Utility of the Addenbrooke's Cognitive Examination in Amyotrophic Lateral Sclerosis

BNT-15: Revised Performance Validity Cutoffs and Proposed Clinical Classification Ranges

BACKGROUND

Abbreviated neurocognitive tests offer a practical alternative to full-length versions but often lack clear interpretive guidelines, thereby limiting their clinical utility.

OBJECTIVE

To replicate validity cutoffs for the Boston Naming Test-Short Form (BNT-15) and to introduce a clinical classification system for the BNT-15 as a measure of object-naming skills.

METHOD

We collected data from 43 university students and 46 clinical patients. Classification accuracy was computed against psychometrically defined criterion groups. Clinical classification ranges were developed using a z -score transformation.

RESULTS

Previously suggested validity cutoffs (≤11 and ≤12) produced comparable classification accuracy among the university students. However, a more conservative cutoff (≤10) was needed with the clinical patients to contain the false-positive rate (0.20-0.38 sensitivity at 0.92-0.96 specificity). As a measure of cognitive ability, a perfect BNT-15 score suggests above average performance; ≤11 suggests clinically significant deficits. Demographically adjusted prorated BNT-15 T-scores correlated strongly (0.86) with the newly developed z -scores.

CONCLUSION

Given its brevity (<5 minutes), ease of administration and scoring, the BNT-15 can function as a useful and cost-effective screening measure for both object-naming/English proficiency and performance validity. The proposed clinical classification ranges provide useful guidelines for practitioners.

Psychometric Properties of Cognitive Assessment in Amyotrophic Lateral Sclerosis: A Systematic Review

Purpose

We aimed to list all tests used to assess cognitive change in patients with amyotrophic lateral sclerosis (ALS) and to provide a descriptive synthesis of the psychometric properties of tests that were evaluated in a population of ALS patients.

Materials and Methods

The protocol is registered in PROSPERO (ID: CRD42017055603). We systematically search for literature in 11 databases. Full-text articles, in any language, with original research were included. All included articles were scrutinised by two independent authors. Disagreement was resolved by consensus. The framework of Lezak informed conceptualises of the tests identified. To evaluate methodological quality, we used the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN). Data were synthesised using criteria proposed by the Cochrane Back Review Group.

Results

Of 319 included articles, 46 articles reported information on the psychometric properties of cognitive tests used in patients with ALS. We found that the highest level of evidence was supported for the Reading the Mind in the Eye Test (RME), Addenbrooke’s Cognitive Evaluation (ACE) and Frontal Assessment Battery (FAB). Moderate level of evidence was found for the screening tests; Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and the Montreal Cognitive Assessment (MoCA).

Conclusion

The screening test, ECAS and the social cognition test, RME, may have some advantages over other tests that have been used for assessing cognitive change in ALS patients. Recommendations of ALS-specific tests with sound psychometric properties are urgently needed.

Magnetic Resonance Spectroscopy in ALS

Proton magnetic resonance spectroscopy (MRS) provides a means of measuring cerebral metabolites relevant to neurodegeneration in vivo. In amyotrophic lateral sclerosis (ALS), neurochemical changes reflecting neuronal loss or dysfunction (decreased N-actylaspartate [NAA]) is most significant in the motor cortex and corticospinal tracts. Other neurochemical changes observed include increased myo-inositol (mIns), a putative marker of gliosis. MRS confirmation of involvement of non-motor regions such as the frontal lobes, thalamus, basal ganglia, and cingulum are consistent with the multi-system facet of motor neuron disease with ALS being part of a MND-FTD spectrum. MRS-derived markers exhibit an encouraging discriminatory ability to identify patients from healthy controls, however more data is needed to determine its ability to assist with the diagnosis in early stages when upper motor neuron signs are limited, and in distinguishing from disease mimics. Longitudinal change of NAA and mIns do not appear to be reliable in monitoring disease progression. Technological advances in hardware and high field scanning are increasing the number of accessible metabolites available for interrogation.

Quantifying changes on susceptibility weighted images in amyotrophic lateral sclerosis using MRI texture analysis

Objective: Susceptibility-weighted imaging (SWI) has been used to identify neurodegeneration in amyotrophic lateral sclerosis (ALS) through qualitative gross visual comparison of signal intensity. The aim of this study was to quantitatively identify cerebral degeneration in ALS on SWI using texture analysis. Methods: SW images were acquired from 17 ALS patients (58.4 ± 10.3 years, 13M/4F, ALSFRS-R 41.2 ± 4.1) and 18 healthy controls (56.3 ± 17.6 years, 9M/9F) at 4.7 tesla. Textures were computed within the precentral gyrus and basal ganglia and compared between patients and controls using ANCOVA with age and gender as covariates. Texture features were correlated with clinical measures in patients. Texture features found to be significantly different between patients and controls in the precentral gyrus were then used in a whole-brain 3D texture analysis. Results: The texture feature autocorrelation was significantly higher in ALS patients compared to healthy controls in the precentral gyrus and basal ganglia (p < 0.05). Autocorrelation correlated significantly with clinical measures such as disease progression rate and finger tapping speed (p < 0.05). Whole brain 3D texture analysis using autocorrelation revealed differences between ALS patients and controls within the precentral gyrus on SWI images (p < 0.001). Conclusion: Texture analysis on SWI can quantitatively identify cerebral differences between ALS patients and controls.