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Biomedical subjects

R G Paulman

Publications and source records attributed to R G Paulman.

8 recordsLinked to original sources
PubMed2000

A comparison of neuropsychological and situational assessment for predicting employability after closed head injury.

The relationships among neuropsychological assessment, situational assessment, and judgments of future employability in 127 survivors of moderate to severe closed head injury were evaluated. Participants received a comprehensive neuropsychological battery and a situational vocational evaluation. Two groups were created, based on employment recommendation from the situational evaluation. A seven-factor model was found to account for the preponderance of variance within the neuropsychological battery used, and one factor was predictive of group assignment from situational assessment. However, the present data reinforce the predominance of findings in the literature that indicate that, in general, no individual neuropsychological test can be used to predict vocational performance in more environmentally relevant environments. Exceptions to this "rule" may occur when comparisons between results of formal neuropsychological tests and situational evaluation are limited to very simple, very circumscribed, and/or very well-defined functions. Thus, situational assessment is seen as a critical adjunct to neuropsychological assessment in making "real-world" predictions. The particular situational assessment used in this study was internally valid, an important finding given the importance of situational assessment in ecologically valid predictions.

Adolescent↗
PubMed1996

Wisconsin card sorting activated regional cerebral blood flow in first break and chronic schizophrenic patients and normal controls.

Dynamic 133Xe single photon emission computed tomography (SPECT) was used to measure regional cerebral blood flow (rCBF) during the Wisconsin Card Sorting test (WCS) and the Number Matching task (NM) in six never-medicated first break schizophrenic and schizophreniform patients, seven chronic schizophrenic patients, and seven normal controls. Because of a difference in mean age between first break patients and normals, we adjusted rCBF data for age effects using ANCOVA. For age-adjusted absolute superior and middle frontal rCBF bilaterally, we found significantly less activation from NM to WCS in first break patients compared to normals. Similarly, for age-adjusted absolute and relative left middle frontal rCBF, we found significantly less activation in chronics compared to normals. Changes in age-adjusted global cerebral blood flow (gCBF) were not statistically significant among the three groups, but were in the same direction as activated absolute frontal rCBF. Because of the small number of subjects in each group, the results of this study should be regarded as preliminary and interpreted cautiously.

Adolescent↗
PubMed1995

Cerebellar blood flow in schizophrenic patients and normal control subjects.

We used 133Xe dynamic single-photon emission computed tomography (DSPECT) to measure the resting cerebellar blood flow in 17 neuroleptic-free schizophrenic and schizophreniform patients and 13 normal control subjects. A subset of these subjects (11 patients and 7 control subjects) additionally underwent activation studies during the Wisconsin Card Sorting (WCS) and Number Matching (NM) tests. Baseline relative cerebellar blood flow was significantly lower in older patients than in age-matched control subjects. For absolute cerebellar flow, there was a significant difference between patients and control subjects in the overall activation response (patients: NM 13.4% increase, WCS 15.7% increase; control subjects: NM 3.1% decrease, WCS 0.0% change). This difference was more pronounced in older subjects. Cerebral blood flow significantly increased during NM (patients: 21.3% increase, control subjects: 6.5% increase) and WCS (patients: 16.5% increase, control subjects: 9.7% increase). The difference in the magnitude of cerebral NM activation between schizophrenic patients and control subjects, although not statistically significant, may call into question the appropriateness of using NM as a control task in schizophrenic patients. Finally, we found no differences between the effects of WCS and NM on cerebellar or cerebral blood flow. Because of the small number of subjects in each group, the results of this study should be interpreted cautiously.

Adult↗
PubMed1995

Regional cerebral blood flow in first break and chronic schizophrenic patients and normal controls.

Dynamic 133Xe Single Photon Emission Computed Tomography (SPECT) was used to measure the resting regional cerebral blood flow (rCBF) in 16 neuroleptic free schizophrenic and schizophreniform male patients and 13 age-matched male normal controls. A subgroup consisting of 'first break' patients who had never been exposed to neuroleptic treatment were age-matched to a subgroup of young chronic patients most of whom had been previously exposed to neuroleptics. The age-adjusted rCBF values were compared among first breaks, young chronics, normal controls, and a subgroup of older, more chronic patients. In first break patients, we found significantly lower absolute global cerebral blood flow and significantly lower superior frontal, middle frontal, and middle temporal absolute rCBF compared to normals. We also found significantly lower relative superior frontal rCBF in first breaks vs. normals, and higher relative superior frontal and relative middle frontal rCBF in older chronics vs. the other groups. For relative posterior temporal rCBF there was greater asymmetry (right side > left) in first breaks and young chronics compared to normals and older chronics.

Acute Disease↗
PubMed1990

Hypofrontality and cognitive impairment in schizophrenia: dynamic single-photon tomography and neuropsychological assessment of schizophrenic brain function.

Regional cerebral blood flow (rCBF) was assessed in 40 chronic male schizophrenic patients (20 medicated, 20 unmedicated) and 31 matched normal controls with Dynamic Single-photon Emission Computed Tomography (D-SPECT). Blind analyses of normalized color-coded tomograms revealed significant bifrontal and bitemporal rCBF deficits in the patient group. Frontal flow deficits were most prominent in paranoid patients (n = 21) and right temporal deficits were most prominent in nonparanoid patients (n = 19). These relative regional declines were observed within the context of significantly elevated hemispheric blood flow in schizophrenics compared with controls. Reduced left frontal rCBF was associated with neuropsychological impairment on the Wisconsin Card Sorting Test and Luria-Nebraska Battery. Increased hemispheric CBF was correlated with the presence of positive schizophrenic symptoms. Medication status was unrelated to rCBF. These findings demonstrate that hypofrontality has important implications for cognitive function in some schizophrenic individuals.

Adult↗
PubMed1989

Cognitive function and regional cerebral blood flow in partial seizures.

Patients with partial seizures have cognitive function impairments that have been attributed to the toxic side effects of anticonvulsants and structural cerebral damage. However, even when these factors are absent, neuropsychological (NP) deficits have been demonstrated, although of milder degree than in structurally brain-damaged patients. Assessment of cerebral metabolism using positron emission tomography and cerebral blood flow with single photon emission computed tomography (SPECT) reveals focal physiologic deficits in structurally normal areas. Using both SPECT and NP assessment with the Halstead-Reitan Battery, we evaluated 50 patients with partial seizures. Comparison of the location of visually identified regional cerebral blood flow (rCBF) deficits in these patients with the location of the NP deficits revealed a significant correlation. Additional analyses indicated that rCBF quantification in visually identified areas of hypoperfusion was significantly lower than in "normal" areas and that quantified NP variables significantly discriminated patients with and without visual rCBF deficits in temporal and frontal brain regions.

Adult↗
PubMed1989

Regional cerebral function and blood flow: complementary single photon emission computed tomography of the brain using xenon-133 and [123I]iodoamphetamine.

Regional cerebral function and blood flow can be imaged using isopropyl[123I]iodoamphetamine (IMP), or 133Xe (DSPECT), respectively. Both of these essentially non-invasive, quantitative, methods are suitable for many nuclear medicine laboratories. This study assessed the in vivo information about intracerebral disease provided by IMP and DSPECT techniques to determine the optimal diagnostic use of these modalities. Single photon emission computed tomograms of 53 subjects were acquired using similar displays for IMP and DSPECT data. Lobar tracer distributions were graded by three experienced observers and analyzed using a kappa statistic to eliminate chance agreements. Overall, both IMP and DSPECT had similar patterns. However, while similar, one or the other technique often displayed abnormalities not present on both. Although technical factors may account for some differences between the modalities, a case of arteriovenous malformation proves that discordant findings can result directly from tracer localization properties. Thus at least some discordances provide truly complementary diagnostic information lacking in either single study taken alone.

Adult↗