In Reply: In answer to Dr Mackinnon and colleagues,
we chose to exclude studies using asymptomatic control subjects because such
studies tend to inflate the specificity of a diagnostic test and overestimate
Clinicians have no difficulty distinguishing a normal, asymptomatic
hand from one with classic CTS. Instead, they are interested in how well bedside
findings distinguish CTS from other diagnoses that cause hand dysesthesias.
If the patient has no symptoms, physical examination for CTS is unnecessary.
In addition, we believe it is important to distinguish patients' subjective
symptoms (eg, Katz hand diagram) from the objective sensory findings (eg,
hypalgesia). Katz et al included the fifth finger in their "classic" pattern
because they, like others, noted that patients with CTS frequently complain
of symptoms in the fifth digit.1 We included
their hand diagram in our analysis because it is a bedside finding that was
clearly defined, and our analysis shows it has modest diagnostic accuracy.
Whether other rating schemes of hand diagrams have better accuracy is unknown.
Nonetheless, in contrast to the subjective phenomenon of symptoms in the fifth
finger, sensory loss is rarely demonstrated in the fifth finger in CTS,1 consistent with the classic anatomic teaching mentioned
by Mackinnon et al.
D'Arcy CA, McGee S. Clinical Diagnosis of Carpal Tunnel Syndrome—Reply. JAMA. 2000;284(15):1924-1925. doi:10-1001/pubs.JAMA-ISSN-0098-7484-284-15-jlt1018