Previous studies have demonstrated that cerebral blood flow (CBF) can be assessed noninvasively by MRI using magnetic labeling of arterial water as a diffusible flow tracer. The purpose of this study was to assess the quality of CBF images obtained from patients with cerebrovascular disease using this method, and to begin to evaluate the potential clinical role for this technique. We recruited 14 patients who presented with stroke, TIA, or severe carotid stenosis and were likely to have altered CBF based on clinical assessment. In many of these patients, CBF imaging disclosed both focal and hemispheric hypoperfusion, either in vascular territories or in watershed regions. In 11 patients with significant proximal arterial stenosis, hemispheric CBF abnormalities localized to the side of most significant stenosis for the anterior circulation distribution. In several patients watershed hypoperfusion was even more pronounced. Our results suggest that good-quality MR CBF images can be obtained reliably from patients with cerebrovascular disease. CBF imaging can be combined with standard structural imaging within a single MRI examination, and provides clinically meaningful information. The capability of measuring CBF easily provides a potentially useful tool for clinical assessment and further investigation of stroke pathophysiology.
We directly stimulated muscle in three patients with acute quadriplegic myopathy to determine whether paralyzed muscle in this syndrome is electrically excitable. Two of the patients had been treated with neuromuscular blocking agents and corticosteroids, and one patient had been treated with corticosteroids alone. We found that paralyzed muscle is electrically inexcitable in affected patients. Muscle regained electrical excitability over weeks to months. The recovery of muscle excitability paralleled the clinical recovery of patients, suggesting that paralysis in this syndrome is secondary to electrical inexcitability of muscle membrane.
Miller Fisher's syndrome is a rare variant of Guillain-Barré's syndrome characterized by the acute development of ataxia, ophthalmoparesis, and areflexia. Most patients have a measureable antibody in serum directed against the GQ1b ganglioside. This antibody is also present in the serum of patients with other forms of Guillain-Barré's syndrome who have prominent ataxia or ophthalmoplegia as part of their clinical presentation. Miller Fisher's syndrome generally is self-limited and has an excellent prognosis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.