Cognitive Impairments, Visual Memory Hindered in Neuromyelitis Optica Spectrum Disorder
Between AQP4-IgG-positive and negative patients with NMOSD, there were no significant differences in cognitive performance, despite having similar demographic and clinical characteristics.
Elisabet Lopez-Soley
Results from a well-characterized cohort of patients with neuromyelitis optica spectrum disorder (NMOSD) revealed slightly more than one-third of patients had cognitive dysfunction, with visual learning, and memory and attention-information processing speed (IPS) being the most affected cognitive domains. Cognitive and psychological assessments may be crucial to achieve a holistic approach in NMOSD patient care, the study investigators concluded.1
The noninterventional, cross-sectional study included 41 patients with NMOSD from 13 Spanish centers, of which 14 (34%) were classified as having global cognitive impairment. Demographic and clinical characteristics were similar (P >.05) between patients regardless of their cognitive status; however, patients with global cognitive impairment had lower satisfaction with life, more severe symptom endorsement, higher levels of perceived stigma, and greater impact of pain interfering with their lives than cognitively preserved patients.
Led by Elisabet Lopez-Soley, PhD student, Center of Neuroimmunology, Universitat de Barcelona, the trial aimed to better describe the cognitive profile of the disease, as well as analyze differences in serostatus. Cognitive performance was assessed using the Brief Repeatable Battery of Neuropsychological tests (BRB-N), which includes several tests assessing cognitive domains of verbal memory, visual memory, attention and processing speed, and semantic fluency and cognitive flexibility. Demographic and clinical characteristics were collected along with a cognitive z-score (Rao Battery) and HRQoL patient-centered measured, and their relationship was explored using linear regression.
Patients were more frequently female (85%) and middle-aged (median, 44 years) with a median disease duration of 8.1 years (IQR, 3.9-15.5) and a median Expanded Disability Status Scale (EDSS) score of 2.0 (range, 0-7.5). Of the cohort, 27 patients (66%) were aquaporin-4 (AQP4) positive, although there were no significant between-group differences in demographic, clinical, and patient-centered measures based on seropositivity. In terms of each cognitive domain, 10 patients (24%) had impairment in verbal memory, 14 (34%) in visual memory, 13 (32%) in attention-IPS, and 3 (17%) in semantic fluency.
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At the conclusion of the study, the global BRB-N z-score was associated with fatigue, as assessed by Fatigue Impact Scale for Daily Use (D-FIS) (ß = –0.322; 95% CI, –0.53 to 0.12; corrected P = .013), physical impact of the disease on quality of life (ß = –0.31; 95% CI, –0.53 to –0.09; P = .028), satisfaction with life (ß = 0.302; 95% CI, 0.09-0.51; P = .024), self-perception of symptoms (ß = –0.322; 95% CI, –0.55 to –0.11; P = 0.019), and perception of stigma (ß = –0.322; 95% CI, –0.53 to –0.12; P = .012). Depression was not related to cognitive performance (ß = –0.188; 95% CI, –0.41 to 0.04; P = .306).
An additional multiple regression model used the Akaike Information Criterion (AIC) to select the variables that best fit based on the whole cohort. Based on the AIC, the final model included gender as well as depression and fatigue scores, satisfaction with life, and perception of the stigma. In the sample, 40% of the variability of the z-score of BRB-N was explained by this model (adjusted R2 = 0.396; P <.001). A change of 1 point in the Beck Depression Inventory-Fast Screen questionnaire, sensitive to depression, was associated with a change of 0.6 points in global cognitive scores. Notably, fatigue, satisfaction of life questionnaire, and perception of stigma for neurological diseases were also related to cognition.
