Symptoms of thoracic outlet syndrome in women with carpal tunnel syndrome.

OBJECTIVE: To evaluate the frequency of symptoms and signs suggestive of thoracic outlet syndrome (TOS) in women aged 60 years or less, with unambiguous carpal tunnel syndrome (CTS).

METHODS: The CTS was clinically and electrodiagnostically defined in 100 upper limbs. Clinical and electrophysiological symptoms and signs suggestive of TOS, true neurogenic TOS (NTOS) and disputed NTOS were tested in each upper limb. The 100 idiopathic median nerve lesions at the wrist occurred in 61 successive and unselected women. Women with ulnar nerve entrapment, root lesions and polyneuropathies were excluded. The main outcome measures were clinical symptoms and signs suggestive of TOS and NTOS as electrodiagnostic evaluation of the lower brachial plexus.

RESULTS: In the 100 upper limbs with definite CTS, no major symptoms and signs suggestive of TOS and NTOS were found. On the contrary, moderate and mild clinical symptoms and signs suggestive of disputed NTOS were frequently found, even if no electrodiagnostically definite major or minor lower brachial plexus lesion was found.

CONCLUSIONS: This study demonstrates the low specificity of clinical symptoms and signs suggestive of disputed NTOS, as they were frequently found in women with unselected and unambiguous CTS, despite no patients had definite lower brachial plexus lesion.

SIGNIFICANCE: Our study shows why CTS can easily be misdiagnosed as disputed NTOS, and stresses the importance of systematic electrodiagnosis with median, ulnar, and medial antebrachial cutaneous nerve conduction studies, in order to rule out CTS, ulnar nerve, root lesion, and to establish lower brachial plexus lesion before treating NTOS.