Functional Neural Correlates of the WAIS-IV Block Design Test in Older Adult with Mild Cognitive Impairment and Alzheimer's Disease

The Wechsler Adult intelligence scale-Revised (WAIS-R) Block design test (BDT) is a neuropsychological test widely used to assess cognitive declines in aging population. Previous studies suggest parietal lobe is the key region to influence the performance on the BDT; yet, it has not been clearly identified. The aim of the current study, therefore, is to identify the functional neural correlates of the BDT in older adults with mild cognitive impairment (MCI) and Alzheimer's disease (AD) dementia patients. The current study includes 213 cognitively impaired mid to old-aged community dwelling Korean. All participants underwent comprehensive clinical and neuropsychological assessments and 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) scans. Performance on the BDT was assessed using the WAIS-IV Korean version. Voxel-wise analyses were used to investigate the correlation between regional cerebral glucose metabolism and BDT performance. The same analyses were conducted on the subgroups categorized by clinical severity based on the Clinical Dementia Rating (CDR). Significant positive correlations between performance on the BDT and regional cerebral glucose metabolism were found bilaterally in the inferior parietal lobules, right thalamus and right middle frontal gyrus. Our results suggest that performance on the BDT in MCI and AD patients functionally relies on the brain regions known to be associated with motor and executive functions in addition to visuospatial function.

Interactive Block Games for Assessing Children's Cognitive Skills: Design and Preliminary Evaluation

Background: This paper presents design and results from preliminary evaluation of Tangible Geometric Games (TAG-Games) for cognitive assessment in young children. The TAG-Games technology employs a set of sensor-integrated cube blocks, called SIG-Blocks, and graphical user interfaces for test administration and real-time performance monitoring. TAG-Games were administered to children from 4 to 8 years of age for evaluating preliminary efficacy of this new technology-based approach. Methods: Five different sets of SIG-Blocks comprised of geometric shapes, segmented human faces, segmented animal faces, emoticons, and colors, were used for three types of TAG-Games, including Assembly, Shape Matching, and Sequence Memory. Computational task difficulty measures were defined for each game and used to generate items with varying difficulty. For preliminary evaluation, TAG-Games were tested on 40 children. To explore the clinical utility of the information assessed by TAG-Games, three subtests of the age-appropriate Wechsler tests (i.e., Block Design, Matrix Reasoning, and Picture Concept) were also administered. Results: Internal consistency of TAG-Games was evaluated by the split-half reliability test. Weak to moderate correlations between Assembly and Block Design, Shape Matching and Matrix Reasoning, and Sequence Memory and Picture Concept were found. The computational measure of task complexity for each TAG-Game showed a significant correlation with participants' performance. In addition, age-correlations on TAG-Game scores were found, implying its potential use for assessing children's cognitive skills autonomously.

Can Lactobacillus acidophilus improve minimal hepatic encephalopathy? A neurometabolite study using magnetic resonance spectroscopy

BACKGROUND AND STUDY AIMS

Minimal hepatic encephalopathy (MHE) is diagnosed when hepatic patients perform worse on psychometric tests compared to healthy controls. This study aimed to evaluate probiotics as alternative therapy in MHE.

PATIENTS AND METHODS

This is an open-label randomised controlled trial, performed in the Department of Tropical Medicine and Infectious Diseases, Tanta University Hospitals, from March 2010 to January 2012. A total of 90 patients with MHE were allocated by simple randomisation to three parallel equal groups. Group A received lactulose, group B a probiotic (Lactobacillus acidophilus) and group C served as the control. After informed consent, patients were tested for gut micrecology, fasting blood ammonia, liver functions and magnetic resonance spectroscopy (MRS) examination to study brain metabolites, mainly choline (Cho), myo-inositol (mI), glutamine+glutamate (Glx) and creatinin (Cre). Patients who developed overt encephalopathy were excluded from analysis. The whole battery of investigations was repeated in the same order after 4weeks.

RESULTS

The probiotic was better tolerated than lactulose. The relative risk reduction (RRR) of developing overt encephalopathy was 60% in the case of lactulose and 80% in the case of probiotic, with a number needed to treat (NNT) of 2.4 and 2.3, respectively. The differential but not total microecology count was significantly shifted towards saccharolytic rather than proteolytic bacteria. The mI/Cre and (Cho+mI)/Glx ratios were significantly increased and the Glx/Cre ratio was significantly reduced after 1month-follow-up in the probiotic group compared to the lactulose group and in both treatment groups compared to the control group.

CONCLUSION

Both probiotic and lactulose therapy can improve blood ammonia and psychometric tests in MHE and reduce the risk of developing overt encephalopathy. MRS showed more improvement in the levels of brain neurometabolites in the probiotic group.

Differential impact of hyponatremia and hepatic encephalopathy on health-related quality of life and brain metabolite abnormalities in cirrhosis

BACKGROUND & AIMS

Hyponatremia (HN) and hepatic encephalopathy (HE) together can impair health-related quality of life (HRQOL) and cognition in cirrhosis. We aimed at studying the effect of hyponatremia on cognition, HRQOL, and brain MR spectroscopy (MRS) independent of HE.

METHODS

Four cirrhotic groups (no HE/HN, HE alone, HN alone (sodium <130 mEq/L), HE+HN) underwent cognitive testing, HRQOL using Sickness Impact Profile (SIP: higher score is worse; has psychosocial and physical sub-scores) and brain MRS (myoinositol (mI) and glutamate+glutamine (Glx)), which were compared across groups. A subset underwent HRQOL testing before/after diuretic withdrawal.

RESULTS

82 cirrhotics (30 no HE/HN, 25 HE, 17 HE+HN, and 10 HN, MELD 12, 63% hepatitis C) were included. Cirrhotics with HN alone and without HE/HN had better cognition compared to HE groups (median abnormal tests no-HE/HN: 3, HN: 3.5, HE: 6.5, HE+HN: 7, p=0.008). Despite better cognition, HN only patients had worse HRQOL in total and psychosocial SIP while both HN groups (with/without HE) had a significantly worse physical SIP (p<0.0001, all comparisons). Brain MRS showed the lowest Glx in HN and the highest in HE groups (p<0.02). mI levels were comparably decreased in the three affected (HE, HE+HN, and HN) groups compared to no HE/HN and were associated with poor HRQOL. Six HE+HN cirrhotics underwent diuretic withdrawal which improved serum sodium and total/psychosocial SIP scores.

CONCLUSIONS

Hyponatremic cirrhotics without HE have poor HRQOL despite better cognition than those with concomitant HE. Glx levels were lowest in HN without HE but mI was similar across affected groups. HRQOL improved after diuretic withdrawal. Hyponatremia has a complex, non-linear relationship with brain Glx and mI, cognition and HRQOL.