A note on the deep abdominal reflex.

Deep abdominal reflexes were recorded electromyographically in six patients with lesions of the upper motor neuron. The responses were bilateral, usually with identical latencies which ranged from 16.5 to 25 ms. Individual variation was never greater than 2 ms. It is postulated that these bilateral responses of abdominal muscles were independent stretch reflexes and were not mediated across the midline through an intraspinal pathway.