Neuropsychology of first-episode schizophrenia: initial characterization and clinical correlates

OBJECTIVE

Neuropsychological impairments are well documented in schizophrenia and are important targets of treatment. Information about the severity and pattern of deficits after treatment for the first psychotic episode and about relationships between these deficits and syndromal characteristics remains limited.

METHOD

Comprehensive neuropsychological assessments including 41 individual tests were given to 94 patients with first-episode schizophrenia after initial stabilization of psychosis and to a comparison group of 36 healthy volunteers. Profiles of neuropsychological deficits and the relationship of deficits to sex and handedness were examined. Correlations of neuropsychological deficit with a broad range of historical and clinical characteristics, including outcome, were explored.

RESULTS

Patients had a large generalized neuropsychological deficit (1.5 standard deviations compared to healthy volunteers). Patients also had, superimposed on the generalized deficit, subtle relative deficits (less than 0.5 standard deviation compared to their own average profile) in memory and executive functions. Learning/memory dysfunction best distinguished patients from healthy individuals; after accounting for this difference, only motor deficits further distinguished the groups. Patients with higher neuropsychological ability had only memory deficits, and patients with lower ability had both memory and executive deficits. No sex differences were observed beyond the normal advantage for men in motor speed. Dextral patients had less severe generalized deficit. Severity of residual symptoms was associated with greater generalized deficit. Executive and attentional deficits were most linked to global functional impairment and poor outcome.

CONCLUSIONS

The results document a large generalized deficit, and more subtle differential deficits, in clinically stabilized first-episode patients. Learning/memory deficits were observed even in patients with less severe generalized deficit, but the pattern was unlike the amnestic syndrome and probably reflects different mechanisms. Executive and attentional deficits marked the more severely disabled patients, and may portend relatively poor outcome. Failure to develop typical patterns of cerebral dominance may increase the risk for greater generalized deficit.

Assessment: transcranial Doppler ultrasonography: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology

OBJECTIVE

To review the use of transcranial Doppler ultrasonography (TCD) and transcranial color-coded sonography (TCCS) for diagnosis.

METHODS

The authors searched the literature for evidence of 1) if TCD provides useful information in specific clinical settings; 2) if using this information improves clinical decision making, as reflected by improved patient outcomes; and 3) if TCD is preferable to other diagnostic tests in these clinical situations.

RESULTS

TCD is of established value in the screening of children aged 2 to 16 years with sickle cell disease for stroke risk (Type A, Class I) and the detection and monitoring of angiographic vasospasm after spontaneous subarachnoid hemorrhage (Type A, Class I to II). TCD and TCCS provide important information and may have value for detection of intracranial steno-occlusive disease (Type B, Class II to III), vasomotor reactivity testing (Type B, Class II to III), detection of cerebral circulatory arrest/brain death (Type A, Class II), monitoring carotid endarterectomy (Type B, Class II to III), monitoring cerebral thrombolysis (Type B, Class II to III), and monitoring coronary artery bypass graft operations (Type B to C, Class II to III). Contrast-enhanced TCD/TCCS can also provide useful information in right-to-left cardiac/extracardiac shunts (Type A, Class II), intracranial occlusive disease (Type B, Class II to IV), and hemorrhagic cerebrovascular disease (Type B, Class II to IV), although other techniques may be preferable in these settings.

Meta-analysis of symptom factors in schizophrenia

Factor and correlational analyses have been used to characterize symptom dimensions in schizophrenia, though they have yielded divergent models. This study used meta-analysis of published work to determine the number and composition of symptom dimensions. Principal components analysis of data from 10 empirical studies (pooled n = 896) yielded three factors, 'positive', 'negative' and 'conceptual disorganization'. The findings suggest that a three-factor solution is a relatively stable outcome of studies assessing these symptoms in chronic patients, and that some symptoms (alogia, attentional impairment) are less likely to load uniquely on a single factor.

Validation of the 16-item Negative Symptom Assessment

The dimensional structure of the 16-item Negative Symptom Assessment (NSA-16) was validated in a sample of 223 unmedicated schizophrenic inpatients and cross-validated on an independent sample of 276 patients with schizophrenia. Using a confirmatory factor analytic procedure, a five factor model was found to best characterize the structure of this rating instrument. These factors include: Communication, Emotion/Affect, Social Involvement, Motivation, and Retardation. The latent structure of the NSA-16 is similar to the larger instrument from which it was derived. The findings provide support for a multidimensional model of negative symptoms in schizophrenia and offer a useful measure for their assessment.

Discriminability of the Wisconsin Card Sorting Test using the standardization sample

The four neurological patient groups and the normals from the Wisconsin Card Sorting Test (WCST) standardization sample were used to examine the discriminability of the WCST's indices. Results reveal consistent differentiation of normals from the patient groups on all WCST variables, with classification rates averaging 71% accuracy. However, patient groups with frontal, diffuse, and nonfrontal lesions were not consistently discriminable from each other. The results suggest that the WCST is most usefully conceptualized as a measure of executive abilities that involves the frontal lobes, but should not be considered solely as a marker of isolated frontal lobe pathology.

Reduced anterior cingulate gyrus volume correlates with executive dysfunction in men with first-episode schizophrenia

Although frontal lobe structural and functional abnormalities have been identified in schizophrenia, their relationship remains elusive. Because the frontal lobes are both structurally and functionally heterogeneous, it is possible that some measures of frontal lobe structure may not have accurately identified relevant frontal lobe subregions. The authors hypothesized that the volumes of two dorsal, 'archicortical' subregions (i.e. superior frontal gyrus and anterior cingulate gyrus), but not a ventral, 'paleocortical' subregion (i.e. orbital frontal region) would be significantly and selectively correlated with executive and motor dysfunction in patients with schizophrenia as previously reported for the anterior hippocampal region. Volumes of these frontal lobe subregions were measured from magnetic resonance images based on sulcal anatomy in 20 men and 15 women with first-episode schizophrenia. All patients completed a comprehensive neuropsychological test battery while clinically stabilized that encompassed six domains of functioning: attention, executive, motor, visuospatial, memory and language. Findings indicated that reduced anterior cingulate gyrus volume was significantly correlated with worse executive functioning in men; among women, there were no significant correlations. Among men, anterior cingulate gyrus volume was significantly more strongly correlated with executive functioning than with attention, visuospatial, memory, language and general intellectual functioning. Neither executive nor motor functioning was significantly more strongly correlated with the dorsal 'archicortical' volumes than with orbital frontal volume. These findings suggest a link between executive deficits and dysfunction of the dorsal 'archicortical' system and implicate sex differences in their relationship in first-episode schizophrenia.

Endothelin induces a sustained rise in intracellular calcium in hippocampal astrocytes

We report that the endothelins, a newly described family of vasoactive peptides, have a profound effect on intracellular calcium levels of cultured rat hippocampal astrocytes that resembles the effect of endothelin (ET) on vascular smooth muscle cells (VSMCs) in many respects. The astrocyte's response has two components that can be distinguished by their extracellular calcium requirement and time course. Within seconds of application, ET induces a transient calcium spike that corresponds to a release of calcium from internal stores. The second component follows immediately, is dependent upon extracellular calcium, and maintains an elevated intracellular calcium level for many minutes. Sustained elevations of intracellular calcium can dramatically alter astrocyte morphology and induce cell division in many other cell types. ET may serve these functions, and thus form a communication link between blood vessels and neurons through astrocytes.

Serum albumin in continuous peritoneal dialysis: its predictors and relationship to urea clearance

We investigated the predictors of serum albumin and the relationship between serum albumin and urea kinetic indices in continuous peritoneal dialysis (CPD). In a training set (TS) of 143 urea kinetic studies performed in 92 CPD patients, stepwise logistic regression identified high/high-average peritoneal solute transport, diabetes, advanced age and high daily drain volume normalized by body water as predictors of low serum albumin (< 35 g/liter). This analysis was then substantiated in a validation set (VS) of 187 kinetic studies performed in another 102 CPD patients. The calculated area under the receiver operating characteristic (ROC) curve by this logistic regression model was 0.782 (95% CI, 0.745 to 0.819). Logistic regression was repeated in the TS using only the first kinetic study from each patient, and it identified high/high-average peritoneal solute transport, diabetes, and advanced age as predictors of low albumin. Using only the first kinetic study from each patient in the VS, the second logistic regression model calculated an area under the ROC curve equal to 0.850 (95% CI, 0.810 to 0.890). The relative risk (RR) of serum albumin < 35 g/liter was computed for all kinetic studies after combining the TS and the VS and using non-diabetic CPD subjects aged < or = 61 years with low/low average peritoneal solute transport as the reference group. The RR with only one risk factor present ranged from 1.076 (age > 61 years) to 6.792 (high/high-average transport). The RR with two risk factors present ranged from 5.200 to 9.729. The RR with all three risk factors present was 9.100 (95% CI, range 3.923 to 21.111). A subset of 37 CPD patients had a second urea kinetic study 8 +/- 5 months after an increase in the amount of dialysis due to low urea clearance and/or uremic symptoms. The weekly KT/V urea increased from 1.40 +/- 0.24 to 2.10 +/- 0.31 after the increase in the CPD dose. With the increase in dialysis, the protein catabolic rate increased substantially; however, the mean serum albumin remained stable (from 33.9 +/- 4.6 to 33.3 +/- 6.2 g/liter; decrease 18; increase 15; same 4). In comparison to the subjects who had a decrease in serum albumin after the increase in KT/V, those with the increase in serum albumin were younger (44.2 +/- 11.2 vs. 54.3 +/- 16.2 years, P = 0.044) and had a higher serum urea after the increase in the dose of CPD (22.4 +/- 7.8 vs. 17.0 +/- 6.0 mmol/liter, P = 0.037). We conclude that the major predictors of low serum albumin in CPD are advanced age, diabetes, and high/high-average peritoneal solute transport, but not urea kinetic studies. An increase in the dose of dialysis does not cause a consistent rise in serum albumin in underdialyzed CPD subjects. However, a subset of younger patients may be able to increase their serum albumin in response to the increase in KT/V.

Measurement of depression and negative symptoms in schizophrenia

The validity of the Hamilton Depression Scale (HAM-D) as a measure of depressive symptomatology in schizophrenic patients is questionable since it was not developed for this purpose, nor has it been validated in a schizophrenic population. Accordingly, 80 schizophrenic inpatients were administered the HAM-D, the 18-item Brief Psychiatric Rating Scale (BPRS), and the Scale for the Assessment of Negative Symptoms (SANS) at drug-free baseline and after 4 weeks of neuroleptic treatment. The findings revealed that the HAM-D total score was nonspecific, while individual HAM-D subfactors provided a better index of various symptom complexes. The HAM-D contained a depressive factor that correlated strongly with the BPRS depression factor and a negative symptom factor that correlated strongly with the SANS and the BPRS negative symptom factor. These findings suggest the need to utilize specific assessment techniques rather than global measures when assessing depression in schizophrenia.

Neuropsychological prediction of treatment efficacy and one-year outcome in schizophrenia

The present study was conducted to establish the degree of interrelationship between neuropsychological functioning in the acute phase of the schizophrenic illness, clinical measures of treatment response (positive and negative symptoms), and 1-year outcome. Nineteen SADS/RDC schizophrenic inpatients were clinically rated during a 2-week drug washout period and again following 4 weeks of neuroleptic treatment. The findings revealed that reduced attentional ability in the baseline phase significantly predicted the presence of higher residual negative symptoms following 4 weeks of treatment, while neurocognitive status was unrelated to positive symptom response. With respect to prediction of the 1-year outcome, poor functional status of this schizophrenic population was significantly associated with the presence of baseline memory dysfunction.

Nasal and cutaneous flora among hemodialysis patients and personnel: quantitative and qualitative characterization and patterns of Staphylococcal carriage

Staphylococcal sepsis is a leading cause of morbidity and mortality among chronic hemodialysis (HD) patients. We studied nasal and cutaneous flora of HD patients and personnel and their patterns of staphylococcal carriage. HD patients had significantly increased cutaneous total bacterial colony counts (p less than 0.01) as well as both nasal (p less than 0.0001) and cutaneous (p less than 0.0001) carriage of Staphylococcus aureus compared to personnel. Cutaneous staphylococcal carriage could be significantly correlated with nasal carriage (p less than 0.01). Cutaneous streptococcal species and gram-negative bacilli were not different between patients and personnel. Staphylococcal phage typing of nasal isolates from staphylococcal carriers revealed a mean of 90% of isolates from each subject belonging to a predominant phage type. Predominant nasal staphylococcal phage types corresponded with respective predominant cutaneous phage types in 93% of HD patients carriers. These studies substantiate autoinoculation of S. aureus from the nasal vestibule to the skin overlying the vascular access site.

Factor structure of the negative symptom assessment

The factor structure of the Negative Symptom Assessment (NSA), a standardized negative symptoms rating scale, was systematically evaluated in a group of 223 inpatients with schizophrenia. Confirmatory factor analyses found that a six-factor model best described the NSA. More specifically, the domains of Communication, Emotion/Affect, Social Involvement, Motivation, Gross Cognition, and Retardation characterized the rating scale. This latent structure of the NSA is consistent with a multidimensional conceptualization of negative symptoms.

Experience-dependent cognitive recovery in alcoholics: a task component strategy

Visuospatial problem-solving deficits following chronic alcohol abuse may not readily recover spontaneously after drinking cessation but may reverse with appropriate environmental stimulation. To determine if such recovery in alcoholics under age 40 may be accelerated by training with components of an initially impaired task (Trails B), this study employed four groups of alcoholics (N = 53) and a group of matched controls (N = 13). Two alcoholic groups received two consecutive cognitive remediation sessions during the latter 2 weeks of a 1-month treatment program, and two groups of alcoholics received no remediation. Results confirmed that recovery of visuospatial problem-solving skills is facilitated by training with task components (experience-dependent recovery) while spontaneous recovery during the first month of abstinence is minimal for this task. These findings demonstrate the efficacy of cognitive remediation in reversing some alcohol-induced cognitive impairment and have important implications for improving alcohol treatment outcome and adaptive functioning.

Comparison of 4% chlorhexidine gluconate in a detergent base (Hibiclens) and povidone-iodine (Betadine) for the skin preparation of hemodialysis patients and personnel

The abnormal cutaneous flora of hemodialysis (HD) patients might contribute to their frequent septic complications. We compared the effects of 13 wk of Betadine and 13 wk of Hibiclens on the skin flora of HD patients and personnel. Skin cultures were obtained weekly immediately prior to the disinfection, preceding each triweekly HD treatment, and monthly, at 2 and 4 hr postdisinfection. Total bacterial counts from predisinfection cultures were not significantly altered over either 13-wk treatment period. Hibiclens reduced total bacterial counts (p less than 0.01) and eradicated cutaneous staphylococci (p = 0.032) at both 2 and 4 hr postdisinfection significantly more than did Betadine. No reduction of staphylococcal sensitivity to either germicidal agent could be demonstrated. Neither agent was associated with severe adverse reactions and Hibiclens could not be detected in the blood. Hibiclens appears to offer short-term advantages over Betadine in the HD setting because of significantly longer duration of antibacterial activity.

Sensitivity of the Mini-Mental State Examination to frontal lobe dysfunction in normal aging

The present study examined the sensitivity of the Mini-Mental State Examination (MMSE) in detecting the frontal lobe dysfunction that occurs with normal aging. Eighty normal, independently living older adults in four age groupings from 50 to 89 were administered the MMSE along with three neurocognitive measures sensitive to frontal lobe functioning. Results revealed age-related cognitive decline on frontal lobe tasks that also was detected by the MMSE. These findings are noteworthy because the MMSE was intended as a measure of gross cognitive status rather than of frontal lobe functioning.

Comparison of Four Wisconsin Card Sorting Test Scoring Guides With Novice Raters

The utility of the Wisconsin Card Sorting Test (WCST) is predicated on the ability of its users to accurately administer and score the task. This study evaluated four different WCST scoring guides in an effort to determine the most reliable and accurate instructional set for use by individuals previously unfamiliar with scoring the WCST. The study targeted the scoring of perseverative responses, as this is the most difficult of the measures to learn. Novice raters using one of four methods (original manual alone, decision tree [key guide] with the original manual, written supplement with the original manual, and revised manual only) and expert raters each scored 20 technically difficult WCST protocols. The results demonstrated that novice raters who used the written supplement to score these difficult protocols were as reliable and accurate in scoring perseverative responses as the experts. Those who used either the original manual alone or the key guide with the manual were less reliable. Scoring perseverative responses with the revised manual's instructions was considerably more reliable and accurate than scoring with the original manual. However, scoring performance for perseverative responses with the revised manual did not achieve that of the novice raters using the written supplement. It is recommended that scoring accuracy for cognitive measures be empirically validated rather than assumed.

Effect of instructional cues on schizophrenic patients' performance on the Wisconsin Card Sorting Test

OBJECTIVE

Schizophrenic patients are particularly deficient on measures of executive functioning, notably the Wisconsin Card Sorting Test. This study was conducted to determine the efficacy of a cuing strategy in facilitating performance on this cognitive measure of the integrity of prefrontal brain structures and functioning.

METHOD

Twenty-four schizophrenic inpatients and 24 demographically matched inpatients with mood disorders were administered the Wisconsin Card Sorting Test either with instructional cues at the beginning of the task or with the standard administration procedure.

RESULTS

There was a significant benefit of cues for the patients with affective disorders as well as for the schizophrenic patients. The schizophrenic subjects in the uncued condition maintained poor but stable performance throughout the course of the task.

CONCLUSIONS

The study suggests that the deficit in executive functioning of schizophrenic patients may lie in the formation of concepts, not in their application.

Severity of illness measures derived from the Uniform Clinical Data Set (UCDSS)

The Health Care Financing Administration (HCFA) plans to use the Uniform Clinical Data Set System (UCDSS) to collect data on hospitalized Medicare patients. This study examined the value of UCDSS data for creating severity of illness measures. UCDSS data were obtained from a study hospital and from a national data set for patients with pneumonia (n = 528) and stroke (n = 565). Models to predict length of stay or an adverse event were derived for each condition using HCFA claims data alone, UCDSS data alone, and UCDSS data supplemented with additional information also abstracted from charts. The models were derived from one set of patients and validated on another. The R2 for predicting length of stay in the validation data for the UCDSS model was 0.29 for pneumonia and 0.19 for stroke compared to R2 values from the claims model of 0.09 for stroke and 0.06 for pneumonia. UCDSS models also were better than claims models for predicting adverse events. The best UCDSS models included International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes and other information requiring clinical judgment, and were improved by adding more information on patient functional status. Some findings were more strongly associated with outcome for the study hospital than for the national data. These results suggest that UCDSS models will predict outcome much better than the claims based models currently used by HCFA for the analysis of hospitalization-related mortality; more functional status information should be added to UCDSS; and despite an extensive objective database, the most predictive UCDSS models require clinician-assigned diagnostic codes.

Comparison of indices of premorbid function in schizophrenia

There has been a resurgence of interest in the area of premorbid functioning in schizophrenia as it provides clues to onset and etiology. Most studies rely on retrospective estimates of premorbid status that are incomplete, such as the Premorbid Adjustment Scale (PAS). Even prospective high-risk studies are hampered by the narrow range of premorbid functions assessed and are thus unable to answer crucial questions related to onset of illness. This study was undertaken to assess the relationship between several indices of premorbid functioning. Sixty four in-patients with schizophrenia were assessed at medication-free baseline and post-treatment with BPRS and SANS. PAS scores were derived from all available sources. Premorbid cognitive ability was estimated by the mean of WAIS-R Vocabulary and Information subscale scores. Estimated premorbid IQ was obtained using a demographic regression formula. Years of education and predicted VIQ, PIQ, and FSIQ were found to correlate with estimated premorbid cognitive ability. Predicted VIQ, PIQ, and FSIQ were associated with years of education and PAS childhood, early and late adolescence, and general scores. Each estimate of premorbid ability demonstrated a different pattern of association with clinical ratings, symptom change, and outcome. The results suggest that education, PAS, predicted IQ, and WAIS-R estimates of premorbid cognitive ability assess different but overlapping areas of pre-morbid functioning.