White Matter Deterioration May Foreshadow Impairment of Emotional Valence Determination in Early-Stage Dementia of the Alzheimer Type

In Alzheimer Disease (AD), non-verbal skills often remain intact for far longer than verbally mediated processes. Four (1 female, 3 males) participants with early-stage Clinically Diagnosed Dementia of the Alzheimer Type (CDDAT) and eight neurotypicals (NTs; 4 females, 4 males) completed the emotional valence determination test (EVDT) while undergoing BOLD functional magnetic resonance imaging (fMRI). We expected CDDAT participants to perform just as well as NTs on the EVDT, and to display increased activity within the bilateral amygdala and right anterior cingulate cortex (r-ACC). We hypothesized that such activity would reflect an increased reliance on these structures to compensate for on-going neuronal loss in frontoparietal regions due to the disease. We used diffusion tensor imaging (DTI) to determine if white matter (WM) damage had occurred in frontoparietal regions as well. CDDAT participants had similar behavioral performance and no differences were observed in brain activity or connectivity patterns within the amygdalae or r-ACC. Decreased fractional anisotropy (FA) values were noted, however, for the bilateral superior longitudinal fasciculi and posterior cingulate cortex (PCC). We interpret these findings to suggest that emotional valence determination and non-verbal skill sets are largely intact at this stage of the disease, but signs foreshadowing future decline were revealed by possible WM deterioration. Understanding how non-verbal skill sets are altered, while remaining largely intact, offers new insights into how non-verbal communication may be more successfully implemented in the care of AD patients and highlights the potential role of DTI as a presymptomatic biomarker

The illiterate brain and the neuropsychological assessment: From the past knowledge to the future new instruments

The lifetime learning of illiterate and low-educated individuals shapes their cognitive skills, which are challenging to grade by the current available neuropsychological tools. Eight hundred million of the global population are illiterate. It is very challenging to interpret the cognitive performance of this population by the available formal neuropsychological tests, mainly developed for higher educated people. From extensive literature investigation, we reviewed the cognitive process and performance of illiterate and low-educated population on various cognitive domains including language, executive function, memory, visual-related function, and motor skills. We also suggested the concept in the development of the appropriate tools for the cognitive assessment among this population. Finally, we provide the available cognitive screening tools validated in the illiterate and low-educated subjects within the last three decades

Validity of the Clinical Dementia Rating Scale Sum of Boxes in Staging and Detection of Cognitive Impairment in Mexican Americans

Objective:We evaluated the utility of the Clinical Dementia Rating Sum of Boxes score (CDR-SB) in staging and detecting amnestic-mild cognitive impairment (a-MCI) and Alzheimer’s disease (AD) among Mexican Americans.Methods:Receiver operator curves were generated to evaluate the validity of the CDR-SB in staging and detecting a-MCI and AD in 1,073 Mexican Americans (758 controls, 163 a-MCI, and 152 AD).Results:Optimal ranges of the CDR-SB were 0, 0.5-4, 4.5-8.0, 8.5-13 and 13.5-18 for staging the global CDR score of 0, 0.5, 1, 2, and 3, respectively. The CDR-SB ≥ 0.5 differentiated the a-MCI patients from the controls (sensitivity 100% and specificity 99.5%) and ≥ 2.0 distinguished the AD from a-MCI patients (sensitivity 83.6% and specificity 87.1%). These cutoffs were also appropriate for patients with ≤6 years of education.Conclusion:The CDR-SB is useful to detect and stage a-MCI and AD in Mexican Americans with diverse education levels.</jats:sec

Psychosis

PURPOSE OF REVIEW: Psychosis can manifest in primary psychotic disorders, neurologic diseases, and medical conditions. This article reviews the definition of psychotic symptoms and the evaluation and management of psychosis in primary psychiatric and neurologic disorders frequently seen in neurologic practice. RECENT FINDINGS: Emerging evidence supports significant connections between psychosis and structural and functional brain changes in both primary psychotic and neurologic disorders. In addition to antidopaminergic activity, the mechanism of new-generation antipsychotics shifts to act on serotonin receptors, which potentially contributes to their benefits in the treatment of negative symptoms of psychosis and a lesser frequency of extrapyramidal side effects compared with typical antipsychotics. This is also helpful in the treatment of psychosis in patients who have neurodegenerative diseases and are vulnerable to developing extrapyramidal side effects from typical antipsychotics. SUMMARY: Even with significant overlap, management of psychosis in primary psychotic disorders differs from the approach of psychosis in neurologic diseases. This article helps clinicians learn how to practically evaluate psychosis from both psychiatric and neurologic perspectives

Validity of the Clinical Dementia Rating Scale Sum of Boxes in Staging and Detection of Cognitive Impairment in Mexican Americans

OBJECTIVE: We evaluated the utility of the Clinical Dementia Rating Sum of Boxes score (CDR-SB) in staging and detecting amnestic-mild cognitive impairment (a-MCI) and Alzheimer\u27s disease (AD) among Mexican Americans. METHODS: Receiver operator curves were generated to evaluate the validity of the CDR-SB in staging and detecting a-MCI and AD in 1,073 Mexican Americans (758 controls, 163 a-MCI, and 152 AD). RESULTS: Optimal ranges of the CDR-SB were 0, 0.5-4, 4.5-8.0, 8.5-13 and 13.5-18 for staging the global CDR score of 0, 0.5, 1, 2, and 3, respectively. The CDR-SB ≥ 0.5 differentiated the a-MCI patients from the controls (sensitivity 100% and specificity 99.5%) and ≥ 2.0 distinguished the AD from a-MCI patients (sensitivity 83.6% and specificity 87.1%). These cutoffs were also appropriate for patients with ≤6 years of education. CONCLUSION: The CDR-SB is useful to detect and stage a-MCI and AD in Mexican Americans with diverse education levels