Pattern of response of National Institutes of Health Stroke Scale components to early recanalization in the CLOTBUST trial.

BACKGROUND AND PURPOSE: Early recanalization is the likely mechanism by which intravenous thrombolysis improves stroke outcomes. Limited data exist on the patterns of early recovery of various brain functions. METHODS: Data from the Combined Lysis of Thrombus in Brain Ischemia Using Transcranial Ultrasound and Systemic t-PA (CLOTBUST) trial was used to determine time-related trends in neurological function recovery, as measured by National Institutes of Health Stroke Scale (NIHSS) components at baseline, 30, 60, 90, 120 minutes, and 24 hours. Repeated-measures ANOVA was used to compare patients with complete recanalization versus no or partial recanalization of the middle cerebral artery (MCA) at 120 minutes from tissue plasminogen activator bolus. The correlation structure of the NIHSS was analyzed with multivariable factor analysis. The ability of individual components to diagnose recanalization was assessed with area under the receiver operating characteristic curves. RESULTS: Altogether, 113 patients from the CLOTBUST trial had complete follow-up NIHSS scores available. All received 0.9 mg/kg IV tissue plasminogen activator within 3 hours of symptom onset (mean age 69+/-12 years; 58% men; median NIHSS 16; complete MCA recanalization 27%). All NIHSS components attributable to MCA occlusion contributed with varying degrees to the decrease of the total NIHSS score after MCA recanalization. NIHSS components responded in 2 major and mutually independent clusters representing left and right brain functions. The best performing component in diagnosing recanalization was gaze deviation (area under the receiver operating characteristic curve=0.80), but its results were similar to the total NIHSS score (area under the receiver operating characteristic curve=0.75). CONCLUSIONS: All neurological functions, impaired because of MCA occlusion, recovered after recanalization, although not to the same extent. The total NIHSS score is more useful than the individual components in detecting MCA recanalization.

Telemedicine-guided carotid and transcranial ultrasound: a pilot feasibility study.

BACKGROUND AND PURPOSE: Transcranial Doppler (TCD) and carotid duplex (CD) provide rapid and safe screening for stroke patients but are highly operator dependent. We explored the feasibility of telemedicine (TM)-guided TCD/CD administered by a health care provider inexperienced with ultrasound. METHODS: Dual video screens transmitted real-time TCD/CD images and sound to a neurosonographer. TM TCD/CD characteristics were compared with an in-person (IP) examination independently obtained on the same patient. We compared carotid stenosis, thrombolysis in brain ischemia (TIBI) flow grades, and the time spent on testing. RESULTS: We examined 8 subjects with a median age of 51 (31 to 63 range). IP and TM successfully examined 100% of internal carotid and middle cerebral arteries, 50% versus 44% of anterior cerebral artery, and 100% versus 88% of the basilar arteries, respectively. The median time in minutes IP versus TM was 15 (range 10 to 35) and 30 (15 to 50) for CD (P=0.07) and 18 (15 to 30) and 45 (30 to 55) for TCD (P=0.002), respectively. TM correctly identified all normal CD/TCD examinations in 7 subjects. In 1 patient, TM identified carotid occlusion but misread TIBI flow grades in both middle cerebral arteries. CONCLUSIONS: Our pilot study showed the feasibility of TCD/CD by an inexperienced health professional guided by a sonographer via TM. Tests were completed within times comparable to outpatient setting in a vascular laboratory.

Flow rate-perfusion pressure relationships in situ in the uterine circulation of pregnant rats.

OBJECTIVE: Our purpose was to study the effects of inhibition of nitric oxide synthesis on perfusion pressure and flow rate-perfusion pressure relationships in the rat uterine circulation in situ. STUDY DESIGN: Nonpregnant, midpregnant (day 14), and late pregnant (day 21) Sprague-Dawley rats were studied. The vascular bed of the intact uterus and its contents were isolated and perfused with Krebs buffer (37 degrees C, pH approximately 7.4, 2% dextran and indomethacin, 10(-5) mol/L) through a cannula inserted into the abdominal aorta close to the iliac artery bifurcation, and perfusion pressure was monitored. After equilibration, the flow rate was increased from 1 mL/min to 8 or 16 mL/min, in the absence and presence of N(omega)-nitro-L-arginine methyl ester (L-NAME), phenylephrine, or both. RESULTS: The flow rate-perfusion pressure relationship in midpregnant rats (n = 9) was not significantly different from that in late pregnant rats (n = 12), but the latter was significantly greater than the relationship in nonpregnant animals (n = 5). L-NAME did not influence perfusion pressure and flow rate-perfusion pressure relationships in any of the groups. However, L-NAME enhanced the phenylephrine-induced and flow rate-induced increase in perfusion pressure in the vascular beds from nonpregnant and midpregnant animals, and to a lesser extent in late pregnant rats. L-arginine did not influence perfusion pressure or the flow rate-perfusion pressure relationship in any group. CONCLUSIONS: Vasoconstriction produced by phenylephrine uncovers basal release of endothelium derived nitric oxide. Vasoconstriction increases perfusion pressure responses to increases in flow rate in the uterine vascular beds of nonpregnant, midpregnant, and late pregnant rats. The release of endothelial nitric oxide in the uterine vascular beds depends on the basal contractile state of the vasculature.