Analyse neuropsychologischer Ausfallprofile bei zerebraler Mikroangiopathie

Abstract

Introduction As the population gets older dementia as a disease of the elderly has to be faced more often. After Alzheimer's dementia (AD) cerebral small vessel disease (CSVD) is the most frequent cause of cognitive deficits. Typically it affects subcortical neuropsychological abilities such as executive functions (goal oriented actions) and visuomotor speed caused by a lack of blood perfusion of the white matter which can be seen as white matter lesions (WML) in MRT. A combination of WML and certain findings in the cerebral spinal fluid (CSF) which indicate towards AD are quite common and result in the term mixed dementia (MD, here CSVD+). Due to the great variability of neuropsychological deficits in patients with CSVD a differential diagnosis based on clinical findings is rather difficult. Aim / Methods This study seeks after further knowledge about neuropsychological deficits and options for differential diagnosis in the dementias mentioned above. We assessed 89 patients with white matter lesions in MRT with a combination of different neuropsychological tests (MMSE, CAMCOG, CLOX, Trailmaking, Boston Naming Test) and gained a sample of CSF. The MRT was evaluated using the Scale for Age-Related White Matter Lesions (ARWMC). By the results in MMSE (&lt;/≥ 28 points) we divided the cohort into healthy (controll group, n = 37 patients) and neuropsychological affected patients. After that we assigned the later into either group 1 CSVD (n = 22 patients) or group 2 CSVD+ (n = 29 patients) by using the CSF results (Aβ-ratio(Aβ1-40/Aβ1-42) and/or Aβ1-42) indicating towards AD (group 2) or not (group 1). With the the CAMCOG-ratio (Memory/Executive functions) we tried to examine a new advance in discrimating patients with CSVD vs. CSVD+. Furthermore possible factors affecting the cognition such as age, duration of education, white matter lesions (as in ARWMC) and gender were assessed. Results CSVD/CSVD+ vs. controls differed significantly in age and duration of education. CSVD vs. CSVD+ differed only in MMSE (p = 0.044). There were no no significant differences concerning the amount of WML. Both groups (CSVD and CSVD+) showed cognitive impairment and significantly lower results than controls in any of the neuropsychological tests. Still even in controls several patients showed pathological results. In CSVD vs. CSVD+ only Clox1 (p = 0.033) and CAMCOG-ratio showed significant differences. With a cutoff at <1.18 the later was able to detect AD in addition to CSVD with a sensitivity of 61% and specificity of 81%. The examination of possible factors affecting cognition age showed to have the biggest negative effect. Regarding the entire cohort duration of education showed significant correlation aswell, whereas gender and the amount of WML didn't. When used by patients with cognitive deficits the CAMCOG-ratio wasn't affected by any of the factors evaluated. Conclusion As expected cognitive deficits could be measured in both groups (CSVD, CSVD+) with lower results in those patients affected by CSVD and AD. However only one of the well-established neuropsychological tests showed significant differences which shows the difficulty in differential diagnosis of pure CSVD vs. CSVD+ by clinical assessement. Concerning this question the new CAMCOG-ratio seems to be a useful tool, which is not affected by any of the factors examined in this study. Age showed to be the biggest factor affecting cognition in the patients included in this study. While duration of education had an certain effect aswell, gender and even the amount of white matter lesions showed no clear correlations. Regarding some pathological test results in control group (MMSE ≥ 28 points) it has to be mentioned that MMSE itself seems to be insufficient in excluding cognitive deficits in patients with white matter lesions.