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Biomedical subjects

R W Angel

Publications and source records attributed to R W Angel.

At least 37 records · Page 2Linked to original sources
PubMed1978

Unloading and shortening reactions in Parkinson's disease.

The unloading reflex was tested on both sides of a patient with asymmetrical Parkinsonism. The motor activity after the silent period was significantly greater on the more affected side. The findings support the hypothesis that the response to unloading and the shortening reaction share a common mechanism which is exaggerated in Parkinsonism.

Action Potentials↗
PubMed1977

The rebound phenomenon of Gordon Holmes.

Contrary to a prevalent belief, the rebound phenomenon of Gordon Holmes is not a sign of cerebellar disease. It is elicited by having the patient attempt to move a limb against resistance. When the resistance is suddenly removed, the limb normally moves a short distance in the desired direction and then rebounds (jerks back in the opposite direction). Gordon Holmes pointed out that the rebound phenomenon is (1) present in normal libs, (2) exaggreated in spastic limbs, and (3) absent in limbs affected by cerebellar disease. An awareness of Holmes's observations may be helpful in the diagnosis of both cerebellar disease and spasticity.

Animals↗
PubMed1977

Antagonist muscle activity during rapid arm movements: central versus proprioceptive influences.

Seven normal subjects were instructed to adduct the arm as fast as possible. On some trials the movement was prevented mechanically. For each movement or attempted movement, the EMG response in the antagonist muscle was measured. On trials in which no movement occurred, the respones were significantly smaller than those obtained during free, ballistic movement. The results demonstrate the role of proprioceptive influences on the contraction of the antagonist muscle.

Adult↗
PubMed1977

Understanding and diagnosing senile dementia.

Dementia is one of the most common syndromes afflicting the aged, and it should be ranked as a major cause of death. Senile dementia and Alzheimer's disease should now be viewed as one and the same. Familiarity with the cardinal signs of dementia enables the physician to differentiate it from various "functional" disorders. Before making a diagnosis of senile dementia, it is important to exclude all forms of treatable disease, including toxic, metabolic, infectious, neoplastic, and traumatic disorders. Most older patients with dementia will be found to have Alzheimer's disease, for which no definitive treatment is available.

Aged↗
PubMed1976

Efference copy in the control of movement.

On a two-choice tracking test of normal subjects, numerous false moves were induced when the directional relation between movement of the hand and the response marker was changed. The mean error-correction times were not consistently less than simple reaction times. When the center of the display was screened to eliminate visual feedback, numerous moves were reversed before the marker was visible. The probability of reversing an error was much greater than that of reversing a correct move. The findings are best explained in terms of a central mechanism that uses efference copy to amend errors of movement.

Adult↗