Temporolimbic volume reductions in schizophrenia

BACKGROUND

Neuroanatomic studies of schizophrenia have reported temporolimbic abnormalities. Most magnetic resonance imaging studies have evaluated small samples of primarily men with chronic schizophrenia. Our goal was to evaluate sex differences in segmented temporal lobe subregions with reliable parcellation methods, relating volume with clinical and neurocognitive parameters.

METHODS

Magnetic resonance imaging was performed in 100 patients with schizophrenia (58 men, 42 women; 39 neuroleptic naive, 61 previously treated) and 110 healthy controls (51 men, 59 women). Gray and white matter volumes of temporolimbic (hippocampus and amygdala) and neocortical regions (superior temporal gyrus and temporal pole) were examined. Symptoms, functioning, and neurocognition were assessed concurrently.

RESULTS

Hippocampal gray matter volume was reduced in men (7%) and women (8.5%) with schizophrenia. In the amygdala, however, decreased volume was evident for men (8%) whereas women (10.5%) had increased volume. Magnetic resonance imaging of the temporal pole showed decreased gray matter in men (10%) and women (8.5%). For the superior temporal gyrus, the decrease exceeded that of whole-brain only in men (11.5%). Volumes were largely uncorrelated with clinical measures, but higher hippocampal volumes were associated with better memory performance for all groups. Cortical volumes were associated with better memory performance in healthy women.

CONCLUSIONS

Schizophrenia is associated with reduced gray matter volume in temporolimbic structures. In men, reduction was manifested in all regions, whereas women showed decreased hippocampal volumes but increased amygdala volumes. The abnormalities are evident in patients with first-episode schizophrenia and correlate more strongly with cognitive performance than with symptom severity.

Regional cerebral glucose metabolism in healthy volunteers determined by fluordeoxyglucose positron emission tomography: appearance and variance in the transaxial, coronal, and sagittal planes

PURPOSE

In this study, the contribution of the transaxial, coronal, and sagittal planes in evaluations of regional cerebral glucose metabolism was investigated in healthy volunteers as determined by fluorine-18-labeled 2-deoxy-2-fluoro-D-glucose (FDG) and high-resolution positron emission tomography (PET).

METHODS

One hundred twenty-seven healthy right-handed volunteers were injected with 4.2 MBq/kg (0.11 mCi) body weight FDG and imaged in a PENN PET H 240 scanner. Images were corrected for scatter and random coincidences and reconstructed in all three planes into 6- to 8-mm-thick slices. The reconstructed images were corrected for attenuation using the Chang algorithm. The transverse, coronal, and sagittal images were read independently of each other using a qualitative scale in which 1 = equal to, 2 = mildly, 3 = moderately, and 4 = markedly less than the area with the highest glucose metabolism in the respective plane.

RESULTS

The areas with the highest glucose metabolisms were the posterior cingulate gyri with mean scores of 1.1 to 1.2, thalami (1.2 to 1.3), basal ganglia (1.5 to 1.9), and visual cortex (1.6). The lowest values were found in the occipital cortex (2.7 to 2.8) and the cerebellum (2.3 to 2.4). Whereas reliable analysis of the mesial temporal aspects was not feasible in the sagittal plane, the anterior poles of the temporal and frontal lobes could not be evaluated in the coronal or the inferior temporal areas in the transaxial slices. In all three planes, regional glucose metabolism was less in the lateral temporal areas on the left than on the right (P < 0.001). The consistency of readings as measured in terms of coefficients of variation was greatest in the coronal plane for the caudates and posterior cingulate gyri, in the transaxial plane for the lateral temporal regions, and in the sagittal plane for the visual cortex. Age-dependent decreases in regional glucose metabolism in the inferior and lateral frontal regions and the parietal lobes were found in all three planes.

CONCLUSIONS

All three projection planes must be used for a comprehensive qualitative evaluation of the regional glucose metabolism of the brain.

Reduced dorsal and orbital prefrontal gray matter volumes in schizophrenia

BACKGROUND

Converging neuroanatomic, neurophysiological, and neurobehavioral evidence implicate prefrontal subregions in schizophrenia. Neuroanatomic studies with magnetic resonance (MR) imaging enable regional volume parcellation. Inconsistent reports may relate to variable methods and small samples. We attempted to resolve volume differences within sectors of the prefrontal lobe in a large sample, relating volumes to clinical and neurocognitive features.

METHODS

Magnetic resonance imaging was performed in 70 patients with schizophrenia (40 men and 30 women; 29 neuroleptic naive and 41 previously treated) and 81 healthy controls (34 men and 47 women). Gray and white matter volumes of the dorsolateral, dorsomedial, orbitolateral, and orbitomedial prefrontal cortex were quantified. Symptoms, functioning, and neurocognition were assessed concurrently.

RESULTS

Reduced prefrontal gray matter volume was observed in patients. The reduction was evident for the dorsolateral area in men (9%) and women (11%), for the dorsomedial area only in men (9%), and for orbital regions only in women (23% and 10% for lateral and medial, respectively). The reduction of orbital volume in women was associated with poorer premorbid functioning, more severe negative symptoms, and depression. Volume of dorsal cortex was positively associated with better performance on abstraction and attention tasks across all groups.

CONCLUSIONS

Schizophrenia is associated with reduced gray matter volume in prefrontal cortex, which affects men and women in the dorsolateral sector. The effects are moderated by sex for dorsomedial and orbital regions and are related to symptom severity and cognitive function. This is not a by-product of treatment, since the differences are evident in neuroleptic-naive patients.

Emotion recognition deficit in schizophrenia: association with symptomatology and cognition

BACKGROUND

Previous investigations have found impaired recognition of facial affect in schizophrenia. Controversy exists as to whether this impairment represents a specific emotion recognition deficit when compared with other face recognition control tasks. Regardless of whether the emotion processing deficit is differential, it may uniquely influence other manifestations of schizophrenia. We compared patients and healthy control subjects on computerized tasks of emotion and age recognition. Performances on emotion and age recognition tasks were correlated with cognitive functioning and with symptomatology.

METHODS

Thirty-five patients with schizophrenia and 45 healthy people underwent computerized testing for emotion and age recognition. Participants were assessed neuropsychologically, and patients were rated for positive and negative symptoms.

RESULTS

The patients with schizophrenia performed worse than control subjects on emotion and age recognition without differential deficit. In both groups, we found higher error rates for identification of emotion in female faces and for identification of sad versus happy faces. In schizophrenic patients, emotion but not age recognition correlated with severity of negative and positive symptoms. In healthy control subjects, neither task correlated with cognitive functions. In schizophrenic patients, emotion but not age recognition correlated with attention, verbal and spatial memory, and language abilities.

CONCLUSIONS

This study did not reveal a specific deficit for emotion recognition in schizophrenia; however, our findings lend support to the concept that emotion recognition is uniquely associated in schizophrenia with core symptomatology and cognitive domains.

The relation between tendency for psychopathology and reduced frontal brain volume in healthy people

OBJECTIVE

We hypothesized that tendency toward psychopathology is associated with lower frontotemporal volumes.

BACKGROUND

Although there is considerable evidence for structural abnormalities in patients with major psychiatric disorders and increased recognition that neural substrates may underlie individual differences in personality, there have been no studies in healthy people attempting to relate personality to volumetric measures of brain structure.

METHOD

We used magnetic resonance imaging with an advanced method for automated segmentation of cranial compartments to gray matter, white matter, and cerebrospinal fluid. We examined the relation between frontal and temporal lobe volumes and Minnesota Multiphasic Personality Inventory measures of tendency toward psychopathology in 59 healthy individuals.

RESULTS

As hypothesized, higher scores on the clinical scales were associated with lower average frontal lobe volume. When the sample was divided according to sex, however, these correlations were significant in men (n = 29) but not in women (n = 30). The highest correlation was observed between lower frontal white matter volume in men and high schizophrenia scale score (r[27] = -0.59, p <0.001).

CONCLUSIONS

The findings suggest that personality dimensions in healthy people can be linked to neural substrates, which can potentially serve as endophenotypic markers of disposition to psychopathology. The sexually dimorphic effects are consistent with gender-related differences in the clinical manifestations of psychiatric disorders and may suggest sex hormone modulation of the psychopathologic processes.

Hemispheric activation of anterior and inferior prefrontal cortex during verbal encoding and recognition: a PET study of healthy volunteers

Evidence of bilateral prefrontal activation during memory encoding and retrieval has increased attention given to anatomical subdivisions within the prefrontal cortex. The current study examined anterior and inferior aspects of the prefrontal cortex to determine their degree of functional and hemispheric overlap during encoding and recognition. Cerebral blood flow of 25 healthy volunteers was measured using PET (15)O-water methods during four conditions: resting baseline, sequential finger movement, word encoding, and word recognition. Resting and motor images were averaged to provide a single reference that was subtracted from encoding and recognition using statistical parametric mapping (SPM96). Memory conditions were also subtracted from each other to identify differences in regional activity. Subjects performed well (86% correct) and had a slightly conservative response bias. Baseline subtraction from encoding revealed focal activation of left inferior prefrontal cortex (area 45) without significant contralateral activation. Recognition minus baseline subtraction produced a focal right anterior prefrontal activation (areas 9 and 10) that was not present in the left hemisphere. Bilateral effects were seen in area 45 during recognition. Subtraction of memory tasks from each other did not reveal any areas of greater activity during encoding. However, the recognition task produced greater activation in right area 9 extending into the anterior cingulate. Greater activity during recognition was also observed in left insula and bilateral visual integration areas. These results are discussed in relation to the prevailing model of prefrontal hemispheric asymmetry during episodic memory.

Reduced olfactory bulb volume in patients with schizophrenia

OBJECTIVE

The authors' goal in this study was to compare the size of olfactory bulbs of patients with schizophrenia and those of healthy subjects.

METHOD

Magnetic resonance imaging scans of olfactory bulbs were obtained from 26 patients with schizophrenia and 22 healthy comparison subjects. A reliable region of interest procedure was used to measure olfactory bulb volume.

RESULTS

Patients exhibited 23% smaller bilateral bulb volume than comparison subjects, independent of acute clinical, demographic, or treatment measures. Bulb volume correlated with odor detection sensitivity in healthy subjects but not in patients with schizophrenia.

CONCLUSIONS

Patients with schizophrenia exhibit structural olfactory deficits as well as functional olfactory deficits. The olfactory system may be a model system in which to study the neurobiology of the disorder.

Evaluation of three commercially available kits for serological diagnosis of dengue haemorrhagic fever

Seventy one acute phase serum samples collected during an epidemic of dengue hemorrhagic fever were tested by immunoblot, a rapid immunochromatographic assay and Dengue Duo ELISA for presence of anti dengue IgM and IgG antibodies. A concordance of 81.7% and 76.1% was seen between the three tests for the detection of anti-dengue IgM antibodies and IgG antibodies respectively. The rapid test takes only five minutes, can be easily carried out in most laboratories and compares well with the ELISA and the immunoblot.

Emotional processing in schizophrenia across cultures: standardized measures of discrimination and experience

Schizophrenia appears quite similar across a range of cultures. However, variability has been noted, and understanding the variant and invariant features of the disorder is necessary for elucidating its biological and environmental basis. Evidence of prominent emotion processing deficits in schizophrenia, including perceptual and experiential aspects, led us to extend the paradigm of standardized measures cross-culturally. We assessed performance of American, German, and Indian patients with schizophrenia and healthy controls on standardized emotion discrimination and experience (mood induction) procedures using happy, sad, and neutral facial expressions of Caucasian actors. Participants were 80 Americans (40 patients; 40 controls), 48 Germans (24 patients; 24 controls), and 58 Indians (29 patients; 29 controls). Face discrimination performance was impaired across patient groups, but was most impaired in those of Indian origin. Lower performance was also found in Indian controls, relative to their American and German counterparts. Mood induction produced weaker effects in all patient groups relative to their respective controls. The results supported the feasibility of cross-cultural comparisons and also emphasized the importance of poser ethnic background for facial affect identification, while poser ethnicity was less consequential for mood induction effects. Emotion processing deficits in schizophrenia may add to the clinical burden, and merit further examination.

P300 subcomponent abnormalities in schizophrenia: III. Deficits In unaffected siblings of schizophrenic probands

BACKGROUND

Reduced P300 amplitude is a robust finding in patients with schizophrenia. In previous investigations, we reported reductions of specific subcomponents of the auditory oddball P300 that were independent of acute symptomatology and persistent over time, consistent with a trait abnormality. To clarify whether these stable deficits represented genetic markers of vulnerability to schizophrenia, event-related brain potentials (ERPs) from patients were compared to those from their own healthy siblings and unrelated control subjects.

METHODS

Auditory P300 ERPs were acquired from 11 schizophrenic patients, 12 healthy siblings and 23 matched control subjects. Five P300 subcomponents were identified using current source density measures: frontal, bilateral parietal, and bilateral temporal.

RESULTS

Consistent with previous reports, patients had reduced parietal and frontal P300 amplitudes. The healthy siblings of the schizophrenic probands had an isolated reduction of the frontal P300.

CONCLUSIONS

Frontal P300 amplitude is a potential endophenotypic marker of genetic vulnerability to schizophrenia in individuals who otherwise show no evidence of clinical symptomatology. Given the functional interpretation of the frontal P300 as a physiological correlate of cognitive orienting, this supports the hypothesis that impairments of the neural substrate underlying attentional mechanisms are selective indicators of genetic susceptibility to schizophrenia in high-risk individuals.

Sex differences in brain-behavior relationships between verbal episodic memory and resting regional cerebral blood flow

Women have better verbal memory, and higher rates of resting regional cerebral blood flow (rCBF). This study examined whether there are also sex differences in the relationship between verbal episodic memory and resting rCBF. Twenty eight healthy right-handed volunteers (14 male, 14 female) underwent a neuropsychological evaluation and a Positron Emission Tomography (PET) (15)O-water study. Immediate and delayed recall was measured on the logical memory subtest of the Wechsler Memory Scale - Revised (WMS-R), and on the California Verbal Learning Test (CVLT). Resting rCBF (ml/100 g/min) was calculated for four frontal, four temporal, and four limbic regions of interest (ROIs). Women had better immediate recall on both WMS-R and CVLT tasks. Sex differences in rCBF were found for temporal lobe regions. Women had greater bilateral blood flow in a mid-temporal brain region. There were also sex differences in rCBF correlations with performance. Women produced positive correlations with rCBF laterality in the temporal pole. Greater relative CBF in the left temporal pole was associated with better WMS-R immediate and delayed recall in women only. These results suggest that trait differences in temporal pole brain-behavior relationships may relate to sex differences in verbal episodic memory.

Working memory constrains abstraction in schizophrenia

BACKGROUND

Abstraction has long been considered an area of differential cognitive deficit in schizophrenia, primarily because of patients' poor performance on the Wisconsin Card Sorting Test (WCST). Yet, the complexity and multidimensional nature of the WCST increases the likelihood that several different cognitive processes, perhaps mediated by different neural systems, are being tapped.

METHODS

In the current study, the Abstraction and Working Memory (AIM) task was designed to disentangle abstraction and working memory so that the effects of each cognitive domain could be independently analyzed. The AIM task and a battery of neuropsychological tests were administered to 62 patients with schizophrenia and 62 matched healthy volunteers.

RESULTS

Whereas patients with schizophrenia demonstrated deficits in simple abstraction, they were disproportionately impaired with the addition of a minimal memory requirement.

CONCLUSIONS

Group differences on WCST performance appear to be attributable to patients' inability to maintain information over a short delay, before that information is used for more complex cognitive operations.

Reduced gray matter volume in schizophrenia

BACKGROUND

There is emerging evidence that gray matter (GM) is reduced in patients with schizophrenia. Information on the extent of global differences in the 3 principal supertentorial compartments is necessary for interpretation of regional effects. The relation of GM reduction to clinical status and neurocognition also requires examination.

METHODS

Magnetic resonance imaging, neurocognitive measures, and clinical assessment of symptoms and functioning were obtained for 130 patients (51 neuroleptic naive, 79 previously treated) and 130 healthy controls (75 men, 55 women in each group).

RESULTS

Overall GM volume was reduced in patients compared with controls. This was evident in men (6% reduction) and women (2% reduction) and was already evident at the first presentation of neuroleptic-naive patients. The reduction sustained correction for age and total intracranial volume. Compartmental volumes did not correlate with the severity of positive (r, -0.08 to 0.23) or negative (r, -0.01 to -0.07) symptoms, but GM volume was associated with better premorbid functioning in women (r, 0.36-0.51). Small but significant correlations (r, 0.19-0.44) were observed between GM volume and performance in 6 neurocognitive domains. These correlations varied by diagnosis, most higher in patients, and were moderated by sex.

CONCLUSIONS

Gray matter volume reduction in schizophrenia is already evident in men and women at first presentation. While this reduction is not correlated with symptom severity, it is associated with cognitive performance. Since GM development accelerates in the later part of gestation, while white matter growth is primarily postnatal, the results may support the hypothesis that neurodevelopmental processes relate to GM deficit.

Olfactory dysfunction in schizophrenia: a qualitative and quantitative review

Olfactory dysfunction in patients with schizophrenia has been a topic of increasing interest, with deficits in odor identification, detection threshold sensitivity, discrimination, and memory being reported. Despite increasing knowledge, controversy has existed about possible differential deficits among olfactory tests as well as the influences of gender, smoking, and medication status on olfactory measures. To help elucidate some of this controversy, we conducted a qualitative and quantitative (meta-analytic) review of the English language literature on olfaction in schizophrenia. Moderator variables such as gender, medication status, and smoking history were also examined. Results indicated that substantial olfactory deficits, across all domains, are observed in patients with schizophrenia. No differential deficits were observed across domains of odor identification, detection threshold sensitivity, discrimination, and memory. The influences of gender, medication status, and smoking on effect sizes were not significant across studies. This supports the hypothesis of primary dysfunction in the olfactory system that is regulated by brain regions where structural and functional abnormalities have also been reported in neuroimaging studies.

Hartshill spinal fixation in vertebral metastasis

Spinal fusion by Hartshill rectangle frame was used in 10 patients with spinal cord compression secondary to vertebral metastasis in the thoracic and lumbar spine, occupying mainly the posterior elements. All patients presented with pain, bone collapse, and neurologic deficit. The procedure is built on a system of sublaminar wires passed under two to three lamina above and below the decompressed area and tightened to a prebent metal frame. This procedure was relatively simple, and the immediate stabilization achieved in our patients was good. All patients experienced immediate pain relief. While only two patients were able to walk before surgery, seven were able to do so at follow-up. During a follow-up period of at least 2 years in two patients, or until death in the other eight patients, one patient had a broken wire that did not affect the correction achieved at surgery. Partial loss of correction in the sagittal plane was found in two patients who had metastasis in the lumbar spine and in another patient who had metastasis in the ninth thoracic vertebra.

Sex differences in brain gray and white matter in healthy young adults: correlations with cognitive performance

Sex-related differences in behavior are extensive, but their neuroanatomic substrate is unclear. Indirect perfusion data have suggested a higher percentage of gray matter (GM) in left hemisphere cortex and in women, but differences in volumes of the major cranial compartments have not been examined for the entire brain in association with cognitive performance. We used volumetric segmentation of dual echo (proton density and T2-weighted) magnetic resonance imaging (MRI) scans in healthy volunteers (40 men, 40 women) age 18-45. Supertentorial volume was segmented into GM, white matter (WM), and CSF. We confirmed that women have a higher percentage of GM, whereas men have a higher percentage of WM and of CSF. These differences sustained a correction for total intracranial volume. In men the slope of the relation between cranial volume and GM paralleled that for WM, whereas in women the increase in WM as a function of cranial volume was at a lower rate. In men the percentage of GM was higher in the left hemisphere, the percentage of WM was symmetric, and the percentage of CSF was higher in the right. Women showed no asymmetries. Both GM and WM volumes correlated moderately with global, verbal, and spatial performance across groups. However, the regression of cognitive performance and WM volume was significantly steeper in women. Because GM consists of the somatodendritic tissue of neurons whereas WM comprises myelinated connecting axons, the higher percentage of GM makes more tissue available for computation relative to transfer across distant regions. This could compensate for smaller intracranial space in women. Sex difference in the percentage and asymmetry of the principal cranial tissue volumes may contribute to differences in cognitive functioning.

Neuropsychological laterality indices of schizophrenia: interactions with gender

Neurobehavioral laterality indices were examined across motor, sensory, language versus spatial, and verbal memory versus spatial memory domains for 75 patients with schizophrenia (45 men, 30 women) and 75 demographically matched healthy controls. Patients were impaired across tasks, and laterality results varied by domain. There was no evidence for diagnosis by hemisphere interactions in motor, sensory, or memory tasks. However, patients were more impaired in language than in spatial domains, which suggests relatively greater left hemisphere dysfunction. This finding was mediated by the sex of the participant. While patients as a group showed greater language than spatial impairment, male patients showed expected superiority in spatial relative to language performance, whereas female patients performed the same on both functions. These results underscore the importance of examining sex differences in laterality effects. The findings also demonstrate that, although the left hemisphere model of schizophrenia may be partially supported by data on higher cognitive functions, this support does not extend to more basic motor and sensory domains.

Laterality in functional brain imaging studies of schizophrenia

Brain laterality in schizophrenia has been examined through the application of functional neuroimaging methods. These methods have included the 133Xenon technique for measuring cerebral blood flow (CBF); positron emission tomography for assessing rates of glucose metabolism, CBF, and neuroreceptor functioning; single photon emission computerized tomography for studying CBF and neuroreceptors; and functional magnetic resonance imaging for measuring changes attributable to CBF. This article highlights the application of this technology in schizophrenia research, emphasizing more recent studies that have evaluated hemispheric differences. There is evidence for lateralized abnormalities in some studies that have examined this dimension. In general, the results implicate abnormalities in left hemispheric activity. Recent advances in basic and clinical neuroscience provide an opportunity for focused application of functional imaging in neurobiological studies of schizophrenia.

Is Schizophrenia a lateralized brain disorder? Editor's introduction

Lateralization of brain function was established on the basis of clinical-pathological correlations over a century ago. In the past two decades, this line of research has attempted to link the complex behaviors evident in schizophrenia to the failure to develop and maintain a normal pattern of hemispheric activity. This issue of Schizophrenia Bulletin reviews and presents data from multiple perspectives of methods applied to the study of laterality in schizophrenia. Brain disorders affecting systems that modulate complex behavior are commonly related to laterality. Therefore, this dimension of brain function merits further investigation in schizophrenia.

Depression in temporal lobe epilepsy before epilepsy surgery

PURPOSE

This study examined the association of depression with laterality of epilepsy surgery in patients with temporal lobe epilepsy before standard lobectomy.

METHODS

Forty-nine patients presented for EEG telemetry for localization of epilepsy and eventual temporal lobectomy. Patients underwent routine neuropsychiatric evaluation blinded for epileptic focus, including ratings on depression. Patients were grouped according to right (n = 25, M = 10/F = 15) and left (n = 24, M = 13/F = 11) temporal lobectomy. Analysis of variance included side of surgery as grouping variable and sex, general depressive, cognitive depressive, and vegetative depressive symptoms as dependent variables. Chi2 analyses included categoric variables of sex, handedness, education, neuropathologic findings, and current affective disorders. t Tests were performed on variables of age, epilepsy duration, and cognitive function.

RESULTS

Right and left temporal epilepsy groups did not differ with regard to sex, handedness, age, duration of epilepsy, education, cognitive function, and neuropathology. Patients with right temporal epilepsy rated higher on general, cognitive. and vegetative depression scores. Women scored higher on general, cognitive, and vegetative depression scores. Current affective disorders were more common in the right temporal epilepsy group.

CONCLUSIONS

Depression ratings and diagnoses were more prominent in patients with right temporal lobe epilepsy and in women in particular. The strength of this laterality finding lies in the selection of patients, as all underwent epilepsy surgery. The finding on gender difference partly reflects the higher incidence of depression in women and needs further exploration. The laterality finding contrasts with recent findings in epilepsy, stroke, and trauma that associate depression with left hemispheric lesions. However, our results are consistent with findings in electrically hyperactive lesions such as gelastic and dacrystic epilepsy.

Proton magnetic resonance spectroscopy in the frontal and temporal lobes of neuroleptic naive patients with schizophrenia

Studies with proton magnetic resonance spectroscopy (MRS) have reported abnormalities in N-acetyl-aspartate (NAA), amino acids (AA) and choline (Cho) to creatine (Cr) ratios associated with schizophrenia. We report data on the three ratios in a sample of 18 neuroleptic naive patients with first-episode schizophrenia (eight studied in the dorsolateral prefrontal and 10 in the midtemporal lobe) and 24 healthy controls (14 studied in prefrontal and 10 in midtemporal lobes). Frontal lobe proton spectra were acquired with the stimulated-echo acquisition mode (STEAM) pulse sequence (echo time 21 ms, repetition time 2 s). Temporal lobe proton spectra were acquired with the point-resolved spectroscopy (PRESS) pulse sequence (echo time 16-21 ms, repetition time 2 s). Upon comparison with normal controls, NAA/Cr ratios were reduced in patients both for the frontal and the temporal lobe. By contrast, Cho/Cr ratios were slightly elevated in frontal and reduced in temporal lobes; whereas, AA/Cr ratios were normal in frontal and markedly increased in the temporal lobe. The reduced NAA/Cr ratios suggest lower neuronal viability in patients and is consistent with findings of reduced brain volume in both frontal and temporal regions.

Subcortical MRI volumes in neuroleptic-naive and treated patients with schizophrenia

OBJECTIVE

This study examined whether subcortical volumes of the basal ganglia and thalamus in schizophrenic patients are related to neuroleptic exposure and symptom severity.

METHOD

Basal ganglia substructures and thalamic volumes were measured with magnetic resonance imaging in 96 patients with schizophrenia (50 men and 46 women) and 128 healthy comparison subjects (60 men and 68 women). Twenty-one of the patients were neuroleptic-naive; of the 75 previously treated patients, 48 had received typical neuroleptics only, and 27 had received typical and atypical neuroleptics. The relation of volume measures to treatment status, exposure to neuroleptics, and symptoms was examined.

RESULTS

The neuroleptic-naive patients did not differ from the healthy comparison subjects in subcortical volumes except for lower thalamic volume. In the neuroleptic-naive group, volumes did not correlate with severity of negative symptoms, but higher volumes in both the thalamus and the putamen were associated with more severe positive symptoms. The previously treated group showed higher volumes in the putamen and globus pallidus than the healthy comparison subjects and the neuroleptic-naive patients. In the treated group, a higher dose of a typical neuroleptic was associated with higher caudate, putamen, and thalamus volumes, whereas a higher dose of an atypical neuroleptic was associated only with higher thalamic volume. Higher subcortical volumes were mildly associated with greater severity of both negative and positive symptoms.

CONCLUSIONS

Increased subcortical volumes in treated schizophrenic patients seem to be medication-induced hypertrophy. This hypertrophy could reflect structural adaptation to receptor blockade and may moderate the effects of neuroleptic treatment.

Regional gray matter, white matter, and cerebrospinal fluid distributions in schizophrenic patients, their siblings, and controls

BACKGROUND

Cortical gray matter volume reductions and cerebrospinal fluid (CSF) volume increases are robust correlates of schizophrenia, but their sources have not been established conclusively.

METHODS

Structured diagnostic interviews and magnetic resonance imaging scans of the brain were obtained on 75 psychotic probands (63 with schizophrenia and 12 with schizoaffective disorder), ascertained so as to be representative of all such probands in a Helsinki, Finland, birth cohort; 60 of their nonpsychotic full siblings; and 56 demographically similar control subjects without a personal or family history of treated psychiatric morbidity.

RESULTS

Patients with schizophrenia and their siblings exhibited significant reductions in cortical gray matter volume and significant increases in sulcal CSF volume compared with controls. The patients, but not their siblings, also exhibited significant reductions in white matter volume and significant increases in ventricular CSF volume. Regional effects were most robust when component volumes were expressed as percentages of overall regional volumes; in this case, for patient and sibling groups, gray matter volume reductions and sulcal CSF volume increases were significantly more pronounced in the frontal and temporal lobes than in the remainder of the brain. None of the group differences varied significantly by sex or hemisphere.

CONCLUSIONS

Structural alterations of the cerebral cortex, particularly in the frontal and temporal lobes, are present in patients with schizophrenia and in some of their siblings without schizophrenia; such changes are thus likely to reflect genetic (or shared environmental) effects. Ventricular enlargement is unique to the clinical phenotype and is thus likely to be affected primarily by nonshared causative factors.

MMPI-2 characteristics of adults diagnosed with attention deficit disorder

Attention Deficit Disorder (ADD) has been increasingly recognized as extending into adulthood, affecting occupational, interpersonal, and psychological functioning. The Minnesota Multiphasic Personality Inventory (MMPI) and its revision (MMPI-2) have been widely used in the assessment of patients with psychiatric disorders, but few studies have attempted to characterize the personality profiles of individuals with ADD and none have used the MMPI-2. Thirty-three patients with ADD and 33 schizophrenia patients were compared to 46 healthy control subjects on the MMPI-2 validity, clinical and Harris-Lingoes scales. With the exception of significantly lower scores for general affective distress (F), thought disorder (Sc), and paranoia (Pa), ADD subjects demonstrated remarkably similar profiles to those seen in the schizophrenia group. Significant differences between the three groups were found on a majority of the clinical scales, with ADD subjects showing similar profile elevations as schizophrenic subjects on both clinical- and sub-scales. These results were consistent with previous research using the original MMPI in adults with ADD, and confirm that examination of MMPI-2 profiles may be a useful diagnostic aid for this disorder.

Frontotemporal cerebral blood flow change during executive and declarative memory tasks in schizophrenia: a positron emission tomography study

Schizophrenia affects prefrontal and temporal-limbic networks. These regions were examined by contrasting regional cerebral blood flow (rCBF) during executive (Wisconsin Card Sorting Test [WCST]), and declarative memory tasks (Paired Associate Recognition Test [PART]). The tasks, and a resting baseline, were administered to 15 patients with schizophrenia and 15 healthy controls during 10 min positron emission tomography 15O-water measures of rCBF. Patients were worse on both tasks. Controls activated inferior frontal, occipitotemporal, and temporal pole regions for both tasks. Similar results were obtained for controls matched to level of patient performance. Patients showed no activation of hypothesized regions during the WCST and activated the dorsolateral prefrontal cortex during the PART. On the PART, occipitotemporal activation correlated with better performance for controls only. Better WCST performance correlated with CBF increase in prefrontal regions for controls and in the parahippocampal gyrus for patients. Results suggest that schizophrenia may involve a breakdown in the integration of a frontotemporal network that is responsive to executive and declarative memory demands in healthy individuals.