COPENHAGEN—Among patients with mild Alzheimer’s disease, lower scores on the Katz Activities of Daily Living (ADL) scale are associated with lower gray matter volume within extensive portions of the prefrontal cortex, including the anterior cingulate, researchers reported at the 2014 Alzheimer’s Association International Conference.
“The findings suggest that a drop in everyday skills might signal progression of atrophy in the frontal lobes beyond a critical threshold that leads to overt behavioral changes,” stated William J. McGeown, PhD, a lecturer at the School of Psychological Sciences and Health, University of Strathclyde in the United Kingdom.
The researchers analyzed 23 patients with minimal to mild Alzheimer’s disease. Subjects had a mean Mini Mental State Examination score of 22.78, a mean age of 77, and had achieved a mean education of 11.26 years. The investigators assessed the participants with multiple neuropsychologic tests that examined verbal and visuospatial memory, language, attention, executive function, comprehension, and reasoning. Functional ability was measured using an extended version of the Katz ADL scale. Dr. McGeown’s group sought to clarify the relationship between everyday abilities and brain structure and to identify brain regions most strongly related to decline in everyday function.
The mean score on the ADL measure was 22.91, with a range of 12 to 28, according to Dr. McGeown. None of the neuropsychologic assessments was significantly correlated with ADL score.
“Correlations were, however, observed between ADL and level of education, the Geriatric Depression Scale, and the Neuropsychiatric Inventory,” he stated. “Age did not correlate significantly with ADL.”
Dr. McGeown noted that his group’s neuroimaging results partially overlapped with findings reported by Marshall et al in 2006 and by Mioshi et al in 2013, “further highlighting the importance of the prefrontal cortex and anterior cingulate in maintaining functional abilities.
“The correlation of ADL with education suggests that this factor may be illustrative of cognitive reserve and may offer neuroprotection against functional decline,” Dr. McGeown continued. “That functional decline, mood disorders, and other neuropsychiatric symptoms co-occur has implications for patient management.”