There is an association between the presence of patent foramen ovale and cryptogenic stroke in both older patients and younger patients. These data suggest that paradoxical embolism is a cause of stroke in both age groups.

Abstract-The controversy as to whether Doppler ultrasonic methods should play a role in clinical decision-making in the prevention of stroke is attributable to reported disagreement between angiographic and ultrasonic results and the lack of internationally accepted ultrasound criteria for describing the degree of stenosis. Foremost among the explanations for both is the broad scatter of peak systolic velocities in the stenosis, the criterion that has so far received most attention. Grading based on a set of main and additional criteria can overcome diagnostic errors. Morphological measurements (B-mode images and color flow imaging) are the main criteria for low and moderate degrees of stenosis. Increased velocities in the stenosis indicate narrowing, but the appearance of collateral flow and decreased poststenotic flow velocity prove a high degree stenosis (Ն70%), additionally allowing the estimation of the hemodynamic effect in the category of high-degree stenosis. Additional criteria refer to the effect of a stenosis on prestenotic flow (common carotid artery), the extent of poststenotic flow disturbances, and derived velocity criteria (diastolic peak velocity and the carotid ratio). This multiparametric approach is intended to increase the reliability and the standard of reporting of ultrasonic results for arteriosclerotic disease of the carotid artery. Key Words: carotid stenosis Ⅲ degree of stenosis Ⅲ duplex sonography Ⅲ peak systolic velocity Ⅲ transcranial sonography Ⅲ ultrasound diagnosis

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Transvenous treatment of CS and transverse/sigmoid sinus AVFs can be effective if all transvenous approaches, including combined surgical/endovascular approaches, are considered.

Background and Purpose-This study investigates dynamic cerebral autoregulation assessed from spontaneous blood pressure (ABP) and cerebral blood flow velocity (CBFV) fluctuations and its time course in acute ischemic stroke. Methods-Forty patients admitted with acute ischemic stroke in the territory of the middle cerebral artery (MCA) were enrolled. Admission National Institutes of Health Stroke score was 6Ϯ4. Study 1 was performed within 22 (Ϯ11) hours and study 2 was performed within 134 (Ϯ25) hours of ictus. The final analysis comprised 33 and 29 patients for study 1 and study 2, respectively. Twenty-five age-and sex-matched controls were studied. ABP (Finapres method) and CBFV in both MCAs (transcranial Doppler) were recorded over 10 minutes. Correlations between diastolic and mean ABP and CBFV fluctuations were averaged, yielding the correlation coefficient indices (Dx, Mx). Transfer function analysis was applied to obtain phase shift and gain between ABP and CBFV oscillations. Results-No disturbance of autoregulation was indicated by all parameters at study 1. Separate analyses for clinical severity, stroke side, and size did not reveal significant differences for the various autoregulatory indices at study 1 and 2. At study 2, MCA flow velocity was significantly increased on both sides, the autoregulation index Mx was slightly but significantly (PϽ0.05) worse on both sides in comparison to study 1, and phase showed a trend toward poorer values on affected sides. No significant differences to controls occurred. Clinical outcome in patients completing both studies was good in all but one patient. Conclusions-Dynamic

Background and Purpose-Estimation of dynamic cerebral autoregulation from spontaneous fluctuations of arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV) is an attractive monitoring option for cerebral hemodynamic impairment. We evaluated the correlation coefficient index method in patients with severe obstructive carotid disease and compared it with transfer function analysis (frequency domain approach to cerebral autoregulation) and CO 2 vasomotor reactivity. Methods-In 139 patients with severe unilateral carotid stenosis (Ն70%) or occlusion, CBFV (transcranial Doppler) and ABP (Finapres method) were recorded over 10 minutes. Correlations between systolic pressure, diastolic pressure, and mean ABP and CBFV oscillations over 1-minute epochs were averaged over 10 minutes to form the correlation coefficient indexes (Sx, Dx, Mx, respectively). Transfer function parameters (phase shift and gain between ABP and CBFV oscillations) were determined from the entire 10-minute period. CO 2 reactivity was assessed by inhalation of 7% CO 2 . Results-The correlation indexes Dx and Mx were significantly higher ipsilateral to stenosis and increased with degree of stenosis, indicating increasing dependence of CBFV on ABP and thus impairment of cerebral autoregulation.

Background: To investigate whether there is: (1) a specific temporal course of cerebral dysautoregulation in acute ischemic stroke, and (2) a separate detrimental effect of recombinant tissue plasminogen activator (rtPA) on autoregulation dynamics in this situation. Methods: We studied 16 patients with acute middle cerebral artery (MCA) occlusion and rtPA thrombolysis (intra-arterial or intravenous application, or both). Controls were 71 healthy adults and 11 patients with minor stroke not receiving rtPA. Dynamic autoregulation was recorded from spontaneous fluctuations of blood pressure and MCA flow velocity (transcranial Doppler) using two well-described approaches (index Mx, phase shift). Three measurements were performed (study 1: 20 ± 9 h of ictus; study 2: 64 ± 10 h; study 3: 112 ± 7 h). Results: Two groups of clinical outcome were identified: good (modified Rankin scale ≤2, n = 9, MCA infarct volume = 14 ± 16%), poor (modified Rankin scale >2, n = 7, MCA infarct volume = 62 ± 21%). In the good outcome group, no relevant changes in Mx and phase were observed on both MCA sides compared with controls. In the poor outcome group, the index Mx deteriorated over studies 1–3 on affected sides, with worse values compared to the controls (p < 0.05). Phase was already impaired on affected sides of poor outcome patients in study 1 (p < 0.01 vs. controls) and tended to decrease further until study 3. Phase also decreased moderately on contralateral sides in poor outcome patients from studies 1 to 3 (p < 0.05, nonsignificant compared with controls). Conclusions: Cerebral autoregulation is increasingly impaired, mainly on the affected side, over the first 5 days of major ischemic stroke after unsuccessful rtPA thrombolysis. It is bilaterally preserved in minor stroke after successful rtPA thrombolysis, indicating no separate detrimental effect of rtPA on the cerebral autoregulatory mechanism.

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