We describe a case of compression of the median nerve by an aneurysm of the superficial palmar arterial arch which presented with symptoms of the carpal tunnel syndrome. The traumatic and occupational nature of true palmar aneurysms are discussed. R t s u m t .
Nous rapportons une cause rare de compression du nerf mddian par un anevrisme de l'arcade palmaire superficielle, se pr~sentan t comme un syndrome du canal carpien. La discussion porte sur l'origine traumatique et souvent professionelle des anevrismes palmaires.
had become progressively worse over the preceding 4 months. Although the symptoms in both hands were worse during work, which involved using pneumatic tools, persistent paraesthesiae after work persisted only in his right hand.
There was typical sensory loss associated with the carpal tunnel syndrome in his right hand, but in the left the sensory changes were limited to the adjacent sides of the index, middle and ring fingers consistent with compression of the medial division of the median nerve. No muscle wasting was detected. Electromyography showed changes consistent with bilateral median nerve compresion between the wrist and middle finger.
Open release of the flexor retinaculum on the left side confirmed median nerve compression within the carpal tunnel. On the fight side, the median nerve was normal within the tunnel, but its medial branch was compressed at the distal end of the retinaculum by a fusiform mass (Fig. 1) lying under the