Showing papers by "David Burke published in 1970"

The quadriceps stretch reflex in human spasticity.

Abstract: The similarity of decerebrate rigidity in the cat and human spasticity has been noted frequently since the initial observation of Sherrington (1897). Walshe (1919, 1929) considered the two conditions to be physiologically identical, although spasticity 'is but a fractional expression of decerebrate rigidity'. More recently Brodal (1962) and Rushworth (1964) have referred to this similarity. Brodal stated: 'It is unfortunate that the experimentally produced condition in animals which appears to correspond to spasticity in man has been termed decerebrate rigidity. However, this discrepancy in nomenclature should not prevent us from recognizing the essential identity of the facts behind the two terms.' The characteristics of the stretch reflex in decerebrate rigidity have been investigated by Liddell and Sherrington (1924), and amplified by Granit (1958) and Matthews (1958, 1959). These workers have shown that reflex tension is proportional to extension, so that, in the words of Liddell and Sherrington, 'so long as the stretch increases, the reflex continues to increase'. This property of the decerebrate stretch reflex clearly differs from human spasticity in which hypertonicity melts away as stretch increases (clasp-knife phenomenon). Since the papers of McCouch, Deering, and Stewart (1950) and Granit (1950), the clasp-knife phenomenon has been attributed to autogenic inhibition from Golgi tendon organs. More recently it has been speculated that the secondary spindle ending may play a part (Granit, 1964; Granit and Kellerth, 1967). The present study analyses the characteristics of the stretch reflex in the quadriceps of the spastic human in order to clarify these points.

A new agent for the control of spasticity

Abstract: In a preliminary controlled trial, CIBA 34,647-Ba, a gamma aminobutyric acid derivative, was found to be more effective than placebo in reducing spasticity due to spinal injuries. In an uncontrolled trial, 34,647-Ba also appeared more effective than diazepam. The intensity of spasticity was measured electromyographically by the amplitude of the stretch reflex at various velocities, and the results were correlated with those obtained by clinical assessment. 34,647-Ba was effective in both complete and incomplete spinal cord lesions and it is suggested that it has an action at the spinal level. No significant side-effects were encountered.