scholarly journals Detection of middle cerebral artery emboli during carotid endarterectomy using transcranial Doppler ultrasonography.

Stroke ◽  
1990 ◽  
Vol 21 (3) ◽  
pp. 415-423 ◽  
Author(s):  
M P Spencer ◽  
G I Thomas ◽  
S C Nicholls ◽  
L R Sauvage
Keyword(s):  
Middle Cerebral Artery ◽  
Carotid Endarterectomy ◽  
Cerebral Artery ◽  
Transcranial Doppler ◽  
Doppler Ultrasonography ◽  
Transcranial Doppler Ultrasonography

Detection of Microemboli by Transcranial Doppler Ultrasonography in Aneurysmal Subarachnoid Hemorrhage

Neurosurgery ◽  
2002 ◽  
Vol 50 (5) ◽  
pp. 1026-1031 ◽  
Author(s):  
Jose G. Romano ◽  
Alejandro M. Forteza ◽  
Mauricio Concha ◽  
Sebastian Koch ◽  
Roberto C. Heros ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Transcranial Doppler ◽  
Doppler Ultrasonography ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Statistical Significance ◽  
Cerebral Arteries ◽  
Transcranial Doppler Ultrasonography ◽  
Control Subjects

Abstract OBJECTIVE: To determine the frequency and characteristics of microembolic signals (MES) in subarachnoid hemorrhage (SAH). METHODS: Twenty-three patients with aneurysmal SAH were monitored with transcranial Doppler ultrasonography for the presence of MES and vasospasm. Each middle cerebral artery was monitored for 30 minutes three times each week. Patients were excluded if they had traumatic SAH or cardiac or arterial sources of emboli. Monitoring was initiated 6.3 days (1–16 d) after SAH and lasted 6.6 days (1–13 d). Eleven individuals without SAH or other cerebrovascular diseases who were treated in the same unit served as control subjects. Each patient underwent monitoring of both middle cerebral arteries a mean of three times; therefore, 46 vessels were studied (a total of 138 observations). Control subjects underwent assessment of each middle cerebral artery once, for a total of 22 control vessels. RESULTS: MES were detected for 16 of 23 patients (70%) and 44 of 138 patient vessels (32%) monitored, compared with 2 of 11 control subjects (18%) and 2 of 22 control vessels (9%) (P < 0.05). MES were observed for 83% of patients with clinical vasospasm and 54% of those without clinical vasospasm. Ultrasonographic vasospasm was observed for 71 of 138 vessels monitored; MES were observed for 28% of vessels with vasospasm and 36% of those without vasospasm. Aneurysms proximal to the monitored artery were identified in 38 of 138 vessels, of which 34% exhibited MES, which is similar to the frequency for vessels without proximal aneurysms (31%). Coiled, clipped, and unsecured aneurysms exhibited similar frequencies of MES. CONCLUSION: MES were common in SAH, occurring in 70% of cases of SAH and one-third of all vessels monitored. Although MES were more frequent among patients with clinical vasospasm, this difference did not reach statistical significance. We were unable to demonstrate a relationship between ultrasonographic vasospasm and MES, and the presence of a proximal secured or unsecured aneurysm did not alter the chance of detection of MES. Further studies are required to determine the origin and clinical relevance of MES in SAH.

EFFECT OF CONTINUOUS TRANSCRANIAL DOPPLER ON THROMBOLYSIS IN ISCHEMIC STROKE DUE TO ACUTE MIDDLE CEREBRAL ARTERY OCCLUSION

2017 ◽  
pp. 110-115
Author(s):  
Quang Thang Tran ◽  
Dat Anh Nguyen ◽  
Van Chi Nguyen ◽  
Van Thinh Le ◽  
Viet Phuong Dao ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Transcranial Doppler ◽  
Doppler Ultrasonography ◽  
Target Group ◽  
Transcranial Doppler Ultrasonography ◽  
Control Group ◽  
Tissue Plasminogen ◽  
To Receive

Purpose: Recombinant tissue plasminogen activator (rtPA) activity may be enhanced with ultrasound, 2 MHz transcranial Doppler (TCD). We performed the trial to determine the efficacy of ultrasound-enhanced thrombolysis compared to the current standard of care (intravenous rtPA). Subjects and methods: We treated 80 patients who had acute ischemic stroke due to occlusion of the middle cerebral artery with intravenous rtPA within 4.5 hours after the onset of symptoms. The patients were randomly assigned to receive continuous 2-MHz transcranial Doppler ultrasonography (the target group) or placebo (the control group). The primary combined end point was complete recanalization as assessed by transcranial Doppler ultrasonography and dramatic clinical recovery at 2 hours. Complete recanalization was defined as thrombolysis in brain ischemia (TIBI) flow grades 4-5. Secondary end points included recovery at 24 hours, a favorable outcome at three months. Results: A total of 80 patients were randomly assigned to receive continuous ultrasonography (40 patients) or placebo (40 patients). Complete recanalization and dramatic clinical recovery within two hours after the administration of a rtPA bolus occurred in 13 patients in the target group (32,5%), as compared with 8 patients in the control group (20%) (P=0.038). At three months, 22 patients in the target group who were eligible for follow-up analysis (55%) and 13 in the control group (32,5%) had favorable outcomes (as indicated by a score of 0 to 1 on the modified Rankin scale) (P=0.012). Intracerebral hemorrhage occurred in five patients in the target group and in four in the control group. Conclusion: In patients with acute ischemic stroke due to occlusion of the middle cerebral artery, continuous transcranial Doppler augments rtPA-induced arterial recanalization, with an increased rate of recovery from stroke, as compared with placebo. Continuous 2-MHz transcranial Doppler ultrasonography for 2 hours is safe. Key words: Stroke, transcranial Doppler, tissue plasminogen activator

Effect of Nimodipine on Cerebrovascular Response to CO2 in Asymptomatic Individuals and Patients with Subarachnoid Hemorrhage: A Transcranial Doppler Ultrasound Study

Neurosurgery ◽  
1990 ◽  
Vol 27 (2) ◽  
pp. 247-251 ◽  
Author(s):  
Rolf W. Seiler ◽  
Arto C. Nirkko
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Transcranial Doppler ◽  
Doppler Ultrasonography ◽  
Transcranial Doppler Ultrasound ◽  
Initial Value ◽  
Ruptured Aneurysms ◽  
Ultrasound Study ◽  
Asymptomatic Individuals

Abstract The cerebrovascular response to CO2was evaluated by measuring relative changes in blood flow velocity within the middle cerebral artery by transcranial Doppler ultrasonography during normo-, hypo-, and hypercapnia. In seven patients without subarachnoid hemorrhage (five with unruptured arteriovenous malformations and two with aneurysms), the CO2vasoreactivity was tested on the side of the middle cerebral artery with normal flow velocities opposite the lesion. A baseline CO2reactivity test was obtained in each patient and then repeated under constant intravenous infusion of nimodipine, 2 mg/hr. Nine patients with ruptured aneurysms who were rated at Hunt and Hess Grades 1 or 2 were operated on within 1 to 3 days after the hemorrhage and treated with nimodipine, 2 mg/hr, given intravenously. In these patients. CO2vasoreactivity was tested during the second week after the hemorrhage, when the middle cerebral artery velocity was increased by at least 50% of the initial value or more. Nimodipine was then discontinued and, 48 hours later, when the middle cerebral artery velocity was still in the same range, CO2vasoreactivity was tested again. Two months later, after full recovery from the subarachnoid hemorrhage and normalization of the velocities, a third measurement of CO2reactivity was obtained as a baseline control. No significant effect of nimodipine on CO2vasoreactivity could be demonstrated in any of the test periods. In the second week after a subarachnoid hemorrhage, a significant reduction of the cerebrovascular response to CO2was found (P < 0.005).

scholarly journals The significance of microemboli detection by means of transcranial Doppler ultrasonography monitoring in carotid endarterectomy

1995 ◽  
Vol 21 (6) ◽  
pp. 963-969 ◽  
Author(s):  
R.G.A. Ackerstaff ◽  
C. Jansen ◽  
F.L. Moll ◽  
F.E.E. Vermeulen ◽  
R.P.H.M. Hamerlijnck ◽  
...  
Keyword(s):  
Carotid Endarterectomy ◽  
Transcranial Doppler ◽  
Doppler Ultrasonography ◽  
Transcranial Doppler Ultrasonography
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