Nitrous oxide and isoflurane have different effects on absolute cerebral blood flow (CBF) and regional distribution of CBF in humans. In this study we examined the effects of isoflurane in combination with nitrous oxide on CBF. We studied 10 patients (two groups of five patients, ASA I) anaesthetized with 50% nitrous oxide and either 0.5 or 1.0 MAC of isoflurane during normocapnia (PaCO2 5.7 kP...

The functional significance of MRI-defined mesial temporal sclerosis in temporal lobe epilepsy (TLE) is not completely established. In order to study the possible relationship between signals of mesial temporal sclerosis on MRI and interictal SPECT findings we selected 18 patients with complex partial seizures, unilateral temporal EEG focus and normal CT. The EEG focus was defined by the presen...

We investigated 32 patients with completed ischemic stroke less than or equal to 6 hours after the onset of symptoms by means of computed tomography, cerebral angiography, and technetium-99m-labeled hexamethylpropyleneamine oxime single-photon emission computed tomography to study cerebral blood flow. Follow-up computed tomography and cerebral blood flow studies were performed 1 week and 1 mont...

Although the distribution of [99mTc]hexamethylpropyleneamine oxime (HM-PAO) in the brain is said to be in a flow-related manner without temporal change, we present cases with leakage of [99mTc]HM-PAO (filling out phenomenon) in the delayed image of brain single photon emission computed tomography (SPECT) and clarify its clinical significance. The filling out phenomenon was observed in seven out...

BACKGROUND AND PURPOSE Transcranial Doppler sonography (TCD) can evaluate noninvasively the blood flow velocities and patency of the main trunk of the middle cerebral artery (MCA). Using TCD we evaluated MCA patency and patterns of flow through the circle of Willis in patients with acute stroke. METHODS Patients with symptoms of hemispheric stroke were evaluated with serial TCD tests during a...

BACKGROUND AND PURPOSE In a feasibility and safety study of thrombolytic therapy in acute ischemic stroke, we explored the usefulness of measurements of regional cerebral blood flow. METHODS Twenty-three patients with acute ischemic stroke were treated with 100 mg recombinant tissue plasminogen activator infused intravenously over 1 hour. Thrombolytic therapy was initiated 78 to 355 minutes a...

BACKGROUND AND PURPOSE This study was conducted to evaluate local cerebral blood flow changes in patients with depression after a subcortical stroke. METHODS Clinical and neuropsychological assessments were performed in 15 patients with a single subcortical lesion. Depression was assessed by DSM-III-R. In addition, the Hamilton Rating Scale for depression, the Zung Self-Rating Depression Scal...

OBJECTIVES Although many previous reports have described age-related changes in regional cerebral blood flow (rCBF), none has used 3D stereotactic surface projection (3D-SSP) analysis, which is able to detect subtle and significant changes in rCBF. METHODS The subjects were 31 healthy volunteers (16 men and 15 women; 50-79 years of age) without abnormal MR imaging and MR angiographic findings...

PURPOSE To report the development and validation of a technique of dual tracer single-photon emission CT brain imaging using technetium-99m hexamethylpropyleneamine oxime and iodine-123 iodoamphetamine agents and the application of this technique in patients with a variety of diagnoses. METHODS Contamination between the two isotopes' energy windows was calculated by opening both energy window...

BACKGROUND AND PURPOSE Increased transcranial Doppler velocities and regional cerebral perfusion defects have been well demonstrated in patients with subarachnoid hemorrhage, but the clinical significance of these changes has not been clearly defined, particularly in the presymptomatic stage of cerebral vasospasm. We have tested the hypothesis that a rapid, massive rise in Doppler velocity deno...