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    ABSTRACT: The phrase "time is brain" emphasizes that human nervous tissue is rapidly lost as stroke progresses and emergent evaluation and therapy are required. Recent advances in quantitative neurostereology and stroke neuroimaging permit calculation of just how much brain is lost per unit time in acute ischemic stroke. Systematic literature-review identified consensus estimates of number of neurons, synapses, and myelinated fibers in the human forebrain; volume of large vessel, supratentorial ischemic stroke; and interval from onset to completion of large vessel, supratentorial ischemic stroke. The typical final volume of large vessel, supratentorial ischemic stroke is 54 mL (varied in sensitivity analysis from 19 to 100 mL). The average duration of nonlacunar stroke evolution is 10 hours (range 6 to 18 hours), and the average number of neurons in the human forebrain is 22 billion. In patients experiencing a typical large vessel acute ischemic stroke, 120 million neurons, 830 billion synapses, and 714 km (447 miles) of myelinated fibers are lost each hour. In each minute, 1.9 million neurons, 14 billion synapses, and 12 km (7.5 miles) of myelinated fibers are destroyed. Compared with the normal rate of neuron loss in brain aging, the ischemic brain ages 3.6 years each hour without treatment. Altering single input variables in sensitivity analyses modestly affected the estimated point values but not order of magnitude. Quantitative estimates of the pace of neural circuitry loss in human ischemic stroke emphasize the time urgency of stroke care. The typical patient loses 1.9 million neurons each minute in which stroke is untreated.
    Stroke 02/2006; 37(1):263-6. DOI:10.1161/01.STR.0000196957.55928.ab · 6.02 Impact Factor
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    ABSTRACT: Current US estimates of recombinant tissue plasminogen activator (rt-PA) use have been based either on extrapolation of regional studies or on administrative database estimates, both of which may have inherent biases. We sought to compare the utilization of rt-PA in acute ischemic stroke in the MEDPAR database to another national hospital database with drug utilization information. Cases were defined as DRG 14,15, and 524 and ICD-9 code 99.1, which indicates cerebral thrombolysis, for fiscal year 2001 to 2004. Additionally, the Premier database was queried for rt-PA utilization documented in pharmacy records in those patients admitted for stroke. Change over time and difference between databases were tested using Poisson regression. When comparing databases, rt-PA use, as identified by ICD-9 code 99.1, was only documented in 0.95% of stroke cases in 2004 in MEDPAR, and 1.2% in the Premier database, which slightly increased by 0.04% to 0.09% over time. Analysis of pharmacy billing records increased the estimate to 1.82%. Exclusion of cases younger than 65 years excluded 43% of cases treated with rt-PA. In 2004, 12.7% of cases receiving thrombolytic had either a TIA or a hemorrhagic stroke ICD-9 code. We estimate the rate of rt-PA use in the United States to be 1.8% to 2.1% of ischemic stroke patients. The rate of thrombolytic use for ischemic stroke was slightly increasing between 2001 and 2004 at a rate of 0.04% to 0.09% per year. A significant proportion of patients treated with rt-PA are likely miscoded as either TIA or hemorrhagic stroke. We conservatively estimate that 10,800 to 12,600 patients received rt-PA in 2004.
    Stroke 04/2008; 39(3):924-8. DOI:10.1161/STROKEAHA.107.490375 · 6.02 Impact Factor
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    ABSTRACT: BACKGROUND: The administration of thrombolysis to eligible patients is often limited to centers with expertise. This study was intended to report on the safety and efficacy (in increasing thrombolysis availability) of telemedicine in the acute assessment and treatment of stroke patients presenting to hospitals in distant locations from a designated stroke center. METHODS: A web-based telestroke tool (remote evaluation of acute ischemic stroke at Medical University of South Carolina [REACH-MUSC]), was implemented to provide acute stroke care 24 hours per day, 7 days per week to 12 community hospitals in South Carolina. RESULTS: Nine hundred sixty-five consults were performed. Among the 525 patients with a National Institutes of Health Stroke Score >3, 185 (35.7%) were treated with intravenous tissue plasminogen activator (t-PA) alone, 15 (2.9%) received combination of intravenous and intra-arterial thrombolysis/thrombectomy, and 11 (2.1%) were treated with intra-arterial therapy alone. Of those who received intravenous t-PA, 119 (64.3%) were transferred to the hub; the medians (interquartile range) for onset to treatment for the intravenous t-PA and the intravenous t-PA and intra-arterial groups were 152 (range 115-193) minutes and 147 (range 107-179) minutes, respectively. Three patients (1.6%) who received intravenous t-PA alone experienced symptomatic intracerebral hemorrhage. The most common reason for not receiving thrombolysis was patient presentation outside the time window for treatment. CONCLUSIONS: Telestroke can have a major impact in increasing thrombolysis rates in remote areas from specialized centers, and in particular in areas where t-PA is underutilized.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 12/2011; 22(7). DOI:10.1016/j.jstrokecerebrovasdis.2011.11.008 · 1.99 Impact Factor