[Note: lactate - or lactic acid - forms when the cells break down carbohydrates to use for energy when oxygen supply is low (anaerobic vs. aerobic energy conversion).]
Chronic fatigue syndrome (CFS) is a controversial diagnosis because of the lack of biomarkers for the illness and its symptom overlap with neuropsychiatric, infectious, and rheumatological disorders.
We compared lateral ventricular volumes derived from tissue-segmented T(1)-weighted volumetric MRI data and cerebrospinal fluid (CSF) lactate concentrations measured by proton MRS imaging ((1)H MRSI) in 16 subjects with CFS (modified US Centers for Disease Control and Prevention criteria) with those in 14 patients with generalized anxiety disorder (GAD) and in 15 healthy volunteers, matched group-wise for age, sex, body mass index, handedness, and IQ.
Mean lateral ventricular lactate concentrations measured by (1)H MRSI:
• In CFS were increased by 297% compared with those in generalized anxiety disorder (P < 0.001)
• And by 348% compared with those in healthy volunteers (P < 0.001), ….
…even after controlling for ventricular volume, which did not differ significantly between the groups.
Regression analysis revealed that diagnosis accounted for 43% of the variance in ventricular lactate.
CFS is associated with significantly raised concentrations of ventricular lactate, potentially consistent with recent evidence of decreased cortical blood flow, secondary mitochondrial dysfunction, and/or oxidative stress abnormalities in the disorder.
Source: NMR in Biomedicine, Oct 21, 2008. E-pub ahead of print. PMID: 18942064, by Mathew SJ, Mao X, Keegan KA, Levine SM, Smith EL, Heier LA, Otcheretko V, Coplan JD, Shungu DC. Department of Psychiatry, Mount Sinai School of Medicine, New York; Department of Radiology, Weill Medical College of Cornell University, New York; Private Practice, Infectious Disease/Internal Medicine, New York; Department of Psychiatry, Downstate Medical Center, Brooklyn, New York, USA. E-mail: Dikoma C. Shungu firstname.lastname@example.org