DYNAMICS OF CEREBRAL METABOLISM IN PATIENTS WITH CHRONIC SUBDURAL-HEMATOMA EVALUATED WITH PHOSPHORUS-31 MR SPECTROSCOPY BEFORE AND AFTER SURGERY

PURPOSE: To determine whether the depression of cerebral bioenergetic metabolism caused by chronic subdural hematomas can account for neurol ogic dysfunction and whether the degree of metabolic depression may be useful for clinical assessment and therapy. METHODS: Sixteen patients who had chronic subdural hematomas with hemiparesis and/or mental dis turbances underwent phosphorous 31 MR spectroscopy before and 10 to 14 days after surgery. Phosphorous 31 MR spectroscopy was also performed on 5 patients who had chronic subdural hematomas with only slight hea daches who were treated by conservative therapy and on 10 healthy volu nteers. RESULTS: The preoperative phosphocreatine-to-inorganic phospha te ratio (2.10 +/- 0.36) improved to normal values (2.69 +/- 0.44) aft er evacuation of hematomas. This improvement was accompanied by comple te disappearance of hemiparesis and/or mental disturbance. Brain tissu e pH also improved from 7.07 +/- 0.11 to 7.205 +/- 0.13 after surgery. On the other hand, patients who had chronic subdural hematomas with o nly slight headaches had the same phosphocreatine-to-inorganic phospha te ratio and brain intracellular pH as healthy volunteers. CONCLUSION: The phosphocreatine-to-inorganic phosphate ratio may be useful for de termining when to operate on patients with chronic subdural hematomas and to assess the efficacy of treatment.