Elevated cerebrospinal fluid and plasma homocysteine levels in ALS

Background: High cerebrospinal fluid (CSF) and plasma levels of homocysteine (HC) have been reported in certain neurodegenerative disorders, such as Alzheimer’s, Parkinson’s diseases and, recently, amyotrophic lateral sclerosis (ALS). Objectives: To assay the CSF and plasma levels of HC in ALS patients and controls, and to evaluate the relationship between HC levels and clinical variables of the disease. Methods: Cerebrospinal fluid from sixty‐nine (M/F 1.87) and plasma from sixty‐five ALS patients (M/F 1.83) were taken and stored at −80°C until use. Controls (CSF = 55; plasma = 67) were patients admitted to our hospital for neurological disorders with no known relationship to HC changes. CSF and plasma from ALS patients and controls were obtained as a necessary step of the diagnostic workup. HC levels in CSF and plasma were assayed using a high performance liquid chromatograph (HPLC) and a fluorimeter detector. Results: The median level of total HC in the CSF of ALS patients was 0.46 μM, significantly higher than that of the controls (0.24 μM, +91.6%, P