Relationship between subjective and objective cognitive performance in multiple sclerosis

Self- and informant reports of patients' cognitive performance are an important source of information for clinicians to consider in neuropsychological evaluation. The aim of the study was to find out whether the relationship between subjective or informant observations of cognitive deterioration and objective cognitive performance differ in patients with relapsing and progressive multiple sclerosis (MS).

One ninety-six MS patients (relapsing-remitting n = 138; progressive n = 58) underwent neuropsychological assessment with the Brief Repeatable Battery of Neuropsychological Tests. Subjective and informant-reported cognitive symptoms, mood, impact of the disease, and quality of life were evaluated with self-reports. According to consistency of evaluations, patients and informants were classified as accurate estimators (consistent subjective and objective cognitive performance), underestimators (subjectively but not objectively cognitively impaired), or overestimators (objectively but not subjectively cognitively impaired).

Patients' and informants' reports on patients' cognitive performance were approximately equally appropriate, slightly over half being accurate. Mood was associated with patients' subjective cognitive complaints. The relapsing group reported more subjective cognitive symptoms than the progressive group, although the objective cognitive performance did not differ between the groups. Overestimation occurred especially among patients with more severe physical disability, progressive phenotype of the disease, more pronounced cognitive impairment, and less education.

Slightly over half of patient and informant observations of cognitive deterioration were appropriate. Patients with progressive phenotype were more prone to overestimation than patients with relapsing phenotype.