No abstract

No abstract

Background and Purpose-Reports of ischemic stroke affecting the hippocampus are rare. In this study we used diffusion-weighted MRI (DWI) to characterize patients with posterior circulation stroke involving the hippocampus. Methods-Fifty-seven consecutive acute stroke patients with hippocampal infarct (HI) on DWI were analyzed with regard to clinical features and ischemic lesion patterns. The last 20 of these underwent additional neuropsychological testing of short-term, working, and episodic long-term memory. Results-We found unilateral HI in 54 and bilateral HI in 3 patients. Visual analysis identified 4 patterns of DWI lesion affecting (1) the complete hippocampus (15/60), (2) the lateral (19/60) or (3) dorsal (22/60) parts of the hippocampal body and tail, and (4) circumscribed lesions in the lateral hippocampus (4/60), corresponding well to hippocampal vascular anatomy. In all cases DWI showed further ischemic lesions in the posterior circulation. Symptoms from lesions outside the hippocampus were the common leading clinical signs. Whereas mnestic deficits were prominent in only 11/57 patients, neuropsychological examination in 20 patients showed deficits of verbal episodic long-term memory in left and of nonverbal episodic long-term memory in right HI. Conclusion-Several phenotypic lesion patterns can be distinguished in HI that usually occur as part of multifocal PCA ischemia. A careful neuropsychological examination is necessary to detect resulting memory deficits.

The recanalization rate of CSVT under OAC was high and the median time to CRec was 6 months. Thrombosis of the superior sagittal sinus is a positive predictor of recanalization. Outcome in this cohort was excellent but no significant association of outcome and recanalization status was found.

This study supports previous observations that migrainous infarction mostly occurs in the posterior circulation, and in younger women with a history of migraine with aura. Acute ischemic lesions were often multiple and located in distinct arterial territories. As there were no overlapping ischemic lesions, hemodynamic compromise during the development of migraine is unlikely the cause of infarction. Differentiation between migrainous infarction and prolonged migraine aura is difficult and associated with delayed admission of patients.

Since decision-making for thrombolysis in acute stroke settings is restricted to a limited time window and based on clinical assessment and CT findings only, thrombolysis is sometimes applied to patients with a final diagnosis other than a stroke. From a prospectively collected stroke/MRI data bank (2004-2010) with 648 suspected ischemic stroke patients treated with rtPA, we identified patients without evidence of acute infarction on follow-up MRI and a final diagnosis other than a stroke or acute cerebrovascular event. We compared demographics, symptoms, complications, and outcome of patients with stroke mimics (SM) to those with acute infarction. In 42 patients, an SM was diagnosed: seizures in 20, conversion disorder in seven, dementia in six, migraine in three, brain tumor in two, and others in four patients. Patients with SM less often had typical stroke symptoms like dysarthria (p < 0.01), facial palsy (p < 0.001), hemiparesis (p < 0.001), horizontal gaze palsy (p < 0.001), and visuospatial neglect (p = 0.03), while aphasia (p = 0.004) and accompanying convulsions (p = 0.01) occurred more often. Independent predictors of SM were known cognitive impairment, aphasia, and accompanying convulsions. Thrombolysis-related complications (orolingual angioedema) occurred in one SM patient and none of the SM patients deteriorated clinically. Stroke mimics comprise neurological/psychiatric disorders and differ from ischemic stroke patients with regard to the clinical presentation at onset. This might be helpful in deciding which patients should undergo acute stroke MRI to rule out SM, facilitate treatment decisions, and reduce the risk of unnecessary therapy.

In contrast to intraparenchymal blood-brain barrier (BBB) dysfunction that is frequently seen in patients with MS, BBB dysfunction of leptomeningeal vessels is usually not detectable in patients with early MS.

Background and Purpose-Molecular imaging of therapeutic interventions with targeted agents that simultaneously carry drugs or genes for local delivery is appealing. We investigated the ability of a novel microbubble carrier (immunobubble) for abciximab, a glycoprotein IIb/IIIa receptor inhibitor, for ultrasonographic molecular imaging of human clots. Methods-Human thrombi were incubated with immunobubbles conjugated with abciximab. Control clots were incubated in either saline or with immunobubbles conjugated with nonspecific antibody. We evaluated immunobubble suspensions with variable concentrations of encapsulated gas and measured mean acoustic intensity of the incubated clots. In vivo molecular imaging of human thrombi with abciximab immunobubbles was evaluated in a rat model of carotid artery occlusion. Results-Mean acoustic intensity was significantly higher for abciximab immunobubbles as compared with control immunobubbles under all conditions tested with maximum difference in intensity at a gas volume of 0.2 L (Pϭ0.0013 for mechanical index 0.05, Pϭ0.0001 for mechanical index 0.7). Binding of abciximab immunobubbles to clots in vitro led to enhanced echogenicity dependent on bubble concentration. In vivo ultrasonic detectability of carotid thrombi was significantly higher for clots targeted with abciximab immunobubbles (PϽ0.05). Quantification of in vivo contrast enhancement displayed a highly significant increment for abciximab immunobubble-targeted clots compared with nonspecific immunobubble-targeted clots (PϽ0.0001) and to native clots (PϽ0.0001). Conclusions-This study demonstrates the feasibility of using a therapeutic agent for selective targeting in vascular imaging. Abciximab immunobubbles improve visualization of human clots both in vitro and in an in vivo model of acute arterial thrombotic occlusion.