Verbal episodic memory in 426 multiple sclerosis patients: impairment in encoding, retrieval or both?

Area of Science:

• Neuroscience
• Neurology
• Cognitive Psychology

Background:

• Episodic memory impairment is a known issue in multiple sclerosis (MS).
• The precise nature of memory deficits in MS, whether retrieval or encoding, remains debated.
• Potential contributing factors include slowed processing speed and poor strategy elaboration.

Purpose of the Study:

• To determine the prevalence and characteristics of verbal episodic memory (VEM) impairment in MS patients.
• To investigate the relationship between VEM deficits and disease parameters like disability and duration.
• To explore potential therapeutic avenues for cognitive rehabilitation.

Main Methods:

• Analysis of VEM performance data from 426 MS patients using the 16 words RL-RI 16 test.
• Assessment included recall, encoding, and recognition phases of memory.
• Correlational analysis with Expanded Disability Status Scale (EDSS) scores and disease duration.

Main Results:

• 66% of MS patients showed impaired VEM recall, with 37.2% having 2-5 impaired recalls.
• 14.2% of patients exhibited encoding deficits, and 5% had recognition difficulties.
• VEM performance correlated with EDSS scores and disease duration, but not with MS form.

Conclusions:

• Verbal episodic memory impairment is highly prevalent in MS patients.
• Deficits initially affect retrieval and later shift to encoding as disability increases.
• Cognitive rehabilitation strategies, such as mental imagery, may be beneficial for MS patients.