Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Case Reports
A case study of hemispatial neglect using finite element analysis and positron emission tomography.
The authors present a patient who developed transient hemispatial neglect following surgical drainage of a large right frontotemporal arachnoid cyst. As symptoms evolved in parallel with brain shift over the subsequent months, the authors hypothesized that the disorder was associated with the appearance of mechanical stresses in the cerebral mantle. ⋯ The authors conclude that brain deformation was a contributing factor in the reversible neglect syndrome by compromising the normal flow of blood and/or the deactivation of subcortical circuits of the parietal lobe.
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To investigate the clinical applicability and validity of [123I] iodobenzofuran (IBF) single-photon emission computed tomography (SPECT), the authors analyzed the changes in striatal dopamine D2 receptor binding among 7 patients with Parkinson's disease (PD), 6 patients with progressive supranuclear palsy (PSP) (Hoehn and Yahr stage II to IV), and 8 normal controls. ⋯ The results predict that [123I] IBF SPECT, especially voxel-by-voxel BP parametric imaging, can discriminate among extrapyramidal diseases such as PD and PSP and may be applicable for clinical use.
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High-intensity transient signals (HITS) are frequently detected by transcranial Doppler (TCD) ultrasound in patients with mechanical prosthetic heart valves (PHVs), but published data about their clinical relevance are controversial. This study was undertaken to determine the clinical relevance of HITS in patients with mechanical PHVs. ⋯ Only age was a significant predictor of HITS in patients with mechanical PHVs. The lack of association between HITS, clinical symptoms, and cognitive functioning suggests that most of these signals represent harmless epiphenomena, and only HITS detected after O2 inhalation have any clinical relevance.
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Despite good clinical criteria for diagnosing optic neuritis (ON), only a few techniques can precisely assess its impact on visual brain function. The authors studied whether functional magnetic resonance imaging (fMRI) of visual activation reliably reflects the cerebral consequences of acute unilateral ON, and how fMRI correlates with clinical function and visual evoked potentials (VEPs). Twenty ON patients, before and after steroid treatment, were compared to 20 controls. ⋯ The higher stimulation frequencies yielded greater fMRI responses from unaffected eyes, but not from affected eyes, in controls. The fMRI responses were quantifiable in every subject, whereas in 11 ON eyes, no VEPs were obtained during the acute stage. The authors conclude that fMRI is sensitive to the cerebral response alteration during ON and might therefore contribute to evaluating the temporal evolution of the visual functional deficit during recovery or therapy.
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Case Reports
Development of a posterior fossa cavernous malformation associated with bilateral venous anomalies: case report.
Venous angiomas (VAs) and cavernous malformations (CMs) are common cerebrovascular malformations. Frequently, these lesions are found in close proximity. The interrelationship between VAs and CMs has not yet been adequately defined. ⋯ The sequential imaging suggests a causal relationship between VAs and some CMs. Furthermore, the detailed MRI permitted radiosurgical treatment of these CMs. The occurrence of de novo CMs adjacent to VAs on future imaging studies in other patients may help confirm the etiology of at least a subset of CMs.