Increased concentrations of homocysteine in the cerebrospinal fluid in patients with fibromyalgia and chronic fatigue syndrome.
Regland, B, Andersson, M, Abrahamsson, L et al. · Scandinavian journal of rheumatology · 1997 · DOI
Quick Summary
Researchers tested the spinal fluid of 12 women who had both fibromyalgia and ME/CFS and found unusually high levels of a molecule called homocysteine in their brains and spinal cords. They also noticed that patients with lower vitamin B12 levels in their spinal fluid reported more severe fatigue. This suggests that a vitamin B12 deficiency might prevent the body from properly breaking down homocysteine, which could contribute to symptoms like exhaustion.
Why It Matters
This study provides early evidence of a specific biochemical abnormality in the central nervous system of ME/CFS patients, moving beyond symptoms to identify potential underlying mechanisms. If replicated, elevated CSF homocysteine could become a biomarker for disease and vitamin B12 supplementation could be explored as a therapeutic target.
Observed Findings
Elevated cerebrospinal fluid homocysteine levels detected in all 12 patients studied
Positive correlation between CSF homocysteine levels and reported fatiguability
Positive correlation between CSF vitamin B12 levels and fatigue severity (CPRS-15)
Blood laboratory values remained generally normal despite CSF abnormalities
Inferred Conclusions
Vitamin B12 deficiency impairs the remethylation of homocysteine, leading to its accumulation in the central nervous system
Increased homocysteine in the CSF is a characteristic biochemical marker in patients with both fibromyalgia and ME/CFS
Central nervous system metabolic dysfunction, rather than systemic disease, may be primary in these conditions
Remaining Questions
How does CSF homocysteine elevation relate to specific ME/CFS symptoms beyond fatigue (cognitive dysfunction, post-exertional malaise, etc.)?
Would vitamin B12 supplementation normalize CSF homocysteine levels and improve clinical outcomes?
Are elevated homocysteine levels present in ME/CFS patients without fibromyalgia, and are they present in healthy controls?
What This Study Does Not Prove
This study does not prove that homocysteine elevation *causes* ME/CFS or fibromyalgia—it only shows a correlation. The small sample size, lack of control group, and female-only population limit generalizability. The study does not establish whether B12 supplementation would reduce homocysteine or improve fatigue.