In-Transit Telemedicine Speeds Ischemic Stroke Treatment: Preliminary Results.

BACKGROUND AND PURPOSE: Time to treatment is critically important in ischemic stroke. We compared the efficacy and cost of teleneurology evaluation during patient transport with that of mobile stroke transport units. METHODS: Using cellular-connected telemedicine devices, we assessed 89 presumptive stroke patients in ambulances in transit. Paramedics assisted remote teleneurologists in obtaining a simplified history and examination, then coordinating care with the receiving emergency department. We prospectively assessed door-to-needle and last-known-well-to-needle times for all intravenous alteplase-treated stroke patients brought to our emergency departments by emergency medical services' transport, comparing those with and without in-transit telestroke. RESULTS: From January 2015 through March 2016, 111 stroke patients received intravenous alteplase at study emergency departments. Mean door to needle was 13 minutes less with in-transit telestroke (28 versus 41; P=0.02). Although limitations in cellular communication degraded transmission quality, this did not prevent the completion of satisfactory patient evaluations. CONCLUSIONS: Improvement in time to treat seems comparable with in-transit telestroke and mobile stroke transport units. The low cost/unit makes this approach scalable, potentially providing rapid management of more patients.

Power M-Mode Doppler and single-gate spectral analysis using a 2-MHz pulsed-wave Doppler transducer to directly detect cervical internal carotid artery stenosis: use of the continuity principle: report of a novel technique.

BACKGROUND AND PURPOSE: We hypothesized that direct cervical investigation with Power M-Mode Doppler (PMD) combined with single-gate Doppler spectral analysis (SGDSA) using a 2-MHz pulsed-wave Doppler transducer would show reasonable accuracy parameters when compared with standard color-coded carotid duplex ultrasound (CDU). METHODS: We prospectively screened for cervical internal carotid artery (ICA) stenosis by direct observation using a 2 MHz PMD/SGDSA device. PMD identified the artery (location, depth, flow direction) and SGDSA assessed waveform; peak systolic, end diastolic, and mean flow velocities (MFV) of the common carotid artery; cervical ICA proximally and distally; and external carotid artery. Diagnostic accuracy was compared with concurrent carotid duplex ultrasound. The continuity principle was applied using the proximal/distal cervical ICA MFV ratio. RESULTS: We examined 456 vessels (228 patients). Using ICA proximally/ICA distally MFV ratio of 1.5 or greater or absence of ICA signature, for 40% to 59% or greater stenosis (including occlusions), sensitivity was 75.4%, specificity 99.8%, positive predictive value 97.7%, negative predictive value 96.6%, and accuracy 96.7%. For MFV ratio 1.6 or greater or absence of ICA signature and 60% to 79% or greater stenosis (including occlusions), sensitivity was 92.3%, specificity 98.1%, positive predictive value 81.8%, negative predictive value 99.3%, and accuracy 97.6%. CONCLUSIONS: Use of combined PMD and SGDSA to directly observe the extracranial ICA is reasonably accurate compared with carotid duplex ultrasound. Using the MFV ratio of proximal/distal extracranial ICA improves accuracy parameters and provides a quick and effective bedside screen for ICA stenosis. This novel technique should be considered part of the standard PMD/transcranial Doppler examination.

Catheter-based treatment for patients with acute ischemic stroke ineligible for intravenous thrombolysis.

BACKGROUND AND PURPOSE: We present our single-center experience using catheter-based therapy for acute ischemic stroke patients who were not candidates for intravenous thrombolytic therapy. METHODS: Neurologic outcomes were assessed in patients with acute ischemic stroke, ineligible for intravenous thrombolysis, treated with an emergent catheter-based therapy. RESULTS: Nonparametric analysis of neurological outcomes demonstrated a benefit in National Institutes of Health Stroke Scale (NIHSS) at long-term follow-up (P=0.036). Independence in daily activities and improvement in NIHSS of > or =4 points were achieved in 38% and 56% of patients, respectively. Four patients (25%) died, including 2 patients (12.5%) who died from intracranial hemorrhage. CONCLUSIONS: Catheter-based treatment offers a promising treatment strategy in patients with acute ischemic stroke ineligible for intravenous thrombolysis.

Early dramatic recovery during intravenous tissue plasminogen activator infusion: clinical pattern and outcome in acute middle cerebral artery stroke.

BACKGROUND AND PURPOSE: Acute-stroke patients receiving standard intravenous tissue plasminogen activator (tPA) have been noted to experience early dramatic recoveries. The prevalence, clinical characteristics, and outcome of patients experiencing dramatic recovery is not well described. METHODS: We prospectively studied all patients presenting with acute middle cerebral artery (MCA) stroke syndromes and transcranial Doppler (TCD) evidence of an MCA obstruction. All patients received intravenous tPA per the National Institute of Neurological and Communicative Disorders and Stroke protocol, with serial National Institutes of Health Stroke Scale (NIHSS) scores and continuous TCD monitoring. Dramatic recovery was defined as an improvement of > or =10 NIHSS points or a decrease to an NIHSS score of < or =3 by the end of infusion. Outcome at the end of infusion, at 24 hours, and at long-term follow-up were obtained. The timing and pattern of deficit recovery during dramatic recovery was also studied. RESULTS: Dramatic recovery occurred in 22% of all patients. Compared with patients who did not experience dramatic recovery, those patients who did had significantly lower end-infusion NIHSS (median 2 and range 0 to 16 for dramatic-recovery patients versus median 17 and range 6 to 35 for non-dramatic-recovery patients, P<0.01) and 24-hour NIHSS (median 2 and range 0 to 16 for dramatic-recovery patients versus median 13 and range 2 to 35 for non-dramatic-recovery patients, P<0.01). A long-term modified Rankin Score benefit was noted (median 1 and range 0 to 6 for dramatic-recovery patients versus median 4 and range 0 to 6 for non-dramatic-recovery patients, P<0.01). Baseline clinical characteristics were similar. The only difference was improved TCD-determined flow values at the end of infusion (normal restoration of flow was 58% in dramatic-recovery patients versus 14% in non-dramatic-recovery patients, P<0.01). A characteristic pattern of recovery of deficit was noted. CONCLUSIONS: Early dramatic recovery in acute MCA stroke patients treated with intravenous tPA is relatively frequent. The benefit of dramatic recovery is maintained at 24 hours and over the long term. TCD monitoring suggests that dramatic recovery is a result of early restoration of MCA flow during the tPA infusion. The consistent pattern of early clinical recovery may help explain the mechanisms by which thrombolysis improves outcome and could suggest targets for enhancing the therapeutic effect of intravenous tPA.

Improving delivery of acute stroke therapy: The TLL Temple Foundation Stroke Project.

BACKGROUND AND PURPOSE: Only a small minority of acute stroke patients receive approved acute stroke therapy. We performed a community and professional behavioral intervention project to increase the proportion of stroke patients treated with approved acute stroke therapy. METHODS: This study used a quasi-experimental design. Intervention and comparison communities were compared at baseline and during educational intervention. The communities were based in 5 nonurban East Texas counties. The multilevel intervention worked with hospitals and community physicians while changing the stroke identification skills, outcome expectations, and social norms of community residents. The primary goal was to increase the proportion of patients treated with intravenous recombinant tissue plasminogen activator (rTPA) from 1% to 6% of all cerebrovascular events in the intervention community. RESULTS: We prospectively evaluated 1733 patients and validated 1189 cerebrovascular events. Intravenous rTPA treatment increased from 1.38% to 5.75% among all cerebrovascular event patients in the intervention community (P=0.01) compared with a change from 0.49% to 0.55% in the comparison community (P=1.00). Among the ischemic stroke patients, an increase from 2.21% to 8.65% was noted in the intervention community (P=0.02). The comparison group did not appreciably change (0.71% to 0.86%, P=1.00). Of eligible intravenous rTPA candidates, treatment increased in the intervention community from 14% to 52% (P=0.003) and was unchanged in the comparison community (7% to 6%, P=1.00). CONCLUSIONS: An aggressive, multilevel stroke educational intervention program can increase delivery of acute stroke therapy. This may have important public health implications for reducing disability on a national level.

Screening for intracranial stenosis with transcranial Doppler: the accuracy of mean flow velocity thresholds.

BACKGROUND: Patients with 50% intracranial arterial stenosis may require more intensive therapies for stroke prevention. Transcranial Doppler (TCD) is a convenient noninvasive screen for intracranial stenosis. The accuracy of different mean flow velocity (MFV) thresholds for determining the degree of stenosis remains uncertain. METHODS: The authors prospectively compared the accuracy of TCD criteria and MFV thresholds to magnetic resonance, computed tomography, and digital subtraction angiography in patients with symptoms of recent or remote stroke or transient ischemic attack. Stenosis on angiography was measured as 0%, < 50%, or > or = 50% diameter reduction. RESULTS: Of 136 consecutive patients, 33 (24%) had distal internal carotid artery (ICA), middle cerebral artery (MCA), posterior cerebral artery, or basilar artery stenosis on angiography (14 patients [10%] were excluded due to incomplete TCD examinations, mainly from a lack of temporal windows). TCD showed 31 true-positive, 9 false-positive, 2 false-negative, and 94 true-negative studies. For all vessels, TCD had a sensitivity of 93.9% (confidence interval [CI] = 89%-98%), a specificity of 91.2% (CI = 87%-96%), a positive predictive value (PPV) of 77.5%, and a negative predictive value (NPV) of 97.9%. The trade-off in sensitivity and specificity for MCA MFV thresholds was as follows: MFV > or = 80 cm/s had a sensitivity of 100%, a specificity of 96.9% (CI = 94%-99%), a PPV of 84%, and an NPV of 100%. MFV > or = 100 cm/s had a sensitivity of 100%, a specificity of 97.9% (CI = 96%-99%), a PPV of 88.8%, and an NPV of 94.9%. MFV > or = 120 cm/s had a sensitivity of 68.7% (CI = 61%-78%), a specificity of 100%, a PPV of 100%, and an NPV of 94.9%. Reasons for false-positive findings include collateralization of flow in the presence of proximal ICA stenosis and prestenotic to stenotic MCA velocity ratios of 1: < or = 2. CONCLUSION: TCD is both sensitive and specific in identifying > or = 50% intracranial arterial stenosis. A MFV threshold cutoff of 100 cm/s has an optimal sensitivity and specificity trade-off for > or = 50% MCA stenosis. To help avoid false-positive results, a prestenotic to stenotic MCA velocity ratio of 1: > or = 2 should be used in addition to the MFV threshold.

Intravenous tissue plasminogen activator and flow improvement in acute ischemic stroke patients with internal carotid artery occlusion.

BACKGROUND AND PURPOSE: It has been suggested that intravenous tissue plasminogen activator (TPA) would not lyse the large thrombus associated with internal carotid artery (ICA) occlusion and, therefore, would be ineffective in this setting. Vascular imaging, safety, and outcome of TPA therapy for ICA occlusion is not well described. Our goal was to determine the site of occlusion, early recanalization after TPA infusion, and its relationship to outcome. METHODS: We reviewed our database of all stroke patients treated with i.v. TPA between July 1997 and July 1999. We identified all cases with carotid occlusion suggested by transcranial Doppler (TCD) and angiography. Occlusion and recanalization were assessed by site including proximal ICA (prICA), terminal ICA (tICA), and middle cerebral artery (MCA). Baseline National Institutes of Health Stroke Scale (NIHSS) scores and follow-up Rankin scores were obtained. RESULTS: We treated 20 patients with carotid occlusion (age 63.9 +/- 10.8 years, 11 males, 9 females). Time to TPA infusion after stroke onset was 128 +/- 66 minutes. Baseline NIHSS scores were 16.4 +/- 5.4. Time to follow-up was 3.5 +/- 4.9 months (2 patients were lost to follow-up). Occlusion sites were prICA 40%, tICA 70%, and concurrent MCA 45%. Multiple sites were involved in 10/20 patients (50%). Among patients with pretreatment and posttreatment vascular imaging studies (n = 18), recanalization in the prICA and tICA was complete in 10%, partial in 16%, and none in 74%. MCA recanalization was complete in 35%, partial in 24%, and none in 41%. At follow-up, Rankin 0-1 was found in 8 patients (44%), Rankin 2-3 in 3 (17%), and Rankin 4-5 in 3 (17%). Mortality was 22% (n = 4) including 1 fatal intracerebral hemorrhage. Improvement was closely related to resumption of MCA flow (P < .01). CONCLUSIONS: Most patients did not recanalize their ICA occlusion after intravenous TPA therapy. However, recanalization of associated proximal MCA clot, found in 45% of our patients, or improved MCA collateral flow was strongly associated with good outcome.

The five ps of acute ischemic stroke treatment: parenchyma, pipes, perfusion, penumbra, and prevention of complications.

Stroke is a treatable disease. Despite the therapeutic nihilism of the past, the advent of thrombolysis has changed the way stroke treatment is approached. Acute ischemic stroke is a challenging and heterogeneous disease, and treatment must be based on an understanding of the underlying pathophysiology of ischemia. Interventions are designed to improve neuronal salvage and outcome. The underlying tenets of stroke therapy focus on the brain parenchyma, arterial flow (pipes), perfusion, the ischemic milieu or penumbra, and prevention of complications. This article focuses on the practical issues of ischemic stroke care with a brief review of supporting literature.

The 5 Ps of acute ischemic stroke treatment: parenchyma, pipes, perfusion, penumbra, and prevention of complications.

Stroke is a treatable disease. Despite the therapeutic nihilism of the past, the advent of thrombolysis has changed the way stroke is approached. Acute ischemic stroke is a challenging and heterogeneous disease. Treatment needs to be based on an understanding of the underlying pathophysiology of ischemia. Interventions are designed to improve neuronal salvage and outcome. The underlying tenets of stroke therapy focus on the brain parenchyma, arterial flow (pipes), perfusion, the ischemic milieu or penumbra, and prevention of complications. This article focuses on the practical issues of ischemic stroke care, with a brief review of supporting literature.

Cell death in experimental intracerebral hemorrhage: the "black hole" model of hemorrhagic damage.

Intracerebral hemorrhage (ICH) has a poor prognosis that may be the consequence of the hematoma's effect on adjacent and remote brain regions. Little is known about the mechanism, location, and severity of such effects. In this study, rats subjected to intracerebral blood injection were examined at 100 days. Stereology (neuronal count and density) and volume measures in the perihematoma rim, the adjacent and overlying brain, and the substantia nigra pars reticulata (SNr) were compared with contralateral brain regions at 100 days and the perihemorrhage region at 24 hours and 7 days. In addition, cytochrome c release was investigated at 24 hours, 3 days, and 7 days. At 100 days, post-ICH rats showed no difference in neuronal density in the perihemorrhagic scar region or regions of the striatum immediately surrounding and distal to the perihemorrhage scar. The cell density index in the ipsilateral field was 16.2 +/- 3.8 versus the contralateral control field of 15.6 +/- 3.2 (not significant). Volume measurements of the ipsilateral striatum revealed a 20% decrease that was compensated by an increase in ipsilateral ventricular size. The area of the initial ICH as measured by magnetic resonance imaging correlated with the degree of atrophy. In the region immediately surrounding the hematoma, cytochrome c immunoreactivity increased at 24 hours and 3 days, and returned toward baseline by day 7. At 24 hours, stereology in the peri-ICH region showed decreased density in the region where cytochrome c immunoreactivity was the highest. Neuronal density of the ipsilateral SNr was significantly less than the contralateral side (9.6 +/- 1.9 vs 11.6 +/- 2.3). Histologic damage from ICH occurred mainly in the immediate perihemorrhage region. Except for SNr, we found no evidence of neuronal loss in distal regions. We have termed this continued destruction of neurons, which occurs over at least 3 days as the neurons come into proximity to the hematoma, the "black hole" model of hemorrhagic damage.

Carotid stents to prevent stroke: a nonsurgical option.

Angioplasty and stent placement have become accepted alternatives to surgery in many vascular territories. The most recent application of percutaneous intervention has been to explore its clinical utility and safety for stroke prevention in carotid arteries. Over the past 8 years, from January 1994 until Nov 2002, we performed 449 elective carotid stent procedures in 426 patients and in 481 vessels. Informed consent was obtained from each patient. Success was achieved in 97.3% of the patients treated. After one month of follow-up, 12 (2.8%) patients experienced stroke or death. After an average of 2.8 ± 1.7 years (range 1 month to 8.8 years) of follow-up, restenosis was found in 11 (2.6%) patients and was treated with balloon angioplasty. Our results, in a predominantly high-risk surgery group of patients, suggest that carotid stent placement is a viable treatment alternative to conventional surgery. It is likely that as the technology continues to evolve, the procedural risks of stroke and death will be minimized by embolic protection devices, making carotid stenting an option for low-risk surgical patients.