Alvarez-Solis G, Estañol-Vidal B, Delgado-García G, García-Pastor C, López L, Rodríguez-Balaguer R

Language: Spanish
References: 24
Page: 3-12
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ABSTRACT

Introduction: The H reflex (HR) of the upper limbs was validated for the study of the integrity and conduct of spinal monosynaptic reflex arc to the C6-C7 level and ran its usefulness in neuropathy and radiculopathies.
Objectives: To record flexor carpi radialis (FCR) HR, compound sensory nerve action potential (SNAP) and compound motor action potential (CMAP) at Erb’s point (EP). To determine the proportion of patients in whom HR, SNAP and CMAP were evoked, and their neurophysiological features.
Methods: We included 22 subjects (9 males, 18- 50 years old), without prior neurological disease, of whom 43 measures were obtained. HR was evoked by stimulation of the median nerve at the elbow, with a submaximal stimulus at a long duration (1 ms), and SNAP, CMAP (both at EP) and FCR-HR were simultaneously recorded. 25 responses were averaged.
Results: FCR-HR and SNAP were obtained 100% of the times, and CMAP was obtained 74%. HR: Latency 13.4±1.6 ms, sensorimotor conduction velocity (CV) 79.55±10.74 m/s, amplitude 2499±1896 µV. SNAP: Latency 4.8±0.6 ms, sensory CV 82.81±10.78 m/s, amplitude 6.08±3.34 µV, morphology with a small initial positive deflection in 67.5% of cases, the remainder showed a negative potential. CMAP: Latency 8.23±1.1 ms, motor CV 88.66±15.52 m/s, amplitude 4.3±3.16 µV, morphology with negative deflection in all cases. Spinal delay of 0.8±0.3 ms.
Conclusions: In the proximal nerve segments of the upper limbs, sensorimotor CV has not been studied. This study presents our findings on 22 healthy subjects and opens the possibility to examine this reflex in patients with spinal cord disorders or proximal diseases (such as C5-C6 radiculopathy, brachial plexus injuries and Guillain- Barré syndrome).

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