HARTFORD, CT — Patients with multiple sclerosis (MS) have been found to have prospective memory (PM) deficits. A new study sought to better understand how and why that occurs.
Researchers from Trinity College in Hartford, CT, and colleagues explored the specific types of errors made by persons with MS (PwMS), including differences between PwMS and healthy controls (HC) and PwMS who do and do not have impairments in processing speed and/or verbal learning and memory. The Rehabilitation Care Service at the VA Puget Sound Health Care System in Seattle participated in the study.
The study involved 111 PwMS and 75 health controls who completed the Memory for Intentions Test (MIST), an objective measure of PM that has five types of errors that can be coded (PM failure, task substitution, loss of content, loss of time and random errors).
The study team calculated the number and types of PM errors for the overall MIST and six subscales, which break down performance by types of delay (2-Minute and 15-Minute), cue (Time and Event) and response (Verbal and Action). For purposes of the study, impairment was defined as performing <1.5 SD on either the Symbol Digit Modalities Test (SDMT) or Rey Auditory Verbal Learning Test (RAVLT).
The results indicated that nearly 93% of PwMS made at least one PM error, compared to 76% of HC (V = 0.24, p = 0.001). “The most commonly made PM error by PwMS was loss of content errors (45.0%). PwMS made significantly more task substitution errors (26.4% vs. 7.6%, p < 0.001) and fewer loss of time errors (9.5% vs. 21.2%, p < 0.001) than HC,” the researchers advised. “Impaired PwMS made more errors than non-impaired PwMS, specifically PM failures on time-based tasks.”
Study findings were published recently in the Journal of Clinical and Experimental Neuropsychology.1
The authors concluded that PM errors are common in PwMS, especially when there are longer delays and time-based cues. “Not only do PwMS make more errors than demographically similar HC, but they exhibit different cognitive process failures,” they added.
- Nguyen CA, Raskin SA, Turner AP, Dhari Z, Neto LO, Gromisch ES. Patterns of prospective memory errors differ in persons with multiple sclerosis. J Clin Exp Neuropsychol. 2024 May 2:1-12. doi: 10.1080/13803395.2024.2348775. Epub ahead of print. PMID: 38695493.