Addenbrooke’s Cognitive Examination-III (ACE-III) test as a new potential tool for screening of cognitive dysfunctions in the course of multiple sclerosis

Purpose
Cognitive dysfunction occurs in more than half of patients with multiple sclerosis (MS). The evaluation of the level of cognitive functioning in MS patients is important for the assessment of the disease course and deciding on appropriate therapeutic interventions. The purpose of the study was to analyse the suitability of the Addenbrooke’s Cognitive Examination-III (ACE-III) as a screening tool for detecting cognitive dysfunctions in MS.

Methods
The study included 28 MS patients and 24 age- and gender-matched controls. The evaluation of cognitive functioning was conducted with ACE-III. The results were subjected to statistical analysis expanded by determining the optimal cut-off points for individual subscales of the test.

Results
The level of all cognitive functions was lower in MS patients. Statistically significant differences (p < 0.005) were demonstrated for the results of the ACE-III total score, memory, Mini-ACE (M-ACE) and fluency. The highest AUC values were obtained for total score, memory, M-ACE and fluency. With the cut-off level of 97 points, the test was characterised by sensitivity of 75% and specificity of over 95%. In terms of memory and fluency, the test was characterised by sensitivity close to 60% and specificity over 90%.

Conclusions
The ACE-III presents high diagnostic accuracy, good sensitivity and diagnostic specificity in the assessment of cognitive dysfunctions in MS. The results of the study concerning the deteriorated functioning of MS patients in terms of memory and fluency coincide with the conclusions from the literature and are an attempt to characterise the profile of cognitive dysfunctions in MS patients.