TY - JOUR
T1 - Sural/radial amplitude ratio in the diagnosis of mild axonal polyneuropathy
AU - Rutkove, Seward B.
AU - Kothari, Milind J.
AU - Raynor, Elizabeth M.
AU - Levy, Michele L.
AU - Fadic, Ricardo
AU - Nardin, Rachel A.
PY - 1997
Y1 - 1997
N2 - As proximal nerves are relatively spared in length-dependent, axonal polyneuropathy, we theorized that a sural/radial amplitude ratio (SRAR) might be a sensitive indicator of mild polyneuropathy. In this study, sural amplitudes and SRARs in patients with signs of mild axonal polyneuropathy were compared to those of normal, age-matched control subjects. Sural and radial sensory responses were measured in a standard fashion in all subjects. Thirty polyneuropathy patients had an average SRAR of 0.29 as compared to 0.71 for the 30 normal subjects. An SRAR of less than 0.40 was a strong predictor of axonal polyneuropathy, with 90% sensitivity and 90% specificity, as compared to an absolute sural amplitude of less than 6.0 μV, which had sensitivity of only 66%. Additionally, unlike the sural amplitude, the ratio did not vary significantly with age. We conclude that the SRAR is a sensitive, specific, age-independent electrodiagnostic test for mild axonal polyneuropathy.
AB - As proximal nerves are relatively spared in length-dependent, axonal polyneuropathy, we theorized that a sural/radial amplitude ratio (SRAR) might be a sensitive indicator of mild polyneuropathy. In this study, sural amplitudes and SRARs in patients with signs of mild axonal polyneuropathy were compared to those of normal, age-matched control subjects. Sural and radial sensory responses were measured in a standard fashion in all subjects. Thirty polyneuropathy patients had an average SRAR of 0.29 as compared to 0.71 for the 30 normal subjects. An SRAR of less than 0.40 was a strong predictor of axonal polyneuropathy, with 90% sensitivity and 90% specificity, as compared to an absolute sural amplitude of less than 6.0 μV, which had sensitivity of only 66%. Additionally, unlike the sural amplitude, the ratio did not vary significantly with age. We conclude that the SRAR is a sensitive, specific, age-independent electrodiagnostic test for mild axonal polyneuropathy.
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U2 - 10.1002/(SICI)1097-4598(199710)20:10<1236::AID-MUS5>3.0.CO;2-D
DO - 10.1002/(SICI)1097-4598(199710)20:10<1236::AID-MUS5>3.0.CO;2-D
M3 - Article
C2 - 9324079
AN - SCOPUS:0030772730
SN - 0148-639X
VL - 20
SP - 1236
EP - 1241
JO - Muscle and Nerve
JF - Muscle and Nerve
IS - 10
ER -