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Transcranial Doppler (TCD) measurements of middle cerebral artery (MCA) blood flow velocities were recorded and synchronized with electrocardiographic (EKG) recordings in 52 EKG/TCD complexes in 4 patients. Thirty-seven normal sinus beats and 13 conductive and 2 nonconductive premature ventricular contractions (PVCs) were examined. Mean velocities averaged 45 ± 4 cm/sec for normal sinus rhythm (NSR) vs 26 ± 4 cm/sec in the PVC group (P = 0.007). Peak systolic velocities averaged 74 ± 6 cm/sec for the NSR and 45 ± 7 cm/sec in the PVC group (P = 0.016). The latency between the QRS complexes and corresponding TCD wave forms (QRS-SU) averaged 0.12 ± 0.03 sec in NSR and 0.17 ± 0.04 sec for the PVC group (P < 0.001). In addition, QRS-SU was inversely related to all velocities. PVCs appeared to be less hemodynamically efficient than NSR. The lower blood flow velocities and increased QRS-SU may result from lower stroke volume and delayed ventricular contraction associated with the aberrant QRS complex.

The transcranial Doppler (TCD) studies performed in 54 patients with various forms of cardiac dysfunction were reviewed and the results compared with those of normal individuals. There were 4 patients with aortic insufficiency, 5 being treated by intra-aortic balloon pumps, 12 patients with atrial fibrillation, 11 with syncope, and 22 undergoing cardiopulmonary resuscitation. In all instances, significantly low or even absent diastolic cerebral perfusion was found. The importance of this parameter, in the future evaluation and management of similar patients, is discussed.

A young woman with a history of classic migraine suffered a large cerebellar infarction . Comprehensive evaluation did not disclose any potential causes for the stroke and she had no other risk factors. Transcranial Doppler (TCD) was useful in identifying vasospasm of the vertebral arteries. Following treatment with propranolol, angiography and repeat TCD revealed resolution of the vasospastic disorder. TCD is a useful noninvasive tool in detecting vasospasm associated with ischemic lesions in certain patients with migraine.

A patient showing a congruous homonymous superior quadrantanopsia was found at autopsy to have infarction of the striate cortex. The lesion involved the inferior bank of the calcarine fissure almost entirely and approximately one fifth of the superior bank. Additionally, infarctions of the visual association cortex and the pontine tegmentum were found. No lesions in the corresponding temporal lobe were present. Two types of visual field defects have been described in association with occipital lobe lesions: a monocular temporal crescentic defect if the lesion is anterior and a congruous homonymous hemianopsia if it is posterior. This patient seems to represent a variant of the latter. The most prominent difference with respect to quadrantanopsias resulting from lesions of the optic radiation is the high degree of congruity, especially in the central portion of the field. Association with nonocclusive vascular events related to vertebrobasilar hypoperfusion rather than embolization is also more common.

A case of ischemic infarction in a young woman who also had angiographic findings consistent with "Moya Moya" disease is presented. Unusual features of the case, such as the presentation as an infarction rather than subarachnoid hemorrhage and the unilaterality of the angiographic abnormalities, are discussed. The literature is reviewed and emphasis is directed to the importance of the inclusion of this entity in the differential diagnosis of cerebral ischemic events in young adults, owing to the possible therapeutic implications.

The technical background and quality of images obtained upon studying the cerebral circulation with high-field MRI are reviewed. Fifty studies were se lected as representative of normal cerebral blood vessels to illustrate the ana tomic information derived from the review. MRI appears to be a safe, easy, and reliable method of imaging the cerebral circulation noninvasively.