Stroke; a journal of cerebral circulation
-
It is well known that significant changes in cerebral hemodynamics may occur during the treatment of cerebral arteriovenous malformations with the complication of intracerebral hemorrhage and parenchymal edema. We used transcranial color-coded duplex sonography to study alterations in blood flow velocities during staged embolization. ⋯ The technical advantage of transcranial color-coded duplex sonography compared with transcranial Doppler sonography is that it allows the exact identification of different feeding arteries in arteriovenous malformations. Repeated measurements during stepwise embolization with corrected insonation angle are easily achieved, and noninvasive quantification of hemodynamic changes is possible. The method may be helpful in the planning of the different steps of embolization.
-
Cerebral emboli can be recognized by typical "high-intensity transient signals" (HITS) in the transcranial Doppler (TCD) spectral curves. Patients with potential cardiac sources of embolism are at higher risk for stroke. ⋯ HITS are common phenomena in patients with potential cardiac sources of embolism. The clinical relevance of these HITS remains unclear.
-
In this established outcome model of cardiac arrest in dogs, we have used total (summed regional) brain histopathologic damage scores. The present study describes the regional progression of necrotic (ischemic) neuron prevalence with increasing duration of cardiac arrest. It tests the hypothesis that increases in the total prevalence of necrotic neurons better correspond to increasing arrest duration and better correlate with neurological deficit than do any individual regional scores. ⋯ Compared with total (summed regional) necrotic neuron prevalence scores, increased regional prevalence scores for cerebellar granule neurons with increasing arrest duration were equally significant, and scores for the caudate nucleus had nearly the same correlation with individual clinical neurological deficit.
-
This study examined whether patients suffering from stroke and other systemic embolic events may be selected for transesophageal echocardiography on the basis of clinical and transthoracic echocardiographic findings. ⋯ Transesophageal echocardiography has a low yield for left atrial spontaneous contrast, left atrial thrombus, or complex aortic atheroma in patients with normal transthoracic echocardiogram and sinus rhythm and in younger patients. Interatrial septal anomalies are more prevalent in younger patients. Transthoracic echocardiogram should be performed in patients after stroke or systemic embolic events as a noninvasive screening tool. We recommend transesophageal echocardiogram for patients with abnormal transthoracic echocardiogram and in younger patients when the finding of a patent foramen ovale may contribute to patient management.
-
This study investigates the usefulness, as a test of dynamic autoregulation, of phase shift angle analysis between oscillations in cerebral blood flow velocity (CBFV) and in arterial blood pressure (ABP) during deep breathing. ⋯ Results confirm the high-pass filter model of cerebral autoregulation: Normal subjects showed predicted positive phase shift angles between CBFV and ABP oscillations. Patients with expected autoregulatory disturbances showed significant decreases in phase shift angles. Close correlations existed between autoregulation and CO2-induced vasomotor reactivity.