Sonographic Evaluation of Patients With Carpal Tunnel Syndrome Following Steroid Injection

Experimental: steroid injection

ultrasound-guided steroid injection using 1ml of 10 mg (10mg/ml) triamcinolone acetonide

Droga: steroid injection

ultrasound-guided steroid injection using 1ml of 10 mg (10mg/ml) triamcinolone acetonide

Otros nombres:

• acetónido de triamcinolona

Cross sectional area

The CSA of the median nerve was measured at 2 levels: at the carpal tunnel inlet (CSA-I; immediately prior to the proximal margin of the flexor retinaculum) and in the mid-carpal tunnel (CSA-M; at the level of the pisiform bone and scaphoid tubercle)

flattening ratio

The flattening ratio was measured only at the mid-tunnel (FR-M). FR was calculated by dividing the horizontal diameter of the nerve by the vertical diameter.

Boston Carpal Tunnel Questionnaire (BQ)

The BQ was interviewed-administered to assess the severity of symptoms and functional status.

Median nerve distal motor latency

the CMAPs were obtained via surface electrodes placed on the abductor pollicis brevis muscle. The active recording electrode was placed on the muscle belly, and the reference electrode was placed on the tendon insertion. The median nerve was stimulated 8 cm proximal to the active recording electrode. Distal motor latencies were measured from the onset of stimulus artifact to the onset of the CMAP

sensory nerve conduction velocity

SNAPs were obtained using an antidromic method and recorded by surface electrodes placed at the proximal and distal interphalangeal joints of the index finger for the median nerve and the same joints of the little finger for the ulnar nerve. The median nerves were stimulated at the wrist at a distance of 14 cm from the wrist to the active electrode. Distal sensory latencies were measured from the onset of the stimulus artifact to the onset of the SNAP. SNCV was calculated dividing the distance of 14 cm by the distal sensory latency.

compound muscle action potential amplitude (CMAP)

the CMAPs were obtained via surface electrodes placed on the abductor pollicis brevis muscle. The active recording electrode was placed on the muscle belly, and the reference electrode was placed on the tendon insertion. The median nerve was stimulated 8 cm proximal to the active recording electrode. The amplitude of CMAP were measured from baseline to negative peak.

sensory nerve action potential amplitudes.

SNAPs were obtained using an antidromic method and recorded by surface electrodes placed at the proximal and distal interphalangeal joints of the index finger for the median nerve and the same joints of the little finger for the ulnar nerve. The median nerves were stimulated at the wrist at a distance of 14 cm from the wrist to the active electrode. The amplitude of SNAP were measured from baseline to negative peak.