Unusual Causes Of Peripheral Nerve Compression

Abstract

summary This paper presents two anatomical variants as possible causes of peripheral nerve compression — the median nerve by a persisting median artery and the ulnar nerve by the muscle anconeous epitrochlearis.

Unusual combination of muscular and arterial variations in the upper extremity: a case report of a variant palmaris longus and an additional tendinous portion of the flexor carpi ulnaris together with a persistent median artery

“…5,6 Its persistence in the human adult has been recorded in two different patterns: as a small and short vessel -antebrachial type (76%), which ends before reaching the wrist joint; or as a large, long vessel -palmar type (1.5-12%) which reaches the hand. 5,8,24 The palmar type is divided into two subtypes: radio-medio-ulnar and medio-ulnar, as in our case. In Bulgarian population the medio-ulnar subtype vary between 5.5-11.1%.…”

“…6 The clinical importance of the persistence of this artery at the wrist level is well documented as a cause of the carpal tunnel syndrome, but it has also been associated with the "pronator teres syndrome" in cases where the persistent median artery pierces the median nerve in the proximal third of the forearm. 4,8 Other authors speculated that this artery may also play a role in "anterior interosseus nerve syndrome" in cases that immediately after its origin, was intimately related with the nerve. 5 Due to the fact that this artery is responsible for the arterial supply to the median nerve and the neighbouring muscles and as in our case for the thumb and radial side of the index finger its damage could have serious affects to blood circulation of the forearm and hand.…”

Separate muscle bundles of the flexor digitorum superficialis overlying the ulnar nerve

“…The muscles thought to be associated with ulnar nerve compression have been the hypertrophied medial head of the triceps brachii [17], and anomalous muscles such as the anconeus epitrochlearis and the anconeus epimedialis muscles [6,8,15] at the elbow, and a hypertrophied FCU in the lower part of the forearm [11]. Nonhypertrophied anomalous muscle bands that crossed the ulnar nerve were also found to cause compressive neuropathy around the wrist [16,22].…”

Ulnar nerve compression at the elbow caused by the epitrochleoanconeus muscle : a case report and surgical approach

“…Chalmers, mentioned the similarity of the anatomic location between the epitrochleoanconeus muscle and Osborne's ligament, accepted both as potential compressive agents for the ulnar nerve, and proposed removal of the epitrochleoanconeus muscle as adequate treatment (4). Removal of the prominent part of the medial head of the triceps, if necessary, was found not to compromise triceps function (17).…”

“…Anterior transposition of the ulnar nerve or medial epicondilectomy are the other less preferred techniques reported (4,9,10,20). In order to avoid ulnar nerve subluxation after excision of the epitrochleoanconeus muscle, anterior subcutaneous transposition has been performed (4,9,20).…”