Malignant Astrocytomas

Abstract

Objective: To determine whether amyloid deposition is associated with impaired neuropsychological (NP) performance and whether cognitive reserve (CR) modifies this association. Methods: In 66 normal elderly controls and 17 patients with Alzheimer disease (AD), we related brain retention of Pittsburgh Compound B (PiB) to NP performance and evaluated the impact of CR using education and American National Adult Reading Test intelligence quotient as proposed proxies. Results: We found in the combined sample of subjects that PiB retention in the precuneus was inversely related to NP performance, especially in tests of memory function, but also in tests of working memory, semantic processing, language, and visuospatial perception. CR significantly modified the relationship, such that at progressively higher levels of CR, increased amyloid deposition was less or not at all associated with poorer neuropsychological performance. In a subsample of normal controls, both the main effect of amyloid deposition of worse memory performance and the interaction with CR were replicated using a particularly challenging memory test. Interpretation: Amyloid deposition is associated with lower cognitive performance both in AD patients and in the normal elderly, but the association is modified by CR, suggesting that CR may be protective against amyloidrelated cognitive impairment.

Instrumental Activities of Daily Living Impairment Is Associated with Increased Amyloid Burden

“…Specifically, global PiB retention was associated with IADL impairment in this mildly impaired group of subjects. This finding is in agreement with another study where the CDR, in which 3 of 6 items rate activities of daily living, was associated with PiB retention across a sample of NC, MCI, and various dementia subjects [7], as well as another study where CDR sum of boxes was related to PiB retention in a sample that included NC and AD subjects [15]. These two studies did not control for global cognitive impairment or memory impairment, as was done in the current study for the entire sample.…”

“…Thus, the results of the current analyses appear to be driven by the MCI subgroup. However, this observation should be interpreted in the context of published findings [15] in the normal elderly relating amyloid deposition to memory performance, particularly in difficult list-learning tasks. It is possible that the measure of IADL used in the current study (FAQ) is insufficiently sensitive to milder forms of functional difficulty and that a more sensitive measure would be more revealing in cognitively normal subjects.…”

“…Although there was no significant correlation between age and FAQ, age was included in the model because of the previously described association between advancing age and greater PiB retention [19,37]. Similarly, AMNART IQ, which did not significantly correlate with FAQ, was included in the model because of a previously described effect of cognitive reserve on PiB retention [15]. …”

“…Several studies have shown an association between increased PiB retention and reduced cognitive performance, especially memory impairment, across a range of subjects with normal cognition, MCI, and AD [13,14,15]. Another study found that the Clinical Dementia Rating (CDR) scale [16], which is highly dependent on activities of daily living, was correlated with PiB retention across subjects with different dementias [7].…”

Age at onset and clinical presentation of urolithiasis in Ajman, UAE

“…Urolithiasis is an increasing problem in the United Arab Emirates (UAE). Renal calculosis has become very frequent in the affluent countries of Arabian Gulf like the UAE, Kuwait and Saudi Arabia, probably because of change in life style (9)(10). Men are twice as likely as women to develop calculi, with the first episode occurring at an average age of 30 years.…”