Effect of intravenous alteplase on ischaemic lesion water homeostasis.

BACKGROUND AND PURPOSE: Intravenous (IV) lysis with alteplase is known to increase biomarkers of blood-brain barrier breakdown and has therefore been associated with secondary injuries such as hemorrhagic transformation. The impact of alteplase on brain edema formation, however, has not been investigated yet. The purpose was to examine the effects of IV alteplase on ischaemic lesion water homeostasis differentiated from final tissue infarct in patients with and without successful endovascular therapy (sET). METHODS: In all, 232 middle cerebral artery stroke patients were analyzed. 147 patients received IV alteplase, of whom 106 patients received subsequent sET. Out of 85 patients without IV alteplase, 50 received sET. Ischaemic brain edema was quantified at admission and follow-up computed tomography using quantitative lesion net water uptake (NWU) and its difference was calculated (ΔNWU). The relationship of alteplase on ΔNWU and edema-corrected final infarct volume was analyzed using univariate and multivariate linear regression models. RESULTS: The mean ΔNWU was 11.8% (SD 7.9) in patients with alteplase and 11.5% (SD 8.3) in patients without alteplase (P = 0.8). Alteplase was not associated with lowered ΔNWU whilst being associated with reduced edema-corrected tissue infarct volume [-27.4 ml, 95% confidence interval (CI) -49.4 to -5.4 ml; P = 0.02], adjusted for the Alberta Stroke Program Early Computed Tomography Score and recanalization status. In patients with sET, ΔNWU was 10.5% (95% CI 6.3%-10.5%) for patients with IV alteplase and 8.4% (95% CI 9.1%-12.0%) for patients without IV alteplase. CONCLUSION: The application of IV alteplase did not significantly alter ischaemic lesion water homeostasis but was associated with reduced edema-corrected tissue infarct volume, which might be directly linked to improved functional outcome.

Incomplete or failed thrombectomy in acute stroke patients with Alberta Stroke Program Early Computed Tomography Score 0-5 - how harmful is trying?

BACKGROUND AND PURPOSE: It is currently unknown whether mechanical thrombectomy (MT) for ischaemic stroke patients with low initial Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is clinically beneficial or even harmful. The purpose of this study was to investigate whether failed or incomplete MT in acute large vessel occlusion stroke with an initial ASPECTS ≤ 5 is associated with worse clinical outcome compared to patients not undergoing MT. METHODS: This observational cohort study included a consecutive sample of patients with anterior circulation stroke and initial ASPECTS ≤ 5 admitted between March 2015 and August 2019. Failed recanalization was defined as Thrombolysis in Cerebral Infarction (TICI) score 0-2a, and incomplete recanalization as TICI 2b. Clinical outcome was assessed using the modified Rankin Scale (mRS) at 90 days defining very poor clinical outcome as mRS > 4. RESULTS: One hundred and seventy patients were included. Ninety-nine patients underwent MT and 71 patients received best medical treatment only. Clinical outcome after failed or incomplete MT (TICI 0-2b) was significantly better compared to patients with medical treatment only (median mRS 5, interquartile range 4-6 vs 5-6, P = 0.03). In multivariable logistic regression analysis, failed or incomplete MT (TICI 0-2b) showed a significantly reduced likelihood for very poor outcome (odds ratio 0.39, 95% confidence interval 0.19-0.83, P = 0.01). Failed MT (TICI 0-2a) was not associated with a worse outcome compared to best medical treatment. CONCLUSIONS: Patients with failed or incomplete recanalization results (TICI 0-2b) showed a reduced likelihood for very poor outcome compared with those who did not receive MT. Evidence from randomized trials is needed to confirm that even failed or incomplete MT is not harmful in these patients.

The impact of lesion location on dysphagia incidence, pattern and complications in acute stroke. Part 2: Oropharyngeal residue, swallow and cough response, and pneumonia.

BACKGROUND AND PURPOSE: Dysphagia is a well-known complication of acute stroke. Given the complexity of cerebral swallowing control it is still difficult to predict which patients are likely to develop swallowing dysfunction based on their neuroimaging. In Part 2 of a comprehensive voxel-based imaging study, whether the location of a stroke lesion can be correlated with further dysfunctional swallowing patterns, pulmonary protective reflexes and pneumonia was evaluated. METHODS: In all, 200 acute stroke cases were investigated applying flexible endoscopic evaluation of swallowing within 96 h from admission. Lesions were mapped using patients' computed tomography/magnetic resonance images and these were registered to a standard space. The percentage of lesioned volume of 137 anatomically defined brain regions was determined on a voxel basis (FSL5.0). Region-specific odds ratios (ORs) were calculated with respect to the presence of oropharyngeal residue, delayed swallow response, insufficient cough reflex and occurrence of pneumonia during hospital stay. Colour-coded lesion location maps of brain regions with significant ORs were created (P < 0.05). RESULTS: Lesion maps for residue and impaired swallow response depicted parietal-temporal areas of the right hemisphere. Limbic structures in the right hemisphere and sensory regions on the left were associated with cough reflex disturbance. There was no overlap of lesion maps for impaired swallow response and insufficient cough reflex or pneumonia, but substantial overlap between the last two conditions. CONCLUSIONS: This study gives new insights on the cortical representation of single components of swallowing and airway protection behaviours. The lesion model may help to risk-stratify patients for dysphagia and pneumonia based on their brain scan.

The impact of lesion location on dysphagia incidence, pattern and complications in acute stroke. Part 1: dysphagia incidence, severity and aspiration.

BACKGROUND AND PURPOSE: Although early identification of patients at risk for dysphagia is crucial in acute stroke care, predicting whether a particular patient is likely to have swallowing problems based on the brain scan is difficult because a comprehensive model of swallowing control is missing. In this study whether stroke location is associated with dysphagia incidence, severity and the occurrence of penetration or aspiration was systematically evaluated relying on a voxel-based imaging analysis approach. METHODS: Two hundred acute stroke patients were investigated applying fiberoptic endoscopic evaluation of swallowing within 96 h from admission. Lesion masks were obtained from each patient's brain scan and registered to standard space. The percentage of lesioned volume of 137 atlas-based brain regions was determined in each case. Region-specific odds ratios were afterwards calculated with respect to presence of dysphagia, its severity and occurrence of penetration or aspiration. RESULTS: In all, 165 patients were diagnosed with dysphagia, 80 of whom had severe swallow impairment. For each investigated item there were significant differences of regional percentage infarction in distinct brain areas between affected patients and those who did not present with that specific dysfunction. In particular, right hemispheric lesions of the pre- and post-central gyri, opercular region, supramarginal gyrus and respective subcortical white matter tracts were related to dysphagia, with post-central lesions being especially associated with severe swallowing impairment. CONCLUSIONS: Distinct brain lesion locations are related to the incidence, severity and pattern of swallowing dysfunction.

Sensitivity of visual and quantitative detection of middle cerebral artery occlusion on non-contrast-enhanced computed tomography.

INTRODUCTION: This study aims to investigate diagnostic sensitivity and reliability for the detection of middle cerebral artery occlusion (MCAO) on non-contrast-enhanced computed tomography (NECT) by visual assessment (VA), Hounsfield unit (HU) measurement, calculation of the Hounsfield unit/hematocrit (HU/Hct) ratio, and combination of visual assessment and attenuation measurement (VA + HU). METHODS: NECT of 18 patients with angiographically proven MCAO and 18 patients without MCAO were reviewed by two blinded observers. Visual assessment of presence or absence of a hyperdense sign was followed by HU measurement of both middle cerebral arteries (MCA). Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for VA, HU measurement, HU/Hct ratio, and VA + HU measurement. Receiver operating characteristic curve analysis (ROC) was performed to determine the optimal cut-off values for MCAO using attenuation measurements or HU/Hct ratio. RESULTS: Diagnostic sensitivity/specificity was 63%/91% for VA, 56%/88% for attenuation measurement, 68 %/81 % for HU/Hct ratio, and 75%/78% for VA + HU. ROC curve analysis revealed cut-off values of >42.5 HU for attenuation measurements and >1.12 HU/Hct for HU/Hct ratio. CONCLUSION: Combination of visual assessment with additional attenuation measurement with a cut-off value of 42.5 HU is recommended for most sensitive and reliable detection of MCAO on NECT.

Adenosine-induced Asystole during AVM Embolization : A Case Series.

BACKGROUND: Adenosine induced cardiac standstill has been used intraoperatively for both aneurysm and arteriovenous malformation (AVM) surgery and embolization. We sought to report the results of adenosine induced cardiac standstill as an adjunct to endovascular embolization of brain AVMs. MATERIAL AND METHODS: We retrospectively identified patients in our prospectively maintained database to identify all patients since January 2007 in whom adenosine was used to induce cardiac standstill during the embolization of a brain AVM. We recorded demographic data, clinical presentation, Spetzler Martin grade, rupture status, therapeutic intervention and number of embolization sessions, angiographic and clinical results, clinical and radiological outcomes and follow-up information. RESULTS: We identified 47 patients (22 female, 47%) with average age 42 ± 17 years (range 6-77 years) who had undergone AVM embolization procedures using adjunctive circulatory standstill with adenosine. In total there were 4 Spetzler Martin grade 1 (9%), 9 grade 2 (18%), 15 grade 3 (32%), 8 grade 4 (18%), and 11 grade 5 (23%) lesions. Of the AVMs six were ruptured or had previously ruptured. The average number of embolization procedures per patient was 5.7 ± 7.6 (range 1-37) with an average of 2.6 ± 2.2 (range 1-14) embolization procedures using adenosine. Overall morbidity was 17% (n = 8/47) and mortality 2.1% (n = 1/47), with permanent morbidity seen in 10.6% (n = 5/47) postembolization. Angiographic follow-up was available for 32 patients with no residual shunt seen in 26 (81%) and residual shunts seen in 6 patients (19%). The angiographic follow-up is still pending in 14 patients. At last follow-up 93.5% of patients were mRS ≤2 (n = 43/46). CONCLUSION: Adenosine induced cardiac standstill represents a viable treatment strategy in high flow AVMs or AV shunts that carries a low risk of mortality and permanent neurological deficits.

3D Printing of Intracranial Aneurysms Using Fused Deposition Modeling Offers Highly Accurate Replications.

BACKGROUND AND PURPOSE: As part of a multicenter cooperation (Aneurysm-Like Synthetic bodies for Testing Endovascular devices in 3D Reality) with focus on implementation of additive manufacturing in neuroradiologic practice, we systematically assessed the technical feasibility and accuracy of several additive manufacturing techniques. We evaluated the method of fused deposition modeling for the production of aneurysm models replicating patient-specific anatomy. MATERIALS AND METHODS: 3D rotational angiographic data from 10 aneurysms were processed to obtain volumetric models suitable for fused deposition modeling. A hollow aneurysm model with connectors for silicone tubes was fabricated by using acrylonitrile butadiene styrene. Support material was dissolved, and surfaces were finished by using NanoSeal. The resulting models were filled with iodinated contrast media. 3D rotational angiography of the models was acquired, and aneurysm geometry was compared with the original patient data. RESULTS: Reproduction of hollow aneurysm models was technically feasible in 8 of 10 cases, with aneurysm sizes ranging from 41 to 2928 mm(3) (aneurysm diameter, 3-19 mm). A high level of anatomic accuracy was observed, with a mean Dice index of 93.6% ± 2.4%. Obstructions were encountered in vessel segments of <1 mm. CONCLUSIONS: Fused deposition modeling is a promising technique, which allows rapid and precise replication of cerebral aneurysms. The porosity of the models can be overcome by surface finishing. Models produced with fused deposition modeling may serve as educational and research tools and could be used to individualize treatment planning.

Prediction of infarction and reperfusion in stroke by flow- and volume-weighted collateral signal in MR angiography.

BACKGROUND AND PURPOSE: In proximal anterior circulation occlusive strokes, collateral flow is essential for good outcome. Collateralized vessel intensity in TOF- and contrast-enhanced MRA is variable due to different acquisition methods. Our purpose was to quantify collateral supply by using flow-weighted signal in TOF-MRA and blood volume-weighted signal in contrast-enhanced MRA to determine each predictive contribution to tissue infarction and reperfusion. MATERIALS AND METHODS: Consecutively (2009-2013), 44 stroke patients with acute proximal anterior circulation occlusion met the inclusion criteria with TOF- and contrast-enhanced MRA and penumbral imaging. Collateralized vessels in the ischemic hemisphere were assessed by TOF- and contrast-enhanced MRA using 2 methods: 1) visual 3-point collateral scoring, and 2) collateral signal quantification by an arterial atlas-based collateral index. Collateral measures were tested by receiver operating characteristic curve and logistic regression against 2 imaging end points of tissue-outcome: final infarct volume and percentage of penumbra saved. RESULTS: Visual collateral scores on contrast-enhanced MRA but not TOF were significantly higher in patients with good outcome. Visual collateral scoring on contrast-enhanced MRA was the best rater-based discriminator for final infarct volume < 90 mL (area under the curve, 0.81; P < .01) and percentage of penumbra saved >50% (area under the curve, 0.67; P = .04). Atlas-based collateral index of contrast-enhanced MRA was the overall best independent discriminator for final infarct volume of <90 mL (area under the curve, 0.94; P < .01). Atlas-based collateral index combining the signal of TOF- and contrast-enhanced MRA was the overall best discriminator for effective reperfusion (percentage of penumbra saved >50%; area under the curve, 0.89; P < .001). CONCLUSIONS: Visual scoring of contrast-enhanced but not TOF-MRA is a reliable predictor of infarct outcome in stroke patients with proximal arterial occlusion. By atlas-based collateral assessment, TOF- and contrast-enhanced MRA both contain predictive signal information for penumbral reperfusion. This could improve risk stratification in further studies.

CTP-Based Tissue Outcome: Promising Tool to Prove the Beneficial Effect of Mechanical Recanalization in Acute Ischemic Stroke.

PURPOSE: To prove the tissue-protecting effect of mechanical recanalization, we assessed the CT perfusion-based tissue outcome ("TO") and correlated this imaging parameter with the 3-month clinical outcome ("CO"). MATERIALS AND METHODS: 159 patients with large intracranial artery occlusions revealing mechanical recanalization were investigated by CCT, CT angiography (CTA) and CT perfusion (CTP) upon admission. For the final infarct volume, native CCT was repeated after 24 h. The "TO" ("percentage mismatch loss" = %ML) was defined as the difference between initial penumbral tissue on CTP and final infarct volume on follow-up CCT. We monitored the three-month modified Rankin Scale (mRS), age, bleeding occurrence, time to recanalization, TICI score and collateralization grade, infarct growth and final infarct volume. Spearman's correlation and nominal regression analysis were used to evaluate the impact of these parameters on mRS.  RESULTS: Significant correlations were found for %ML and mRS (c = 0.48, p < 0.001), for final infarct volume and mRS (c = 0.52, p < 0.001), for TICI score and mRS (c = - 0.35, p < 0.001), for initial infarct core and mRS (c = 0.14, p = 0.039) as well as for age and mRS (c = 0.37, p < 0.001). According to the regression analysis, %ML predicted the classification of mRS correctly in 38.5 % of cases. The subclasses mRS 1 and 6 could be predicted by %ML with 86.4 % and 60.9 % reliability, respectively. No correlations were found for time to recanalization and mRS, for collateralization grade and mRS, and for post-interventional bleeding and mRS.  CONCLUSION: Better than the TICI score, CT-based TO predicts the clinical success of mechanical recanalization, showing that not recanalization, but reperfusion should be regarded as a surrogate parameter for stroke therapy. KEY POINTS: • %ML as well as the final infarct volume can make a direct point about the immediate effect of successful mechanical recanalization.• The clinical outcomes after mechanical recanalization are reliably predicted by %ML, reflecting the benefit of escalation therapy including interventional reopening of parent vessel occlusions.• Not recanalization but rather reperfusion should be regarded as a surrogate parameter for successful stroke therapy.

ANTONIA perfusion and stroke. A software tool for the multi-purpose analysis of MR perfusion-weighted datasets and quantitative ischemic stroke assessment.

OBJECTIVES: The objective of this work is to present the software tool ANTONIA, which has been developed to facilitate a quantitative analysis of perfusion-weighted MRI (PWI) datasets in general as well as the subsequent multi-parametric analysis of additional datasets for the specific purpose of acute ischemic stroke patient dataset evaluation. METHODS: Three different methods for the analysis of DSC or DCE PWI datasets are currently implemented in ANTONIA, which can be case-specifically selected based on the study protocol. These methods comprise a curve fitting method as well as a deconvolution-based and deconvolution-free method integrating a previously defined arterial input function. The perfusion analysis is extended for the purpose of acute ischemic stroke analysis by additional methods that enable an automatic atlas-based selection of the arterial input function, an analysis of the perfusion-diffusion and DWI-FLAIR mismatch as well as segmentation-based volumetric analyses. RESULTS: For reliability evaluation, the described software tool was used by two observers for quantitative analysis of 15 datasets from acute ischemic stroke patients to extract the acute lesion core volume, FLAIR ratio, perfusion-diffusion mismatch volume with manually as well as automatically selected arterial input functions, and follow-up lesion volume. The results of this evaluation revealed that the described software tool leads to highly reproducible results for all parameters if the automatic arterial input function selection method is used. CONCLUSION: Due to the broad selection of processing methods that are available in the software tool, ANTONIA is especially helpful to support image-based perfusion and acute ischemic stroke research projects.

A statistical cerebroarterial atlas derived from 700 MRA datasets.

OBJECTIVES: The cerebroarterial system is a complex network of arteries that supply the brain cells with vitally important nutrients and oxygen. The inter-individual differences of the cerebral arteries, especially at a finer level, are still not understood sufficiently. The aim of this work is to present a statistical cerebroarterial atlas that can be used to overcome this problem. METHODS: Overall, 700 Time-of-Flight (TOF) magnetic resonance angiography (MRA) datasets of healthy subjects were used for atlas generation. Therefore, the cerebral arteries were automatically segmented in each dataset and used for a quantification of the vessel diameters. After this, each TOF MRA dataset as well as the corresponding vessel segmentation and vessel diameter dataset were registered to the MNI brain atlas. Finally, the registered datasets were used to calculate a statistical cerebroarterial atlas that incorporates information about the average TOF intensity, probability for a vessel occurrence and mean vessel diameter for each voxel. RESULTS: Visual analysis revealed that arteries with a diameter as small as 0.5 mm are well represented in the atlas with quantitative values that are within range of anatomical reference values. Moreover, a highly significant strong positive correlation between the vessel diameter and occurrence probability was found. Furthermore, it was shown that an intensity-based automatic segmentation of cerebral vessels can be considerable improved by incorporating the atlas information leading to results within the range of the inter-observer agreement. CONCLUSION: The presented cerebroarterial atlas seems useful for improving the understanding about normal variations of cerebral arteries, initialization of cerebrovascular segmentation methods and may even lay the foundation for a reliable quantification of subtle morphological vascular changes.

Decomposing the Hounsfield unit: probabilistic segmentation of brain tissue in computed tomography.

PURPOSE: The aim of this study was to present and evaluate a standardized technique for brain segmentation of cranial computed tomography (CT) using probabilistic partial volume tissue maps based on a database of high resolution T1 magnetic resonance images (MRI). METHODS: Probabilistic tissue maps of white matter (WM), gray matter (GM) and cerebrospinal fluid (CSF) were derived from 600 normal brain MRIs (3.0 Tesla, T1-3D-turbo-field-echo) of 2 large community-based population studies (BiDirect and SEARCH Health studies). After partial tissue segmentation (FAST 4.0), MR images were linearly registered to MNI-152 standard space (FLIRT 5.5) with non-linear refinement (FNIRT 1.0) to obtain non-binary probabilistic volume images for each tissue class which were subsequently used for CT segmentation. From 150 normal cerebral CT scans a customized reference image in standard space was constructed with iterative non-linear registration to MNI-152 space. The inverse warp of tissue-specific probability maps to CT space (MNI-152 to individual CT) was used to decompose a CT image into tissue specific components (GM, WM, CSF). RESULTS: Potential benefits and utility of this novel approach with regard to unsupervised quantification of CT images and possible visual enhancement are addressed. Illustrative examples of tissue segmentation in different pathological cases including perfusion CT are presented. CONCLUSION: Automated tissue segmentation of cranial CT images using highly refined tissue probability maps derived from high resolution MR images is feasible. Potential applications include automated quantification of WM in leukoaraiosis, CSF in hydrocephalic patients, GM in neurodegeneration and ischemia and perfusion maps with separate assessment of GM and WM.

Reperfusion by combined thrombolysis and mechanical thrombectomy in acute stroke: effect of collateralization, mismatch, and time to and grade of recanalization on clinical and tissue outcome.

BACKGROUND AND PURPOSE: Our research focuses on interventional neuroradiology (stroke treatment including imaging methods) and general neuroimaging with an emphasis on functional MR imaging. Our aim was to determine the efficacy of revascularization (TIMI) of middle cerebral and/or carotid artery occlusion by means of mechanical recanalization techniques and to evaluate the impact of collateralization, mismatch in perfusion CT, time to revascularization, grade of revascularization on tissue, and clinical outcome in patients with acute ischemic stroke. MATERIALS AND METHODS: Thirty-one patients with MCA and/or ICA occlusion were included. Ischemic stroke was diagnosed by NECT, CTA, and volume PCT for grading collateralization and mismatch. Time to recanalization was measured from the onset of stroke to the time point of DSA-proved mechanical recanalization. Tissue outcome was calculated by segmentation of infarct size between pre- and postinterventional CT and percentage mismatch lost. Clinical outcome was determined by the mRS. RESULTS: Twenty-one of 31 patients (61.8%) presented with MCA and 10/31 patients (38.2%), with distal ICA occlusions. Sufficient recanalization (TIMI 2 and 3) was achieved in 23/31 (75%). Clinical evaluation revealed an mRS score of ≤2 in 25.5%. Age (r = 0.439, P = .038) and TIMI (r = 0.544, P = .002) showed the strongest correlation with clinical outcome. Time to recanalization, TIMI score, and mismatch were associated with a good tissue outcome in ANOVA. CONCLUSIONS: Favorable outcome after mechanical recanalization of acute MCA and ICA occlusion depends on time to and grade of recanalization, mismatch, and collateralization. These results indicate that multimodal stroke imaging is helpful to guide therapy decisions and to indicate patients amenable for mechanical recanalization.

Malignant CTA collateral profile is highly specific for large admission DWI infarct core and poor outcome in acute stroke.

BACKGROUND AND PURPOSE: Large admission DWI lesion volumes are associated with poor outcomes despite acute stroke treatment. The primary aims of our study were to determine whether CTA collaterals correlate with admission DWI lesion volumes in patients with AIS with proximal occlusions, and whether a CTA collateral profile could identify large DWI volumes with high specificity. MATERIALS AND METHODS: We studied 197 patients with AIS with M1 and/or intracranial ICA occlusions. We segmented admission and follow-up DWI lesion volumes, and categorized CTA collaterals by using a 5-point CS system. ROC analysis was used to determine CS accuracy in predicting DWI lesion volumes >100 mL. Patients were dichotomized into 2 categories: CS = 0 (malignant profile) or CS>0. Univariate and multivariate analyses were performed to compare imaging and clinical variables between these 2 groups. RESULTS: There was a negative correlation between CS and admission DWI lesion volume (ρ = -0.54, P < .0001). ROC analysis revealed that CTA CS was a good discriminator of DWI lesion volume >100 mL (AUC = 0.84, P < .001). CS = 0 had 97.6% specificity and 54.5% sensitivity for DWI volume >100 mL. CS = 0 patients had larger mean admission DWI volumes (165.8 mL versus 32.7 mL, P < .001), higher median NIHSS scores (21 versus 15, P < .001), and were more likely to become functionally dependent at 3 months (95.5% versus 64.0%, P = .003). Admission NIHSS score was the only independent predictor of a malignant CS (P = .007). CONCLUSIONS: In patients with AIS with PAOs, CTA collaterals correlate with admission DWI infarct size. A malignant collateral profile is highly specific for large admission DWI lesion size and poor functional outcome.

An unusual case of neuralgic amyotrophy presenting with bilateral phrenic nerve and vocal cord paresis.

BACKGROUND: Neuralgic amyotrophy (brachial plexus neuropathy, brachial plexus neuritis, or Parsonage-Turner syndrome) is an uncommon inflammatory condition typically characterized by acute and severe shoulder pain followed by paresis with muscle weakness and atrophy of the upper limb or shoulder girdle. We report an unusual clinical manifestation of neuralgic amyotrophy, namely bilateral phrenic nerve palsy with concomitant laryngeal paresis. CASE REPORT: A 55-year-old male presented with orthopnea and aphonia after an episode of bilateral shoulder pain preceded by an upper respiratory tract infection. Spirometry, chest X-ray and videolaryngoscopy revealed bilateral and simultaneous paresis of the diaphragm and the vocal cords. Clinical examination at admission and at the 2-month follow-up did not show upper limb weakness or atrophy, except for a mild atrophy of the right supraspinatus muscle. An electromyography of the upper limb muscles and nerve conduction studies did not reveal signs of denervation. Analysis of the cerebrospinal fluid and an MRI of the neuraxis were unremarkable. After treatment with prednisolone, vocal cord function markedly improved within 8 weeks, whereas paresis of the diaphragm persisted. CONCLUSION: Shoulder pain followed by diaphragmatic paralysis with dyspnea and hoarseness may be a manifestation of neuralgic amyotrophy even if upper limb or shoulder girdle palsies are absent.

Predicting language improvement in acute stroke patients presenting with aphasia: a multivariate logistic model using location-weighted atlas-based analysis of admission CT perfusion scans.

BACKGROUND AND PURPOSE: Prediction of functional outcome immediately after stroke onset can guide optimal management. Most prognostic grading scales to date, however, have been based on established global metrics such as total NIHSS score, admission infarct volume, or intracranial occlusion on CTA. Our purpose was to construct a more focused, location-weighted multivariate model for the prediction of early aphasia improvement, based not only on traditional clinical and imaging parameters, but also on atlas-based structure/function correlation specific to the clinical deficit, using CT perfusion imaging. MATERIALS AND METHODS: Fifty-eight consecutive patients with aphasia due to first-time ischemic stroke of the left hemisphere were included. Language function was assessed on the basis of the patients admission and discharge NIHSS scores and clinical records. All patients had brain CTP and CTA within 9 hours of symptom onset. For image analysis, all CTPs were automatically co-registered to MNI-152 brain space and parcellated into mirrored cortical and subcortical regions. Multiple logistic regression analysis was used to find independent imaging and clinical predictors of language recovery. RESULTS: By the time of discharge, 21 (36%) patients demonstrated improvement of language. Independent factors predicting improvement in language included rCBF of the angular gyrus GM (BA 39) and the lower third of the insular ribbon, proximal cerebral artery occlusion on admission CTA, and aphasia score on the admission NIHSS examination. Using these 4 variables, we developed a multivariate logistic regression model that could estimate the probability of early improvement in aphasia and predict functional outcome with 91% accuracy. CONCLUSIONS: An imaging-based location-weighted multivariate model was developed to predict early language improvement of patients with aphasia by using admission data collected within 9 hours of stroke onset. This pilot model should be validated in a larger, prospective study; however, the semiautomated atlas-based analysis of brain CTP, along with the statistical approach, could be generalized for prediction of other outcome measures in patients with stroke.

Baclofen prevents morphine withdrawal irrespective of seasonal variation.

In previous studies we have demonstrated a possible interaction between the gamma-aminobutyric acid (GABA)ergic and opioid systems involved in the antinociceptive effect of the GABAB agonist, baclofen (BAC). In addition, we have demonstrated that BAC was able to prevent the morphine (MOR) withdrawal syndrome in female, as well as male mice. On the other hand, seasonal variations have been observed in some MOR effects. In the present study, we analysed the effects of BAC on naloxone (NAL)-precipitated withdrawal, during two different seasons. The experiments were performed during two seasons: spring-summer (SS) and autumn-winter (AW) for two years, on male Swiss-Webster albino mice (27-33 g). Mice were rendered dependent by intraperitoneal (i.p.) injection of MOR (2mg/kg), twice daily for 9 days. On the tenth day the dependent animals were divided into two groups: one received NAL (6mg/kg, i.p.) 60 min after the last dose of MOR, to develop the NAL-precipitated withdrawal; the other group received BAC (2mg/kg, i.p.) followed by NAL (6mg/kg, i.p.), injected 30 and 60 min after the last dose of MOR, respectively. Behavioural signs were recorded in the open field for 30 min. Although there were seasonal variations in the MOR withdrawal syndrome, we found that BAC prevents MOR withdrawal irrespective of seasonal variation.

Lack of sex-related differences in the prevention by baclofen of the morphine withdrawal syndrome in mice.

In previous studies we have demonstrated a possible interaction between the GABAergic and opioid systems involved in the antinociceptive effect of the GABA(B) agonist, baclofen (BAC). On the other hand, sex differences have been observed for the antinociceptive effect of morphine (MOR). In the present study, we analyzed sex-related differences in the MOR abstinence syndrome and its prevention with BAC. Prepubertal male and female Swiss-Webster albino mice (27-33 g) were rendered dependent by intraperitoneal (i.p.) injection of MOR (2, 4 and 8 mg/kg), twice daily for 9 days. On the tenth day the dependent animals were divided into two groups: one received naloxone (NAL) (6 mg/kg, i.p.) 60 min after the last dose of MOR, to precipitate the abstinence syndrome; the other group received BAC (2 mg/kg, i.p.) followed by NAL (6 mg/kg, i.p.), injected 30 and 60 min after the last dose of MOR, respectively. Behavioral signs were recorded in the open field for 30 min. Although there were sex differences in the MOR withdrawal syndrome, we found a lack of sex differences in the prevention of the MOR abstinence syndrome by BAC.

La manipulación colónica laparoscópica y la exfoliación celular: investigación experimental / Laparoscopic colic manipulation and malignant cells exfoliation: experimental research

La manipulación traumática del colon portador de una neoplasia, durante la ejecución de una colectomía laparoscópica podría aumentar la exfoliación de células malignas dentro de la cavidad peritoneal, y por consiguiente ser una de las causas de los implantes cutáneos. Objetivo: Desarrollar un modelo de cáncer colónico experimental con similitud al del hombre y determinar si la manipulación laparoscópica instrumental del carcinoma de colon y recto comparada con la laparotomía, aumenta la exfoliación de células malignas en la cavidad peritoneal, instrumental y trócares. Material y Métodos: Se desarrolló un protocolo de cáncer colorrectal experimental con inyección subcutánea de 1-2 Dimethylhydrazina a una dosis de 20 mg/kg de peso, semanalmente y durante 20 semanas, en 40 ratas Wistar, sexo masculino. Se operaron a la semana 21º, dividiéndolas en 2 grupos (1 y 2). Grupo 1 (n 23) sometidas a laparotomía y manipulación instrumental del colon. Grupo 2 (n 17) se efectuó neumoperitoneo con CO2 hasta una presión de 12 mm Hg, laparoscopia y manipulación instrumental del colon y recto. Un tercer grupo lo constituyeron las ratas controles (n 5). Se realizó citología de: líquido de lavado peritoneal pre y post manipulación intestinal, del instrumental convencional y laparoscópico, de la aguja de Verres y de los trócares. Se efectuó el estudio histológico del colon y recto, ganglios mesentéricos, hígado y peritoneo. Resultados: El 80 por ciento de las ratas desarrollaron adenocarcinomas de colon. No existió diferencia significativa entre la exfoliación celular de ambos grupos de animales. Conclusiones: El carcinoma colorrectal inducido por la 1-2 Dimethylhydrazina tiene características muy similares al del ser humano y es un modelo válido para la investigación. La manipulación instrumental con una prolija técnica durante los procedimientos laparoscópicos no aumenta la exfoliación celular