Urinary Dysfunction in Myasthenic Syndromes: A Scoping Review of Clinical Features and Treatment-Related Associations

Urinary dysfunction has been reported in association with myasthenic syndromes, including myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS), and congenital myasthenic syndromes (CMS), but evidence regarding its prevalence, clinical impact, pathophysiology, and management remains limited. This scoping review synthesizes the available evidence on urinary symptoms, diagnostic approaches, pathophysiological features, treatment-related associations, and sex-specific findings in these disorders. A literature search was conducted in PubMed, LIVIVO, Epistemonikos, and the Cochrane Library in accordance with PRISMA guidelines. Of 774 records identified, eight studies met the inclusion criteria, comprising two case reports, three case-control studies, one prospective study, and two retrospective observational studies. Seven studies addressed MG and one addressed LEMS; no eligible studies were identified for CMS. Reported urinary symptoms were predominantly storage lower urinary tract symptoms (LUTS), including urinary incontinence, urgency, nocturia, and increased frequency, whereas voiding and bladder-emptying abnormalities were described less consistently. Diagnostic approaches were heterogeneous and included questionnaires, clinical examination, urodynamic testing, imaging, and autonomic assessments. Proposed mechanisms remain uncertain, with limited evidence supporting contributions from pelvic floor weakness, autonomic dysfunction, and cholinesterase inhibitor exposure. Treatment-related associations were largely observational and most consistently implicated pyridostigmine in symptom worsening, while evidence for specific treatment of urinary symptoms was sparse. Sex-specific analyses were limited and did not identify consistent sex-related patterns. Current evidence indicates that urinary symptoms have been reported in myasthenic syndromes and have been associated with reduced quality of life in the included studies, but the available data remain insufficient to define prevalence, mechanisms, or optimal management.