Subtle Cognitive Impairment and Alzheimer's Disease-Type Pathological Changes in Cerebrospinal Fluid are Common Among Neurologically Healthy Subjects.

BACKGROUND: The neuropathology of Alzheimer's disease (AD) has previously been shown to be rather common among the elderly. OBJECTIVE: The aim of this study was to inspect the associations between cerebrospinal fluid (CSF) AD biomarker concentrations, age, the APOEɛ4 allele, cardiovascular diseases, diabetes, and cognitive performance in a cohort of a neurologically healthy population. METHODS: This study included 93 subjects (42 men, mean age 67 years) without previous neurological symptoms or subjective cognitive complaints. Their cognition was assessed, and CSF biomarkers and APOEɛ4 status were analyzed. RESULTS: Of the studied subjects, 8.6% (n = 8) had a pathological CSF AD biomarker profile. An increase in age correlated positively with CSF tau pathology and negatively with global cognitive performance. CONCLUSION: AD-type pathological changes in CSF and subtle cognitive impairment are common within a population with no previous memory complaints. Age was the main risk factor for the changes.

Low Cerebrospinal Fluid Amyloid-Beta Concentration Is Associated with Poorer Delayed Memory Recall in Women.

BACKGROUND: Data on the association of memory performance with cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) are inconsistent. The Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery (CERAD-NB) is a commonly used validated cognitive tool; however, only few studies have examined its relationship with CSF biomarkers for AD. We studied the correlation of pathological changes in CSF biomarkers with various CERAD-NB subtests and total scores. METHODS: Out of 79 subjects (36 men, mean age 70.5 years), 63 had undergone an assessment of cognitive status with CERAD-NB and a CSF biomarker analysis due to a suspected memory disorder, and 16 were controls with no memory complaint. RESULTS: In women we found a significant correlation between CSF amyloid-beta (Aß1-42) and several subtests measuring delayed recall. Word List Recall correlated with all markers: Aß1-42 (r = 0.323, p = 0.035), tau (r = -0.304, p = 0.050) and hyperphosphorylated tau (r = -0.331, p = 0.046). No such correlations were found in men. CONCLUSIONS: CSF biomarkers correlate with delayed memory scores in CERAD-NB in women, and women may have more actual AD pathology at the time of the investigations than men.