Neal M. Rao

Thoracic outlet syndrome: a review.

Background:Arterial and venous thoracic outlet syndrome (TOS) were recognized in the late 1800s and neurogenic TOS in the early 1900s. Diagnosis and treatment of the 2 vascular forms of TOS are generally accepted in all medical circles. On the other hand, neurogenic TOS is more difficult to diagnose because there is no standard objective test to confirm clinical impressions. Review Summary:The clinical features of arterial, venous, and neurogenic TOS are described. Because neurogenic TOS is by far the most common type, the pathology, pathophysiology, diagnostic tests, differential and associate diagnoses, and treatment are detailed and discussed. The controversial area of objective and subjective diagnostic criteria is addressed. Conclusion:Arterial and venous TOS are usually not difficult to recognize and the diagnosis can be confirmed by angiography. The diagnosis of neurogenic TOS is more challenging because its symptoms of nerve compression are not unique. The clinical diagnosis relies on documenting several positive findings on physical examination. To date there is still no reliable objective test to confirm the diagnosis, but measurements of the medial antebrachial cutaneous nerve appear promising.

Risk–Benefit Profile of Long-Term Dual- Versus Single-Antiplatelet Therapy Among Patients With Ischemic Stroke: A Systematic Review and Meta-analysis

BACKGROUND Dual-antiplatelet regimens for prevention of recurrent stroke promote antithrombotic effects but may increase the risk for hemorrhage. PURPOSE To qualitatively and quantitatively examine the risk for recurrent stroke and intracranial hemorrhage (ICH) linked to long-term dual- and single-antiplatelet therapy among patients with ischemic stroke and transient ischemic attack. DATA SOURCES PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials through March 2013 without language restrictions. STUDY SELECTION The search identified 7 randomized, controlled trials that involved a total of 39,574 participants and reported recurrent stroke and ICH as outcome measures. DATA EXTRACTION All data from eligible studies were independently abstracted by 2 investigators according to a standard protocol. DATA SYNTHESIS Recurrent stroke risk did not differ between patients receiving dual-antiplatelet therapy and those receiving aspirin monotherapy (relative risk [RR], 0.89 [95% CI, 0.78 to 1.01]) or clopidogrel monotherapy (RR, 1.01 [CI, 0.93 to 1.08]). Risk for ICH did not differ between patients receiving dual-antiplatelet therapy and those receiving aspirin monotherapy (RR, 0.99 [CI, 0.70 to 1.42]) but was greater among patients receiving dual-antiplatelet therapy than among those receiving clopidogrel monotherapy (RR, 1.46 [CI, 1.17 to 1.82]). LIMITATION Agents used in dual- and single-antiplatelet therapies varied across trials, and the relatively modest number of trials limited subgroup analysis. CONCLUSION Compared with monotherapy, dual-antiplatelet therapy lasting more than 1 year after an index ischemic stroke or transient ischemic attack is not associated with a greater reduction in overall recurrent stroke risk. However, long-term dual-antiplatelet therapy is linked to higher risk for ICH than clopidogrel monotherapy in this patient population. PRIMARY FUNDING SOURCE Chang Gung Memorial Hospital.

The Forgotten Pectoralis Minor Syndrome: 100 Operations for Pectoralis Minor Syndrome Alone or Accompanied by Neurogenic Thoracic Outlet Syndrome

BACKGROUND Since 2005 when we became aware of pectoralis minor syndrome (PMS), more than 75% of patients diagnosed with neurogenic thoracic outlet syndrome (NTOS) also have neurogenic PMS (NPMS), and about 30% have only NPMS, without NTOS. METHODS Diagnosis was made based on history, physical examination, pectoralis minor (PM), and scalene muscle blocks with lidocaine. Pectoralis minor tenotomy was performed as an outpatient procedure under local anesthesia with heavy sedation through a 5-7 cm transaxillary incision. RESULTS The clinical picture included pain or tenderness in the anterior chest wall and axilla, together with physical findings of tenderness over the pectoralis minor tendon. Other symptoms were extremity pain, weakness, and paresthesia, similar to symptoms of NTOS. In 76 patients, 100 operations were performed: 48 for NPMS combined with NTOS and 52 for NPMS-alone. Features distinguishing the PM-alone group were fewer and milder occipital headaches, less neck pain, and fewer positive physical findings. Preoperatively, 85% of the of the PM-alone group were still employed compared to only 57% of the combined group (p=0.01). Success rates with 1-3-year follow-up for the PM-alone group were 90% good-excellent, 2% fair, and 8% failed; for the combined group success rates were 35% good-excellent, 19% fair, and 46% failed. All but one of the failures was immediate, only one was late. The only complication was 3 wound infections. Most patients returned to work within a few days. In the combined PMS/TOS group, most of the failed patients subsequently had thoracic outlet operations. CONCLUSION PMS commonly accompanies NTOS and frequently exists alone. Its recognition is important as many patients with suspected NTOS can be treated successfully with a simple, essentially risk-free PM tenotomy. Should this fail, thoracic outlet decompression can always be performed at a later date.

Effect of Blood Pressure Lowering in Early Ischemic Stroke: Meta-Analysis

Background and Purpose— Elevated blood pressure is common in acute stage of ischemic stroke and the strategy to manage this situation is not well established. We therefore conducted a meta-analysis of randomized controlled trials comparing active blood pressure lowering and control groups in early ischemic stroke. Methods— Pubmed, EMBASE, and Clinicaltrials.gov from January 1966 to March 2015 were searched to identify relevant studies. We included randomized controlled trials with blood pressure lowering started versus control within 3 days of ischemic stroke onset. The primary outcome was unfavorable outcome at 3 months or at trial end point, defined as dependency or death, and the key secondary outcome was recurrent vascular events. Pooled relative risks and 95% confidence intervals were calculated using random-effects model. Results— The systematic search identified 13 randomized controlled trials with 12 703 participants comparing early blood pressure lowering and control. Pooling the results with the random-effects model showed that blood pressure lowering in early ischemic stroke did not affect the risk of death or dependency at 3 months or at trial end point (relative risk, 1.04; 95% confidence interval, 0.96–1.13; P=0.35). Also, blood pressure lowering also had neutral effect on recurrent vascular events, as well as on disability or death, all-cause mortality, recurrent stroke, and serious adverse events. Conclusions— This meta-analysis suggested blood pressure lowering in early ischemic stroke had a neutral effect on the prevention of death or dependency.

Defining Clinically Relevant Cerebral Hemorrhage After Thrombolytic Therapy for Stroke Analysis of the National Institute of Neurological Disorders and Stroke Tissue-Type Plasminogen Activator Trials

Background and Purpose Several definitions have been proposed to distinguish clinically relevant from incidental cerebral hemorrhagic transformation after thrombolytic therapy for acute ischemic stroke. We investigated which definition best identifies cerebral hemorrhages that alter long-term functional outcome in The National Institute of Neurological Disorders and Stroke (NINDS) tPA Trials.Background and Purpose— Several definitions have been proposed to distinguish clinically relevant from incidental cerebral hemorrhagic transformation after thrombolytic therapy for acute ischemic stroke. We investigated which definition best identifies cerebral hemorrhages that alter long-term functional outcome in the National Institute of Neurological Disorders and Stroke (NINDS) tissue-type plasminogen activator (tPA) trials. Methods— We analyzed 4 candidate hemorrhage definitions for which the NINDS tPA trials public data set had relevant data. For each, we identified tPA-treated patients having that hemorrhage type and compared their actual functional outcomes at 90 days with their predicted outcomes had they not received tPA and not had the hemorrhage. Projected outcomes without tPA were based on a 17-variable prognostic model derived from the NINDS tPA trials placebo group. Results— Among the 312 patients treated with intravenous tPA, 33 (10.6%) experienced any radiological intracerebral hemorrhage <36 hours of treatment, 16 (5.1%) a radiological parenchymal hematoma, 20 (6.4%) a NINDS tPA trials–defined symptomatic intracerebral hemorrhage, 12 (3.8%) an European-Australian Cooperative Acute Stroke Study 2 (ECASS2)–defined symptomatic intracerebral hemorrhage, and 6 (1.9%) a modified version of the Safe Implementation of Thrombolysis in Stroke Monitoring Study (mSITS-MOST)–defined symptomatic intracerebral hemorrhage. The ECASS2 and mSITS-MOST definitions identified the largest hemorrhage-related change in 90-day modified Rankin Scale scores (2.26−0.32=1.94, P=0.0001; 2.81−0.63=2.18, P=0.0002, respectively). These definitions also distinguished the largest hemorrhage-related change in 90-day mortality (64.7%–7.6%=57.1%; P=0.0004 for ECASS2; 68.4%–19.5%=48.9%; P=0.0152 for mSITS-MOST). Conclusions— The ECASS2 and mSITS-MOST symptomatic intracerebral hemorrhage definitions, which combine radiological features and occurrence of substantial early neurological deterioration, best identify tPA hemorrhages that alter final patient outcome.

Cognitive impairment and risk of future stroke: a systematic review and meta-analysis

Background: Several studies have assessed the link between cognitive impairment and risk of future stroke, but results have been inconsistent. We conducted a systematic review and meta-analysis of cohort studies to determine the association between cognitive impairment and risk of future stroke. Methods: We searched MEDLINE and Embase (1966 to November 2013) and conducted a manual search of bibliographies of relevant retrieved articles and reviews. We included cohort studies that reported multivariable adjusted relative risks and 95% confidence intervals or standard errors for stroke with respect to baseline cognitive impairment. Results: We identified 18 cohort studies (total 121 879 participants) and 7799 stroke events. Pooled analysis of results from all studies showed that stroke risk increased among patients with cognitive impairment at baseline (relative risk [RR] 1.39, 95% confidence interval [CI] 1.24–1.56). The results were similar when we restricted the analysis to studies that used a widely adopted definition of cognitive impairment (i.e., Mini-Mental State Examination score < 25 or nearest equivalent) (RR 1.64, 95% CI 1.46–1.84). Cognitive impairment at baseline was also associated with an increased risk of fatal stroke (RR 1.68, 95% CI 1.21–2.33) and ischemic stroke (RR 1.65, 95% CI 1.41–1.93). Interpretation: Baseline cognitive impairment was associated with a significantly higher risk of future stroke, especially ischemic and fatal stroke.

Warfarin Use and Risk of Stroke in Patients With Atrial Fibrillation Undergoing Hemodialysis: A Meta-Analysis.

AbstractIn spite of the substantial burden of atrial fibrillation and associated elevated ischemic stroke risk in patients undergoing hemodialysis, the role of warfarin in these high-risk patients remains uncertain. Our objective was to clarify the association between warfarin use and risk of stroke for patients with atrial fibrillation undergoing dialysis.PubMed and Embase from January 1966 to January 2015 were searched to identify relevant studies. Inclusion criteria were cohort studies, patients with atrial fibrillation undergoing hemodialysis, and reported quantitative estimates of the multivariate adjusted relative risk (RR) and 95% confidence interval (CI) for future stroke associated with warfarin use. We identified 8 studies, with a total of 9539 participants and 706 stroke events. Three studies reported total stroke as primary endpoint and other studies reported ischemic stroke as primary endpoint. Pooling the results showed that warfarin use was associated with higher risk of any stroke (RR 1.50, 95% CI: 1.13–1.99). By stroke type, warfarin was not significantly linked to risk of ischemic stroke (RR 1.01, 95% CI: 0.65–1.57, P = 0.97), but was related to greater hemorrhagic stroke risk (RR 2.30, 95% CI: 1.62–3.27). Warfarin heightened overall bleeding risk (RR 1.27, 95% CI: 1.03–1.56), but not death (RR 0.67, 95% CI: 0.37–1.21).Among patients with atrial fibrillation undergoing hemodialysis, use of warfarin is associated with a higher risk of hemorrhagic stroke, but did not increase overall mortality.

Is clopidogrel better than aspirin following breakthrough strokes while on aspirin? A retrospective cohort study

Objective There is insufficient evidence on which to base a recommendation for optimal antiplatelet therapy following a stroke while on aspirin. The objective was to compare clopidogrel initiation vs aspirin reinitiation for vascular risk reduction among patients with ischaemic stroke on aspirin at the time of their index stroke. Design Retrospective. Setting We conducted a nationwide cohort study by retrieving all hospitalised patients (≥18 years) with a primary diagnosis of ischaemic stroke between 2003 and 2009 from Taiwan National Health Insurance Research Database. Participants Among 3862 patients receiving aspirin before the index ischaemic stroke and receiving either aspirin or clopidogrel after index stroke during follow-up period, 1623 were excluded due to a medication possession ratio <80%. Also, 355 were excluded due to history of atrial fibrillation, valvular heart disease or coagulopathy. Therefore, 1884 patients were included in our final analysis. Interventions Patients were categorised into two groups based on whether clopidogrel or aspirin was prescribed during the follow-up period. Follow-up was from time of the index stroke to admission for recurrent stroke or myocardial infarction, death or the end of 2010. Primary and secondary outcome measures The primary end point was hospitalisation due to a new-onset major adverse cardiovascular event (MACE: composite of any stroke or myocardial infarction). The leading secondary end point was any recurrent stroke. Results Compared to aspirin, clopidogrel was associated with a lower occurrence of future MACE (HR=0.54, 95% CI 0.43 to 0.68, p<0.001, number needed to treat: 8) and recurrent stroke (HR=0.54, 95% CI 0.42 to 0.69, p<0.001, number needed to treat: 9) after adjustment of relevant covariates. Conclusions Among patients with an ischaemic stroke while taking aspirin, clopidogrel initiation was associated with fewer recurrent vascular events than aspirin reinitiation.

Early Loss of Immediate Reperfusion While Stent Retriever in Place Predicts Successful Final Reperfusion in Acute Ischemic Stroke Patients

Background and Purpose— Degree of stent retriever engagement with target thrombi may be reflected by (1) immediate reperfusion (IR) on first deployment, indicating displacement of clot toward the vessel wall, and (2) by early loss of IR (ELOIR), indicating penetration of retriever struts through the thrombus. The relation of these early findings to final reperfusion and clinical outcomes has not been well delineated. Methods— We investigated IR and ELOIR in patients undergoing stent retriever mechanical thrombectomy at an academic medical center between March 2012 and June 2014. Results— Among 56 patients, IR itself was not associated with final successful reperfusion, which occurred in 66.7% of IR patients and 71.4% of non-IR patients (P=0.999). However, ELOIR was associated with a higher rate of final successful reperfusion (92% versus 44%; P=0.046). Patients with ELOIR had a higher nominal rate of final favorable outcome (42% versus 22%; P=0.64). Conclusions— ELOIR during the embedding period after deployment of stent retrievers is associated with successful final reperfusion, likely because of greater thrombus engagement with the stent retriever. ELOIR may be a useful finding to guide duration of embedding time in clinical practice and design of novel stent retrievers.

Drip, ship, and grip, then slice and dice: comprehensive stroke center management of cervical and intracranial emboli

Background and Purpose: Tandem acute thrombotic emboli in the cervical and intracranial arteries are an unusual cause of stroke presenting unique management challenges. In regional systems of acute stroke care anchored by Comprehensive Stroke Centers (CSC), combined fibrinolytic, endovascular, and open surgical intervention is a new therapeutic option. Summary of Case: A 28-year-old male underwent retinal surgery, including post-operative neck compression and the next day presented to a primary stroke center with aphasia and right hemiplegia. Intravenous tissue plasminogen activator therapy was initiated and the patient was transferred to a CSC for higher level of care (drip and ship). Imaging at the CSC demonstrated tandem thrombi: a near occlusive lesion at the origin of the left cervical internal carotid artery and a total occlusion of the M1 segment of the left middle cerebral artery. Endovascular thrombectomy with the Solitaire stent retriever resulted in intracranial recanalization (grip). Immediately after the endovascular procedure, open carotid thrombectomy was performed to achieve cervical carotid revascularization without systemic heparinization (slice). Both cervical carotid and intracranial thrombi were processed for proteomic analysis via mass spectrometry (dice). Conclusion: Combined fibrinolytic, endovascular, and open surgical intervention can yield revascularization and good clinical outcome in cases of tandem lesions.