Complication In Acute Stroke Patients Research Articles

The Relationship between Level of D-Dimer Serum with Mortality in Acute Stroke Patiens with COVID-19

Background: COVID-19 has significantly increased morbidity and mortality in Indonesia, particularly at Gambiran General Hospital in Kediri, East Java, following the WHO's pandemic declaration. The global incidence of acute stroke with COVID-19 is 1.4%, presenting varying clinical features from mild to severe outcomes, and even death. The identification of specific biomarkers, such as elevated D-dimer serum levels, is crucial for predicting severe complications in acute stroke patients with COVID-19. Objective: This study aimed to explore the correlation between elevated levels of mild, moderate, and severe D-dimer serum and mortality in acute stroke patients with COVID-19. Methods: Conducted as an observational analytical study using a cross-sectional approach, this research utilized secondary data from medical records at Kediri Gambiran General Hospital (March 2020 to June 2023). Inclusion and exclusion criteria were applied to hospitalized patients, categorized based on D-dimer levels: normal, mild, moderate, and severe. Statistical analyses, including the Spearman correlation test and Chi-square correlation test, were employed to assess the relationship between D-dimer levels and total mortality. Results: Among the 101 enrolled patients, 53 were male (52.48%), with 90 exhibiting elevated D-dimer levels. Out of these, 44 patients died. The Spearman correlation test showed a non-significant value of 0.069 (p>0.005). The Chi-square correlation test for mild, moderate, and severe D-dimer levels on total mortality also yielded a non-significant value of 0.878. Conclusion: This study found no significant relationship between elevated levels of mild, moderate, and severe D-dimer serum and mortality in acute stroke patients with COVID-19 at Gambiran General Hospital.

Impact of delirium on acute stroke outcomes: A systematic review and meta-analysis.

Delirium is a common complication in acute stroke patients. A 2011 meta-analysis showed an increased risk of in-hospital mortality and mortality within 12months post-stroke, longer hospitalization durations, and increased likelihood of being discharged to a nursing home for patients experiencing post-stroke delirium. There is a need for an updated meta-analysis with several new studies having been since published. The PubMed and Scopus databases were screened for relevant studies. Inclusion criteria were as follows: retrospective or prospective studies reporting on the effects of delirium accompanying acute stroke on mortality, functional outcomes, length of hospital stay and need for re-admission. Strength of association was presented as pooled adjusted relative risk (RR) for categorical outcomes and weighted mean difference (WMD) for continuous outcomes. Statistical analysis was done using STATA version 16.0. The meta-analysis included 22 eligible articles. Eighteen of the 22 studies were prospective follow ups. Included studies were of good quality. Post-stroke delirium was associated with increased risk of in-hospital mortality, as well as mortality within 12months post-stroke. Patients with delirium experienced increased hospital stay durations, were at greater risk for hospital readmission, and showed elevated risk for poor functional outcome. Compared to those who did not have delirium, stroke patients with delirium were 42% less likely to be discharged to home. Acute stroke patients with delirium are at an increased risk for poor short- and long-term outcomes. More research is needed to identify the best set of interventions to manage such patients and improve outcomes.

The RAPID-score: Risk Assessment and PredIction of Delirium in acute stroke patients based on very early clinical parameters.

Post-stroke delirium (PSD) is a common complication in acute stroke patients, and guidelines recommend routine screening and various preventive and treatment measures. However, there is a substantial lack of standardized approaches in diagnostic and therapeutic management of PSD. Here, we aimed to develop a new pragmatic and easily assessable screening tool to predict PSD based on early parameters, which are already integral to acute stroke diagnostics. We enrolled acute stroke patients admitted to our stroke unit or intensive care unit and developed the scoring system using retrospective single-center patient data. The Confusion Assessment Method for the Intensive Care Unit was used for prospective score validation. Logistic regression models were employed to analyze the association of early clinical and paraclinical parameters with PSD development. N = 525 patients (median age: 76 years; 45.7% female) were enrolled, with 29.7% developing PSD during hospitalization. The resulting score comprises 6 items, including medical history, clinical examination findings, and non-contrast computed tomography results at admission. Scores range from -15 to +15 points, with higher values indicating a higher likelihood of PSD, ranging from 4% to 79%. The accuracy was 0.85, and the area under the curve was 0.89. The new RAPID (Risk Assessment and PredIction of Delirium in acute stroke patients)-score shows high accuracy in predicting PSD among acute stroke patients and offers precise odds of PSD for each corresponding score value, utilizing routine early clinical and paraclinical parameters. It can identify high-risk populations for clinical study interventions and may be suitable to guide prophylactic PSD measures.

Improving The Accuracy of Screening Pharyngeal Dysphagia Using Ultrasonography in Acute Stroke Patient: A Case Report

Introduction: Dysphagia is a common complication in acute stroke patients that require early screening to reduce the risk of aspiration pneumonia, disability, and mortality. Bedside examinations such as the Gugging Swallowing Screen (GUSS) test and ultrasonography are non-invasive methods that may improve early diagnosis of dysphagia after stroke.
 Case Report: We report a 49-year-old man with a history of cerebrovascular event that had difficulty swallowing, followed by coughing and choking after drinking.
 Discussion Case: The GUSS score indicated moderate dysphagia with a high risk of aspiration. The swallowing ultrasonography showed conformity to the GUSS score and improved the screening accuracy for silent aspiration risk in the pharyngeal swallowing phase.
 Conclusion: In conclusion, ultrasonography examination may improve the screening accuracy of the GUSS test, particularly for the detection of silent aspiration in pharyngeal dysphagia.

A Preliminary Investigation of Relationships among Pharyngeal Acidity, Dysphagia, and Pneumonia in Acute Stroke

Individuals with acute stroke on nonoral feeding regimens frequently develop pneumonia, questioning the long-held belief that pneumonia in stroke patients is a caused by food and liquid aspiration alone. Refluxate and colonized oral secretions are thought to contribute to an acidic oropharyngeal environment. If aspirated, these colonized oral secretions with increased acidity, can result in increased risk to the respiratory system. This study aimed to investigate the relationship between pharyngeal acidity, dysphagia, and pneumonia in acute stroke patients. Twenty-one patients (mean age 67 years) admitted to a stroke unit were recruited into this study. We evaluated their stroke and dysphagia severity via clinical measures. Pharyngeal acidity was measured using a Restech Dx-pH measurement probe placed transnasally for 24 hours. Sixty two (62%) patients presented with moderate to severe stroke and 38% with dysphagia. Seven patients (33%) were positive for pharyngeal acidity. Two patients with pharyngeal acidity were diagnosed with chest infection. Pharyngeal acidity was significantly correlated with stroke severity (r = 0.487, P = 0.03) and significantly and inversely correlated to clinical swallow performance (rho = -0.626, p = 0.02). Additionally, pharyngeal acidity was significantly associated with categorical dysphagia scores (c2(3,21) = 10.5, p<0.01), functional oral intake (c2(3,21) = 15.7, p<0.001), presence of modified diets (χ2(1,21) = 14.0, p=0.0001), and tube feeding (χ2 (1,21) = 9.992, p = 0.002). Preliminary results suggest that acute stroke patients with dysphagia may present with increased risk for increased pharyngeal acidity. Pharyngeal acidity can result in negative sequelea, including respiratory complications. A better understanding of these potential relationships may lead to enhanced assessment and treatment approaches that limit pharyngeal acidity and resulting respiratory complications in acute stroke patients.

Oral neuromuscular training in patients with dysphagia after stroke: a prospective, randomized, open-label study with blinded evaluators

BackgroundOral and pharyngeal swallowing dysfunction are common complications in acute stroke patients. This primary aim of this study was to determine whether oral neuromuscular training improves swallowing function in participants with swallowing dysfunction after stroke. A secondary aim was to assess how well results of the timed water-swallow test (TWST) correspond with swallowing dysfunction diagnosed by videofluoroscopy (VFS).MethodsThis was an intention-to-treat two-centre prospective randomized open-label study with blinded-evaluators (PROBE) design. At 4 weeks after stroke onset, participants with swallowing dysfunction were randomized to 5 weeks of continued orofacial sensory-vibration stimulation with an electric toothbrush or additional oral neuromuscular training with an oral device (Muppy®). Participants were examined with TWST, a lip-force test, and VFS before (baseline), after 5 weeks’ treatment (the end-of-treatment), and 12 months after treatment (follow-up). The baseline VFS results were compared with the TWST results. The primary endpoint was changes in swallowing rate assessed using TWST, from baseline to the end of training and from baseline to follow-up based on intention-to-treat analyses. The secondary endpoint was the corresponding changes in lip-force between baseline, the end of treatment, and follow-up.ResultsThe participants were randomly assigned as controls (n = 20) or for intervention with oral neuromuscular training (n = 20). After treatment, both groups had improved significantly (intervention, P < 0.001; controls, P = 0.001) in TWST but there was no significant between-group difference in swallowing rate. At the 12-month follow-up, the intervention group had improved further whereas the controls had deteriorated, and there were significant between-group differences in swallowing rate (P = 0.032) and lip force (P = 0.001). A TWST < 10 mL/sec at baseline corresponded to VFS-verified swallowing dysfunction in all assessed participants.ConclusionThe 5-week oral neuromuscular training improved swallowing function in participants with post-stroke dysphagia compared with the controls 12 months after intervention, but there was no between-group difference in improvement immediately after treatment. TWST results corresponded with VFS results, making TWST a feasible method for identifying persons with swallowing dysfunction after stroke. Larger randomized controlled trials are required to confirm our preliminary positive long-term results.Trial registrationRetrospectively registered at ClinicalTrials.gov: NCT04164420. Registered on 15 November 2019.

Quantitative and Qualitative EEG as a Prediction Tool for Outcome and Complications in Acute Stroke Patients.

Currently, the relevance of EEG measurements in acute stroke patients is considered low in clinical practice. However, recent studies on the predictive value of EEG measurements after stroke for various outcomes may increase the role of EEG in patients with stroke. We aimed to review the current literature on the utility of EEG measurements after stroke as a tool to predict outcome and complications, focusing on studies in which the EEG measurement was performed in the acute phase after the event and in which long-term outcome measures were reported. In our literature review, we identified 4 different outcome measures (functional outcome, mortality, development of post-stroke cognitive decline, and development of post-stroke epilepsy) where studies on the utility of acute EEG measurements exist. There is a large body of evidence for the prediction of functional outcome, in which a multitude of associated quantitative and qualitative EEG parameters are described. In contrast, only few studies focus on mortality as outcome parameter. We found studies of high methodical quality on the prediction of post-stroke cognitive decline, though the number of patients in these studies often was small. The role of EEG as a prediction tool for seizures and epilepsy after stroke could increase after a recently published study, especially if its result can be incorporated into already existing post-stroke epilepsy prediction tools. In summary, EEG is useful for the prediction of functional outcome, mortality, development of post-stroke cognitive decline and epilepsy, even though there is a discrepancy between the large amount of studies on EEG in acute stroke patients and its underuse in clinical practice.

The Efficacy of Prophylactic Antibiotics on Post-Stroke Infections: An Updated Systematic Review and Meta-Analysis.

Post-stroke infections are common complications in acute stroke patients and are associated with an unfavorable functional outcome. However, reports on the effects of prophylactic antibiotics treatment on post-stroke infections are conflicting, especially those on post-stroke pneumonia and outcomes. We searched the PubMed, Embase, and Web of Knowledge databases up through March 11th, 2016. Seven randomized controlled trials including 4261 patients were analyzed among this systematic review and meta-analysis. We found preventive antibiotics treatment at the time of stroke onset did reduce the incidence of infections in adults with acute stroke (OR = 0.57, 95% CI: 0.38–0.85, P = 0.005), including reducing the number of urinary tract infections (OR = 0.34, 95% CI: 0.26–0.46, P < 0.001), but did not significantly decrease the rate of post-stroke pneumonia (OR = 0.91, 95% CI: 0.73–1.13, P = 0.385). Importantly, antibiotics treatment also showed no significant effect on the number of fatalities among stroke patients (OR = 1.07, 95% CI: 0.90–1.26, P = 0.743) and functional outcome scores on the modified Rankin Scale (OR = 1.76, 95% CI: 0.86–3.63, p = 0.124). Our study indicated that preventive antibiotics treatment not reduced the rate of post-stroke pneumonia or mortality, even though decreased the risk of infections, especially urinary tract infections. Thus, preventive antibiotics treatment may not be recommended for acute stroke patients.

Risk assessment of deep-vein thrombosis after acute stroke: a prospective study using clinical factors.

Deep-vein thrombosis (DVT) represents a serious complication in acute stroke patients with pulmonary embolus (PE) as a potential outcome. Prediction of DVT may help with formulating a proper prevention strategy. To assess of the risk of deep venous thrombosis (DVT) in acute stroke patients, we developed and validated a clinical score in a cohort study. Incidence of Deep Venous Thrombosis after Acute Stroke in China (INVENT-China) is a multicenter prospective cohort study. The potential predictive variables for DVT at baseline were collected, and the presence of DVT was evaluated using ultrasonography on the 14 ± 3 days. Data were randomly assigned to either a training data set or a test data set. Multivariate logistic regression analysis was used to develop risk scores to predict DVT in the training data set and the area under the receiver operating characteristic curve to validate the score in the test data set. From 2006-2007, 862 hospital-based acute stroke patients were enrolled in China. The overall incidence of DVT after acute stroke within two weeks was 12.4% (95%CI 10.3-14.7%). A seven-point score derived in the training data set (age [≥65 years = 1], sex [female gender = 1]), obesity [BMI ≥ 25 kg/m(2) = 1], active cancer [yes = 2], stroke subtype [cerebral hemorraghe = 1], muscle weakness [≥2 on Lower limb NIHSS score = 1] was highly predictive of 14-day risk of DVT(c statistic = 0.70, 95% CI, 0.64-0.76, P < 0.001), in the overall study population(c statistic = 0.65, 95% CI 0.59-0.70, P < 0.001). This clinical score may help identify acute stroke patients with high risk of DVT. In addition, it also serves as a platform to develop further models of DVT prediction in stroke patients based on clinical factors.

Predictors of pneumonia in acute stroke inpatients in emergency unit

Background: Pneumonia is a serious complication in acute stroke patients. Several mechanisms might be implicated including impairment of the immune system and aspiration. The analyses of clinical predictors are useful to guide the clinical management and to adopt preventive measures in order to improve the patients' outcome.

Central obesity in the poorest region in Chile

WCN 2013 No: 1900 Topic: 3 — Stroke Central obesity in the poorest region in Chile R.J. Rivas, C.A. Klapp, C.A. Daroch, H.M. Vasquez. Neurology Department, Universidad de La Frontera, Chile; Stroke Unit, Clinica Alemana de Temuco, Temuco, Chile; Neurology Department, Clinica Alemana de Temuco, Temuco, Chile; Nutrition Department, Clinica Alemana de Temuco, Temuco, Chile Background: Stroke is the first most common specific cause of death in Chile, since 2008. The increased risk in our region is explained by the prevalence of poverty, diabetes, a sedentary lifestyle and overweight. Object: Is to assess the waist circumference (WC) in Clinica Alemana Temuco, during January 2011 to March 2013, in patients with a stroke. Methods: We evaluated patients with a stroke diagnosis, in our primary Stroke Unit, who were hospitalized for ≥72 h. Waist circumference (WC) was measured according to WHO's recommendations, by two nutritionists. The study patients were divided into 3 groups according to WC for cardiovascular risk, low risk (LR): b94 cm (men); b80 cm (women); moderate risk (MR): 94–102 cm (men); 80–88 cm (women); and high risk (HR): N102 cm (men); N88 cm (women). We obtained a diagnosis of central obesity (CO) using NCEP-ATP-III criteria. Results: 81 patients were included. 48 were males (59.3%). Men mean aged: 62 years (32–89), mean WC: 103.9 (SD: ±9.9). BMI: 29. LR: 14.6%, MR: 37.5%, HR: 47.9% (CO). Women mean age: 57.4 years (35–81). Mean WC: 102.3 (SD: ±13.6), BMI: 29.9. LR: 3%; MR: 15.2%; HR: 81.8% (CO). Total sample corresponds to LR: 9.9%, MR: 28.4%; and HR: 61.7% (CO). Conclusion: Central obesity is a major risk factor for cardiovascular disease. This series of cases only shows that the problem is very important in Chile. The obesity and central obesity are epidemic. We should perform behaviors to lower these indicators, with much education and government guidelines. doi:10.1016/j.jns.2013.07.921 Abstract — WCN 2013 No: 2198 Topic: 3 — Stroke Preliminary evaluation of diffusion kurtosis imaging in acute stroke patients WCN 2013 No: 2198 Topic: 3 — Stroke Preliminary evaluation of diffusion kurtosis imaging in acute stroke patients Y.-L. Guo, S.-J. Li, P. Zhe Sun, R.-H. Wu. Department of Radiology, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China; Athinoula A. Martinos Center, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Aims: To translate and evaluate diffusion kurtosis imaging (DKI) in stroke patients. Methods: Four patients underwent DKI and conventional MRI (including T1WI, T2WI, FLAIR and DWI) using a GE 1.5T HDx echo speed plus an MRI scanner. Mean kurtosis (MK), radial kurtosis (Kr) and axial kurtosis (Ka) were derived using DKI software in GE ADW4.3 workstation. Fourteen regions of interest (ROI) were outlined in infarction regions of stroke patients, including 2 ROIs in super-acute, 3 ROIs in acute, 6 ROIs in subacute and 3 ROIs in chronic lesions. The stroke duration was determined from onset time and DWI signal intensity. Stroke prognosis was evaluated by follow-upMRI and clinical manifestations. Results: During super-acute stroke, regions of hyperintensive MK and Kr progressed to infarction with mild bleeding without noticeable DWI and ADC abnormalities. For the case of sub-acute stroke, DKI (MK and Kr) appeared hypointensive without significant change in DWI and ADC maps. In addition, 10 ROIs showed abnormality in both DKI and DWI/ADC maps. Conclusions: DKI displayed contrast different from the standard DWI and ADC maps. DKI remains promising to address false negative signals in the standard DWI and ADC maps, and complement existing stroke MRI for improved stroke diagnosis. doi:10.1016/j.jns.2013.07.922 Abstract — WCN 2013 No: 2301 Topic: 3 — Stroke Predictors of pneumonia in acute stroke inpatients in emergency unit WCN 2013 No: 2301 Topic: 3 — Stroke Predictors of pneumonia in acute stroke inpatients in emergency unit S.R. Almeida, M. Bahia, F.O. Lima, T.A.M.O. Cardoso, I. Paschoal, L.M. Li, Neurovascular Disease. Neurology, University of Campinas, UNICAMP, Campinas, Brazil; Medical Pathophysiology Department, University of Campinas, UNICAMP, Campinas, Brazil; Medical Clinic, University of Campinas, UNICAMP, Campinas, Brazil Background: Pneumonia is a serious complication in acute stroke patients. Several mechanisms might be implicated including impairment of the immune system and aspiration. The analyses of clinical predictors are useful to guide the clinical management and to adopt preventive measures in order to improve the patients' outcome. Objective: To determine the independent predictors of pneumonia in patients with acute stroke. Methods: This is a retrospective study from July to December 2011. All patients admitted with a diagnosis of stroke in an academic medical center were included. We review all the medical charts and Abstracts / Journal of the Neurological Sciences 333 (2013) e215–e278 e236

Myocardial Infarction as an early complication in acute stroke patients: Results from the Austrian Stroke Unit Registry

Myocardial Infarction as an early complication in acute stroke patients: Results from the Austrian Stroke Unit Registry

Abstract 3445: Predictors and Outcomes of Merci Device Fracture during Mechanical Thrombectomy for Acute Ischemic Stroke

Background and Purpose: Merci device fracture is an adverse event during mechanical thrombectomy for acute ischemic stroke. The purpose of this study was to describe the frequency and predictors of this complication in acute stroke patients after thrombectomy and its impact on clinical outcome. Methods: We retrospectively analyzed acute ischemic stroke patients treated by mechanical thrombectomy with the Merci Retriever and identified the presence of device fracture. The predictors of device fracture were assessed. We evaluated the impact of device fracture on potential hemorrhage and clinical outcome. Results: Of 136 patients treated by thrombectomy, 6 (4.4%) experienced intra-procedural device fracture. Internal carotid artery occlusion was associated with device fracture (OR 13.06; 95% CI 1.47 to 115.62, P =0.01). The fractured X and L series devices were successfully ensnared by a Merci device or a microsnare in 4 patients. Compared with patients with non-fractured devices, those with fractured devices had similar rates of Thrombolysis and Myocardial Infarction (TIMI) grade II and III revascularization (66.7% versus 72.3%; p =0.67), decreased rates of arterial occlusive lesion (AOL) grade III recanalization (0% versus 48.5%; p =0.03) and longer mean procedure time (2.5 hours versus 1.8 hours; p =0.03). In patients with fractured devices, no parenchymal hematomas were found, while hemorrhagic infarction and subarachnoid hemorrhage were found in 3 and 2 patients, respectively. Decompressive craniectomy following thrombectomy for malignant edema was associated with device fracture ( P =0.02). Patients with fractured devices had similar rates of independence at discharge (modified Rankin Scale≤2, 0% versus 25%; P =0.34) and in-hospital mortality (16.7% versus 23.4%; P &gt;0.99). Conclusions: Device fracture is relatively infrequent in acute ischemic stroke patients treated by Merci thrombectomy. Target occlusion in the internal carotid artery is an independent predictor of intra-procedural device fracture. This complication is not associated with parenchymal hematomas or poor clinical outcomes after thrombectomy.

Assessment of aspiration risk in acute ischaemic stroke—evaluation of the simple swallowing provocation test

Background:Aspiration is a common complication in acute stroke patients and is strongly associated with a poor outcome. Due to an insufficient sensitivity and specificity of clinical bedside tests, further refinements...

Upper extremity complications in acutestroke patients

Upper extremity complications in acutestroke patients

Low rate of contrast-induced Nephropathy after CT perfusion and CT angiography in acute stroke patients

The aim of the study was to assess (i) the rate of contrast-induced nephropathy (CIN), (ii) the amount and time course of renal dysfunction, (iii) the identification of risk factors and calculation of a risk score for CIN in acute stroke patients after CT perfusion (CTP) and CT angiography (CTA). 162 patients were investigated,who had received 140 ml of non-ionic low osmolar contrast agent (300 mg iodine per ml, Ultravist 300, Schering AG) for CTA and CTP. We assessed electrolytes, creatinine, and creatinine clearance before and up to 7 days after administration of contrast agent. In addition, the risk factors for CIN were recorded and a previously validated risk score for CIN was calculated. We also assessed the amount of crystalloid fluid substitution and newly prescribed drugs. CIN was defined as an increase of the serum creatinine-level of > 0.5 mg/dl or > 25% above baseline within 48 hours after contrast agent administration. 154 patients (94 %) received crystalloid fluid substitution (mean 6.1 l) within 48 h after contrast agent administration. During follow-up the creatinine values and the creatinine clearance remained stable while sodium and potassium increased significantly (p < 0.0001) after contrast agent administration. In patients with a pathological creatinine value on admission (n = 40), the creatinine clearance did not decrease significantly (p = 0.18). The risk score for developing a CIN was low in the majority of stroke patients. A manifest CIN occurred in 3 patients (2 %). No patient had to be hemodialysed. CIN is a rare complication in acute stroke patients examined by multimodal contrast-based CT due to the low prevalence of risk factors associated with CIN. In conjunction with appropriate fluid substitution, low osmolar nonionic contrast agents seem to be safe in clinical routine.

Lack of immunoreactivity for myoglobin in skeletal muscle of acute stroke patients.

Sternothyroid muscle biopsy specimens, obtained during tracheostomies from 15 patients with acute stroke and respiratory failure, were examined immunohistochemically to immunoreactivity to myoglobin (Mb). A marked decrease or lack of Mb immunoreactivity in association with hyaline degeneration was observed in 0.8 to 44.4% of the muscle fibers on both the paretic and non-paretic sides of all patients. The percentages of negative staining for Mb were less than 3.1% in 5 patients with acute respiratory failure due to causes other than stroke. The pattern and incidence of attenuated Mb immunoreactivity in the muscle fibers was found to be distinctively different in the two patients groups. In one group of 5 patients, a large number of muscle fibers (24.8 +/- 15.6%) had no Mb staining and were clearly bordered and grouped. In another 10-patient group, only a limited number of muscle fibers (3.3 +/- 2.5%) had no staining for Mb and these fibers were scattered. Four patients in the former group had catastrophic outcomes, while all the patients in the latter group survived. Ischemia, produced by an increase in catecholamines, and the consequent vasoconstriction, rather than hypoxemia seemed to be the cause of the negative immunoreactivity for Mb in the group pattern. In contrast, hypoxemia may have caused the scattered pattern of negative Mb immunoreactivity. It was concluded that negative immunostaining for Mb in muscle fibers represents a common and characteristic complication in acute stroke patients.