Features of cerebral atrophy in age-related pathology with cognitive impairment – Alzheimer’s disease and cerebral small vessel disease

Age-related diseases of the nervous system, such as Alzheimer’s disease (AD) and cerebral small vessel disease (cSVD), are characterized by cerebral atrophy. The use of modern neuroimaging techniques determines the possibility of moving from qualitative approaches to atrophy assessment to quantitative ones. Data on the characteristics of cerebral atrophy in vascular pathology of the brain compared to neurodegenerative diseases are limited. The aim of the research is to clarify the differences in regional atrophy in AD and cSVD and the sensitivity of various approaches to its assessment. Material and methods . The study included 45 patients with cSVD (48.9 % women, 51.1 % men, age 64.6 ± 5.7 years, mean ± standard deviation), 26 patients with AD (61.5 % women, 38.5 % men, mean age 66.1 ± 7.9 years), 19 healthy volunteers (68.4 % women, 31.6 % men, age 63.2 ± 4.5 years). The groups were comparable by age and gender. MRI scanning was performed on a Siemens Magnetom Prisma tomograph (Siemens AG, FRG, 3 T). Qualitative assessment of parietal lobe atrophy was performed using the Koedam scale, frontal and occipital lobes – using the global cortical atrophy scale (GCA), hippocampi – using the medial temporal atrophy scale (MTA). For all study participants, the following parameters were calculated: ventriculocranial coefficients for assessing internal cerebrospinal fluid spaces, volumetric indices (gray and white matter volume, white matter hyperintensity, cerebrospinal fluid and total intracranial volume), as well as the thickness of individual areas of the cerebral cortex using the surface morphometry method. Results . Statistically significant differences in the atrophy pattern were revealed: a decrease in the total intracranial volume was noted in AD with a predominant regional decrease in the volume and thickness of the cortex in the temporal and parietal lobes, whereas in cSVD the atrophy affected the anterior parts of the frontal lobes to a greater extent. The minimum thickness of the cortex in cSVD was obtained in the cingulate gyri. Conclusions. The use of volumetric and morphometric methods for the evaluation of MRI images allowed us to identify differences in regional atrophy in AD and cSVD with the detection of special patterns that suggest differences in the mechanisms of development and progression of the studied diseases. The use of various approaches to atrophy assessment may be important in identifying mixed forms of the pathology.