A normal development of the central nervous system is an essential process
to a healthy the adult brain. After birth, some brain areas are still maturating and, even
in the adulthood, the brain networks are in constant reorganization. The physiological
and morphological changes that occur during nervous system maturation can be the key
to the insurgence of neurodegenerative diseases such Alzheimer’s disease (AD). AD is
the most common cause of severe cognitive decline in elderly. The set of neuronal
morphological changes presented even before clinical symptoms onset is strongly
correlated with future cognitive impairments. However, it is not clear yet which
morphofunctional features are more accurate to distinguish the healthy and the
abnormal brain as well as its future susceptibility in developing AD. In this chapter, we
described the neuroanatomic aspects of AD. Specifically, we focused on the
progression of affected areas throughout AD stages and on the selective aspects that
make several neuronal populations and brain areas more vulnerable to pathological
changes. External and internal factors that might influence morphological features are
also addressed. While intrinsic characteristics such as myelination and pigmentation
could help to predict the pattern of anatomic advance of AD, on the other hand,
cognitive reserve is an example of how external input and lifestyle can delay the
appearance of clinical symptoms even when morphologic changes are already
pronounced. The early diagnosis and staging are fundamental steps to provide
information for more specific therapeutic approaches. Ultimately, some of the advances
and techniques for this challenging diagnosis are also detailed.
Keywords: AD diagnosis, AD stages, Cognitive reserve, Dementia, Elderly,
Entorhinal cortex, Medial temporal lobe, Myelination, Neurodegeneration,
Neuronal susceptibility, Pigmentation.
