Plasma 24S-hydroxycholesterol and other oxysterols in acute closed head injury

Primary objective: To determine if plasma levels of 24S-hydroxycholesterol, the primary catabolite of brain cholesterol, provide a measure of axonal damage in acute brain trauma. Research design: Determination of plasma 24S-hydroxycholesterol in a series of persons admitted to an intensive care unit for treatment of closed head injury. Methods and procedures: Levels of 24-S-hydroxycholesterol, 27-hydroxycholesterol, lathosterol and total cholesterol were measured in peripheral blood from 38 persons from 14-55 years of age treated by craniotomy and ventriculostomy for intractable intracerebral hypertension. Severity of brain injury was estimated by the Glasgow Coma Scale (range = 3-13, median = 6 points) and overall injury by the Injury Severity Scale (range = 10-48, median = 29). All subjects were intubated and anaesthetized with intravenous propofol. Plasma sterol levels were compared with those of age-matched control subjects. Outcomes and results: There was no significant increase in plasma 24-S-hydroxycholesterol in subjects with head injury, but measures of peripheral cholesterol synthesis were markedly reduced as compared with values for age-matched normal control subjects. Conclusion: Plasma 24S-hydroxycholesterol levels do not change with severe closed head injury.