Background and purpose: Sexual dysfunction (SD) is an important subject and unfortunately an overlooked symptom of multiple sclerosis (MS) especially in women. The aim of this study was to investigate the impact of affected functional systems on primary sexual dysfunction.

Materials and methods: A cross-sectional study was carried out in Tehran, Iran in which a sample of female patients with MS was recruited consecutively from an outpatient clinic. Sexual function was evaluated by the Multiple Sclerosis Intimacy and Sexuality Questionnaire. A neurologist evaluated the clinical characteristics including disease progress, duration, and affected functional systems. The neurological impairment was assessed by the Kurtzke Expanded Disability Status Scale (EDSS).

Results: There were 226 women in whom brainstem and/or cerebellum (OR for suffering from Brainstem and/or cerebellum=2.54, 95% CI=1.40-4.60, P=0.002), pyramidal dysfunction (OR for suffering from pyramidal dysfunction = 3.14, 95% CI= 1.363-7.26, P=0.002), and sensory dysfunction (OR for suffering from sensory dysfunction = 3.13, 95% CI= 1.56-6.25, P<0.028) were significant contributing factors to primary sexual dysfunction.

Conclusion: This study emphasized that sexual dysfunctions are associated with affected functional systems.  Therefore, more consultations and sensitive approaches are suggested in treatment of these systems.