AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Oct 2008
Whole-brain voxel-based morphometry in Kallmann syndrome associated with mirror movements.
There are 2 main hypotheses concerning the cause of mirror movements (MM) in Kallmann syndrome (KS): abnormal development of the primary motor system, involving the ipsilateral corticospinal tract; and lack of contralateral motor cortex inhibitory mechanisms, mainly through the corpus callosum. The purpose of our study was to determine white and gray matter volume changes in a KS population by using optimized voxel-based morphometry (VBM) and to investigate the relationship between the abnormalities and the presence of MM, addressing the 2 mentioned hypotheses. ⋯ The VBM study did not show significant white matter changes in patients with KS but showed gray matter alterations in keeping with a hypertrophic response to a deficient pyramidal decussation in patients with MM. In addition, gray matter alterations were observed in patients without MM, which can represent more complex mechanisms determining the presence or absence of this symptom.
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AJNR Am J Neuroradiol · Oct 2008
Assessment of dural arteriovenous fistulas of the cavernous sinuses on 3D dynamic MR angiography.
Flow voids within the cavernous sinuses and/or certain venous drainage on spin-echo MR imaging and time-of-flight (TOF) flow enhancement on MR angiography (MRA) have indicated high-velocity shunt flow and have been used for screening patients with dural arteriovenous fistulas (DAVFs) of the cavernous sinuses. In this investigation, the capabilities of 3D dynamic MRA as a flow-independent approach and those of conventional MR imaging techniques were compared with selective angiography for the diagnosis of DAVFs of the cavernous sinuses. ⋯ In this small series, screening 3D dynamic MRA directly demonstrates DAVFs of the cavernous sinuses and has improved diagnostic capability.
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AJNR Am J Neuroradiol · Oct 2008
Wall shear stress on ruptured and unruptured intracranial aneurysms at the internal carotid artery.
Hemodynamics is often recognized as one of the major factors in aneurysm rupture. Flow impingement, greater pressure, and abnormal wall shear stress are all indications for aneurysm rupture. Characterizing wall shear stress for intracranial aneurysms at similar anatomic locations may help in understanding its role. ⋯ For intracranial aneurysms at the internal carotid artery, an area of low wall shear is associated with aneurysm rupture.
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AJNR Am J Neuroradiol · Oct 2008
Essential head tremor is associated with cerebellar vermis atrophy: a volumetric and voxel-based morphometry MR imaging study.
Our aim was to investigate the presence of brain gray matter (GM) abnormalities in patients with different forms of essential tremor (ET). ⋯ Atrophy of the cerebellar vermis detected in patients with h-ET strongly supports the evidence for the involvement of the cerebellum in the pathophysiology of ET. The lack of a significant CV loss observed in patients with a-ET suggests that a-ET and h-ET might represent distinct subtypes of the same disease.
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AJNR Am J Neuroradiol · Oct 2008
Arterial spin-labeling MR imaging measurements of timing parameters in patients with a carotid artery occlusion.
Arterial spin-labeling (ASL) with image acquisition at multiple delay times can be exploited in perfusion MR imaging to visualize and quantify the temporal dynamics of arterial blood inflow. In this study, we investigated the consequences of an internal carotid artery (ICA) occlusion and collateral blood flow on regional timing parameters. ⋯ Regional assessment of timing parameters with ASL may provide valuable information on the cerebral hemodynamic status. In patients with leptomeningeal collaterals, the most impaired territory was found in the frontal lobe.