not significantly different from that of the female comparison subjects. Analysis of area measurements revealed no significant differences.

CONCLUSIONS

As gyrification is an ontogenetic stable feature unaffected by atrophic processes during aging, the gyrification abnormalities of the prefrontal region provide further evidence of the importance of a neurodevelopmental mechanism in the etiology of schizophrenia, at least in males.

Linkage of familial schizophrenia to chromosome 13q32

Over the past 4 years, a number of investigators have reported findings suggestive of linkage to schizophrenia, with markers on chromosomes 13q32 and 8p21, with one recent study by Blouin et al. reporting significant linkage to these regions. As part of an ongoing genome scan, we evaluated microsatellite markers spanning chromosomes 8 and 13, for linkage to schizophrenia, in 21 extended Canadian families. Families were analyzed under autosomal dominant and recessive models, with broad and narrow definitions of schizophrenia. All models produced positive LOD scores with markers on 13q, with higher scores under the recessive models. The maximum three-point LOD scores were obtained under the recessive-broad model: 3.92 at recombination fraction (theta).1 with D13S793, under homogeneity, and 4.42 with alpha=.65 and straight theta=0 with D13S793, under heterogeneity. Positive LOD scores were also obtained, under all models, for markers on 8p. Although a maximum two-point LOD score of 3.49 was obtained under the dominant-narrow model with D8S136 at straight theta=0.1, multipoint analysis with closely flanking markers reduced the maximum LOD score in this region to 2. 13. These results provide independent significant evidence of linkage of a schizophrenia-susceptibility locus to markers on 13q32 and support the presence of a second susceptibility locus on 8p21.

Synaptic and plasticity-associated proteins in anterior frontal cortex in severe mental illness

Abnormalities of proteins involved in neurotransmission and neural plasticity at synapses are reported in schizophrenia, and may be markers of dysregulated neural connectivity in this illness. Studies of brain development and neural regeneration indicate a dynamic interplay between neural and oligodendroglial mechanisms in regulating synaptic plasticity and axonal sprouting. In the present study, markers of synapses (synaptophysin), plasticity (growth-associated protein-43) and oligodendrocytes (myelin basic protein) were investigated in anterior frontal cortex homogenates from individuals with schizophrenia and depression. Synaptophysin immunoreactivity was reduced in schizophrenics who died of natural causes relative to controls. Myelin basic protein immunoreactivity was decreased in both schizophrenics and depressed individuals who died by suicide. Overall, no changes were observed in growth-associated protein-43 immunoreactivity. However, a slight increase in immunoreactivity in depressed suicides relative to control was observed. These findings support the hypothesis that synaptic abnormalities are a substrate for disordered connectivity in severe mental illness, and suggest that synaptic-oligodendroglial interactions may contribute to the mechanism of dysregulation in certain cases.

Organization of the secretory machinery in the rodent brain: distribution of the t-SNAREs, SNAP-25 and SNAP-23

Vesicular transport events appear to be facilitated by the VAMP/synaptobrevin family of membrane proteins in the vesicle (v-SNAREs) and a heterodimeric complex of syntaxin and SNAP-23/25 family members in the target membrane (t-SNAREs). In this manuscript we examine the tissue distribution and composition of the heterodimeric t-SNARE complexes in adult rodent brain. Analysis of protein extracts from brain regions shows that SNAP-25, syntaxin 1, and 4 are broadly distributed, while SNAP-23, syntaxin 3, and 7 show distinct patterns of expression. Further immunohistochemistry and fractionation studies show that while SNAP-25 is enriched in axons and nerve terminals, SNAP-23 is concentrated in cell bodies. Both SNAP-23 and SNAP-25 associate with the plasma membrane and can be metabolically labeled with [(3)H] palmitate in AtT-20 cells. Anti-SNAP-25 antibodies co-immunoprecipitate t-SNARE heterodimers from brain extracts that predominantly contain syntaxin 1 and 2. Contrary to results from in vitro binding assays, SNAP-23 was found predominantly associated with syntaxin 3. These observations suggest that t-SNARE, heterodimer composition is governed more by SNARE expression and localization than by simple protein-protein affinity.

Olfactory identification and psychosis

BACKGROUND

Olfactory identification performance has been investigated in several psychiatric populations, with deficits most commonly reported in patients with schizophrenia. In this study, olfactory identification performance was investigated in a more homogenous group of treatment-refractory patients with schizophrenia (T-RS) and in two additional psychiatric groups who demonstrate some similarities to the patients with schizophrenia in terms of symptomotology and medication regime.

METHODS

The olfactory identification performance of 16 T-RS patients was assessed using the University of Pennsylvania Smell Identification Test (UPSIT) and compared to that of 16 normal control subjects and two other psychiatric patient groups: 19 affective disorder patients requiring maintenance antipsychotic medication and 20 affective disorder patients not receiving antipsychotic medication.

RESULTS

The olfactory identification performance of T-RS patients was significantly lower than that of normal controls but not significantly different from either affective disorder group. The olfactory identification performance of affective disorder patients receiving antipsychotic medication was significantly lower than that of affective disorder patients not receiving antipsychotic medication.

DISCUSSION

Results are discussed in the context of a possible link between psychotic symptomotology and olfactory identification performance.

Assessing the machinery of mind: synapses in neuropsychiatric disorders

Neural connectivity in postmortem human brain can now be studied with the use of antibodies that react with synapse-enriched proteins. Using a range of antibody-based techniques, the authors observed abnormalities in connectivity in Alzheimer's disease, temporal lobe epilepsy, and schizophrenia. They also found disease-related differences in the individual protein markers affected and in the anatomical distribution of differences from controls. Molecular and cellular abnormalities in neural connectivity may underlie functional abnormalities observed in vivo using positron emission tomography or functional magnetic resonance imaging.

No evidence for astrogliosis in brains of schizophrenic patients. A post-mortem study

Schizophrenia is clinically and neuropsychologically characterized by severe cognitive and functional impairment suggesting the presence of a neurodegenerative process in the brains of affected individuals. A variety of neuroanatomical changes have been described such as loss and disorientation of neurons in grey and white matter and cortical atrophy. However, the neuropathological basis for schizophrenia is still unclear. In the present study we monitored the density of GFAP-positive astrocytes in brains of 33 schizophrenic patients and 26 healthy controls. Both grey matter (entorhinal cortex and subiculum) and white matter (premotor cortex, subventricular zone of the third ventricle and next to inferior horn) structures were measured bilaterally. The overall finding was that there is no evidence for increased astrogliosis in brains of schizophrenic patients vs healthy controls. Therefore, degeneration is unlikely to be the main neuropathological mechanism in schizophrenic brains.

Left nostril olfactory identification impairment in a subgroup of male patients with schizophrenia

Abnormal structural brain asymmetries have been reported in schizophrenia in brain areas which overlap with olfactory processing regions, with abnormalities more often described within the left hemisphere. We attempted to determine whether the olfactory agnosia observed in some male patients with schizophrenia was more likely left-hemisphere based. We assessed unirhinal (single nostril) olfactory identification and detection threshold in 65 male patients who met DSM-IV criteria for the diagnosis of schizophrenia and 59 healthy male control subjects. A two-way, mixed-design ANCOVA with diagnosis as the between-group factor, nostril as the within-subject factor and age as covariate was used to compare olfactory identification ability. This analysis demonstrated that patients with schizophrenia performed more poorly than the healthy controls across nostrils, but no differences were observed in either group between nostrils. However, when patients were classified according to unirhinal olfactory status (impaired left < right, impaired right < left, normosmic left < right, normosmic right < left), impaired patients were more than twice as likely to be classified as having a left nostril disadvantage than right nostril disadvantage. In contrast, within the normosmic group of patients, this pattern was reversed. Moreover, when those patients whose unirhinal olfactory scores differed by less than two points were removed from the analysis, a 2:1 ratio of left < right versus right < left was observed in the impaired patients. These results suggest that for impaired male patients with schizophrenia, olfactory identification deficits are more likely found for the left nostril, perhaps indicative of abnormalities in olfactory processing within the left hemisphere.

Localization of a novel septin protein, hCDCrel-1, in neurons of human brain

Synaptic function is critical for cell-cell communication and the characterization of proteins that function during vesicle formation, transport and fusion events will yield further insight into the mechanisms of synaptic transmission. We have cloned and characterized a gene product expressed in human brain called hCDCrel-1. This protein is a new member of the septin family of gene products that functions during cytokinesis in lower eukaryotes. In this study we characterize the expression of the hCDCrel-1 gene and localize the hCDCrel-1 protein to neurons in adult human brain. hCDCrel-1 co-purifies with SNAP-25 and synaptophysin marked synaptosomes, suggesting a novel function for this gene family in the brain. Our data indicate that members of the septin family of proteins may function in synaptic vesicle transport, fusion or recycling events in the human brain.

Compartmental volumetry of the superior temporal gyrus reveals sex differences in schizophrenia--a post-mortem study

Brain imaging studies have shown superior temporal gyrus (STG) volume loss and abnormal patterns of asymmetry in schizophrenia; however, these are not consistent findings. Post-mortem volumetry of three different STG regions (defined by external landmarks) was used to compare 17 schizophrenics to 20 age- and sex-matched controls. Total STG volumes did not differ. A significant gray-matter volume reduction in schizophrenics was observed in the middle compartment (reaching from the mamillary body to the lateral geniculate body). This may have been related to reduced length of this region, particularly in schizophrenic females. These results reflect the problematic issue of defining boundaries of macroscopic brain structures.

Obstetric complications, treatment response and brain morphology in adult-onset and early-onset males with schizophrenia

BACKGROUND

Substantial variability in age at onset of illness and course of illness exists between patients with schizophrenia. Recent studies suggest that age at illness onset may be useful in defining biologically and clinically distinct subgroups of patients.

METHODS

Two hundred and ten males with schizophrenia were classified as early-onset or adult-onset according to their age at first hospitalization. Birth history, clinical functioning and treatment response was assessed in a subgroup of patients. Brain anatomy was assessed from CT scans in all patients and in 32 non-psychiatric control subjects.

RESULTS

Patients with an early-onset were likely to have a history of obstetric complications, a poor response to neuroleptic treatment, and showed no relationship between ventricle size and duration of illness. Adult-onset patients were less likely to have obstetric complications, more likely to respond to treatment in the first years of illness, and showed an association between brain structure and duration of illness.

CONCLUSIONS

The distinction between early- and adult-onset patients may have important aetiological and treatment implications.

SNAP-25 deficit and hippocampal connectivity in schizophrenia

Regional abnormalities of brain connectivity may be an important substrate for the expression of schizophrenia, a severe form of mental illness. Brain imaging and postmortem morphometric studies indicate hippocampal structure is abnormal in schizophrenia. To study molecular components of hippocampal connectivity the presynaptic proteins SNAP-25 and synaptophysin were assayed in postmortem samples. Immunocytochemical studies indicated reduced SNAP-25 immunoreactivity in schizophrenia compared to controls, particularly in the terminal fields of entorhinal cortex projections. Although there were no overall changes in synaptophysin immunoreactivity, in the granule cell layer of the dentate gyrus synaptophysin immunoreactivity was increased in schizophrenia. These results indicate that disconnection of a subset of hippocampal circuitry from the entorhinal cortex, as well as intrinsic changes in hippocampal connectivity, may contribute to the mechanism of illness in schizophrenia.

Olfactory deficits in patients with schizophrenia and severe polydipsia

BACKGROUND

The present study was designed to assess olfactory function in severely polydipsic/hyponatremic patients with schizophrenia who also had intermittent water intoxication.

METHODS

The University of Pennsylvania Smell Identification Test and an olfactory acuity battery were administered to three groups of male subjects: 9 patients with schizophrenia and severe polydipsia/hyponatremia, 9 control nonpolydipsic/normonatremic patients with schizophrenia, and 9 normal controls.

RESULTS

Male patients with severe polydipsia/hyponatremia and intermittent water intoxication had marked olfactory acuity and identification deficits when compared to the patient control group of similar age and age at illness onset, and to normal controls.

CONCLUSIONS

The finding of deficient acuity (detection threshold) in the polydipsic/hyponatremic group but not the nonpolydipsic, normonatremic group suggests that for this subgroup, abnormalities of olfactory sensory function may occur in a pattern previously reported for other brain disorders such as Alzheimer's disease.

Olfactory function in monozygotic twins discordant for schizophrenia

OBJECTIVE

Abnormalities of olfactory identification ability have been proposed as a marker of cerebral dysfunction in schizophrenia. The authors studied the potential role of genetic factors in olfactory dysfunction by assessing monozygotic twins discordant for schizophrenia and matched comparison subjects.

METHOD

The subjects were 12 pairs of monozygotic twins discordant for schizophrenia and 12 healthy subjects matched for sex and age. Each subject completed the University of Pennsylvania Smell Identification Test.

RESULTS

The combined twin group scored significantly lower on smell identification than did the comparison group. The affected and unaffected twin groups did not differ from each other.

CONCLUSIONS

Genetic factors may contribute to cerebral dysfunction as assessed by olfactory identification ability.

An open comparison of clozapine and risperidone in treatment-resistant schizophrenia

BACKGROUND

Clozapine and risperidone are used in treatment-resistant schizophrenia. At present, there are few reported comparisons of these drugs in this population. We report on a consecutive series of treatment-resistant schizophrenics given either clozapine or risperidone in open clinical trials.

METHOD

Subjects were treated with clozapine (n = 57) or risperidone (n = 29). Pretreatment GAF, CGI, and PANSS scores did not differ between the groups, nor did demographic variables including age, age at first hospitalization, years ill, number of previous hospitalizations, or gender. The mean treatment trial was 12.1 weeks, with mean doses of clozapine 420 mg, and risperidone 7.75 mg. The length of the trial did not differ significantly between the groups. Response was taken to be a 20% decrease in the PANSS score.

RESULTS

Using repeated measures ANOVA, PANSS total scores (F = 5.3, p = 0.02) and positive subscore (F = 7.4, p = 0.008) showed greater improvement in the clozapine group than the risperidone group, while other PANSS subscores showed a trend toward greater improvement with clozapine. The PANSS-derived factors of excitement (F = 6.7, p = 0.01), psychosocial withdrawal (F = 3.8, p = 0.05), and psychomotor retardation (F = 3.9, p = 0.05) improved more in the group treated with clozapine. The GAF (F = 10.9, p = 0.0014), CGI (F = 11.5, p = 0.0011), and CGI improvement (p = 0.0001) scores also improved more in the clozapine group. Of the clozapine group, 25 (44%) responded, while 8 (28%) of the risperidone group responded to treatment.

DISCUSSION

Clozapine had better efficacy in subjects with treatment-resistant schizophrenia compared to risperidone, although risperidone appears to yield better response rates than those previously reported for typical antipsychotics. Double-blind, controlled trials of risperidone are needed to establish its efficacy in treatment-resistant schizophrenia.

Use of a quantitative trait to map a locus associated with severity of positive symptoms in familial schizophrenia to chromosome 6p

A number of recent linkage studies have suggested the presence of a schizophrenia susceptibility locus on chromosome 6p. We evaluated 28 genetic markers, spanning chromosome 6, for linkage to schizophrenia in 10 moderately large Canadian families of Celtic ancestry. Parametric analyses of these families under autosomal dominant and recessive models, using broad and narrow definitions of schizophrenia, produced no significant evidence for linkage. A sib-pair analysis using categorical disease definitions also failed to produce significant evidence for linkage. We then conducted a separate sibpair analysis using scores on positive-symptom (psychotic), negative-symptom (deficit), and general psychopathology-symptom scales as quantitative traits. With the positive symptom-scale scores, the marker D6S1960 produced P = 1.2 x 10(-5) under two-point and P = 5.4 x 10(-6) under multipoint analyses. Using simulation studies, we determined that these nominal P values correspond to empirical P values of .034 and .0085, respectively. These results suggest that a schizophrenia susceptibility locus on chromosome 6p may be related to the severity of psychotic symptoms. Assessment of behavioral quantitative traits may provide increased power over categorical phenotype assignment for detection of linkage in complex psychiatric disorders.

A comprehensive method of assessing routine CT scans in schizophrenia

Morphological brain abnormalities are common in schizophrenia, although the aetiological and clinical significance of these findings is largely unknown. Substantial between-subject variability suggests that large samples are needed to study the full implications of brain pathomorphology. Computerized tomography (CT) is frequently used routinely in schizophrenia, and large numbers of scans are available for study. This article describes the development and statistical properties of a rapid and simple method of assessing CT scans. The CT Rating Scale for Schizophrenia (CTRSS) is minimally affected by variability in scanning procedures, is reliable, and accurately estimates area and volumetric measures of brain spaces. By promoting the comprehensive assessment of large numbers of routinely obtained scans, the CTRSS would allow the investigation of variables that may systematically affect results (e.g. gender and age) and variables with low prevalence. The CTRSS provides a useful adjunct to technologically more sophisticated methods of assessment such as magnetic resonance imaging (MRI).

Absence of linkage for schizophrenia on the short arm of chromosome 5 in multiplex Canadian families

A VNTR for the human dopamine transporter gene (DAT-1) has been localized to chromosome 5p15.3. Silverman et al. [1996] found evidence for genetic linkage of the D5S111 locus, located just centromeric to DAT-1, to schizophrenia and related disorders in a large Hispanic family. We evaluated five markers on 5p, including D5S111 and the DAT-1 VNTR, in five multiplex schizophrenic families, assuming autosomal dominant transmission (subjects assessed n = 122, DNAs available n = 96, individuals with schizophrenia and schizoaffective disorder n = 36, broader spectrum disorders n = 14). LOD scores were negative across all families for all markers tested, and overall LOD scores were strongly negative (<-2.0, theta = 0) across all five families for each of the markers typed. Thus, there is no evidence to support the linkage of markers in this region of chromosome 5 to schizophrenia in this sample of families.

Schizencephaly associated with psychosis

Schizencephaly is a rare disorder of brain development resulting in the formation of abnormal unilateral or bilateral clefts in the cerebral hemispheres. It is often accompanied by partial seizures, mental retardation, and hemiparesis. Two patients are described with clear psychotic symptoms with either unilateral or bilateral schizencephaly. The implications of the association between schizencephaly and psychosis in these patients for understanding the biology of the psychoses are discussed.

Extrapyramidal signs and clinical symptoms in first-episode schizophrenia: response to low-dose risperidone

The purpose of this study was to determine the prevalence of extrapyramidal signs or symptoms (EPS) and clinical symptoms in first-episode schizophrenia, before any treatment, during and after treatment with a novel antipsychotic, risperidone. Twenty-two (17 men; 5 women) patients were examined using the Extrapyramidal Symptom Rating Scale, Positive and Negative Syndrome Scale (PANSS), Clinical Global Impressions-Severity of Illness and Improvement, and Global Assessment of Functioning. Three patients (14%) had distinct EPS at baseline, whereas all were free of EPS after treatment with risperidone. On the maximum dose of risperidone (5-8 mg), 32% of the total sample developed mild akathisia or parkinsonism, both of which diminished with dosage reduction. No clinically significant EPS were observed in patients receiving 2 to 4 mg of risperidone. Analysis of symptom response of the lower (2-4 mg) versus the higher (5-8 mg) doses of risperidone resulted in superior outcome in the 2- to 4-mg group for all three symptom clusters of the PANSS. In addition, 91% of the low-dose group achieved a 20% or greater reduction in total PANSS score compared with 27% for the high-dose group. These findings have clinical relevance directed at the early and longer-term treatment of schizophrenia.

Increased concentrations of presynaptic proteins in the cingulate cortex of subjects with schizophrenia

BACKGROUND

Cytoarchitectural and neurochemical studies demonstrate disorganization in the cerebral cortex in schizophrenia, which perhaps underlies the severe behavioral disturbances of the disease. This neuronal disarray should be accompanied by synaptic abnormalities. As such, presynaptic proteins have proved valuable indexes of synaptic density and their concentrations have correlated markedly with synaptic loss. Our study sought to determine whether abnormalities exist in the concentrations of presynaptic proteins in the postmortem cerebral cortex of subjects with schizophrenia.

METHODS

Presynaptic protein immunoreactivities were assessed in 4 different cerebrocortical regions derived from 16 elderly controls, 19 elderly subjects with schizophrenia, and 24 subjects with Alzheimer's disease. Tissues were assayed with the monoclonal antibodies EP10 and SP4, which recognize synaptophysin, and the monoclonal antibodies SP6 and SP14, which detect syntaxin and synaptosomal-associated protein-25-kd immunoreactivities, respectively.

RESULTS

In subjects with schizophrenia relative to controls, presynaptic proteins were increased in the cingulate cortex, but were unchanged in the temporal, frontal, and parietal cortices. In contrast, when cases with Alzheimer's disease were compared with controls, presynaptic proteins were decreased in the frontal, temporal, and parietal samples.

CONCLUSIONS

These findings reveal changes in the synaptic organization of the cingulate cortex in schizophrenia relative to other areas examined. These changes are distinct from the deficits in presynaptic proteins observed in Alzheimer's disease.

Cingulate cortex synaptic terminal proteins and neural cell adhesion molecule in schizophrenia

The neuronal organization and patterns of afferent innervation are abnormal in the cingulate cortex in schizophrenia, and associated changes in synaptic terminals could be present. A panel of monoclonal antibodies was defined with biochemical and fusion protein studies as detecting syntaxin (antibody SP6), synaptophysin (antibody SP4) and synaptosomal-associated protein-25 (antibody SP12). These antibodies and a polyclonal antibody reactive with neural cell adhesion molecule were used to investigate the cingulate cortex in schizophrenia. Immunocytochemistry indicated that syntaxin immunoreactivity had a considerably wider distribution than synaptophysin. Overall, multivariate analysis indicated increased synaptic terminal protein immunoreactivity in schizophrenia compared to controls (P=0.004). Controlled for age and post mortem interval, syntaxin immunoreactivity was significantly elevated in schizophrenia (P=0.004), and neural cell adhesion molecule immunoreactivity was also elevated (P=0.05). The neural cell adhesion molecule to synaptophysin ratio was increased (P=0.005), possibly indicating the presence of less mature synapses in schizophrenia. Elevated syntaxin immunoreactivity is consistent with increased glutamatergic afferents to the cingulate cortex in schizophrenia, and combined with the neural cell adhesion molecule to synaptophysin ratio results suggests that synaptic function in this region in schizophrenia may be abnormal.

Cholinergic fibre loss associated with diffuse plaques in the non-demented elderly: the preclinical stage of Alzheimer's disease?

Diffuse plaques are the earliest Alzheimer-type lesions in Down's syndrome and are a putative marker for the preclinical stage of Alzheimer's disease (AD). As a cerebral cortical cholinergic deficit is one of the characteristics which defines AD, we examined the brains of individuals who had died without a history of neurological disease to determine whether this deficit is present in association with diffuse plaques. Of the 24 cases collected, 14 were older than 60 years of age (mean 69.2 years) and 10 were younger (mean 29.6 years). Of the 14 older cases, 9 had diffuse plaques in the entorhinal cortex (ECx) and/or inferior temporal gyrus (ITG). The older cases were divided into two groups (plaque-positive or plaque-negative cases). These groups did not differ significantly with respect to age, post-mortem delay, synaptophysin immunoreactivity or neurofibrillary tangle density. Cholinergic fibre densities were estimated in sections stained using acetylcholinesterase (AChE) enzyme histochemistry. Mean AChE fibre density was decreased in both the ITG and ECx (approximately 30% and 50% depletion, respectively) in the plaque-positive group compared to the plaque-negative group and in both areas the mean fibre density of the plaque-positive group was about 50% of that in the younger group. These results suggest that diffuse plaques in the non-demented elderly are associated with an accelerated age-related cortical cholinergic deficit and, therefore represent the preclinical stage of AD.

Clinical features of schizophrenia in a woman with hyperandrogenism

Ample evidence supports sex differences in the clinical features of schizophrenia. In this regard, estrogen may contribute to later onset and less severe course of illness in women. Direct investigation of hormonal status in schizophrenia is extremely difficult. The present report documents the clinical features of schizophrenia in a young woman with long-standing hyperandrogenism related to polycystic ovarian disease. We postulate that hyperandrogenism contributed to a relatively early onset, olfactory dysfunction, and other clinical features of schizophrenia more commonly associated with men. Additionally, acute estrogen depletion following cessation of oral contraceptives may have precipitated psychosis, while recommencement of oral contraceptives could have contributed to subsequent improvement in symptoms.

The use of risperidone in severely demented patients with persistent vocalizations

OBJECTIVE

The hypothesis being tested was that low doses of risperidone would diminish persistent, purposeless vocalizations in two severely demented geriatric women. A secondary hypothesis was that the severe tardive dyskinesia observed in one patient would improve after risperidone treatment.

DESIGN

An intrasubject on-off-on design was employed.

SETTING

A chronic care facility in Canada.

SUBJECTS

Two inpatients with DSM-IV (American Psychiatric Association) diagnosis of combined Alzheimer vascular dementia.

MEASURES

Nursing assessment of frequency of vocalizations. Extrapyramidal System Rating Scale (ESRS) and Folstein Mini Mental State Examination (MMSE).

RESULTS

With risperidone treatment, the vocalizations diminished to less than 20% of baseline ratings. For the patient with dyskinesia, ESRS dyskinetic movement scores decreased (baseline = 27; after risperidone 8 weeks = 16). No change was observed for the MMSE.

CONCLUSIONS

The findings support the main hypothesis. The secondary hypothesis was also supported. Further studies of larger numbers of subjects are required to substantiate these preliminary findings.

NCAM and schizophrenia: genetic studies

The hypothesis of a neurodevelopmental dysfunction being involved in the etiology of schizophrenia is suggested by the observation of morphological alterations in the brains of schizophrenia patients. These alterations may be caused by defects in neural cell differentiation or migration, which could lead to disrupted neuronal circuitry and to the schizophrenia symptomatology. The neural cell adhesion molecule (NCAM) plays a major role in cell migration and axon outgrowth, and is involved in synaptic plasticity mechanisms implicated in adult cognitive functions. Altered levels of the NCAM polysialylated form, PSA-NCAM, in the brain of schizophrenia patients have been reported, and are supportive of a role for this molecule in the disorder. To investigate the possible involvement of the NCAM gene in schizophrenia, we conducted a comprehensive genetic study, which included linkage analysis and an association study employing the Haplotype Relative Risk (HRR) design in nuclear families. Our results indicate that structural alterations in the NCAM gene are unlikely to play a major role in schizophrenia, although a function for the NCAM molecule in the etiology of the disease remains an intriguing hypothesis.

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.

Search for unstable DNA in schizophrenia families with evidence for genetic anticipation

Evidence for genetic anticipation has recently become an important subject of research in clinical psychiatric genetics. Renewed interest in anticipation was evoked by molecular genetic findings of a novel type of mutation termed "unstable DNA." The unstable DNA model can be construed as the "best fit" for schizophrenia twin and family epidemiological data. We have performed a large-scale Southern blot hybridization, asymmetrical PCR-based, and repeat expansion-detection screening for (CAG)n/(CTG)n and (CCG)n/(CGG)n expansions in eastern Canadian schizophrenia multiplex families demonstrating genetic anticipation. There were no differences in (CAG)n/(CTG)n and (CCG)n/(CGG)n pattern distribution either between affected and unaffected individuals or across generations. Our findings do not support the hypothesis that large (CAG)n/(CTG)n or (CCG)n/(CGG)n expansions are the major etiologic factor in schizophrenia. A separate set of experiments directed to the analysis of small (30-130 trinucleotides), Huntington disease-type expansions in individual genes is required in order to fully exclude the presence of (CAG)n/(CTG)n- or (CCG)n/(CGG)n-type unstable mutation.

Reproductive fitness in familial schizophrenia

BACKGROUND

Reproductive fitness is an important factor in understanding inheritance in genetic disorders. The purpose of this study was to determine whether fitness is reduced in familial schizophrenia (FS) and if fitness in siblings differs from the norm.

METHOD

The number of offspring in 36 subjects with RDC schizophrenia or schizoaffective disorder (SZ) and their 101 siblings from large FS families was compared with age-adjusted census figures.

RESULTS

Fitness in the SZ group was significantly reduced: 23% of expected in males and 51% of expected in females. Fitness of unaffected siblings was within census expectations. However, female siblings with schizophrenia spectrum features had increased fitness over census norms. Reduced fitness was correlated with low marital rates, poor functioning and positive symptoms.

CONCLUSIONS

These results indicate that reduced fitness is an important genetic force in FS and is likely inherent to the illness. Sex differences are important and would need to be considered when examining maternal and paternal transmission of schizophrenia. The results support a proposed high mutation rate for schizophrenia, consistent with a dynamic mutation mechanism.

Left cerebral hemiatrophy and schizophrenia-like psychosis in an adolescent

A previous report of cerebral hemiatrophy and schizophrenia added to the list of neurodevelopmental abnormalities associated with schizophrenia. In a new case, the birth history indicated perinatal hemorrhage and prematurity (30-31 weeks of gestation). CT and MR imaging showed reduction in left hemisphere size with ventricular enlargement and mild skull thickening. Loss of periventricular white matter was detected. Changes in skull thickness, size of air cells and volume of the cranial vault may be measurable correlates of putative developmental abnormalities in schizophrenia.

A centralized system for monitoring clozapine use in British Columbia

The Clozapine Resource Centre in British Columbia is a centralized information source for all physicians wishing to prescribe clozapine and also performs back-up hematological and compliance monitoring. Laboratories fax weekly hematology results to physicians and to the center. The center enters results in a national database and compiles twice-weekly noncompliance reports; physicians are notified of abnormal results, and caregivers of noncompliance. The centralized system obviates the practice in some jurisdictions of hiring case coordinators to oversee these procedures and may reduce physician reluctance to prescribe clozapine. It improves coordination among monitoring and treatment parties and ensures better continuity of care.

Linkage analysis between schizophrenia and the Darier's disease region on 12q

There have been reports of an association between Darier's disease, an autosomal dominant genodermatosis, and psychiatric illness. Recently the gene causing Darier's disease has been mapped to an area on 12q, between D12S58 and D12S84. The findings of linkage analysis of 4 markers in the Darier's disease region on 12q in five families segregating schizophrenia are presented. They fail to support close linkage between schizophrenia and the Darier's disease region on 12q.

A case study of temporal lobe development in familial schizophrenia

Case studies of patients with familial schizophrenia may help to define the pathophysiology of this illness and indicate potential candidate genes for genetic linkage studies. In this regard, the clinical, radiological and pathological assessments of a 39-year-old affected man from a pedigree with familial schizophrenia are presented. Brain imaging with CT indicated moderate cortical atrophy, particularly of the temporal lobes. Neuropathological examination revealed granular ependymitis, indicating possible past ventricular pathology. Granular ependymitis was reported to occur in genetic developmental disorders with neuronal migration abnormalities. In the present case, heterotopic clusters of neurons were visualized in the entorhinal cortex, suggesting that temporal lobe development was not entirely normal. This case study suggests that genetic factors could be investigated further as one possible aetiology of certain neurodevelopmental abnormalities observed in schizophrenia.

The temporal lobes, reversed asymmetry and the genetics of schizophrenia

Mechanisms determining temporal lobe structural asymmetries may be involved in the pathogenesis of schizophrenia. To investigate the temporal lobes in familial schizophrenia, computed tomographic scans were obtained from 51 subjects (seven families). Enlargement of sylvian fissures and temporal lobe sulcal spaces was observed in family members with schizophrenia. The posterior one-third of the sylvian fissure was larger on the left side in subjects with schizophrenia, and larger on the right side in unaffected individuals. This disturbed pattern of posterior sylvian fissure asymmetry suggests that adjacent language regions may be affected in schizophrenia. An intermediate degree of disturbance in subjects who had schizophrenia-related illnesses or were obligate carriers suggests that genetic factors may be important determinants of temporal lobe asymmetries in familial schizophrenia.

Developmental abnormalities and cortical sulcal enlargement in psychosis

Neurodevelopmental abnormalities and cortical sulcal enlargement both occur in schizophrenia. To test the hypothesis that these abnormalities were related, CT scans from 164 psychotic patients (80 with schizophrenia) were reviewed. Neurodevelopmental abnormalities were observed in 11%. Abnormalities were equally prevalent in schizophrenia and other psychotic disorders. Cortical sulcal enlargement was observed in 39% of patients with schizophrenia, and was not associated with developmental abnormalities. Different mechanisms may contribute to distinct structural abnormalities.

Regional cortical anatomy and clozapine response in refractory schizophrenia

Regional measures of cortical sulcal and ventricular enlargement on computed tomography scan were studied in a clinical sample of patients treated with clozapine. Cortical sulci were significantly enlarged in clozapine nonresponders compared to responders. The Clinical Global Impressions score at discharge was related to the size of the posterior frontal and lateral temporal sulci, with large sulci predicting a poorer response to clozapine treatment.

Routine assessment of patient progress: a multiformat, change-sensitive nurses' instrument for assessing psychotic inpatients

A new instrument, the Routine Assessment of Patient Progress (RAPP), is a standardized scale with a unique format that allows trained nurses to incorporate both interview and observational data into a comprehensive assessment of psychiatric inpatients. The scale was developed to accurately document treatment effects, assist in treatment planning, and provide ancillary judgments of psychopathology that may affect diagnosis. The RAPP demonstrates satisfactory interrater reliability and internal consistency. The RAPP total score and its two subscales correlated highly, where expected, with an observation-based nursing scale, global measures, and an interview-based psychopathology scale. RAPP scores demonstrated sensitivity to change over time in patient functioning. It reliably discriminated among patients discharged to settings with varying degrees of independent living. The use of the RAPP over several years on a psychiatric inpatient unit has shown it to be a practical clinical tool that eases nurses' charting demands, helps create care plans, and facilitates interdisciplinary communication.

Olfactory identification ability in pre- and postmenopausal women with schizophrenia

Previously we reported olfactory deficits in young male but not female patients with schizophrenia. In the present report, olfactory identification ability in pre- and postmenopausal women with schizophrenia and normal control subjects was assessed using the University of Pennsylvania Smell Identification Test (UPSIT). Additionally, serum estradiol levels were measured on the same 2 days as smell testing was completed. Olfactory deficits were observed in pre- and postmenopausal women with schizophrenia but were more pronounced in the postmenopausal patients. Regarding estradiol levels, women with schizophrenia had lower estradiol levels than did normal control subjects. The findings of this study indicate that olfactory deficits do exist in women with schizophrenia and may be accentuated by estrogen depletion.

A clinical study of clozapine treatment and predictors of response in a Canadian sample

OBJECTIVE

To study the clinical response to clozapine in patients with refractory schizophrenia.

METHOD

Open trial of clozapine in 61 consecutively-treated patients.

RESULTS

Following clozapine, the level of function of patients was improved relative to admission (p = 0.0001) and to the highest level in the previous year (p = 0.0001). Severity of illness was decreased (p = 0.0001). Overall, 31% of the patients were classified as responders to clozapine and the responders were all identified by 32 weeks of treatment. Poor functioning in the previous year was associated with less favourable response. At a mean interval of 26 months following discharge, 72% of the patients were continuing clozapine treatment.

CONCLUSIONS

This open trial of patients who were treated consecutively indicates a comparable degree of response to clozapine as observed in controlled clinical trials, and that level of functioning in the previous year was the best predictor of response.