Cognitive correlates of diffuse cerebral atrophy determined by computed tomography

Practical one-dimensional measurements of age-related brain atrophy are validated by 3-dimensional values and clinical outcomes: a retrospective study

Background

Age-related brain atrophy has been represented by simple 1-dimensional (1-D) measurements on computed tomography (CT) for several decades and, more recently, with 3-dimensional (3-D) analysis, using brain volume (BV) and cerebrospinal fluid volume (CSFV). We aimed to show that simple 1-D measurements would be associated with 3-D values of age-related atrophy and that they would be related to post-traumatic intracranial hemorrhage (ICH).

Methods

Patients ≥60 years with head trauma were classified with central atrophy (lateral ventricular body width >30 mm) and/or cortical atrophy (sulcus width ≥2.5 mm). Composite atrophy was the presence of central or cortical atrophy. BV and CSFV were computed using a Siemens Syngo workstation (VE60A).

Results

Of 177 patients, traits were age 78.3 ± 10, ICH 32.2 %, central atrophy 39.5 %, cortical atrophy 31.1 %, composite atrophy 49.2 %, BV 1,156 ± 198 mL, and CSFV 102.5 ± 63 mL. CSFV was greater with central atrophy (134.4 mL), than without (81.7 mL, p < 0.001). BV was lower with cortical atrophy (1,034 mL), than without (1,211 mL; p < 0.001). BV was lower with composite atrophy (1,103 mL), than without (1,208 mL; p < 0.001). CSFV was greater with composite atrophy (129.1 mL), than without (76.8 mL, p < 0.001). CSFV÷BV was greater with composite atrophy (12.3 %), than without (6.7 %, p < 0.001). Age was greater with composite atrophy (80.4 years), than without (76.3, p = 0.006). Age had an inverse correlation with BV (p < 0.001) and a direct correlation with CSFV (p = 0.0002) and CSFV÷BV (p < 0.001). ICH was greater with composite atrophy (49.4 %), than without (15.6 %; p < 0.001; odds ratio = 5.3). BV was lower with ICH (1,089 mL), than without (1,188 mL; p = 0.002). CSFV÷BV was greater with ICH (11.1 %), than without (8.7 %, p = 0.02). ICH was independently associated with central atrophy (p = 0.001) and cortical atrophy (p = 0.003).

Conclusions

Simple 1-D measurements of age-related brain atrophy are associated with 3-D values. Clinical validity of these methods is also supported by their association with post-injury ICH. Intracranial 3-D software is not available on many CT scanners and can be cumbersome, when available. Simple 1-D measurements, using the study methodology, are a practical method to objectify the presence of age-related brain atrophy.

Brain atrophy and white-matter hyperintensities are not significantly associated with incidence and severity of postoperative delirium in older persons without dementia

Postoperative delirium is a common complication in older people and is associated with increased mortality, morbidity, institutionalization, and caregiver burden. Although delirium is an acute confusional state characterized by global impairments in attention and cognition, it has been implicated in permanent cognitive impairment and dementia. The pathogenesis of delirium and the mechanisms leading to these disabling consequences remain unclear. The present study is the first to address the potential predisposing role of brain morphologic changes toward postoperative delirium in a large prospective cohort of patients undergoing elective surgery using state-of-the-art magnetic resonance imaging (MRI) techniques conducted before admission. We investigated the association of MRI-derived quantitative measures of white-matter damage, global brain, and hippocampal volume with the incidence and severity of delirium. Presurgical white-matter hyperintensities (WMHs), whole brain, and hippocampal volume were measured in 146 consecutively enrolled subjects, ≥70 years old, without dementia who were undergoing elective surgery. These 3 presurgical MRI indices were tested as predictors of incidence and severity of subsequent delirium. Out of 146 subjects, 32 (22%) developed delirium. We found no statistically significant differences in WMH, whole brain, or hippocampal volume between subjects with and without delirium. Both unadjusted and adjusted (age, gender, vascular comorbidity, and general cognitive performance) regression analyses demonstrated no statistically significant association between any of the MRI measures with respect to delirium incidence or severity. In persons without dementia, preexisting cerebral WMHs, general and hippocampal atrophy may not predispose to postoperative delirium or worsen its severity.

The use of 'dementia care mapping' as a method of evaluating care received by patients with dementia--an initiative to improve quality of life

'Dementia care mapping' (DCM) is a method of assessing care standards as received by dementia victims. Through the application of this tool, short-comings in care practice can be highlighted in the hope of achieving improvements. The method was employed by the Elderly Mentally III (EMI) unit of a National Health Service trust in South Wales. Baseline evaluations were undertaken on each of the EMI wards containing dementia patients, and reports delivered to the appropriate members of staff. Mean care scores for the unit as a whole were found to lie in the "good' category, as defined by the method. Staff training in the underlying principles of DCM will be followed by re-evaluations of care standards to evaluate the outcome of the attempts made to engender improvements.

Effect of advanced brain atrophy and vitamin deficiency on cognitive functions in non-demented subjects

The relationship between the cognitive functions, structural changes of the brain and vitamin levels was evaluated in 36 non-demented subjects with advanced brain atrophy, and 57 age- and sex-matched healthy controls. In the control subjects ageing was associated with mild decline of cognitive skills, but the cognitive changes were not linked to the structural changes of the brain. In contrast, advanced brain atrophy and vitamin deficiency was related to the decline of complex cognitive functions in the atrophy group. Our results indicate that there are limits of normal age-related changes of the brain structure, and advanced brain atrophy on CT scans increase the probability of mild deficits of the cognitive skills.

The use of positron emission tomography in the clinical assessment of dementia

A number of reasons can be cited for performing a test that identifies patients early in their course who have fatal and currently untreatable neurological disorders. At this stage of illness there is clinical ambiguity. The patient, family, and physician are typically faced with a battery of negative test results and an ambiguous clinical impression that can lead to periodic repetition of tests that involve cost, inconvenience, potential morbidity to the patient, and lack of definitive diagnosis. An accurate test would lead to the avoidance of these low-yield, repetitive, and costly evaluations. In addition, such studies can identify homogeneous groups of individuals with degenerative disorders leading to dementia who could be enrolled in experimental therapeutic programs. In these programs therapies could be monitored in an objective and noninvasive fashion using positron emission tomography (PET). The magnitude of the health problems resulting from the dementing illnesses is great in terms of medical practice, economics, and family hardship. The number of individuals with these disorders is predicted to increase dramatically in the future. The ability to provide an accurate diagnosis and more clear prognosis early in the disease course should diminish ambiguity for patients, families, and physicians. Ample evidence is cited in this article to show that PET has the ability to provide such information objectively and noninvasively.

An evaluation of cranial CT scanning in clinical psychiatry

From 6,300 psychiatric admissions over a 37 month period, all 54 patient referrals for CT were identified and their charts reviewed. CT influenced diagnosis, management or prognosis in 11.7 percent of patients scanned. There was poor correlation between organicity on CT scan and findings on physical examination, laboratory testing, EEG and psychological testing. The mental state examination was the single significant correlate of CT abnormality. We suggest that the use of a formalised mental state examination such as the Mini Mental State, in addition to the usual clinical assessment of mental state, may improve the accuracy of prediction of abnormality on CT scan. The introduction of X-ray computed tomography (CT) is recognised to be one of the most important innovations in the recent history of clinical medicine. In neurology the value of a non-invasive technique for examining the intracranial contents was quickly realised in the areas of diagnosis, particularly in the detection of vascular accidents and tumours. CT has also attained a significant place in psychiatry. In research studies, it has provided important information on schizophrenia, alcoholism and chronic organic reactions. The place of CT in clinical psychiatry is less clear. As its availability has increased, such scans are being requested with increasing frequency in psychiatric patients. Cranial CT is a highly sensitive diagnostic procedure which, when used unselectively, may result in the discovery of incidental findings. Until recently, a function of the psychiatrist in relation to diagnosis was to first seek to distinguish symptoms produced by organic pathology from those produced by functional illness.(ABSTRACT TRUNCATED AT 250 WORDS)

Computerized tomography findings among workers with chronic intoxication of the brain

Among the subjects classified as possibly or definitely demented 60% had suspected or definitely cerebral atrophy on CTs. Among the subjects classified as definitely demented 42% had definite cerebral atrophy. None of the referents had definite atrophy on CT. Regional cerebral blood flow was significantly decreased among subjects with cerebral atrophy. Some group overlap was evident as 12 subjects classified as definitely demented had normal CTs. This overlap showed that the absence of cerebral atrophy did not exclude the presence of dementia. On the other side, cerebral atrophy should not be found by a mere coincidence among persons under the age of sixty but indicates the presence of dementia.

Computed tomography brain changes in parkinsonian dementia

In order to evaluate the relationship between brain atrophy and the motor and cognitive function in Parkinson's disease, we have evaluated CT changes in 132 consecutive patients and compared them to measures of physical and mental decline, using intercorrelations and variance analysis. The result demonstrated age as a most important factor relating to brain atrophy. After correction for this determinant, it became clear that the motor and cognitive parameters were interdependent but they affected similar CT parameters. The effect of motor decline was the stronger of the two and it was the only one which correlated with cortical atrophy. The results support the notion of subcortical changes underlying the dementia of Parkinson's disease.

Ventricle size, cortical atrophy and the relationship with neuropsychological status in closed head injury: a quantitative analysis

Forty-eight patients with a history of moderate to severe closed-head injury (CHI) were examined with neuropsychological measures and computerized tomography (CT). CT scans were assessed with computerized techniques to determine estimated ventricular volumes (VV) and the degree of cortical atrophy (ATVOL) in each patient. VV's then were used to determine volumetric ventricle-brain ratios (VBR) to correct for head size. The WAIS, Wechsler Memory Scale (WMS) and Halstead-Reitan Neuropsychological Test Battery (HRNTB) were administered to all patients. Correlational analyses were undertaken between VBR and ATVOL measures. PIQ but not VIQ was negatively correlated with VBR and ATVOL, particularly in terms of right-hemisphere measures. WMS Memory Quotient (MQ) also was negatively correlated with VBR and ATVOL with no lateralization. Several HRNTB measures similarly were correlated with ventricular and atrophy estimates. Correlational results also were analyzed in terms of the influence of higher and lower VBR and ATVOL, and the prior presence of hematoma. Results are discussed in terms of the latent effects of cerebral damage secondary to CHI on neuropsychological functioning.

Cerebral blood flow and brain atrophy correlated by xenon contrast CT scanning

Correlations between cerebral blood flow (CBF) measured during stable xenon contrast CT scanning and standard CT indices of brain atrophy were investigated in the patients with senile dementia of Alzheimer type, multi-infarct dementia and idiopathic Parkinson's disease. Compared to age-matched normal volunteers, significant correlations were found in patients with idiopathic Parkinson's disease between cortical and subcortical gray matter blood flow and brain atrophy estimated by the ventricular body ratio, and mild to moderate brain atrophy were correlated with stepwise CBF reductions. However, in patients with senile dementia of Alzheimer type and multi-infarct dementia, brain atrophy was not associated with stepwise CBF reductions. Overall correlations between brain atrophy and reduced CBF were weak. Mild degrees of brain atrophy are not always associated with reduced CBF.

Examining the relationship between computed tomography and neuropsychological measures in normal and demented elderly

Correlational analysis of CT and neuropsychological measures in patients with dementia revealed more predictive relationships in degenerative and vascular subgroups that in a multi-aetiology group. Normal and dementia patients were then matched for age, sex and educational background, and analysed together. The ventricular/brain ratios of the bodies of the lateral ventricles and of the third ventricle correlated most highly with neuropsychologic performance. Canonical analysis revealed a correlation coefficient of 0.725 between the sets of CT and neuropsychological measures, which increased to 0.78 when a degenerative subgroup only was considered. Discriminant function analysis indicated that the combination of CT and neuropsychological measures was more powerful in discriminating normals from dementia patients than CT or neuropsychological measures alone.

Peripheral neuropathy, cerebral atrophy, and intellectual impairment in chronic alcoholics

Peripheral neuropathy, cerebral atrophy, and intellectual impairment was investigated in 46 males with alcoholic nervous system damage. An overall correlation was found between peripheral neuropathy and cerebral atrophy and between several of the individual neurophysiological and neuroradiological variables examined. There was also a correlation between cerebral atrophy and intellectual impairment. The findings support the view that alcohol in itself is toxic to central and peripheral nervous tissues, although a dose-response dependence could not be established.

Neuropsychological evaluation in transient ischaemic attack and minor stroke

Two groups of patients with transient ischaemic attack and minor stroke without detectable haemodynamic stenotic lesions were evaluated by neuropsychological tests and compared with a control group. The mean values of the scores adjusted for age and educational background demonstrated that the patients with transient ischaemic attack did not have a worse performance than normal subjects in any of the tests, the patients with minor stroke had a worse performance than normals, particularly in Rey's figure-copying test (P less than 0.025), and the latter test was not affected by educational background or age of the subjects. The results are discussed with reference to other case series, and the importance of age and cerebral damage in causing intellectual impairment evaluated by neurophysiological tests is stressed.

Measurement of the area of the anterior horn of the right lateral ventricle for the diagnosis of brain atrophy by CT. Correlation with several ventricular indices

The area of the anterior horn of the right lateral ventricle and five ventricular indices: (1) maximum width of the anterior horns, (2) minimum width of the anterior horns, (3) sum of these maximum and minimum widths, (4) ventricular index, and (5) cella media index were measured from the CT scans of 198 cases considered to be "normal". The area of the right anterior horn and indices 1-4 were measured on the slice which most clearly showed Monro's foramina and index 5 was measured on the slice 2 cm above. The size of the ventricular system increased steadily with age. The sum of the maximum and minimum widths of the anterior horns was most highly correlated with the area of the right anterior horn. Using this ventricular index, we graded brain "atrophy" in each age group.

Cerebral atrophy in motor neuron disease evaluated by computed tomography

Thirty-two (64%) of 50 patients with motor neuron disease showed various patterns of cerebral atrophy (cortical, ventricular or both) at CT examination. The incidence of cerebral atrophy, particularly cortical atrophy, in motor neuron disease was greater than in a matched control group.

Relation between central cerebral atrophy, memory defects and prolactin secretion

Concentrations of prolactin in cerebrospinal fluid (CSF) and in serum were determined from 26 neurological patients with or without minor central cerebral atrophy. Neuropsychological memory tests also were performed on these patients. Twenty-eight neurological patients with peripheral nervous lesions and without endocrine dysfunctions served as controls for prolactin levels. Patients with central cerebral atrophy had significant loss of recall capacity, though they did not differ significantly from the normal population in their intellectual performances. CSF and serum prolactin levels in the patients with central cerebral atrophy and/or memory defects did not differ from the values obtained in the patients without cerebral atrophy. Thus, prolactin levels do not appear to reflect either central cerebral atrophy or memory dysfunctions, most likely due to the minor degree of neuronal atrophy around the third ventricle that occurs in patients with these findings.