Explore the vast range of titles available.

PurposeThe A/T/N model is a research framework proposed to investigate Alzheimer’s disease (AD) pathological bases (i.e., amyloidosis A, neurofibrillary tangles T, and neurodegeneration N). The application of this system on clinical populations is still limited. The aim of the study is to evaluate the topography of T distribution by 18F-flortaucipir PET in relation to A and N and to describe the A/T/N status through imaging biomarkers in memory clinic patients.MethodsEighty-one patients with subjective and objective cognitive impairment were classified as A+/A− and N+/N− through amyloid PET and structural MRI. Tau deposition was compared across A/N subgroups at voxel level. T status was defined through a global cut point based on A/N subgroups and subjects were categorized following the A/T/N model.ResultsA+N+ and A+N− subgroups showed higher tau burden compared to A−N− group, with A+N− showing significant deposition limited to the medial and lateral temporal regions. Global cut point discriminated A+N+ and A+N− from A−N− subjects. On A/T/N classification, 23% of patients showed a negative biomarker profile, 58% fell within the Alzheimer’s continuum, and 19% of the sample was characterized by non-AD pathologic change.ConclusionMedial and lateral temporal regions represent a site of significant tau accumulation in A+ subjects and possibly a useful marker of early clinical changes. This is the first study in which the A/T/N model is applied using 18F-flortaucipir PET in a memory clinic population. The majority of patients showed a profile consistent with the Alzheimer’s continuum, while a minor percentage showed a profile suggestive of possible other neurodegenerative diseases. These results support the applicability of the A/T/N model in clinical practice.

Chemotherapy-induced cognitive deficits in patients with breast cancer, predominantly in attention and verbal memory, have been observed in numerous studies. These neuropsychological findings are corroborated by the results of neuroimaging studies. The aim of this paper was to survey the reports on cerebral structural and functional alterations in women with breast cancer treated with chemotherapy (CTx). First, we discuss the host-related and disease-related mechanisms underlying cognitive impairment after CTx. We point out the direct and indirect neurotoxic effect of cytostatics, which may cause: a damage to neurons or glial cells, changes in neurotransmitter levels, deregulation of the immune system and/or cytokine release. Second, we focus on the results of neuroimaging studies on brain structure and function that revealed decreased: density of grey matter, integrity of white matter and volume of multiple brain regions, as well as their lower activation during cognitive task performance. Finally, we concentrate on compensatory mechanisms, which activate additional brain areas or neural connection to reach the premorbid cognitive efficiency.

Patients with early Alzheimer’s disease (AD) have difficulty in learning new information and in detecting novel stimuli. The underlying physiological mechanisms are not well known. We investigated the electrophysiological correlates of the early (< 400 ms), automatic phase of novelty detection and encoding in AD. We used high-density EEG Queryin patients with early AD and healthy age-matched controls who performed a continuous recognition task (CRT) involving new stimuli (New), thought to provoke novelty detection and encoding, which were then repeated up to 4 consecutive times to produce over-familiarity with the stimuli. Stimuli then reappeared after 9–15 intervening items (N-back) to be re-encoded. AD patients had substantial difficulty in detecting novel stimuli and recognizing repeated ones. Main evoked potential differences between repeated and new stimuli emerged at 180–260 ms: neural source estimations in controls revealed more extended MTL activation for N-back stimuli and anterior temporal lobe activations for New stimuli compared to highly familiar repetitions. In contrast, AD patients exhibited no activation differences between the three stimulus types. In direct comparison, healthy subjects had significantly stronger MTL activation in response to New and N-back stimuli than AD patients. These results point to abnormally weak early MTL activity as a correlate of deficient novelty detection and encoding in early AD.

The recent studies in patients with chronic pain indicate that opioids have an ambiguous influence on cognitive and psychomotor functions. The aim of the study was to evaluate cognitive functioning of the patients with chronic pain treated with nonsteroidal anti-inflammatory drugs, in whom a single short-acting morphine dose was administered. The patients (n = 8) were orally supplied with a single dose of 10 or 20 mg morphine. The control group included patients (n = 9) with chronic pain who were still being treated with NSAIDs. In the patients examined, the pain intensity was evaluated with the use of the numerical rate scale (NRS), symptoms of depression and anxiety were evaluated with the use of the Hospital Anxiety and Depression Scale - HADS, and general mental state with the use of the Mini-Mental State Examination (MMSE). The neuropsychological examination was carried out by means of the Trial-Making Test A and B, the Stroop Test and the examination of eye movements. In the patients treated with morphine, tests were conducted before and 45 minutes after the application of the drug. In the first group, after 1 hour since the morphine application pain intensity lowered significantly (p = 0.016), the duration of part A of the TMT-A Test (p = 0.079) was shortened and the duration of the second part of the Stroop Test increased. The average latention time increased and the maximal saccade speed was lowered. The remaining cognitive parameters did not change after the drug application. Morphine applied orally influences the reduction of pain intensity, not significantly deteriorating the cognitive parameters evaluated with the Stroop Tests and the Trial Making Test B (TMT-B). It was also shown that morphine influences the improvement of psycho-motor parameters evaluated with the TMT-A test. These research studies also proved the influence of morphine on some complex sensor-motor processes in the saccadometric examination.