Lactic dehydrogenase isoenzymes in cerebrospinal fluid associated with hydrocephalus

Various neurological disorders are associated with specific changes in the level of total lactic dehydrogenase and concentrations of its isoenzymes in the cerebrospinal fluid. We describe the lactic dehydrogenase isoenzyme values in children with hydrocephalus. Cerebrospinal fluid samples collected from 10 patients (2 to 16 mo) with hydrocephalus were analysed for total lactic dehydrogenase activity and lactic dehydrogenase isoenzymes. Findings were compared with those in samples from 15 paediatric patients, with normal results. Mean total lactic dehydrogenase activity in the cerebrospinal fluid was significantly higher in the patients with hydrocephalus (101 +/- 23.11 U/L) than in the controls (33.53 +/- 5.75 U/L) (p <0.001). In the control samples, lactic dehydrogenase-1 was the main fraction, followed by lactic dehydrogenase-2 and 3; only small concentrations of lactic dehydrogenase-4 and lactic dehydrogenase-5 were detected. By contrast, patients with hydrocephalus had lower concentrations of the lactic dehydrogenase-1 fraction and higher lactic dehydrogenase-2 and lactic dehydrogenase-3 concentrations, the differences between these results and those in the control group being statistically significant (p < 0.001). The values for lactic dehydrogenase-4 and lactic dehydrogenase-5 were similar in both groups.

Findings should be considered together with computed tomography/magnetic resonance imaging and ultrasound scans. The cerebrospinal fluid lactic dehydrogenase profile may prove to be an important predictor of cerebral injury, obstructive hydrocephalus and long-term neurodevelopmental problems.