Effects of Decompressive Craniectomy on Regional Cerebral Blood Flow in Severe Head Trauma Patients Assessed by HMPAO SPECT

Abstract

Using single photon emission computerized tomography (SPECT) with 99mTc-Hexamethylpropyleneamine oxime (HMPAO), we investigated the effect of deconqpressive craniectomy (DC) on regional cerebral blood flow (rCBF) in the patient with severe head trauma (SHT). SPECT studies were repeated three times in six SHT patients who underwent unilateral large DC 2–14 h after trauma; within 24 h after DC, 1 week, and then 1 month after DC. In the first 24 h of DC, SPECT uniformly found 1) PERFUSION DEFECT associated with brain contusion, and 2) HYPERPERFUSION area in the decompressed brain. The simultaneous X-CT observed mild/moderate swelling of the decompressed brain. One week after DC, SPECT found that HYPERPERFUSION area in the decompressed brain not only enlarged but also increased the severity. X-CT showed marked swelling of the decompressed brain. One month after DC, SPECT observed no HYPERPERFUSION areas in the decompressed brain. PERFUSION DEFECT associated with contusion was found to ameliorate. X-CT found no swelling of the decompressed brain. The chronology of HYPERPERFUSION area in the decompressed brain corresponded to the chronological change in the brain swelling after DC. In the SHT patient, DC significantly affects regional CBF and increases a focal CBF of the decompressed brain in the acute posttraiamatic period.