Sex and gender as contributors to brain pathophysiology, clinical course, and therapeutic response in multiple sclerosis.

Multiple sclerosis (MS) is a chronic autoimmune demyelinating disorder that affects the brain and spinal cord. MS is characterized by different neurological and cognitive impairments. Several lines of evidence suggest sex-based differences in the incidence, clinical course and pathophysiology of the disease. Epidemiological data show that women are three times more likely to suffer from MS compared to men and tend to present symptoms earlier. Other evidence indicates that men experience more aggressive forms of MS and women respond better to certain disease-modifying drugs. In this mini review, we summarized recent findings on biological, hormonal and psychological factors underpinning these differences, with reproductive stage being recognized as a key variable to be considered in drug safety and efficacy. Beyond biology, sex and gender influence perception of the disease, quality of life and management. Recognizing sex and gender as important factors in MS supports the move toward precision medicine, leading to care that is not only more effective but also more equitable.