Trail Making Test Could Predict Impairment in Cognitive Domains in Patients with Multiple Sclerosis: A Study of Diagnostic Accuracy

Abstract

Objective: Cognitive impairment (CI) and executive dysfunction (ED) are prevalent in patients with multiple sclerosis (PwMS). The Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) is the gold standard neuropsychological battery (NPB) for detecting CI. Delis-Kaplan Executive Function System (DKEFS) NPB evaluates ED. We aimed to find practical test(s) from DKEFS with acceptable diagnostic utility for early detection of impairment in cognitive and executive domains.

Methods: Cognitive and executive tasks, physical disability, and depression scores of 30 PwMS were assessed (17 women, age: 38.1). Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), and Controlled Oral Word Association Test (COWAT) from MACFIMS and Trail Making Test (TMT), Design Fluency Test (DFT), and Verbal Fluency Test (VFT) from DKEFS were selected. The association between patients' characteristics and performance in tests, and diagnostic accuracy of DKEFS tests in detecting impairment in cognitive tasks were evaluated, using Pearson correlation and receiver operator characteristic curve analyses, respectively.

Results: A significant correlation was found between disease duration and SDMT and TMT subtests. Expanded Disability Status Scale was significantly related to SDMT, VFT-switching, and TMT subtests. Beck Depression Inventory was significantly related to DFT. TMT-switching detected abnormalities in SDMT and PASAT with 100% sensitivity, 93.3% (for SDMT), and 85.7% specificity (for PASAT). TMT-letter showed 100% sensitivity and 90% specificity in identifying abnormalities in COWAT.

Conclusions: TMT, particularly the switching condition, is a practical paper-based test that could predict impairment in cognitive tasks. Clinicians may use TMT as a screening tool among PwMS.

Keywords: Delis–Kaplan Executive Function System; Minimal Assessment of Cognitive Function in Multiple Sclerosis; Multiple sclerosis; Neuropsychological Tests; Symbol Digit Modalities Test; Trail Making Test.