Letters to the Editor

Indian Pediatrics 1999; 36:729

The Brachioradialis Reflex

The elicitation of the deep tendon reflexes is an important part of the neurological examination. Their presence or absence, exaggeration or depression can give important clues not only in determining the type of lesion (whether upper or lower motor neuron), but also the site of lesion, depending on the root value of the reflex.

The supinator or the brachioradialis reflex is also a deep tendon reflex with a root value of C5 and C6. All texts on examination of the nervous system both pediatric as well as adult, recommend the reflex to be elicited by tapping the tendon of the brachioradialis just above the styloid process of the radius(1-5). The reflex results in flexion and supination of the forearm. While this reflex is readily seen in adults, the authors have noted that the reflex is usually not elicited by this method in children. However, when the muscle is tapped with the hammer at the lateral border of the forearm at the upper and middle thirds with the forearm in mid prone position, it is seen that in children a good contraction of the muscle occurs and there is easily visible supination and flex ion of the forearm. The reason for this is not clear but it is possible that in children that the tendon of the brachioradials is very thin and small, and the hammer misses its mark when it is tapped above the styloid process. Since the localization value of a positive reflex would be the same whether the reflex is elicited by tapping the tendon or by tapping the muscle directly we recommend that the brachioradialis reflex be elicited by tapping the muscle directly in children.
 

Veena Kalra,
Professor,
Department of Pediatrics,
All India Institute of Medical Sciences,
New Delhi 110029, India.
Rekha Mittal,
Pediatrician and Pediatric Neurologist,
Army Hospital (Research and Referral)
Delhi Cantt 110 010, India.