SUMMARY: RCVS is a clinical condition of recurrent severe headaches that may be associated with ischemic or hemorrhagic stroke and that is defined by the presence of segmental vasoconstriction in multiple cerebral arteries. The angiographic appearance resembles vasculitis, except that the abnormalities resolve during the course of several months. Because the treatment of RCVS differs from that for vasculitis, radiologists must understand the clinical and radiologic features so as to better guide imaging algorithms and facilitate diagnosis. We present a series of 6 cases of RCVS that highlight the imaging features across multiple modalities.ABBREVIATIONS: IPH ϭ intraparenchymal hemorrhage; MIP ϭ maximum intensity projection; NSAID ϭ nonsteroidal anti-inflammatory drug; PACNS ϭ primary angiitis of the CNS; PRES ϭ posterior reversible encephalopathy syndrome; RCVS ϭ reversible cerebral vasoconstriction syndrome; SDH ϭ subdural hematoma; TCD ϭ transcranial Doppler R CVS is an under-recognized clinical-radiologic entity characterized by a history of sudden severe headaches, sometimes associated with ischemic or hemorrhagic stroke, focal neurologic deficits, or seizures. First described by Call et al in 19881 , RCVS encompasses a wide variety of entities previously described by other names, including postpartum angiopathy, migrainous vasospasm, migrainous stroke, druginduced angiopathy, and benign angiopathy of the CNS. 2,3The condition is defined by reversible segmental cerebral vasoconstriction on angiography.1-3 The angiographic findings are similar to those of other vasculopathies, including PACNS.4 Unlike PACNS, the vascular abnormalities of RCVS resolve within several months. 1,2,5,6 RCVS typically occurs following exposure to a trigger, commonly sympathomimetic or vasoactive agents, including amphetamines, phenylpropanolamine, pseudoephedrine, serotonergic antidepressants, nicotine, caffeine, cannabis, and triptan-or ergot-containing medications.2,7-9 Other triggers include the peripartum period, 10 eclampsia, strenuous physical activity, bathing or showering, sexual activity, and binge alcohol drinking.2 Most patients with RCVS are young and middle-aged women. 3Patients with RCVS exhibit a range of parenchymal abnormalities, including convexal SAH, IPH, ischemic infarcts, and PRES.2,9,11-13 Alternatively, imaging findings may be normal.2,9 Findings of CSF analysis are usually normal or nearnormal.3 Because of the overlap with other causes of headache and stroke in adults and because the vascular abnormalities early in the course of the disease may be subtle or absent, the diagnosis of RCVS is easily missed. Early recognition of RCVS allows appropriate clinical management aimed at reducing the frequency, duration, and severity of vascular complications, primarily through identification and removal of triggers. Because management and outcome of RCVS differ from those of other vasculopathies, it is critical that radiologists recognize its typical imaging appearance, time course, and clinical features. Case Series...

Compared with the traditional ambulance model, telemedicine-enabled ambulance-based thrombolysis resulted in significantly decreased time to imaging and treatment.

The bone morphogenic proteins (BMPs) play a key role in skeletal development and patterning. Using the technique of differential display polymerase chain reaction (ddPCR), we have identified a novel gene whose expression is increased during BMP-2-induced differentiation of the prechondroblastic cell line, MLB13MYC clone 17, to an osteoblastic phenotype. The 6.5-kilobase mRNA recognized by this ddPCR product is increased 10-fold by BMP-2 treatment of the MLB13MYC clone 17 cells. The mRNA recognized by this ddPCR product is also increased as MC3T3-E1 cells recapitulate the program of osteoblast differentiation during prolonged culture. The full-length transcript corresponding to this ddPCR product was cloned from a MLB13MYC clone 17 cell cDNA library. Analysis of the deduced amino acid sequence demonstrated that this gene encodes a novel 126-kDa putative serine/threonine protein kinase containing a nuclear localization signal. The kinase domain, expressed in Escherichia coli, is capable of autophosphorylation as well as phosphorylation of myelin basic protein. The gene was, therefore, named BIKe (BMP-2-Inducible Kinase). The BIKe nuclear localization signal is able to direct green fluorescent protein to the nucleus in transfected COS-7 cells. When stably expressed in MC3T3-E1 cells, BIKe significantly decreases alkaline phosphatase activity and osteocalcin mRNA levels and retards mineral deposition relative to vector control. This novel kinase, therefore, is likely to play an important regulatory role in attenuating the program of osteoblast differentiation.Numerous investigations have been directed at elucidating factors that regulate osteoblast differentiation (1). The bone morphogenetic proteins (BMPs) 1 are potent local factors that promote osteoblast differentiation during development as well as during bone remodeling (2). The molecular events downstream of BMP signaling that result in tissue-specific gene expression and skeletal development have only been partially elucidated. The binding of BMPs to their receptors leads to the assembly of a receptor complex in which the type II receptor phosphorylates and activates the type I receptor. As a result, pathway-restricted SMADs are phosphorylated, leading to interactions with the common mediator SMAD, smad4 (3). This complex is then translocated to the nucleus, where it modulates transcription of target genes. BMP signaling can also interfere with the effects of other growth and differentiation factors. It has been demonstrated that BMP-2 treatment of mesangial cells prevents phosphorylation of a transcription factor, Elk1, in response to platelet-derived growth factor (PDGF) signaling. This effectively inhibits PDGF-induced Elk-1-mediated transcription, and blocks PDGF-induced transcription of c-fos, an Elk-1 target (4). BMP-7 has been shown to be a potent inducer of Cbfa1, a transcription factor belonging to the runt-domain gene family that, in turn, regulates the expression of several genes in the osteoblast (5). Although Cbfa1 expression is necessary, it a...