Unilateral Reference Values for Hoffmann’s Reflex in Patients with Suspected Lumbosacral Radiculopathies ()
ABSTRACT
Unilateral reference values for Hoffmann’s amplitude could be applied to the diagnosis of lumbosacral radiculopathy, especially in patients with bilateral lesions. Here, we assessed Hoffmann’s reflex by measuring H-wave amplitude and the ratio of H-wave amplitude to M-wave amplitude (the H/M ratio). We performed a cross-sectional survey of patients from a Taiwan rehabilitation center (n = 64, age 20 - 87) who presented with lower back pain that radiated to the leg and received a referral for electrodiagnostic examinations. Reference values for H-wave profile parameters were determined using data from lumbosacral radiculopathy-negative patients (n = 10, age 22 - 53), who had normal big toe test results, ankle reflex test results, motor and sensory nerve conductive studies and F-wave latency and who displayed no evidence of radiculopathy in electromyography and imaging studies. The 50th percentile values for H/M ratio and H-wave amplitude were 28% and 6.25 mV, respectively. An H-wave profile <5th percentile (H/M ratio <11% or H-wave amplitude <2.5 mV) was significantly related to both electromyography-confirmed current and chronic lumbosacral radiculopathy (n = 64). Approximately 41% of patients with an H-wave profile <5th percentile showed electromyography-confirmed chronic radiculopathy. Electromyography-confirmed current radiculopathy was observed in 35% of patients with an H/R ratio <11% and 42% of patients with an H-wave amplitude <2.5 mV.
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I. Tsai and H. Tsai, "Unilateral Reference Values for Hoffmann’s Reflex in Patients with Suspected Lumbosacral Radiculopathies,"
Open Journal of Orthopedics, Vol. 3 No. 3, 2013, pp. 178-182. doi:
10.4236/ojo.2013.33032.