Anmar Razak

Predictors of Occult Paroxysmal Atrial Fibrillation in Cryptogenic Strokes Detected by Long-Term Noninvasive Cardiac Monitoring

Background and Purpose. Paroxysmal Atrial fibrillation/Flutter (PAF) detection rates in cryptogenic strokes have been variable. We sought to determine the percentage of patients with cryptogenic stroke who had PAF on prolonged non-invasive cardiac monitoring. Methods and Results. Sixty-two consecutive patients with stroke and TIA in a single center with a mean age of 61 (+/− 14) years were analyzed. PAF was detected in 15 (24%) patients. Only one patient reported symptoms of shortness of breath during the episode of PAF while on monitoring, and 71 (97%) of these 73 episodes were asymptomatic. A regression analysis revealed that the presence of PVCs (ventricular premature beats) lasting more than 2 minutes (OR 6.3, 95% CI, 1.11–18.92; P = .042) and strokes (high signal on Diffusion Weighted Imaging) (OR 4.3, 95% CI, 5–36.3; P = .041) predicted PAF. Patients with multiple DWI signals were more likely than solitary signals to have PAF (OR 11.1, 95% CI, 2.5–48.5, P < .01). Conclusion. Occult PAF is common in cryptogenic strokes, and is often asymptomatic. Our data suggests that up to one in five patients with suspected cryptogenic strokes and TIAs have PAF, especially if they have PVCs and multiple high DWI signals on MRI.

Carotid Artery Dissection due to Elongated Styloid Process: A Self‐Stabbing Phenomenon

Elongated styloid process (ESP) is an anatomical variant that has been described as the cause of Eagle syndrome. Until recently, the styloid process has not been appreciated as a significant contributor to carotid artery dissection (CAD), which is not part of Eagle syndrome. We present a case of a 41‐year‐old male who presented with acute right middle cerebral artery occlusion and was found to have ESP projecting to and abutting the lateral wall of a dissected right internal carotid artery (ICA). Forced sustained head turning with maximal muscle contraction was the initiating event driving the styloid process into the wall of the ICA in a manner that can be likened to being stabbed with a pointed object. Knowing the association between ESP, Eagle syndrome, and CAD shall lead to increased awareness and appropriate diagnosis and treatment.

Clinical Significance of Serum Zinc Levels in Cerebral Ischemia

Background. Zinc mediates several vital physiological, enzymatic and cellular functions. The association between serum zinc and stroke outcome has not been previously evaluated. Methods. This single center retrospective study was conducted on consecutive stroke (n = 158) and TIA (n = 74) patients. We sought to determine whether serum zinc concentrations in patients with acute ischemic strokes were associated with stroke severity and poor functional status at discharge, respectively. Results. Overall, out of the 224 patients analyzed (mean age 67 years), 35.7% patients had low zinc levels (65 mcg/dL). Patients with stroke (n = 152) were more likely to have low zinc levels (OR = 2.62, CI 1.92–3.57, P < .003) compared to patients with TIA (n = 72). For patients with stroke (n = 152), multivariate analysis showed that low serum zinc levels (OR 2.82, CI 1.35–5.91, P = .035) and strokes with admission severe strokes (NIHSS > 8) (OR 2.68, CI 1.1–6.5, P = .03) were independently associated with poor functional status (MRS > 3) at discharge from the hospital. Conclusion. Low serum zinc concentrations are associated with more severe strokes on admission and poor functional status at discharge.

Wallenberg’s syndrome with extradural–extracranial origin of the posterior inferior cerebellar artery

We report a case of lateral medullary syndrome (LMS) with extradural origin of the posterior inferior cerebellar artery (PICA). A 45-year-old construction worker presented with acute signs and symptoms of typical LMS. Prolonged work-related neck extension was reported just prior to the onset of symptoms. Cerebral angiography revealed a patent vertebrobasilar tree with an extradural origin of an otherwise normal appearing PICA ipsilaterally. Workup did not show evidence for cardioembolic or atheroembolic source. The presence of an extradural origin of PICA may be considered a predisposing factor for non-traumatic LMS associated with head and neck movement.

ABCD2 Score and Large-Artery Atherosclerosis.

Background and Purpose: Extracranial stenosis (ECS) or intracranial stenosis (ICS) are independent risk factors for stroke after transient ischemic attack (TIA). We examined the association of the age, blood pressure, clinical features, duration of symptoms and diabetes (ABCD2) score, a validated risk prediction model for stroke after TIA, and the presence of ICS or ECS. Methods: Vascular imaging and ABCD2 scores were obtained in a retrospective cohort of 77 consecutive patients diagnosed with TIA in a single center emergency department. The association between vascular stenosis and ABCD2 scores and how each related to clinical outcome was examined. Results: In all, 30 (39.2%) TIA patients had 37 stenotic lesions; 15 (40.5%) stenotic lesions were ICS and 22 (59.5%) stenotic lesions were ECS. A total of 7 patients (9.5%) had both ECS and ICS lesions. Patients with ABCD2 > 3 were more likely to have ICS (odds ratio [OR] = 6.25, confidence interval [CI] 1.39-32.44, P = .009) and ECS (OR = 5.25, CI = 1.56-17.66, P = .005). Of the 37 stenotic lesions, 21 (56.7%) were symptomatic; 4 (19.2%) of these had an ABCD2 ≤ 3. At 7 days, there were 4 ischemic strokes, 3 had previously demonstrated symptomatic stenotic lesions, and all had ABCD2 scores > 3. Conclusions: Compared to patients in the low-risk ABCD2 scores, the patients with medium- to high-risk ABCD2 scores are more likely to have symptomatic and asymptomatic vascular stenotic lesions. However, 1 in 5 patients with low-risk ABCD2 score has symptomatic stenotic lesions, indicating ABCD2 score does not identify all patients with symptomatic stenotic lesions.

Post-IV thrombolytic headache and hemorrhagic transformation risk in acute ischemic stroke

Background:Headache during or soon after administration of IV tissue plasminogen activator (tPA) in patients with acute ischemic stroke (AIS) is a concern for hemorrhagic transformation (HT). However, no data are available regarding the incidence of HT in these patients or the prognostic indication of these headaches. We examine the importance of tPA-associated headaches among AIS patients in terms of HT rates and clinical outcomes. Methods:AIS patients treated with IV tPA at a comprehensive stroke center between January 2007 and November 2012 were retrospectively reviewed for documented tPA-associated headache in the first 24 hours post-tPA. We compared the headache and nonheadache groups for differences in various clinical and radiologic outcomes. Results:Of the 193 patients, 63 (32.6%) had tPA-associated headache. Headache patients (HP) were younger than nonheadache patients (NHP) (mean ± SD, 59.5 ± 17.4 years vs 69.9 ± 15.5 years, p < 0.0001), and 53% of HP were men, compared to 49.2% of NHP (p = 0.537). Comorbid conditions did not differ between the 2 groups. There were no statistical differences between HP and NHP in admission NIH Stroke Scale (NIHSS) score (11.2 ± 5.7 vs 11.5 ± 5.5, p = 0.646), NIHSS score at 24 hours (6.5 ± 5.7 vs 7.4 ± 6.9, p = 0.466), NIHSS score at discharge (6.7 ± 10.1 vs 8.1 ± 11.6, p = 0.448), HT (12.7% vs 18.4%, p = 0.3), cervical artery dissection (4.7% vs 5.38%, p = 0.764), length of hospitalization (6.29 ± 5 days vs 6.35 ± 4.7 days, p = 0.935), and disposition. Conclusion:tPA-associated headache does not predict increased risk of HT and has no other prognostic importance in patients with AIS. Prospective studies with a larger cohort may be needed to further explore this relationship.

Arteriovenous Malformations of the Brain

Arteriovenous malformations (AVM) of the brain (also known as pial or parenchymal AVMs) are defined as intracranial space-occupying lesions composed of feeding arteries, draining veins, and a nidus of tangled vessels without an intervening capillary bed. There is no normal interposed brain tissue, but there can be surrounding gliosis. Morphology can vary, but AVMs are typically triangular in shape with the base towards the cortex and the apex towards the ventricular system [Brown et al. Mayo Clin Proc 80(2):269–81, 2005; Winn. Youmans neurological surgery. 6th edn. Elsevier, Philadelphia, PA, 2011; Moftakhar et al. Neurosurg Focus 26(5):E10, 2009]. While much of the pathophysiology, epidemiology, and natural history remain unclear, there has been successful advancement in the understanding and management of these complex lesions, especially with regard to the application of microsurgical, radiosurgical, and endovascular therapies.

Neurointerventional Therapies for Stroke in Atrial Fibrillation: Illustrated Cases

Approximately 800,000 strokes occur in the United States every year, resulting in 200,000 deaths. Strokes may be ischemic (80%) or hemorrhagic (20%). Strokes caused by atrial fibrillation (AF) are thromboembolic, and AF is the leading cause of ischemic stroke. Rapid distinction between these forms of strokes is critical because approaches to treatment are different. The goal for acute ischemic stroke is reperfusion of ischemic brain tissue, whereas the treatment of hemorrhagic stroke is supportive therapy and correction of the underlying conditions. The treatment of acute ischemic strokes is similar to treatment of acute myocardial infarction, which requires timely reperfusion for optimal results.