Neuroradiology
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Reversible focal lesions in the splenium of the corpus callosum (SCC) have recently been reported. They are circumscribed and located in the median aspect of the SCC. On MRI, they are hyperintense on T2-W and iso-hypointense on T1-W sequences, with no contrast enhancement. ⋯ Edema and diffusion restriction in focal reversible lesions of the SCC have been attributed to excitotoxic mechanisms that can result from different mechanisms; no unifying relationship has been found to explain all the pathologies associated with SCC lesions. In our opinion, the similar imaging, clinical and prognostic aspects of these lesions depend on a high vulnerability of the SCC to excitotoxic edema and are less dependent on the underlying pathology. In this review, the relevant literature concerning reversible focal lesions in the SCC is analyzed and hypotheses about their pathogenesis are proposed.
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Stable insertion of guide catheters via the femoral route can prove difficult because of tortuous vasculature leading to failure of endovascular treatment of intracranial aneurysms. ⋯ The use of a long introducer sheath, by enhancing stability in the aortic arch and supraaortic vessels, provides another solution to the problem of vascular tortuosity that hinders endovascular treatment of intracranial lesions.
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Transient global amnesia (TGA) is characterized by a sudden onset of anterograde amnesia without alteration of consciousness or personal identity. Interestingly, recent studies have reported a high frequency of small high-signal abnormalities in the hippocampus with diffusion-weighted (DW) imaging, and ischemia has been proposed as an etiology of TGA. We hypothesized that TGA lesions occur preferentially in the CA1 region of the hippocampus, known to be susceptible to ischemia. ⋯ Lesions associated with TGA were localized exclusively to the lateral portion of the hippocampus corresponding to the CA1 region. This finding supports the ischemic etiology of TGA; however, the pathophysiological mechanism involved requires further study.
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Idiopathic inflammatory-demyelinating diseases (IIDDs) include a broad spectrum of central nervous system disorders that can usually be differentiated on the basis of clinical, imaging, laboratory and pathological findings. However, there can be a considerable overlap between at least some of these disorders, leading to misdiagnoses or diagnostic uncertainty. The relapsing-remitting and secondary progressive forms of multiple sclerosis (MS) are the most common IIDDs. ⋯ Although some of these uncommon IIDDs are variants of MS, others probably correspond to different entities. MR imaging of the brain and spine is the imaging technique of choice for diagnosing these disorders, and together with the clinical and laboratory findings can accurately classify them. Precise classification of these disorders may have relevant prognostic and treatment implications, and might be helpful in distinguishing them from tumoral or infectious lesions, avoiding unnecessary aggressive diagnostic or therapeutic procedures.
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Review Case Reports
A case report of Wyburn-Mason syndrome and review of the literature.
Wyburn-Mason syndrome is a distinct congenital neurocutaneous entity comprised of ipsilateral arteriovenous malformations (AVMs) of the midbrain, vascular abnormalities affecting the visual pathway, and facial nevi. ⋯ The presentation of patients with Wyburn-Mason syndrome can vary greatly according to the site and the extent of vascular lesions. Intracranial AVMs occasionally hemorrhage with significant morbidity. Treatment is controversial, and patients are typically managed conservatively by observation.