Cognitive impact of anticholinergic medication in MS: Adding insult to injury?

Cognitive impairment in Multiple Sclerosis (MS) is well recognized, being documented even in the earliest stages of the disease. Anticholinergic drugs (ACD) are frequently used to address bladdder symptoms in this population. ACD are known for their deleterious cognitive effects in older individuals; however their potential impact on cognition has received less attention in the context of MS.

To explore possible detrimental effects of bladder-directed ACD on cognitive functioning in MS.

42 MS patients who had been on classical, bladder-directed ACD for ≥6 months were compared to 46 patients not receiving ACD, in terms of their scores on Symbol Digit Modality Test (SDMT) and Selective Reminding Test (SRT). Patients also completed questionnaires for fatigue (Modified Fatigue Impact Scale - MFIS) and depression (Beck Depression Inventory-Fast Screen - BDIFS).

Patients using ACD showed significantly lower SDMT and SRT scores compared to those not using ACD (p<0.001; t-test). The association of lower cognitive test performance with ACD usage was robust, even when other variables (like age, gender, EDSS, etc.) were considered.

Our results suggest that chronic use of classical ACD for bladder symptoms may have a negative impact on cognitive functioning in MS patients. These potential cognitive side effects need to be considered both in clinical practice and research settings.