PURPOSE: Primary lymphedema is often misconstrued as a localized disorder; however, it represents a systemic condition characterized by systemic lymphatic insufficiency, which can progressively affect various body regions. In addition to its more recognized manifestations such as swelling in the extremities, trunk, and face, emerging evidence suggests that primary lymphedema also impacts cognitive function. This study aims to explore the relationship between primary lymphedema and cognitive function by evaluating brain fog symptoms and cognitive performance using the Montreal Cognitive Assessment (MoCA) and the Brain Fog Scale (BFS).
METHODS: A total of 81 patients diagnosed with primary lymphedema (67 females, 14 males, mean age: 44.72 ± 18.02) was enrolled in the study. Cognitive function was assessed using the MoCA, with a cut-off score of <26 indicating mild cognitive impairment. Brain fog symptoms were assessed using the BFS, which includes measures of mental fatigue, impaired cognitive acuity, and confusion. Comparative analysis was performed against a control group of 1046 individuals without lymphedema. Additionally, a subgroup analysis was performed comparing patients who underwent surgical intervention (n=12) with sthose who did not (n=69). Independent t-tests were employed to evaluate differences between groups.
RESULTS: Patients with primary lymphedema had a mean BFS score of 28.10 ± 18.92 and a mean Montreal Cognitive Assessment (MoCA) score of 27.92 ± 2.28. When compared to the control group, lymphedema patients demonstrated significantly elevated levels of brain fog symptoms, including mental fatigue (10.58 ± 5.44 vs. 8.62 ± 4.63, p=0.0022), impaired cognitive acuity (10.57 ± 8.44 vs. 7.81 ± 6.18, p=0.0050), confusion (6.95 ± 6.56 vs. 5.18 ± 5.71, p=0.0203), and total BFS scores (28.10 ± 18.92 vs. 21.61 ± 17.04, p=0.0035). Notably, patients reporting subjective cognitive complaints (n=21) had significantly higher BFS scores across all domains compared to those without complaints (p<0.0001). Furthermore, patients who underwent surgical intervention reported significantly lower brain fog symptoms compared to those who did not have surgery in two key areas: impaired cognitive acuity (6.25 ± 5.22 vs. 11.32 ± 8.69, p=0.011) and total BFS score (19.75 ± 11.87 vs. 29.55 ± 19.59, p=0.027).
CONCLUSION: Patients with primary lymphedema demonstrate substantial cognitive impairments when compared to control group. This thorough analysis underscores the considerable cognitive burden experienced by primary lymphedema patients, particularly among those with cognitive complaints or who have not undergone surgical intervention.