The clinical significance of cerebrospinal fluid lipid peroxides in central nervous system disease

Forty-four dogs were referred to our hospital presenting with neurological symptoms such as seizure or paraparesis. Magnetic resonance imaging (MRI) revealed abnormal results in 21 (abnormal MRI group) and normal results in 23 dogs (normal MRI group). Cerebrospinal fluid (CSF) (normal MRI group, n = 22; abnormal MRI group, n = 21) and serum lipid peroxide (LP) concentrations (normal MRI group, n = 11; abnormal MRI group, n = 15) were measured in a number of these dogs, and revealed a significant difference in the CSF/serum LP values (normal MRI group, n = 10; abnormal MRI group, n = 14) between the abnormal and the normal MRI groups (t-test and Mann-Whitney U-test p < 0.05). No other significant differences were observed. CSF/serum LP values exceeding 1.0 were exhibited in 10 of 14 dogs (71%) in the abnormal MRI group, and in 1 of 10 dogs (10%) in the normal MRI group. In the remaining animals, 4 dogs of the abnormal MRI group showed CSF/serum values lower than 1.0, 3 dogs had morphological abnormalities but no abnormal MRI signals in the central nervous system, and 1 dog had an abnormal MRI signal but no pathological abnormality. In the CSF analysis, 3 of 16 dogs (19%) of the abnormal MRI group showed abnormal cell counts and/or protein content. We conclude that the CSF/serum LP value can be used for the detection of neurological lesions such as oedema, inflammation and tumour.