The role of thoracic outlet syndrome in the double crush syndrome.

The association between thoracic outlet syndrome (TOS) and carpal tunnel syndrome (CTS) (40 cases), ulnar neuropathy (UN) (19 cases) and radial tunnel syndrome (29 cases) is investigated. The possibility of a double crush syndrome is considered with reference to the difficulties in diagnosis. It is demonstrated that in approximately half of all cases the proximal neuropathy precedes the distal one. Despite the fact that surgical treatment of the thoracic outlet syndrome appears to improve the distal neuropathy it is still difficult to decide, in a given case, which decompression takes priority with the exception of carpal tunnel release which is generally to be performed first. The historical background and theoretical basis of the management of double crush syndrome is outlined and arguments for and against the association of the various neuropathies are presented.