***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: PURPOSE To prospect ively evaluate , with magnetic resonance ( MR ) imaging , long-term outcome of the brain after endovascular versus neurosurgical treatment for aneurysmal subarachnoid hemorrhage ( aSAH ) . MATERIAL S AND METHODS Institutional review board approval and informed consent were obtained . One hundred sixty-eight ( 77 men , 91 women ; mean age + /- st and ard deviation , 51 years + /- 13 ) patients were r and omly assigned to surgical versus endovascular treatment of the ruptured aneurysm with 138 ( 67 endovascular , 71 surgical ) MR examinations 1 year after aSAH . The presence , localization , volumes , and cause of lesions were analyzed with chi(2 ) , Mann-Whitney U , and Student t tests . Furthermore , correlation between MR-detectable brain parenchymal high-signal intensity ( SI ) lesions on T2- and intermediate-weighted MR images and neuropsychologic outcome was evaluated by using Spearman correlation coefficient . RESULTS Only 44 ( 31.9 % ) of 138 patients had no lesions associated with aSAH . According to intention to treat , lesions were more frequent after surgical rather than endovascular treatment , predominating in the frontal ( surgical : n = 50 , [ 70.4 % ] vs endovascular : n = 34 [ 50.7 % ] , P = .018 ) and temporal ( n = 34 [ 47.9 % ] vs n = 15 [ 22.4 % ] , P = .002 ) lobes . Only endovascular patients had subtentorial lesions ( n = 4 [ 6.0 % ] , P = .037 ) . Ischemic lesions in the parental artery territory were more frequent in surgical ( n = 33 [ 46.5 % ] ) than in endovascular ( n = 15 [ 22.4 % ] , P = .003 ) patients , with corresponding mean lesion volumes of 20.9 cm(3 ) + /- 46.5 versus 17.6 cm(3 ) + /- 35.8 ( P = .209 ) . Ischemic lesions in remote vascular territories were equal in frequency and size . Retraction injuries were common in the surgical ( n = 40 , [ 56.3 % ] ) treatment group . Ischemic lesion volumes correlated with neuropsychologic test scores . CONCLUSION Parenchymal high-SI lesions on T2- and intermediate-weighted MR images are more frequent after early surgical rather than endovascular treatment of the ruptured aneurysm , and lesion volumes correlate with the neuropsychologic test performance Objective To determine if ischaemia is a mechanism of early brain injury at the time of aneurysm rupture in subarachnoid haemorrhage ( SAH ) and if early MRI ischaemia correlates with admission clinical status and functional outcome . Methods In a prospect i ve , hypothesis-driven study patients with SAH underwent MRI within 0–3 days of ictus ( prior to vasospasm ) and a repeat MRI ( median 7 days ) . The volume and number of diffusion weighted imaging ( DWI ) positive/apparent diffusion coefficient ( ADC ) dark lesions on acute MRI were quantitatively assessed . The association of early ischaemia , admission clinical status , risk factors and 3-month outcome were analysed . Results In 61 patients with SAH , 131 MRI were performed .  Early ischaemia occurred in 40 ( 66 % ) with a mean DWI/ADC volume 8.6 mL ( 0–198 mL ) and lesion number 4.3 ( 0–25 ) . The presence of any early DWI/ADC lesion and increasing lesion volume were associated with worse Hunt-Hess grade , Glasgow Coma Scale score and Acute Physiology and Chronic Health Evaluation II physiological subscores ( all p<0.05 ) . Early DWI/ADC lesions significantly predicted increased number and volume of infa rcts on follow-up MRI ( p<0.005 ) . At 3 months , early DWI/ADC lesion volume was significantly associated with higher rates of death ( 21 % vs 3 % , p=0.031 ) , death/severe disability ( modified Rankin Scale 4–6 ; 53 % vs 15 % , p=0.003 ) and worse Barthel Index ( 70 vs 100 , p=0.004 ) . After adjusting for age , Hunt-Hess grade and aneurysm size , early infa rct volume correlated with death/severe disability ( adjusted OR 1.7 , 95 % CI 1.0 to 3.2 , p=0.066 ) . Conclusions Early ischaemia is related to poor acute neurological status after SAH and predicts future ischaemia and worse functional outcomes . Treatments addressing acute ischaemia should be evaluated for their effect on outcome Background : Aneurysmal subarachnoid hemorrhage ( SAH ) and surgical clipping of intracranial aneurysms are associated with substantial morbidity and mortality . Objective : To compare cognitive outcome and structural damage in patients with aneurysmal SAH treated with surgical clipping or endovascular coiling .  Methods : Forty case-matched pairs of patients with aneurysmal SAH treated by surgical clipping or endovascular coiling  were prospect ively assessed by use of a battery of cognitive  tests . Twenty-three case-matched pairs underwent MRI 1 year after the procedure . Matching was based on grade of SAH on admission , location of aneurysm , age , and premorbid IQ . Results : Both groups were impaired in all cognitive domains when compared with age-matched healthy control subjects . Comparison of cognitive outcome between the two groups indicated an overall trend toward a poorer cognitive outcome in the surgical group , which achieved significance in four tests . MRI showed focal encephalomalacia exclusively in the surgical group . This group also had a significantly higher incidence of single or multiple small infa rcts within the vascular territory of the aneurysm , but both groups had similar incidence of large infa rcts and global ischemic damage . Conclusion : Endovascular treatment may cause less structural brain damage than surgery and have a more favorable cognitive outcome . However , cognitive outcome appears to be dictated primarily by the complications of SAH OBJECTIVE To assess whether subarachnoid hemorrhage ( SAH ) and its treatment is followed by volume loss in temporomesial structures . METHODS One hundred fifty-five consecutive patients with aneurysmal SAH were r and omly assigned to surgical or endovascular treatment . Volumetric MRI was performed in 77 SAH patients with good or moderate clinical outcome 1 year after hemorrhage . A comprehensive neuropsychological test battery was used to evaluate the cognitive performance of the subjects . Thirty healthy individuals were imaged as MRI controls . RESULTS The normalized hippocampal ( HC ) volumes were 24.7/23.7 ( right/left ) , and the amygdaloid ( AM ) volumes were 21.0/20.5 in the matched control population . In SAH patients , the corresponding volumes were smaller , HC 23.2/21.3 ( p = 0.072/0.002 ) and AM 18.4/18.7 ( p = 0.012/0.045 ) . In addition , the AM ipsilateral to the ruptured aneurysm was smaller in patients who had undergone surgical treatment ( 15.7 ) vs endovascular treatment ( 20.3 ; p < 0.001 ) . Treatment modality did not significantly affect the measured HC volumes . The hippocampal but not amygdaloid volumes correlated with the scores of several neuropsychological tests . CONCLUSION Subarachnoid hemorrhage and its treatment may be followed by atrophy in temporomesial structures . A clear correlation was demonstrated between neuropsychological performance and reduced temporomesial volumes Introduction Volume measurements performed on brain MRI after aneurysmal subarachnoid hemorrhage ( aSAH ) may provide insight into the structural abnormalities that underlie the commonly occurring and persistent long-term functional deficits after aSAH . We examined the pattern of long-term cerebral structural changes on MRI in relation to known risk factors for poor functional outcome . Methods We studied MRI scans from 38 patients who received endovascular treatment and were not dependent for activities of daily life at 18 months after aSAH . Risk factors for poor functional outcome ( clinical condition , Hijdra score , and bicau date index on admission ; occurrence of hydrocephalus or delayed cerebral infa rct ion during hospitalization ) were related to supratentorial cerebral parenchymal and lateral ventricular volumes on MRI with linear regression analyses adjusted for age , sex , and intracranial volume . Results Clinical condition , Hijdra score , and bicau date index on admission were not related to cerebral parenchymal volume at 18 months . A higher bicau date index on admission was related to lateral ventricular enlargement at 18 months after aSAH ( Beta ; 95%CI : 0.51 ; 0.14↔0.88 ) . Delayed cerebral infa rct ion was related to smaller cerebral parenchymal volumes ( −0.14 ; −0.25↔−0.04 ) and to lateral ventricular enlargement ( 0.49 ; 0.16↔0.83 ) at 18 months . Conclusion Volume measurements of the brain are able to quantify patterns of long-term cerebral damage in relation to different risk factors after aSAH . Application of volumetric techniques may provide more insight into the heterogeneous underlying pathophysiological processes . After confirmation of these results in larger studies , volumetric measures might even be used as outcome measures in future treatment studies OBJECTIVE In the course of performing systematic review s on the prevalence of low back and neck pain , we required a tool to assess the risk of study bias . Our objectives were to ( 1 ) modify an existing checklist and ( 2 ) test the final tool for interrater agreement . STUDY DESIGN AND SETTING The final tool consists of 10 items addressing four domains of bias plus a summary risk of bias assessment . Two research ers tested the interrater agreement of the tool by independently assessing 54 r and omly selected studies .  Interrater agreement overall and for each individual item was assessed using the proportion of agreement and Kappa statistic . RESULTS Raters found the tool easy to use , and there was high interrater agreement : overall agreement was 91 % and the Kappa statistic was 0.82 ( 95 % confidence interval : 0.76 , 0.86 ) . Agreement was almost perfect for the individual items on the tool and moderate for the summary assessment . CONCLUSION We have addressed a research gap by modifying and testing a tool to assess risk of study bias . Further research may be useful for assessing the applicability of the tool across different conditions OBJECTIVE To prospect ively determine temporal changes in regional cerebral perfusion in patients with acutely ( < 72 h ) ruptured cerebral aneurysms treated either endovascularly or surgically . METHODS Cerebral perfusion was measured both before and 1 week after treatment by use of a 99mTc-labeled ethyl-cysteine dimer and single-photon emission computed tomographic ( SPECT ) studies in 46 of 81 consecutive patients included in a prospect i ve r and omized study of early treatment of ruptured aneurysms . In addition to visual analysis of the SPECT images , corticocerebellar perfusion ratios were calculated for seven predefined bilateral regions . Late ischemic deficits were evaluated after 12 months by magnetic resonance imaging of the brain . RESULTS Acute perfusion deficits were commonly seen before treatment . In the visual comparison between the first and second SPECT studies , the number of new or enlarged deficits ( P = 0.006 ) and deficits that exp and ed from unilateral to bilateral ( P = 0.020 ) significantly increased in the surgical group but not in the endovascular group . In the second SPECT study , surgical patients had decreased corticocerebellar perfusion ratios in the right frontobasal cortex ( P = 0.012 ) compared with the endovascular patients , and in the ipsilateral frontobasal cortex ( P = 0.002 ) and ipsilateral temporal apex ( P = 0.002 ) compared with the contralateral side of the ruptured aneurysm . The 12-month magnetic resonance imaging of the brain revealed no significant difference in the number of ischemic deficits between the endovascular and surgical groups . CONCLUSION Disturbances in cerebral perfusion both before and after treatment are common . Although no major differences in the findings were detected between patients treated with either clips or coils , progression of perfusion deficits was more common in the surgical group . However , the 12-month magnetic resonance imaging of the brain revealed equal numbers of ischemic deficits in the treatment groups OBJECT The calcium antagonist nimodipine has been shown to reduce the incidence of ischemic complications following aneurysmal subarachnoid hemorrhage ( SAH ) . Although most r and omized studies have been focused on the effect of the peroral administration of nimodipine , intravenous infusion is an alternative and the preferred mode of treatment in many centers . It is unknown whether the route of administration is of any importance for the clinical efficacy of the drug . METHODS One hundred six patients with acute aneurysmal SAH were r and omized to receive either peroral or intravenous nimodipine treatment . The patients were monitored for at least 10 days 
    Output:
    
The results according to aim , with levels of evidence , were : ( 1 ) 25 to 81 % of aneurysmal subarachnoid hemorrhage patients show infa rcts ( strong ) ; there is a higher ratio of cerebrospinal fluid-to-intracranial volume in patients compared to controls ( strong ) ; ( 2 ) there is a negative relation between age ( moderate ) , DCI ( low ) and brain volume measurement outcomes ; ( 3 ) lower brain parenchymal volume ( strong ) and the presence of infa rcts or infa rct volumes ( moderate ) are associated with a worse outcome .
Conclusion Patients after aneurysmal subarachnoid hemorrhage may demonstrate brain infa rcts and decreased brain parenchyma , which is related to worse outcome .
Thereby , both brain infa rcts and brain volume measurements could be used as outcome markers in pharmaceutical trials .