Disorientation as a Sign of Cognitive Decline: the Spatial Memory Deficit is Associated with Pathological Aging

A new study coordinated by the Departments of Psychology and Human Neuroscience has investigated which cognitive processes linked to the ability to orientate in the environment are involved in pathological aging and in some neurodegenerative diseases such as Alzheimer's. The results have been published in the Journal of Alzheimer’s Disease

The difficulty in spatial navigation, that is the ability to orientate in the environment, often represents the first symptom of pathological aging and of some neurodegenerative diseases such as Alzheimer's.

The research team coordinated by Cecilia Guariglia of the Department of Psychology and Carlo de Lena of the Department of Human Neuroscience conducted a cross-sectional study, comparing normal and pathological aging, with the aim of investigating the neuropsychological processes involved in cognitive decline. The results of the research have been published in the Journal of Alzheimer’s Disease.

The study, conducted in collaboration with the Neuropsychology Laboratory of visual-spatial disorders and navigation of the IRCCS Santa Lucia Foundation in Rome, involved 19 healthy individuals and 19 patients diagnosed with Mild Cognitive Impairment (MCI).

MCI is a "mild cognitive impairment" or a clinical condition characterized by a difficulty in one or more cognitive domains (such as memory, attention or language) in individuals with preserved functional autonomy.

In the specific case study 3 among patients with MCI diagnosis showed only a memory deficit (Mild Cognitive Impairment single domain, MCIsd) and 16 a memory deficit associated with deficits in other cognitive domains (Mild Cognitive multi-domain Impairment, MCImd).

All participants completed a memory tests of positions within the peripersonal and navigational space, respectively the space around the body reachable with the hands and where a person arrives with the movement, and a navigation tests in the real environment, in which participants were asked to learn and recall a path and to recognize the points of reference encountered along the route filled with distractors.

"The results show," says Cecilia Guariglia, "that MCIs patients have lower performance in learning positions in the navigational space; moreover these patients show deficient performances in learning pathways in the real environment, although the recognition of the reference points is still intact."

The researchers then analyzed the individual case of MCIsd patients (those who only showed a memory deficit) and identified, in 2 out of 3 cases, a dissociation between learning of positions in the peripersonal and in the navigational's: patients demonstrate difficulties in learning positions in the navigational space, while they behave similarly to healthy individuals in the peripersonal space. This dissociation between the two categories of spatial learning had never been demonstrated in the case of pathological aging.

"The study," concludes Carlo de Lena, "suggests that the memory of positions within the navigational space could be a useful neuropsychological marker for the early diagnosis of pathological aging and for the prompt activation of pharmacological treatments."

References:

Is Losing One’s Way a Sign of Cognitive Decay? Topographical Memory Deficit as an Early Marker of Pathological Aging - Boccia, M., Di Vita, A., Diana, S., Margiotta, R., Imbriano, L., Rendace, L., Campanelli, A., D’Antonio, F., Trebbastoni, A., de Lena, C., Piccardi, L., & Guariglia, C. - Journal of Alzheimer’s Disease 2019 DOI: 10.3233/JAD-180890