Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Comparative Study
Acute optic neuritis: association with paranasal sinus inflammatory changes on magnetic resonance imaging.
The authors compared the frequency of paranasal sinus inflammatory changes (SIC) on brain magnetic resonance imaging (MRI) obtained from 23 patients with new onset acute optic neuritis (ON) and 48 control patients who underwent outpatient MRI of the brain for reasons other than ON. The authors found a higher frequency of paranasal SIC in patients with ON (83%) than in controls (54%) (p = 0.02). The distribution of paranasal SIC (in ON and in controls) was maxillary (83% and 52%), ethmoid (4% and 2%), frontal (9% and 14%), and sphenoid (4% and 10%). ⋯ Grade I SIC did not significantly differ between the groups. There was a trend (p = 0.09) toward a higher prevalence of bilateral sinus inflammatory changes in patients with bilateral ON. These findings suggest that ON may be associated with sinus inflammatory changes.
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Case Reports
Cortical reorganization in linear nevus sebaceous syndrome: a multimodality neuroimaging study.
The authors report the findings of multimodal structural, functional, and metabolic imaging in a patient with linear nevus sebaceous syndrome, intractable seizures, and right megalencephaly. Despite nearly continuous paroxysmal electrical activity from the megalencephalic region, imaging studies suggested nonfunctional tissue in this region with reorganization of cortical function to the unaffected ipsilateral hemisphere. Hemispherectomy has been successfully performed in previous patients; however, it could have led to marked left hemiparesis with significant functional morbidity in this patient because of ipsilateral reorganization of the primary motor cortex.
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Case Reports
Rapidly progressive stroke in a young adult with very low high-density lipoprotein cholesterol.
Ischemic strokes can affect young adults (15-45 years old). Most such strokes are caused by cardioembolic events, small vessel disease, or illicit drug use, and less frequently by large vessel atherosclerosis. Large vessel cerebral atherosclerosis is usually associated with high levels of low-density lipoprotein (LDL) cholesterol, but a low level of high-density lipoprotein (HDL) is also a risk factor for ischemic strokes. ⋯ Advanced atherosclerosis developed in the patient in this study, with HDL of 3 mg/dL, leading to rapidly progressive stroke with a fatal outcome. The disease primarily affected the posterior circulation. The course of this case illustrates that very low HDL may be associated with advanced cerebrovascular atherosclerosis and fatal stroke, and as such should be considered in young individuals with stroke.
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Previous functional neuroimaging studies performed during transient global amnesia (TGA) have not answered the central question regarding the etiology of TGA, namely: whether the observed hypoperfusion in the mesial temporal lobe structures reflects a primarily ischemic process or whether it represents a secondary phenomenon resulting from locally decreased metabolism. The authors performed Tc 99-m-bicisate brain single photon-emission computed tomography (SPECT) scanning in a 66-year-old man during an episode of TGA, 24 hours after the episode and 3 months after the episode. To the authors' knowledge, this is the only reported study in which a follow-up SPECT scan was performed within 24 hours. ⋯ Resolution of the SPECT scan abnormalities correlated well with resolution of the memory loss. These findings agree with previously reported SPECT, positron-emission tomography (PET), and diffusion magnetic resonance imaging (MRI) studies that indicate the mesial temporal lobe structures as the major site of pathology in TGA. The authors suggest that a process causing decreased local metabolism, such as cortical spreading depression, constitutes the primary pathophysiologic mechanism in this case.
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Bell's palsy (idiopathic facial paralysis) is the most common cause of unilateral peripheral facial neuropathy. Bilateral involvement occurs in less than 10% of cases. The authors describe a 20-year-old man with bilateral idiopathic facial weakness. ⋯ There was no facial nerve swelling. Three months later he had improving residual bifacial weakness. To the authors' knowledge, this is the first report of abnormal MRI findings in bilateral Bell's palsy.