Cognitive impairment following kidney transplantation: a narrative review of risk factors, mechanisms and management

By Ariana STRAKOSHA, Vilma CADRI, Nevi PASKO, Elvana RISTA

Abstract:
Background: Cognitive impairment (CI) is increasingly recognised as a clinically important, yet under addressed, complication after kidney transplantation. Reported prevalence figures vary widely, and the underlying mechanisms and potential interventions remain incompletely integrated in the literature.
Objectives: To synthesise current evidence (up to 31 March 2025) on the prevalence, longitudinal trajectory, determinants, clinical impact and emerging management strategies for CI in adult kidney-transplant recipients (KTRs).
Methods: A narrative review was conducted following a systematic search of PubMed/MEDLINE, Embase, Scopus and the Cochrane Library from inception to 31 March 2025. Inclusion criteria comprised original human studies reporting quantitative or qualitative cognitive outcomes in adult KTRs; paediatric, animal, case series < 5 patients and non-English articles were excluded. Two reviewers independently screened records and extracted data. Risk of bias was assessed with the Newcastle–Ottawa Scale (observational studies) and ROB-2 (trials). Findings were synthesised thematically.
Results: Fifty-seven primary studies (2006-2025) involving 9 873 KTRs met eligibility criteria. Point prevalence of CI ranged from 6.5 % to 58 % (median ≈ 38%), with executive function and processing speed most frequently affected. Eighteen longitudinal cohorts delineated a “recover–stabilise–diverge” trajectory: rapid gains within 3 months post-transplant, plateau to 24 months, then divergence according to age and vascular burden. Consistent determinants included advanced age, diabetes,hypertension, lower eGFR, frailty and high tacrolimus exposure; mechanistic pathways converged on microvascular injury, calcineurin-inhibitor neurotoxicity and modifiable systemic factors (anaemia, inactivity). CI was associated with poorer adherence, higher rehospitalisation and reduced graft survival. Seven interventional trials demonstrated clinically relevant cognitive improvements with structured exercise, yoga/mindfulness programmes and low-dose tacrolimus, supporting the modifiability of CI.
Conclusions: CI affects roughly one-third to one-half of KTRs and is driven by intersecting vascular, pharmacological and lifestyle factors. Routine MoCA-based screening, risk-stratified follow-up and multidisciplinary interventions—including exercise rehabilitation and judicious immunosuppression titration—should be integrated into standard transplant care while larger multicentre trials are awaited.