H-reflex latency and nerve root tension sign correlation in fluoroscopically guided, contrast-confirmed, translaminar lumbar epidural steroid-bupivacaine injections.
OBJECTIVE
To examine the correlation between physical examination parameters, commonly referred to as "nerve root tension signs," and H-reflex latency measurements both pre- and postepidural steroid-bupivacaine (Marcaine) injection, and to propose mechanisms of pain alleviation.


METHODS
Prospective observational, with H-reflex latency measurement and physical examination at baseline and at 10 minutes postinjection.


METHODS
Physical medicine and rehabilitation practice, outpatient surgical center, and community setting.


METHODS
Ten consecutively recruited patients (6 women, 4 men; age range, 40-71 y) with clinical radiculopathy and compatible magnetic resonance imaging findings, who were unaware of the outcome measures.


METHODS
Patients received a fluoroscopically guided, contrast-confirmed, paramedian translaminar lumbar epidural injection of 120 mg of methylprednisolone acetate (80 mg/mL) and 2.0 mL of .25% preservative-free Marcaine.


METHODS
Seated slump testing (SST), straight-leg raising (SLR), and H-reflex latency were measured bilaterally both pre- and postinjection. Differences were measured by using the paired t test in an A-B design.


RESULTS
All SST of the affected (injected) side improved from pre- to postinjection, with 3 patients reporting discordant hamstring pain and 7 reporting no pain. SLR ability increased by an average of 29 degrees +/-12 degrees, corresponding to an average relative increase of 54% on the affected side. A statistically significant difference was found (Student t test, P=.02) between pre and post H-reflex latency on the affected side but not when comparing changes between affected and unaffected sides (Student t test, P=0.6).


CONCLUSIONS
Significant improvements in SST and SLR result from low volume epidural injection of Marcaine, with questionable prolongation of the H-reflex to the gastrocnemius-soleus complex on the affected side.
Stretanski
Michael F
MF
Surgical Neurology of North Central Ohio, Mansfield, OH, USA. Stretanski@POL.net
D000328:Adult; D000368:Aged; D000779:Anesthetics, Local; D000893:Anti-Inflammatory Agents; D001340:Autonomic Nerve Block / Q000379:methods; D002045:Bupivacaine; D016903:Drug Monitoring; D004359:Drug Therapy, Combination; D004569:Electroencephalography; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006181:H-Reflex / Q000187:drug effects*; D006801:Humans; D007268:Injections, Epidural / Q000379:methods*; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D008775:Methylprednisolone / Q000031:analogs & derivatives*; D000077555:Methylprednisolone Acetate; D008875:Middle Aged; D009460:Neurologic Examination / Q000379:methods; D011446:Prospective Studies; D011843:Radiculopathy / Q000175:diagnosis / Q000188:drug therapy*; D015641:Radiography, Interventional / Q000379:methods; D011930:Reaction Time / Q000187:drug effects; D013126:Spinal Nerve Roots / Q000187:drug effects; D016896:Treatment Outcome
D000779:Anesthetics, Local; D000893:Anti-Inflammatory Agents; D000077555:Methylprednisolone Acetate; D008775:Methylprednisolone; D002045:Bupivacaine