CT scan studies of superficial cerebral regions: frequency and distribution of abnormalities in elderly psychiatric patients

Neural correlates of impaired functional independence in early Alzheimer's disease

Cognitive and physical decline are important predictors of functional independence in Alzheimer's disease (AD). However, little is known about AD-related neural change leading to decreased independence. We hypothesized that regional gray matter atrophy, including the medial frontal cortex, would be related to cognition, physical function, and functional independence. Individuals without dementia (n=56) and subjects with early-stage AD (n=58) underwent MRI and a comprehensive cognitive and physical function evaluation. The relationship of cognitive and physical function measures and independence performing complex daily activities was explored using correlation and mediation analysis. These results suggest that cognition had both a strong direct effect and mediated the influence of physical function on independence for those with AD. We followed this with a voxel-based morphometric global conjunction analysis of imaging data within each group to identify neural substrates common to our function measures. Imaging evidence supported our mediation analysis results. Imaging evidence revealed that in AD, regional gray matter atrophy measures in medial frontal and temporo-parietal areas were related to decreased cognition, physical function, and independence. Loss of independence in early AD is closely related to impaired cognition associated with performing complex behaviors. People with early AD may have decreased gray matter volume in the medial frontal and temporal-parietal cortices that is associated with loss of independence in activities of daily living. These results are the first to identify regionally specific brain volume changes that may be related to functional dependence seen in early AD.

The somatics of psyche: structural neuromorphometry of bipolar disorder

Many neuroimaging investigations report structural differences in subjects with bipolar disorder; however, conflicting results are common in the limited number of available investigations. Thus, the structural correlates of bipolar disorders remain poorly understood. The authors reviewed the early investigations using computed tomography and examined gross structural differences, such as cerebral atrophy, ventricular enlargement, or cerebellar atrophy. Many of these investigations report significant differences in these features compared with controls, whereas others found no such differences. More recent magnetic resonance imaging (MRI) investigations have employed increasingly sophisticated imaging and research methodologies, allowing for the quantitative examination of specific brain regions. Because neuropsychological and functional studies suggest abnormalities in frontal, temporal and subcortical regions, many investigators have focused their MRI neuromorphometric studies on these temporal limbic structures. However, the number of investigations examining each of these regions remains small, and conflicting results continue to be reported. It seems clear that for many brain regions, the structural changes from normal may be subtle, and that the differences in the reported studies may be due to differences in research methodologies between studies and across centers.

Bilateral anterior cortical atrophy and subcortical atrophy in reduplicative paramnesia: a case-control study of computed tomography in 10 patients

OBJECTIVE

Reduplicative paramnesia (RP) is thought to be related to other delusional misidentification syndromes (DMS) such as Capgras syndrome. DMS are thought to occur when brain lesions disrupt cortical functioning. This study tests this hypothesis and tries to understand whether focal lesions are as important in the etiology of RP as they are in other types of DMS.

METHOD

The computed tomography (CT) scans of 10 consecutive psychiatric inpatients with RP and another principal psychiatric diagnosis were compared with those of control patients without RP matched for age, sex, and principal psychiatric diagnosis. The scans were assessed blindly by a neuroradiologist using a previously published rating scale for the presence of lesions in 11 discrete anatomic areas. The differences between the 2 groups were examined statistically using log-linear analysis.

RESULTS

Statistical analysis revealed that index patient cortical atrophy, cortical fissure enlargement, and deep brain atrophy distinguished the 2 groups significantly (P < 0.05).

CONCLUSIONS

Bilateral anterior cortical, brain stem, and cerebellar vermis atrophy and dysfunction may be important in the pathogenesis of RP in particular and of DMS in general.

Temporal lobe abnormalities in multigenerational families with schizophrenia

Brain structure in familial schizophrenia was studied with computerized tomography in 42 individuals from six multigenerational families. Sulcal enlargement in the lateral temporal cortex, and ventricular and cisternal enlargement in the medial temporal region were observed in psychotic individuals compared to unaffected family members. Genetic factors in familial schizophrenia may exert part of their effect through determining or altering temporal lobe structure.

Relationships between brain CT scan findings and cortisol in psychotic and nonpsychotic depressed patients

In this report, data are presented on pre- and postdexamethasone cortisol levels, neuropsychological testing, and computed tomography (CT) scan findings in 30 depressed patients (15 psychotic and 15 nonpsychotic). Particularly significant findings were observed when data from the unipolar subgroup (n = 22) were analyzed separately. Unipolar psychotic depressed patients had significantly larger (p less than 0.05) anterior pole and cella media ventricle-to-brain ratios (VBRs) and significantly greater (p less than 0.05) left and right inferior parietal brain "atrophy" than nonpsychotic depressed patients. Higher rates of Dexamethasone Suppression Test (DST) nonsuppression were observed in psychotic depressed patients and in patients with larger cella VBRs. Inferior parietal brain atrophy and large VBRs were also associated with greater cognitive impairment on psychometric testing. Implications of these findings are discussed.

Behavioral correlates of computed tomographic (CT) scan changes in older psychiatric patients

Fifty psychiatric inpatients aged 50 and over, with no hard neurologic findings, and with a variety of DSM-III diagnoses (adjustment disorder, affective illness, and dementia), were rated for behavioral and psychiatric symptoms using the Geriatric Rating Scale and the Nurse's Assessment of Global Symptomatology-Elderly. These clinical ratings were correlated with computed tomographic (CT) scan assessments of various superficial cerebral regions as well as with linear measures of ventricular size. Behavioral deficits in activities of daily living (ADL) plus an interactional variable, inability to respond to requests, were correlated with superior temporal and inferior parietal CT abnormalities, particularly on the left side. Suspiciousness and peculiar thinking, mood lability and irritability, as well as impaired memory with confusion, perplexity, and disorientation were also associated with atrophy in these same regions. Prefrontal area defects correlated with mood lability and deficits in visual-interactional responsiveness. Statistically controlling for effects of age and alcohol abuse did not alter the basic nature of these results. Regional cerebral specialization in relation to these results are discussed using concepts developed by Luria.