Biomedical subjects

Todd Crocco

Publications and source records attributed to Todd Crocco.

5 recordsLinked to original sources

PubMed2006

Selective MCA occlusion: a precise embolic stroke model.

The present study describes a method for improving the precision and accuracy of clot placement within the middle cerebral artery (MCA) of rats, utilizing a micro-catheter and laser Doppler flowmetry. This technique reduces the size of clot needed to achieve stable occlusion with no failed embolizations and a low percentage of early recanalizations. Infarctions were consistent in both size and distribution within the MCA perfusion territory. Selective embolization in aged animals (n = 10) resulted in substantially larger infarctions than those seen in aged animals (n = 10) following non-selective embolization (P < 0.05), or young animals (n = 10) subjected to filamentous occlusion (P < 0.001). Clots were localized to the MCA by direct examination at 0, 60 and 120 min post-embolization (n = 14). All aged animals surviving 24h exhibited moderate to severe functional deficits, with selectively occluded animals having a higher mean score on the modified neurologic severity scale (P = 0.002). This model provides a highly reproducible method for embolization of the MCA and reliable reperfusion with rt-PA.

Aging↗

PubMed2005

Influence of age on stroke outcome following transient focal ischemia.

OBJECT: More than 100 clinical trials based on animal models have failed to identify a clinically effective neuroprotectant for stroke. Current models of stroke do not account adequately for aging nor do they incorporate the use of female animals. The authors evaluated the pathological and physiological differences in stroke in young, adult, and elderly female rats. METHODS: Three groups of female Sprague-Dawley rats were studied. Nine rats were divided into three groups: young (3 months); adult (9 months); and elderly (18 months). Intraluminal filament occlusion was performed for 120 minutes while cerebral blood flow was monitored. Physiological parameters were assessed. Infarction volumes were quantified at 24 hours. The mean arterial pressure increased in the young animals (103 +/- 3.51 mm Hg; p < 0.001) during occlusion and decreased in the elderly group (65.56 +/- 3.03 mm Hg; p < 0.01). Cortical and striatal infarction volumes in the elderly animals were substantially larger (p < 0.05). Young animals exhibited a lesser decrement in cerebral blood flow (p < 0.05) during ischemia. CONCLUSIONS: This study reinforces the importance of using older animals for the researching and treatment of stroke. Elderly animals show differences in response mechanisms, ischemic consequences, and histological changes. These differences may partially explain the current lack of success involved in using young-animal models to predict the clinical efficacy of neuroprotective agents.

Age Factors↗

PubMed2003

Feasibility of neuroprotective agent administration by prehospital personnel in an urban setting.

BACKGROUND AND PURPOSE: Studies have demonstrated the importance of early stroke treatment. If a neuroprotective agent (NA) clinical trial is successful, the greatest benefit might be attained with early prehospital administration. This study determined the potential reduction in time to treatment of stroke patients when NAs were administered in the prehospital setting. METHODS: Twenty-three urban emergency medical services (EMS) agencies participated in this study. Prehospital personnel completed a stroke assessment checklist on any potential stroke victim. The checklist collected clinical inclusion/exclusion criteria for NA administration and event/decision times. Patients meeting the hypothetical clinical inclusion criteria were enrolled into this study. Time data included scene arrival/departure, emergency department (ED) arrival, and estimated time of theoretical NA administration. The reduction in time to stroke treatment was calculated as the difference between the time of ED arrival and the reported time of NA administration. The t test and simple linear regression were used to probe for differences in treatment time reduction between selected subgroups. EMS personnel's ability to obtain informed consent for theoretical NA administration was calculated. RESULTS: Two hundred twenty-two patients were enrolled in this study; of these, 75 were deemed eligible for hypothetical NA administration and had complete time data. On average, EMS personnel documented the theoretical time of NA administration at 12.04+/-2.07 minutes before arrival at the ED (17.06+/-1.74 minutes when the NA was given on scene [n=43]; 6.65+/-1.14 minutes when the NA was given en route [n=32]). CONCLUSIONS: Prehospital NA administration can potentially significantly reduce the time to first intervention in stroke patients.

Aged↗

PubMed2002

Prehospital care of the stroke patient.

Acute stroke care is a multidisciplinary effort. It crosses the boundaries of traditional hospital-based medicine, relying heavily on prehospital providers to obtain a significant amount of clinical information. Currently, modifications of existing EMS systems are underway to support the idea that "time is brain." Dispatchers and EMS providers are vital players in the Chain of Recovery, and are challenged to perform within this new paradigm for acute stroke care. In the near future, optimal management of the acute stroke patient may include the administration of neuroprotective medications in the prehospital setting. Educational efforts targeting high risk and elderly populations also continue to be a priority for healthcare providers and public interest groups such as the NSA. Stroke victims, family members, and caregivers must all be aware of the warning signs and symptoms of stroke. The importance of using EMS during the initial phase of acute stroke cannot be overstated. Emergency physicians must lead in coordinating the resources, placing greater emphasis on educating and assessing the performance of prehospital providers [50]. These leaders must ensure that prehospital providers understand they are integral members of the stroke team, vital to improving stroke care in the community.

Algorithms↗

PubMedDate not supplied

Predictors of stroke during 9-1-1 calls: opportunities for improving EMS response.

OBJECTIVE: Only 31%-52% of stroke calls are accurately identified by 9-1-1 dispatchers according to prior studies. Recognizing the time-dependent nature of acute stroke, better identification of stroke patients at the time of their 9-1-1 calls may allow an improved prehospital response. We sought to identify any words/phrases that 9-1-1 dispatchers could use to identify more stroke calls. METHODS: Potential stroke calls were identified from emergency medical services run sheets, and the discharge diagnosis for each of these patients was obtained. The emergency medical services tapes were independently reviewed by two listeners who were blinded to the final diagnosis. Words/phrases previously associated with 9-1-1 stroke calls mentioned by the caller were recorded. Other pertinent words/phrases were also recorded. Using the final diagnosis of stroke as the gold standard, the sensitivity, specificity, and positive likelihood ratio of each word and phrase were calculated. Cohen's kappa was calculated to assess interrater agreement. Data were collected for runs from October 2003 to July 2004. RESULTS: A total of 176 tapes were reviewed (40 strokes, 136 nonstrokes). The presence of at least one of four criteria predicted 80% of all stroke calls: the word "stroke," facial droop, weakness/fall, and impaired communication. All criterion elements had very good interrater agreement (kappa > 0.7). The word "stroke" was highly predictive of actual stroke (positive likelihood ratio, 2.27). CONCLUSIONS: The majority of stroke patients in this study could be identified by 9-1-1 dispatchers if the caller reported any one of the following four complaints: stroke, facial droop, weakness/fall, or impaired communication.

Cohort Studies↗