Transcranial cerebral oximetry and transcranial doppler sonography in patients with ruptured cerebral aneurysms and delayed cerebral vasospasm.

Background: Vasospasm is a major cause of ischemic neurological deficits developing after subarachnoid hemorrhage. The goal was to identify hemodynamic changes and the presence of clinical vasospasm in patients suffering from subarachnoid hemorrhage secondary to ruptured intracranial aneurysms.

Material/methods: Pre- and postoperative serial transcranial cerebral oximetry and transcranial doppler sonography (TCD) examinations were performed in 75 patients operated for aneurysmal subarachnoid hemorrhage.

Mapping of the cerebral response to acetazolamide using graded asymmetric spin echo EPI.

Cerebral vascular reactivity in different regions of the rat brain was quantitatively characterized by spatial and temporal measurements of blood oxygenation level-dependent (BOLD)-fMRI signals following intravenous administration of the carbonic anhydrase inhibitor acetazolamide: this causes cerebral vasodilatation through a cerebral extracellular acidosis that spares neuronal metabolism and vascular smooth muscle function, thus separating vascular and cerebral metabolic events. An asymmetric spin echo-echo planar imaging (ASE-EPI) pulse sequence sensitised images selectively to oxygenation changes in the microvasculature; use of a surface coil receiver enhanced image signal-to-noise ratios (SNRs). Image SNRs and hardware integrity were verified by incorporating quality assurance procedures; cardiorespiratory stability in the physiological preparations were monitored and maintained through the duration of the experiments.

A delayed class of BOLD waveforms associated with spreading depression in the feline cerebral cortex can be detected and characterised using independent component analysis (ICA).

An application of independent component analysis to blood oxygenation level- dependent MRI (BOLD-MRI) results was used to detect cerebrovascular changes that followed the initiation of cortical spreading depression (CSD) in feline brain. The cortical images were obtained from a horizontal plane at 28 s intervals before, and for 1.4-1.

Laypersons' expectation of the sequelae of whiplash injury: a cross-cultural comparative study between Canada and Greece.

Background: The objective of the present study is to compare the frequency and nature of expected 'whiplash' symptoms in Greece [a country where the chronic whiplash syndrome is rare or unknown] with that in Canada.

Material/methods: A symptom checklist was administered to 2 subject groups selected from local companies in Patras Greece, and Edmonton, Canada, respectively. Subjects were asked to imagine having suffered a neck sprain [whiplash injury] with no loss of consciousness in a motor vehicle collision, and to check which, of a variety of symptoms, they would expect might arise from the injury.

Cortical spreading depression in the feline brain following sustained and transient stimuli studied using diffusion-weighted imaging.

Cortical spreading depression (CSD) was induced by transient (10 min) applications of KCl in agar upon the cortical surface of alpha-chloralose anaesthetised cats. Its features were compared with CSD resulting from sustained applications of crystalline KCl through a mapping of the apparent diffusion coefficient (ADC) using diffusion-weighted echo planar imaging (DWI) over a poststimulus period of 60-100 min. Individual CSD events were computationally detected with the aid of Savitzky-Golay smoothing applied to critically sampled data derived from regions of interest (ROIs) made up of 2 x 2 pixel matrices.