EC-IC BYPASS IMPROVES CHRONIC ISCHEMIA IN A PATIENT WITH MOYAMOYA DISEASE SECONDARY TO SICKLE-CELL DISEASE - AN IN-VIVO MICRODIALYSIS STUDY

Patients with sickle cell disease may develop intracranial vascular di sease, with the occlusion or obstruction of the large or small arterie s, which may lead to the secondary development of moyamoya disease. In this report, we describe the neurochemical changes in the brain befor e, during, and after an extracranial-intracranial bypass procedure on a patient with sickle cell disease and a moyamoya disease like pattern on angiography. We used the in vivo microdialysis technique to measur e the on-line pH, lactate and amino acid concentrations in the extrace llular fluid There were relatively high resting glutamate levels and a lower-than-normal pH in the extracellular fluid prior to the bypass, associated with chronic ischemia. During the bypass there was a short- lived increase in the glutamate levels. After revascularization, there was a rapid decrease in the glutamate levels and an increase in the p H value. The patient's preoperative neurological deficit improved post -operatively, corresponding to the biochemical changes towards normal values. These changes after revascularization suggest that chronic bio chemical abnormalities due to brain ischemia may improve after cerebra l revascularization.