Occult cerebral vascular malformations: high-field MR imaging

Occult cerebral vascular malformations (OCVMs) have characteristic appearances on high-field magnetic resonance (MR) images. These consist of circumscribed regions of low intensity, most prominent on T2-weighted images and representing hemosiderin deposits. Interspersed within most of these lesions are multiple areas of various signal intensity patterns, which correspond to hematomas in different stages of evolution and to fibrous regions containing calcium as well as hemosiderin. Forty-six lesions were found in 19 patients (34 supratentorial and 12 infratentorial). The supratentorial lesions tended to be subcortical or periventricular. Computed tomography depicted 24 of the 46 lesions demonstrated by high-field MR. Comparison of images obtained with both low-field MR (0.12 T and 0.35 T) and high-field MR (1.5 T) revealed that high-field MR imaging was superior in depicting OCVMs. High-field MR appears to be both sensitive and specific for OCVMs and may obviate the need for possible biopsy of these lesions.     

Topical corticosteroids in psoriasis: strategies for improving safety

Corticosteroids are a mainstay of topical therapy for psoriasis. While efficacious and relatively safe when used carefully, the potential for side effects, notably skin atrophy and adrenal suppression, have been associated with excesses in potency, prolonged or widespread use. The International Psoriasis Council Working Group on Topical Therapy has reviewed the efficacy and safety of topical corticosteroids and recommends strategies for safe, long‐term use of these agents.     

Type IIB Tampa: a variant of von Willebrand disease with chronic thrombocytopenia, circulating platelet aggregates, and spontaneous platelet aggregation

Type IIB von Willebrand disease is characterized by enhanced ristocetin- induced platelet aggregation and absence of large von Willebrand factor multimers from plasma. An alteration of the von Willebrand factor molecule resulting in increased reactivity with platelets appears to be the basis for these abnormalities. We have now identified a new variant of type IIB von Willebrand disease in a family in which the four affected members also have chronic thrombocytopenia, in vivo platelet aggregate formation, and spontaneous platelet aggregation in vitro. In spite of repeatedly prolonged bleeding times and persistent thrombocytopenia, their bleeding diathesis is only moderate.     

Corpus callosum and limbic system: neuroanatomic MR evaluation of developmental anomalies

Agenesis of the corpus callosum is a complex malformation of the brain that has been associated with varying degrees of limbic system maldevelopment. We retrospectively reviewed the records of 11 patients with callosal agenesis (seven total, four partial) who underwent magnetic resonance (MR) imaging, with particular attention to the associated malformations of the limbic system. Comparison was made with selected images from MR examinations of healthy volunteers and with necropsy specimens from other patients with callosal agenesis. Ten of 11 patients demonstrated limbic anomalies (severe motion artifact precluded evaluation of these structures in one patient). MR depicted not only the abnormalities intrinsic to callosal agenesis but also the frequently associated malformations of the limbic system.