Cerebrospinal fluid lactate and pyruvate concentrations in patients with malignant hypertension

Lactate and pyruvate concentrations and acid-base parameters in cerebrospinal fluid (CSF) and arterial blood were measured in 21 patients with malignant hypertension ( MHT ), 19 with benign hypertension (BHT) and 21 normotensive subjects (NT). Average values for CSF lactate and lactate/pyruvate (L/P) ratio were significantly higher in MHT (1.90 +/- 10 mM/1, 19.2 +/- 1.0) than in either BHT (1.50 +/- 0.05 mM/l, 15.7 +/- 0.7) or NT (1.44 +/- 0.04 mM/1, 15.7 +/- 0.4). There was a linear correlation between CSF lactate and CSF pressure (r = 0.565, P less than 0.01), and the latter was also related to mean arterial pressure exceeding 150 mm Hg (r = 0.553, P less than 0.01). Such increases in the acid metabolites in CSF indicate that brain metabolism becomes anaerobic in MHT , probably due to increased intracranial pressure. Increased cerebrovascular permeability is also discussed as participating in causal mechanisms.