Distribution of muscle weakness of central and peripheral origin
- Dr NC Notermans, Department of Neurology, University Hospital Utrecht C03.236, PO Box 85500, 3508 GA Utrecht, The Netherlands.
Telephone 0031 30 2506564; fax 0031 30 2542100.
- Received 23 September 1997
- Revised 13 February 1998
- Accepted 9 April 1998
Abstract
According to the established clinical tradition about the distribution of weakness, the ratios of flexor/extensor strength of patients with upper motor neuron lesions are expected to be relatively high for the elbow and wrist and low for the knee. To assess the diagnostic value of these patterns of weakness, muscle strength of 70 patients with limb weakness of central or peripheral origin was measured with a hand held dynamometer. The ratios of flexor/extensor strength at the knee, elbow, and wrist did not differ significantly between patients with central or peripheral origin of muscle weakness. The examination of tendon jerks proved to be of more value as a localising feature. The traditional notion about the distribution of weakness in upper motor neuron lesions may be explained by an intrinsically greater strength in antigravity muscles, together with the effects of hypertonia.
