8/14/2019 8/12/92 Dr. Neal Barnard letter to the editor
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methods and management of these disorders, bu t much r e-
,.mains unknown. We attem pted to draw conclusions that wouldhelp
the general practitioner.We agree w ith Dr Bohr that it is probably
best to use eitherthe term "ulnar neuropathy at the elbow" or
"ulnar nerveentrapment at the elbow" rather than the more specific
andmore widely used term "cubital tunnel synd rome." There
areseveral causes of ulnar nerve entrapments at the elbow;entrapm
ent a t the cubital tunnel is one.1 Pronator syndromeshould no t be
considered a wasteb aske t diagnosis. It occurs,but ac curate
diagnosis of this condition is n ot easy.1The diagnostic tests for
CTS or eervieal root syndromes werenot proposed to be used in
isolation in a clinical evaluation. Nosingle test differentiates
patients with CTS. The Tinel's signand the Pha len tes t should be
p art of the w orkup for someonewith suspected CTS and mu st be
considered toge ther with acareful history, o ther physical
examinationfindings,and nerveconduction studies. As far as we know,
most neurologists continue to use the Tinel's sign and Phalen test
as pa rt of heir evaluation of subjects with suspected CTS. The
authors of DrBohr's reference 8 concluded th at th e S purling tes
t had highspecificity but low sensitivity for diagnosing roo t
compression,but was still a valuable aid in th e clinical exam
ination when combined with other appropriate m aneuvers.
Conclusions regarding t he use of vibrometry in clinical
practice await studies comparing normal subjects with subjects h
aving CTS. Grant et al2 recently authored such a study.
Using120-Hzfrequencyvibration, they reported a false-negative
rateof28% using a threshold of a single standa rd deviation (SD)
fromthe mean and 59% using two S Dsfrom he mean. For th e protocol
used, the sensitivity of vibrom etry tes ting w as low.The
sensitivity of nerve conduction studies varies withtechnique and
interpretation. Kimura8 reported false-negative rates decreasing
from 28% to 8% with th e add ition ofpalmar stimulation. Not all
neurologists perform palmar stimulation. Stevens4 reported an
overall false-negative rate of27% at the Mayo Clinicfrom1961 to
1980. For the same years,he reported that in the Rochester study
the false-negativerate was 9% in right-affected hands and 18% in
left-affectedhands (overall mean, 13%). General practitione rs
should knowthat the sensitivities and specificities of the n erve
conductionstudies vary depending on the m ethods used.
Nathan et al 5 make a good point by indicating that CTS,like
many occupationally related diseas es, may b e caused b ymultiple
factors. We will look forward to his article now inpress. We
disagree, however, with his assertion that occupation contributes
minimally to the prevalence of CTS andtha t interventions directed
at reductions in the prevalence ofCTS not include job
modifications. In Nathan's own article,Table 4 dem onstrates a
clear difference (P
8/14/2019 8/12/92 Dr. Neal Barnard letter to the editor
