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BACKGROUND AND PURPOSE Dynamic autoregulation has been studied predominantly in the middle cerebral artery (MCA). Because certain clinical conditions, ie, presyncopal symptoms or hypertensive encephalopathy, suggest a higher vulnerability of autoregulation within posterior parts of the brain, we investigated whether the cerebral blood flow velocity (CBFV)(More)
OBJECTIVE Alerted by the number of patients with transient global amnesia (TGA) in whom Valsalvalike activities immediately preceded the onset of TGA, we have investigated the frequency of patent foramen ovale (PFO) as the prerequisite for paradoxical embolism. DESIGN Case series with comparison to a control group. SETTING Hospitalized and ambulatory(More)
BACKGROUND AND PURPOSE The overall mortality rate of primary pontine hemorrhage (PPH) in recent studies is 40-50%. The aim of the present study was to analyze the predictive value of clinical and neuroradiologic parameters concerning the outcome of patients with PPH. METHODS We reviewed the clinical data of 29 consecutive patients (mean age, 59 +/- 13.5(More)
Patent foramen ovale (PFO) is increasingly recognized in association with cryptogenic stroke. Using transesophageal echocardiography (TEE) and transcranial Doppler sonography with ultrasonic contrast medium (contrast-TCD), we evaluated the frequency of a PFO as the fundamental condition of paradoxical embolism in 111 patients after cerebral ischemia. There(More)
OBJECTIVES We sought to evaluate whether transthoracic contrast echocardiography using second harmonic imaging (SHI) is a diagnostic alternative to transesophageal contrast echocardiography (TEE) for the detection of atrial right to left shunt. BACKGROUND Paradoxic embolism is considered to be the major cause of cerebral ischemic events in young patients.(More)
Carotid artery disease was assessed in 180 patients by means of color Doppler flow imaging. Color Doppler findings in 360 carotid arteries were compared with the results of standard Doppler sonography, and color Doppler findings in 60 bifurcations were compared with the results of intraarterial angiography. The sensitivity of color Doppler for the detection(More)
BACKGROUND AND PURPOSE Cross-spectral analysis (CSA) of spontaneous oscillations in cerebral blood flow velocity (CBFV) and arterial blood pressure is considered a sensitive and convenient method for dynamic autoregulation testing. So far, it has been unclear whether CSA can be used to assess stenoses of the intracranial arteries. METHODS This study for(More)
Sixty-six patients (72 carotid arteries) were examined after carotid endarterectomy (CEA) using Doppler colour flow imaging (DCFI). Examinations were performed 4-18 days (mean: 7 days) after surgery (32 patients, 34 arteries) or between 2 and 100 months (mean: 39 months) after CEA (34 patients, 38 arteries). Minor vessel wall abnormalities were found in 36%(More)
BACKGROUND AND PURPOSE Carotid artery disease (CAD) is able to critically impair cerebral autoregulation which increases the risk for stroke. As therapeutic strategy largely depends on the degree of CAD, we investigated whether this gradation is also related to significant changes in autoregulatory capacity. We applied cross-spectral analysis (CSA) of(More)
One hundred and nine carotid bifurcations of 56 healthy subjects were examined by means of a Doppler color flow imaging (DCFI) system. Flow separation was found in 102 (93.6%) bifurcations. Different patterns of the spatial and temporal distribution of flow separation zones could be distinguished: separated flow was either restricted to the proximal(More)