Michael Forsting

Decompressive craniectomy, reperfusion, or a combination for early treatment of acute "malignant" cerebral hemispheric stroke in rats? Potential mechanisms studied by MRI.

BACKGROUND AND PURPOSEnBoth early reperfusion and decompressive craniectomy have proved beneficial in the treatment of large space-occupying malignant hemispheric stroke. The aim of this study was to directly compare the benefit of reperfusion with that of craniectomy and to study the effects of combined treatment in a rat model of focal cerebral ischemia.nnnMETHODSnCerebral ischemia was introduced in 28 rats. Four groups were investigated: (1) no treatment, (2) decompressive craniectomy, (3) reperfusion, and (4) reperfusion and craniectomy as treatment at 1 hour after middle cerebral artery occlusion. Perfusion- and diffusion-weighted MRI were performed serially from 0.5 to 6 hours after middle cerebral artery occlusion.nnnRESULTSnThe 6-hour DWI-derived hemispheric lesion volumes in the reperfusion group (10.2+/-3.9%), the craniectomy group (23.0+/-6.4%), and the combination group (21.8+/-12.4) were significantly smaller than that in the control group (44.1+/-5.4%) (P<0.05). Reperfusion, craniectomy, and combined treatment led to higher perfusion in the cortex compared with the control group, whereas only reperfused animals achieved significantly higher perfusion in the basal ganglia. In 5 animals, combined reperfusion and decompressive craniectomy resulted in an early contrast media enhancement.nnnCONCLUSIONSnEarly reperfusion and craniectomy were shown to be effective in decreasing infarction volume by improving cerebral perfusion. Reperfusion remains the best therapy in malignant hemispheric stroke. Combined treatment yields no additional benefit compared with single treatment, probably because of early blood-brain barrier breakdown.

Multilocal magnetic resonance perfusion mapping comparing the cerebral hemodynamic effects of decompressive craniectomy versus reperfusion in experimental acute hemispheric stroke in rats

This study examined the hemodynamic effects of craniectomy compared to reperfusion on the temporal evolution of cerebral perfusion in different brain regions in a rat model of focal cerebral ischemia. Three groups were investigated: no treatment, reperfusion or craniectomy at 1 h. Perfusion-weighted magnetic resonance imaging (PWI) was performed serially from 0.5 to 6 h. Relative regional cerebral blood flow was calculated for different regions and infarct volume was assessed by histology at 24 h. As conclusion, both, craniectomy and reperfusion increased cerebral perfusion in the acute phase of cerebral ischemia. While reperfusion resulted in a homogeneous improvement of perfusion in the cortex and basal ganglia, craniectomy improved only cortical perfusion in areas directly under the craniectomy site. PWI is well suited to non-invasively monitor perfusion alterations after aggressive therapeutical approaches in stroke.

Developmental Venous Anomalies

Developmental venous anomalies (DVAs) represent the most common vascular variant n n nDVAs consist typical of medullary veins forming a caput medusae draining into a transcerebral collector vein which empties into a dural, subependymal or cortical vein n n nDVAs are low-flow, low-resistance abnormalities draining normal brain parenchyma! n n nDVAs have been associated with vague neurological symptoms, such as nonspecific headaches and dizziness, or with seizures. In most cases it is an incidental finding n n nUp to one third of DVAs is associated with cavernomas; therefore susceptibility weighted MRI-sequences should be included into the imaging protocol, especially if a seizure was the indication for the examination. Therapy should be focussed on the cavernoma n n nRarely, congenital abnormalities (e.g. heterotopia) might also be associated with DVAs n n nVenous thrombosis in DVAs might occur but no more often than in any other intracranial vein n n nSurgical resection or radiation therapy of DVAs should be avoided n n nEndovascular therapy of DVAs is also not an option

Decompressive Craniectomy, Reperfusion, or a Combination for Early Treatment of Acute "Malignant" Cerebral Hemispheric Stroke in Rats? : Potential Mechanisms Studied by MRI Editorial Comment: Potential Mechanisms Studied by MRI

BACKGROUND AND PURPOSEnBoth early reperfusion and decompressive craniectomy have proved beneficial in the treatment of large space-occupying malignant hemispheric stroke. The aim of this study was to directly compare the benefit of reperfusion with that of craniectomy and to study the effects of combined treatment in a rat model of focal cerebral ischemia.nnnMETHODSnCerebral ischemia was introduced in 28 rats. Four groups were investigated: (1) no treatment, (2) decompressive craniectomy, (3) reperfusion, and (4) reperfusion and craniectomy as treatment at 1 hour after middle cerebral artery occlusion. Perfusion- and diffusion-weighted MRI were performed serially from 0.5 to 6 hours after middle cerebral artery occlusion.nnnRESULTSnThe 6-hour DWI-derived hemispheric lesion volumes in the reperfusion group (10.2+/-3.9%), the craniectomy group (23.0+/-6.4%), and the combination group (21.8+/-12.4) were significantly smaller than that in the control group (44.1+/-5.4%) (P<0.05). Reperfusion, craniectomy, and combined treatment led to higher perfusion in the cortex compared with the control group, whereas only reperfused animals achieved significantly higher perfusion in the basal ganglia. In 5 animals, combined reperfusion and decompressive craniectomy resulted in an early contrast media enhancement.nnnCONCLUSIONSnEarly reperfusion and craniectomy were shown to be effective in decreasing infarction volume by improving cerebral perfusion. Reperfusion remains the best therapy in malignant hemispheric stroke. Combined treatment yields no additional benefit compared with single treatment, probably because of early blood-brain barrier breakdown.