Differences in the neural correlates of frontal lobe tests

Diagnostic performance and neural basis of the combination of free- and pre-drawn Clock Drawing Test

OBJECTIVES

This study aimed to clarify the diagnostic performance and neural basis of the Clock Drawing Test (CDT) combining free- and pre-drawn methods.

METHODS

This retrospective study included 165 participants (91 with Alzheimer disease [AD], 52 with amnestic mild cognitive impairment [aMCI], and 22 healthy controls [HC]), who were divided into four groups according to their free- and pre-drawn CDT scores: group 1, could do both; group 2, impaired in both; group 3, impaired in pre-drawn CDT; and group 4, impaired in free-drawn CDT. The diagnostic performances of the free-drawn, pre-drawn, and combination methods were compared using receiver operating characteristics analysis; in voxel-based morphometry analysis, the gray matter (GM) volume of groups 2-4 were compared with that of group 1.

RESULTS

The area under the curve of the combination method was greater than that of the free- or pre-drawn method alone when comparing AD with HC or aMCI. Group 2 had a significantly smaller GM volume in the bilateral temporal lobes than group 1. Group 3 had a trend toward smaller GM volumes in the right temporal lobe when a liberal threshold was applied. Group 4 had significantly smaller GM volumes in the left temporal lobe than group 1.

CONCLUSIONS

This study suggests that the combination method may be able to screen for a wider range of brain dysfunction. Combined use of free- and pre-drawn CDT may be useful for screening for AD and its early detection and treatment.

Validity and Reliability of the New Chinese Version of the Frontal Assessment Battery-Phonemic

BACKGROUND

Alzheimer's disease dementia (ADD) is an important health problem in the world.

OBJECTIVE

The present study investigated the validity and reliability of a new version of the Frontal Assessment Battery (FAB) named the FAB-phonemic (FAB-P).

METHODS

A total of 76 patients with ADD, 107 patients with amnestic mild cognitive impairment (aMCI), 37 patients with non-amnestic MCI (naMCI), and 123 healthy controls were included in this study. All participants were evaluated with the FAB-P and the cognitive assessments according to a standard procedure.

RESULTS

The global FAB-P scores in patients with ADD were lower than those of patients with aMCI, patients with naMCI, and healthy controls (p < 0.001). Patients with aMCI performed worse than healthy controls (p < 0.001). The interrater reliability, test-retest reliability, and Cronbach's alpha coefficient for the FAB-P were 0.997, 0.819, and 0.736, respectively. The test could distinguish the patients with mild ADD, aMCI, and naMCI from healthy controls with classification accuracy of 89.4%, 70.9%, and 61.6%, respectively. It could also discriminate between the patients with ADD and aMCI, between those with ADD and naMCI, and between those with aMCI and naMCI with classification accuracy of 73.8%, 83.9%, and 58.0%, respectively. The regression analysis revealed that the Montreal Cognitive Assessment and the Stroop Color Word Test Part C had the greatest contribution to FAB-P score variance.

CONCLUSION

The FAB-P is a valid and reliable tool for evaluating frontal lobe function and can effectively discriminate ADD, aMCI, and naMCI.

An update on magnetic resonance imaging markers in AD

The purpose of the present review is to provide an update of the available recent scientific literature on the use of magnetic resonance imaging (MRI) in Alzheimer's disease (AD). MRI is playing an increasingly important role in the characterization of the AD signatures, which can be useful in both the diagnostic process and monitoring of disease progression. Furthermore, this technique is unique in assessing brain structure and function and provides a deep understanding of in vivo evolution of cerebral pathology. In the reviewing process, we established a priori criteria and we thoroughly searched the very recent scientific literature (January 2018-March 2020) for relevant articles on this topic. In summary, we selected 73 articles out of 1654 publications retrieved from PubMed. Based on this selection, this review summarizes the recent application of MRI in clinical trials, defining the predementia stages of AD, the clinical utility of MRI, proposal of novel biomarkers and brain regions of interest, and assessing the relationship between MRI and cognitive features, risk and protective factors of AD. Finally, the value of a multiparametric approach in clinical and preclinical stages of AD is discussed.

Cognitive abilities underlying performance on the modified card sorting test: novel and traditional scores

The Modified Card Sorting Test (MCST) is a widely used variation of the Wisconsin Card Sorting Test. It is faster to administer, less frustrating for respondents and less ambiguous in its scoring but has been criticized for its task impurity and low discriminability between control participants and clinical groups prone to executive dysfunction. This study aimed to examine the executive functions (EF) underlying traditional (number of categories completed, perseverative errors) and novel scores for the MCST, and compare their ability to differentiate between control and clinical samples. Novel and traditional MCST scores were compared between 94 control participants, 87 with bipolar disorder and 64 with major depression. The relationship between MCST scores and traditional EF tasks was examined through correlation and regression analyses. All MCST scores were associated with at least one measure of EF, the most common of which were the Trail Making or Hayling Tests. IQ predicted most scores on the MCST, save for nonperseverative errors and categorizing efficiency. Traditional and novel scores differentiated between clinical and control groups. These findings support the utility of the MCST in detecting executive dysfunction and highlight the importance of new scoring methods in increasing the specificity and interpretability of this task.

Clock drawing and neuroanatomical correlates: A systematic review

OBJECTIVE

The popular clock drawing test (CDT) is easy to administer, acceptable to patients, and has excellent psychometric properties. Although it has been used primarily as a cognitive screening test, many studies have attempted to establish the CDT's ability to localize specific brain lesions or pathology. This systematic review aimed to summarize the evidence on the neuroanatomical correlates of the CDT.

METHODS

Using PRISMA guidelines, the authors systematically reviewed the evidence on neuroanatomical correlates of clock drawing by a systematic search in six databases (Pubmed, CINHL, PsychINFO, HealthStar, Embase, and Web of Science) until January 2018. Studies were included if they reported CDT correlations with anatomical brain lesions documented by neuroimaging.

RESULTS

Forty-five papers met inclusion criteria. Thirty-one studies identified distinct areas of neuroanatomical correlates of CDT utilizing different scoring methods and imaging techniques. Nine articles reported on the degree of white matter hyperintensities that correlated with lower scores on CDT and the severity of cognitive deficits. Five articles focused on postacute cerebrovascular accidents correlated with CDT performance. A variety of different anatomical lesions, located in all areas of the brain, were associated with abnormalities on the CDT.

CONCLUSIONS

The CDT, regardless of scoring method and population studied, was not associated with any consistent, specific brain localization. This systematic review supports the use of the CDT as a cognitive screening test rather than a method of localizing brain lesions.