Transcranial Doppler Emboli Monitoring for Infective Endocarditis.

BACKGROUND AND PURPOSE: Ischemic stroke can occur in 20-55% of patients with infective endocarditis (IE) with 75% occurring during the first 2 weeks of treatment. CT or MRI brain can diagnose the sequelae of stroke but transcranial Doppler (TCD) can document active embolization. We undertook a retrospective review of our patient cohort and a systematic review of literature to assess the role of TCD in early diagnosis and management of ischemic stroke in IE. METHODS: Retrospective chart review and literature review. RESULTS: We found 89 patients with stroke caused by IE at our institution from December 2011 to April 2018. TCDs were obtained on 26 patients; 16 were abnormal for cerebrovascular abnormalities. Only 4 patients had 30-minute emboli monitoring performed, of which one revealed emboli. We found 3 studies investigating the role of TCDs in IE that showed promise in its use as a predictive tool in stroke risk stratification. CONCLUSIONS: Presence of embolization in the form of high-intensity transient signals (HITS) detected on TCDs can be used for early diagnosis of IE, assessing efficacy of antibiotic therapy, and stratification of stroke risk in IE. This can aid further research into testing preventative interventions for reducing stroke burden in IE such as earlier valvular surgery or vacuum-assisted vegetation extraction.

Successful use of closed-loop allostatic neurotechnology for post-traumatic stress symptoms in military personnel: self-reported and autonomic improvements.

BACKGROUND: Military-related post-traumatic stress (PTS) is associated with numerous symptom clusters and diminished autonomic cardiovascular regulation. High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology that produces real-time translation of dominant brain frequencies into audible tones of variable pitch and timing to support the auto-calibration of neural oscillations. We report clinical, autonomic, and functional effects after the use of HIRREM® for symptoms of military-related PTS. METHODS: Eighteen service members or recent veterans (15 active-duty, 3 veterans, most from special operations, 1 female), with a mean age of 40.9 (SD = 6.9) years and symptoms of PTS lasting from 1 to 25 years, undertook 19.5 (SD = 1.1) sessions over 12 days. Inventories for symptoms of PTS (Posttraumatic Stress Disorder Checklist - Military version, PCL-M), insomnia (Insomnia Severity Index, ISI), depression (Center for Epidemiologic Studies Depression Scale, CES-D), and anxiety (Generalized Anxiety Disorder 7-item scale, GAD-7) were collected before (Visit 1, V1), immediately after (Visit 2, V2), and at 1 month (Visit 3, V3), 3 (Visit 4, V4), and 6 (Visit 5, V5) months after intervention completion. Other measures only taken at V1 and V2 included blood pressure and heart rate recordings to analyze heart rate variability (HRV) and baroreflex sensitivity (BRS), functional performance (reaction and grip strength) testing, blood and saliva for biomarkers of stress and inflammation, and blood for epigenetic testing. Paired t-tests, Wilcoxon signed-rank tests, and a repeated-measures ANOVA were performed. RESULTS: Clinically relevant, significant reductions in all symptom scores were observed at V2, with durability through V5. There were significant improvements in multiple measures of HRV and BRS [Standard deviation of the normal beat to normal beat interval (SDNN), root mean square of the successive differences (rMSSD), high frequency (HF), low frequency (LF), and total power, HF alpha, sequence all, and systolic, diastolic and mean arterial pressure] as well as reaction testing. Trends were seen for improved grip strength and a reduction in C-Reactive Protein (CRP), Angiotensin II to Angiotensin 1-7 ratio and Interleukin-10, with no change in DNA n-methylation. There were no dropouts or adverse events reported. CONCLUSIONS: Service members or veterans showed reductions in symptomatology of PTS, insomnia, depressive mood, and anxiety that were durable through 6 months after the use of a closed-loop allostatic neurotechnology for the auto-calibration of neural oscillations. This study is the first to report increased HRV or BRS after the use of an intervention for service members or veterans with PTS. Ongoing investigations are strongly warranted. TRIAL REGISTRATION: NCT03230890 , retrospectively registered July 25, 2017.

Prevalence and predictors of carotid stenosis in Thai patients with ocular disorders.

There are limited data on prevalence and predictors of carotid stenosis (CS) in Thai and Asian patients with ocular disorders. A total of 135 of 2849 patients enrolled in the Neurosonology Registry had an ocular indication (OI). Demographics, the nature of the OI, risk factors (RF), presence of CS >50% and non-stenotic carotid plaque (NSCP) were analyzed. The mean age of patients was 60.40 ± 14.02 years. The RF included hypertension (47.4%), hypercholesterolemia (34.07%), diabetes mellitus (DM) (31.11%) and current smoking (41.48%). NSCP was found in 20% of Thai patients with OD. CS was found in 11.11% (ipsilateral 10.37%). Predictors of CS were ocular ischemic syndrome (odds ratio [OR] 19.63, p = 0.000), retinal artery occlusion (OR 14.13, p = 0.000), anterior ischemic optic neuropathy (OR 9.75, p = 0.002), neovascularized glaucoma (OR 8.15, p = 0.018), and DM (OR 2.53, p = 0.037). The presence of CS (11.11%), and CS or NSCP (31%) are markers of atherosclerotic risk. The nature of the OI predicted carotid findings. Carotid ultrasound helps to identify the risk for cardiovascular events and should be considered in patients with OI.

Practice standards for transcranial Doppler (TCD) ultrasound. Part II. Clinical indications and expected outcomes.

INTRODUCTION: Transcranial Doppler (TCD) is a physiological ultrasound test with established safety and efficacy. Although imaging devices may be used to depict intracranial flow superimposed on structural visualization, the end-result provided by imaging duplex or nonimaging TCD is sampling physiological flow variables through the spectral waveform assessment. SUMMARY OF RESULTS: Clinical indications considered by this multidisciplinary panel of experts as established are: sickle cell disease, cerebral ischemia, detection of right-to-left shunts (RLS), subarachnoid hemorrhage, brain death, and periprocedural or surgical monitoring. The following TCD-procedures are performed in routine in- and outpatient clinical practice: complete or partial TCD-examination to detect normal, stenosed, or occluded intracranial vessels, collaterals to locate an arterial obstruction and refine carotid-duplex or noninvasive angiographic findings; vasomotor reactivity testing to identify high-risk patients for first-ever or recurrent stroke; emboli detection to detect, localize, and quantify cerebral embolization in real time; RLS-detection in patients with suspected paradoxical embolism or those considered for shunt closure; monitoring of thrombolysis to facilitate recanalization and detect reocclusion; monitoring of endovascular stenting, carotid endarterectomy, and cardiac surgery to detect perioperative embolism, thrombosis, hypo- and hyperperfusion. CONCLUSION: By defining the scope of practice, these standards will assist referring and reporting physicians and third parties involved in the process of requesting, evaluating, and acting upon TCD results.

Enhancing the effectiveness of community stroke risk screening: a randomized controlled trial.

Stroke risk factors are routinely assessed in community screening programs; however, the rate of patient follow-up for health care once risk factors are identified is known to be low. This study was conducted to test the effectiveness of a brief behavioral telephonic intervention in an ongoing community stroke prevention screening program on health care seeking for stroke risk. A total of 227 participants with 2 or more stroke risk factors were randomly allocated to either an attention control arm or a behavioral intervention arm. The control group received standard information on risk and advice, whereas the intervention group received a brief Health Belief Model telephonic intervention designed to motivate care-seeking. The effect of treatment on the participants who completed a health care visit for stroke risk concerns was assessed using logistic regression. Cox survival analysis was used to compare time to physician visit between the 2 groups. Participants in the intervention arm were 1.85 times more likely to visit a primary care physician than controls. At 3 months, 69.2% of subjects in the intervention arm and 52.9% of those in the controls arm reported a new primary care visit after screening (P = .02), with 56.0% in the intervention arm and 38.4% in the control arm reporting a primary care visit specifically to discuss the stroke screening results (P < .01). Our data indicate that the brief, low-cost, motivational intervention effectively promoted adherence to screening advice and merits further testing.

Indications for carotid artery surgery and stent: the role of carotid ultrasound.

Carotid artery disease is the most frequently identified cause of ischemic stroke and is mostly due to atherosclerotic disease. Landmark trials have demonstrated that surgical intervention in cases of high-grade carotid stenosis can reduce the risk of subsequent stroke. Endovascular approaches continue to be evaluated in ongoing trials. Careful patient selection is critical if the potential benefits of carotid revascularization are to be realized. Ultrasound is a safe, accurate, readily available method to evaluate carotid artery disease. The degree of stenosis is the parameter most frequently used to make decisions about therapeutic approaches. Plaque characteristics may also be useful for identifying high-risk patients. Microembolic signals detected by transcranial Doppler ultrasound can identify cerebral embolization before or after carotid intervention. This review discusses the current clinical role of carotid ultrasound in the selection of patients for the two most frequently used carotid interventions: carotid endarterectomy or carotid angioplasty and stenting.

Guidelines for screening of extracranial carotid artery disease: a statement for healthcare professionals from the multidisciplinary practice guidelines committee of the American Society of Neuroimaging; cosponsored by the Society of Vascular and Interventional Neurology.

The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the screening for asymptomatic carotid artery stenosis in the general population and selected subsets of patients. Recommendations are included for high-risk persons in the general population; patients undergoing open heart surgery including coronary artery bypass surgery; patients with peripheral vascular diseases, abdominal aortic aneurysms, and renal artery stenosis; patients after radiotherapy for head and neck malignancies; patients following carotid endarterectomy, or carotid artery stent placement; patients with retinal ischemic syndromes; patients with syncope, dizziness, vertigo or tinnitus; and patients with a family history of vascular diseases and hyperhomocysteinemia. The recommendations are based on prevalence of disease, anticipated benefit, and concurrent guidelines from other professional organizations in selected populations.

Measurement of carotid stenosis: comparisons between duplex and different angiographic grading methods.

BACKGROUND AND PURPOSE: Endarterectomy has been proved to be an effective stroke prevention procedure. However, there are still inconsistencies between the results of different preoperative evaluation methods, which may sometimes complicate treatment plans. This study measured the discrepancies between different angiographic grading methods and attempted to further assess the accuracy of the carotid duplex examination according to these different angiographic grading methods. METHODS: One hundred seventy-one preendarterectomy carotid duplex examinations and angiograms were reviewed. All angiograms were measured blindly by one of the authors using the North American Symptomatic Carotid Endarterectomy Trial (N), the European Carotid Surgery Trial (E), and the common carotid (C) methods. The measurement results were further converted into the area of stenosis indices (N2, E2, and C2, respectively). By using regression testing, all results could be compared. The duplex examination data were then compared with the results of different angiographic measurement methods to evaluate their accuracy. RESULTS: The measurement results of all angiographic grading methods were well correlated. Using different angiographic grading systems as the gold standard, duplex examination for screening endarterectomy candidates produced the following results: According to the N method, accuracy was 74%; according to the E method, accuracy was 90%; and according to the C method, the accuracy rate was 92%. According to N2, accuracy was 88%; according to E2, accuracy was 94%; and according to C2, the accuracy rate was 93%. CONCLUSIONS: The measurement results of all 3 commonly used angiographic grading methods were linearly correlated with one another. (It is important to note that none of those standards should be treated as the only gold standard.) In this study, the duplex criteria have a greater accuracy rate according to E or C rather than N. However, this study also demonstrated that the cut point of the Doppler criteria is the determinant factor for accuracy rather than which gold standard was compared. Through careful adjustment of the cutoff criteria, carotid duplex can be highly accurate, despite the use of different reference standards.