GLYCEROL INDUCED DECREASE CEREBROSPINAL FLUID FORMATION

Abstract

Glycerol is used in the treatment of increased intracranial pressure, cerebral edema, and hydrocephalus in infants. The effects of glycerol on cerebrospinal fluid (CSF) dynamics have not been studied. Accordingly, we studied the acute effect of glycerol administration on CSF production in nine anaesthetized mongrel dogs. CSF formation rates were measured by ventriculo-cisternal perfusion utilizing artificial spinal fluid and albumin - I131. Serial measurements of CSF formation rates and serum osmolalities were obtained during an eight hour period, four hours preceding and following the nasogastric administration of 3gm/kg of glycerol. The mean rate of CSF formation during the control period was 0.04±0.02 ml/min decreasing to a trough of 0.01±0.01 ml/min at both 90 and 120 minutes post glycerol administration P < 0.025. When analyzing the decrease in CSF production using each dog as its own control, the change was significant at P < 0.001 level. Mean serum osmolality increased from 296 ± 4 mOsm/kg water to a maximum of 308 ± 7 mOsm/kg water at 90 minutes after glycerol administration. CSF production and serum osmolality were inversely related with an r value of -0.85. In summary, acute glycerol administration decreases CSF production in dogs. The rate of CSF production is inversely related to the increase in serum osmolality after glycerol administration.