Cryptogenic Stroke—The Appropriate Diagnostic Evaluation

Elevated Red Blood Cell Distribution Width May Be a Novel Independent Predictor of Poor Functional Outcome in Patients Treated with Mechanical Thrombectomy

Purpose

Red blood cell distribution width (RDW) evaluates the variation (size heterogeneity) in red blood cells. Elevated RDW has been identified as a predictor of poor functional outcomes for acute ischemic stroke. The association between elevated RDW level and poor functional outcome in stroke patients undergoing mechanical thrombectomy has not been reported before. This study aims to investigate this relationship.

Materials and Methods

This was a multicenter retrospective study involving the prospectively and consecutively collected data of 205 adult stroke patients who underwent mechanical thrombectomy for anterior circulation large vessel occlusion (middle cerebral artery M1, anterior cerebral artery A1, tandem ICA-MCA, carotid T) between July 2017 and December 2019. RDW cut off levels were accepted as >16%. The effect of elevated RDW on poor functional outcome (modified Rankin scale 3–6) was investigated using bivariate and multivariate regression analysis.

Results

Elevated RDW was significantly associated with poor functional outcome in bivariate and multivariate analysis (odds ratio [OR] for RDW >16%, 2.078; 95% confidence interval [95% CI], 1.083–3.966; P=0.027 and OR for RDW >16%, 2.873; 95% CI, 1.342–6.151; P=0.007; respectively).

Conclusion

These findings suggest that elevated RDW may be an independent predictor of poor functional outcomes in ischemic stroke patients undergoing mechanical thrombectomy.

Cryptogenic Stroke: Anatomy of the Stroke Work-Up

Despite advances in understanding the cause of ischemic stroke, cryptogenic stroke remains a diagnostic and therapeutic challenge for clinicians. Approximately 15% to 40% of all ischemic strokes have no identifiable cause. CS is a diagnosis of exclusion after completing the standard stroke work-up. Further investigation needs to be tailored individually according to results of the clinical evaluation so appropriate secondary prevention strategies can be applied.

Decompressive craniectomy for malignant middle cerebral artery infarction in a 16-year old boy: a case report

Background

Cryptogenic stroke frequently occurs in younger patients and has a high risk of recurrence. Consequently, secondary prevention is often suboptimal as there is no known risk factor to target. This case demonstrates an unexpected finding of middle cerebral artery infarction and extensive malignant transformation in a 16-year-old boy more than a day post-admission. The lack of a proven culprit lesion makes this case even more intriguing and subsequently raises questions of cryptogenic mechanisms in the context of unrelated trauma.

Case presentation

A 16-year-old white boy had been stabbed in his chest but had a Glasgow Coma Scale score of 15. Over a day later he developed sudden signs and symptoms consistent with a neurological event of unknown etiology. Computed tomography demonstrated significant cerebral edema but was equivocal in its list of differentials. A computed tomography scan of his chest demonstrated no cardiac wall or vascular injury and he was transferred to our neurosurgical unit for intracranial pressure monitoring. A computed tomography angiogram revealed an unexpected finding of malignant middle cerebral artery infarction. Failure to medically manage his intracranial pressure resulted in a decompressive craniectomy less than 12-hours postictus. Despite extensive diagnostic investigations no culprit lesion was identified and no patent foramen ovale found. Since discharge he has returned to full functional status. He was the youngest patient (mean age of 43 years) out of a 10-year institutional retrospective on decompressive craniectomies for malignant middle cerebral artery infarction (n = 40) and had the singularly best Glasgow Outcome Scale score of 5.

Conclusions

This case highlights the preponderance of cryptogenic stroke in younger patients and its etiological elusiveness. It further demonstrates that age is predictive in terms of survival and functional outcome in the context of malignant middle cerebral artery infarction.

Red blood cell distribution width in patients with cryptogenic stroke

BACKGROUND

There is no information about a possible association of red blood cell distribution width (RDW) with cryptogenic stroke (CS). We aimed to analyze the association of RDW with CS.

PATIENTS AND METHODS

One hundred and sixty-three patients with CS were included along with 186 healthy controls. Fibrinogen, leukocytes, hemoglobin, and erythrocyte indices were evaluated.

RESULTS

Patients showed higher RDW, leukocyte count, and body mass index (BMI) than controls (P < .05). No differences were observed in the erythrocyte indices or in glucose, cholesterol, and triglycerides levels (P > .05). When patients with anemia were excluded from the study (6 controls and 5 cases), the differences between cases and controls persisted (P = .005). Multivariate logistic regression revealed that, after adjusting for potential confounders (anemia, age > 40 years, gender, and fibrinogen >382 mg/dL, total cholesterol >240 mg/dL, and BMI > 28.7 kg/m(2)), RDW >14% was the only parameter that independently increased the risk of CS.

CONCLUSION

The RDW >14% increased the risk of CS by 2.5-fold, irrespectively of anemia, inflammation, and lipidic profile.