The interconnection of multiple sclerosis and neurofibromatosis type 1: A single institution retrospective study and systematic review.

Background: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic neurocutaneous disorder. Multiple sclerosis (MS) is an immune-mediated demyelinating disorder of the central nervous system. The rates of occurrence are higher than expected by chance, suggesting that an underlying predisposition may exist. We aimed to systematically review the literature to better understand the concurrence and contribute four additional patients to the existing literature. Methods: This study is a systematic review as well as retrospective case series. Pubmed, Embase, Cochrane, Scopus, and Web of Science were queried for full articles in English reporting on cases of concurrent NF1 and MS between 1990 and 2023. Results: The systematic review revealed 34 reported cases of patients with both NF1 and MS across 18 papers. Ten patients had primary progressive MS, seven had relapse-remitting MS, five had secondary progressive MS, and 12 did not have a specific MS classification. Thirty-three had at least one reported brain lesion and 18 had at least one reported spine lesion. Our cohort contains four female patients; all with brain lesions and three with spinal lesions. Conclusion: Although rare, NF1 and MS can occur within the same patient. Previous literature has been inconsistent in the information reported about patients with these concurrent diagnoses. Additional research is required to better understand the concurrent disease processes, whether a predisposition exists, as well as the best therapeutic approaches for these patients.