Rucksack Paralysis and Brachial Neuritis

To the Editor:— Two types of acute upper extremity weakness—rucksack paralysis and brachial neuritis—are often seen in military personnel. In a recent article (JAMA208:2447, 1969) Daube presented an excellent description of the former and pointed out that the diagnosis of pack paralysis can be made when a history of sustained compression of the brachial plexus can be obtained from a patient with shoulder weakness. However, differentiating between pack paralysis and brachial neuritis is often difficult, especially when weakness develops after intermittent pack bearing and recent inoculations. Unfortunately for the diagnostician, this is a situation frequently encountered during basic training and field activity. Pack paralysis, as Dr. Daube has pointed out, is produced by sustained compression of the upper portion of the trunk of the brachial plexus. However, our recent studies of shoulder neuritis have shown that this disease produces dysfunction of distal portions of peripheral nerves innervating the