The ubiquity of contraction enhanced H reflexes: normative data and use in the diagnosis of radiculopathies

✍ Scribed by James C. White

• Book ID: 119134500
• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 809 KB
• Volume: 81
• Category: Article
• ISSN: 0168-5597
• DOI: 10.1016/0168-5597(91)90052-y

✦ Synopsis

Surface recorded contraction enhanced H reflexes to single stimuli were obtained from muscles supplied by the C5, 6, 7, 8, L3, 4, 5, SI and 2 nerve roots. For each of 12 such muscles, these reflexes were recorded from 25 control subjects as well as standard unenhanced H reflexes from the gastrocnemius muscles. Amplitude and latency criteria for normality were determined. Thirty-two patients with typical histories and physical findings of radiculopathy secondary to degenerative disease of the spine (C6 nerve root -9 patients, C7 -10, C8 -4, L4 -4, L5 -4, S1 -1) were studied with these H reflexes and the needle electrode. Thirty patients had H reflex abnormalities appropriate to the signs and symptoms. Eighteen had absent H reflexes and 16 had abnormalities to amplitude criteria. None were abnormal by latency criteria. Twelve patients had abnormal needle examinations and all also had abnormal H reflexes.These results indicate that contraction enhanced H reflexes are ubiquitous, readily obtainable and sensitive to the presence of clinically clear-cut radiculopathies.