Leukoaraiosis, cognitivity and affectivity in elderly patients: on the lack of correlations between neurodiagnostic and psychometric findings

Visual attention capacity after right hemisphere lesions

Recently there has been a growing interest in visual short-term memory (VSTM) including the neural basis of the function. Processing speed, another main aspect of visual attention capacity, has received less investigation. For both cognitive functions human lesion studies are sparse. We used a whole report experiment for estimation of these two parameters in 22 patients with right side stroke. Psychophysical performance was analyzed using Bundesen's [Bundesen, C. (1990). A theory of visual attention. Psychological Review, 97, 523-547] Theory of Visual Attention (TVA) and compared statistically to lesion location and size measured by MRI. Visual processing speed was impaired in the contralesional hemifield for most patients, but typically preserved ipsilesionally, even after large cortico-subcortical lesions. When bilateral deficits in processing speed occurred, they were related to damage in the right middle frontal gyrus or leukoaraiosis. The storage capacity of VSTM was also normal for most patients, but deficits were found after severe leukoaraiosis or large strokes extending deep into white matter. Thus, the study demonstrated the importance of white-matter connectivity for both VSTM capacity and ipsilesional processing speed. The study also showed that lesions in a large region of the right hemisphere, including the putamen, insula, and inferior frontal cortex, do not lead to general deficits in the capacity of visual attention.

Linear measures of temporal lobe atrophy on brain magnetic resonance imaging (MRI) but not visual rating of white matter changes can help discrimination of mild cognitive impairment (MCI) and Alzheimer's disease (AD)

Clinical discrimination of the early stages of AD and MCI is challenging. MRI indices which are simple enough to be applied by non-radiologists on hard copies would be of practical importance in the discrimination. We studied 45 consecutive patients (17 with MCI, 25 with AD, 3 with normal cognitive findings) with at least one white matter lesion (WML) on axial fluid-attenuated inversion recovery (FLAIR) MRI sequences. WML load was evaluated by Fazekas' scoring system; temporal lobe atrophy by interuncal distance (IUD) measurement. WML pattern had no significant discriminative value of AD and MCI. No significant correlation between periventricular/subcortical WML scores and neuropsychological test results was observed. The mean IUD was significantly smaller in patients with MCI compared to those with AD. The cut-off value of IUD was 28.3 mm with receiver operating curve (ROC) analysis. Area under the curve was 0.925 (95% CI: 0.800-0.983). A significant negative correlation between IUD and the mini mental state examination (MMSE), verbal fluency, clock drawing, and Rey Auditory verbal learning test (AVLT) was noted. The results indicate that measurement of IUD is a clinically useful test in discrimination of AD and MCI patients with WML(s) on brain MRI. However, severity of these lesions is not useful for distinctions.

A 4-year follow-up of very old patients presenting with frontal-subcortical dysfunction compared with Alzheimer's disease patients

BACKGROUND

Frontal-subcortical clinical syndrome (FSCS) is frequently described in elderly patients and consists of specific alterations in cognition and motor functions. This clinical picture may be associated with a high level of dependence and a high mortality risk.

OBJECTIVE

We report the risks of institutionalization and death during a follow-up of 4 years in patients showing FSCS.

METHODS

The study was initiated in 1998 to compare FSCS patients showing postural and gait abnormalities with Alzheimer's disease (AD) patients. Follow-up was conducted by means of telephone interviews with the patient's general practitioner over a 4-year period (1998-2002).

RESULTS

Both institutionalization and mortality rates were significantly higher (p < 0.05) in the FSCS group compared to the AD group.

CONCLUSIONS

The high risk of disability and death in FSCS patients suggests that they might require specific care programs that include stimulation in daily living activities in order to reduce the risk of institutionalization and to improve quality of life.

Cardiovascular characteristics and cerebral CT findings in elderly subjects with psychomotor disadaptation syndrome

BACKGROUND AND AIMS

In previous studies, we described a clinical picture typically observed in frail old people, called "Psychomotor Disadaptation Syndrome" (PDS), but we have never studied etiopathogenic data. The aim of this study was to complete the clinical picture, record cardiovascular risk factors and provide cerebral CT scan findings in patients with PDS.

METHODS

73 patients with PDS were recruited in the Geriatric Medicine departments of the University Hospitals of Dijon (Burgundy, France) and Strasbourg (Alsace, France); this group included prospectively all hospitalized patients showing postural and gait abnormalities according to the following criteria: trend towards backward falling and gait pattern alteration characterized by hesitancy in initiation, small steps, and increase in the double support durations. General characteristics, neurological and cardiovascular information were collected for each patient. For the detection of white matter changes (WMC), we used a third-generation CT scanner (GE CT HSA) evaluating a section of 7 mm at each interval of 8 mm.

RESULTS

Neurological examination showed that "reactional hypertonia" was observed in more than 90% of the patients, and that no patient showed normal reactive postural responses. Prior history of hypertension was noted in 49% of the patients, while a current antihypertensive treatment was taken by 13% of the patients. Orthostatic hypotension was observed in 44% of patients. Severe or moderate periventricular lucencies on CT scan were found in 67% of the patients, and severe ventricular enlargement in 50.5% of the patients.

CONCLUSIONS

We advance that PDS might be associated with WMC, and that hypotension might be an important etiologic factor of WMC in causing reduction of the cerebral blood flow in subcortical areas.