R R Young

EEG was monitored at bilateral scalp sites outside the operative field during hypotensive aneurysm surgery in 21 patients. Mean arterial blood pressure at axillary level was 50-60 mm Hg (average 55 mm) for 1.9-5.3 hours (average 3.6). Four new deficits were noted immediately post-operatively, all related to the operated site: these were attributable to intra-operative rupture with forced vascular clipping, vasospasm, or edema. In no instance was hypotension solely responsible for a new ...

Physiological and pharmacological studies of more than 150 patients with movement disorders are reported. Particular attention is paid to the differentiation of various types of tremor on the basis of rate, rhythm, and pattern of EMG activity in antagonistic muscles. The typical 'tremor-at-rest' of Parkinson's disease--3-7 Hz activity which alternates between antagonistic muscles--is suppressed, at least briefly, during voluntary activity, at which time typical 8--12 Hz 'physiological ...

A method is described to measure reproducibly stiffness, and therefore "tone", at the elbow of patients with Parkinson's disease using a torque motor. In Parkinsonian versus normal patients (previously reported) it was observed that: the neutral angle in Parkinson's disease patients was significantly smaller (92 degrees +/- 15 degrees) than in normals (107 degrees +/- 10 degrees), and in Parkinson's disease patients, even with relatively mild symptoms, the upper limb was stiffer than ...

The usefulness of performing late response studies for the detection of peripheral nerve dysfunction has been demonstrated. It has been shown that significant prolongation of the minimal latencies of the H reflex and the F response is present at a time when conventional methods of motor and sensory conduction do not show an abnormality in individual patients. Abnormalities of late responses have been shown to occur in a variety of peripheral neuropathies with "axonal" as well as ...

Three hundred sixty-seven carotid endarterectomies were monitored using routine electroencephalographic (EEG) techniques. In 9.8%, changes in the EEG followed clamping of the internal carotid artery and could roughly be grouped into 6 patterns. The most common (47%) was rapid unilateral or bilateral attenuation of background anesthetic-induced fast EEG activity. Conclusions drawn from studies of the 9 patients who had immediate postoperative neurological deficits of varying degrees are ...

Ichnofossils (burrow casts) and fossils from an extinct form of prairie dog, Cynomys niobrarius churcherii, in the Hand Hills of south-central Alberta, have provided an important Late Pleistocene stratigraphic marker. The marker fossils provide relative and chronostratigraphic (radiocarbon) ages for nonglacial, periglacial, glacial, and glaciotectonic events and environments in the region. The high-elevation, hilltop position of the fossil sites (~200 m above the surrounding plains) ...