Pathogenesis and electrodiagnosis of cubital tunnel syndrome / 中华神经科杂志

ABSTRACT

Objectives To determine the causes of cubital tunnel syndrome by performing operation,and to assess the clinical value of neurophysiologic diagnosis in cubital tunnel syndrome Methods Twenty one patients (22 limbs from 16 men and 5 women, aged from 22 to 63 years, with mean age of 49 years)suspected of ulnar nerve involved in clinical symptoms and the signs of ulnar distribution were recorded with motor conduction velocity at different sites along with the ulnar nerve and sensory conduction velocity in the hand,and underwent anterior transposition of the ulnar nerve Results Electromyographic abnormality was seen in 21/22 (range MCV 15.9～47.5 m/s,mean 32.7 m/s) of patients with motor conduction velocity in across elbow segment of the ulnar nerve. And slowing was seen in 13/22 (MCV 15.7～59.6 m/s, mean 40.4 m/s )patients with MCV in the forearms. The absent or abnormal evoked sensory nerve action potential was seen in 14/22 patients in the little finger. The factors of ulnar compressed in this study by operation were15 ulnar nerves compressed by arcuate ligaments, or muscle tendons, or bone hyperplasia; two were involved in fibrous by adhesion;three compressed by venous plexus or concurrent thick vein;two compressed by cysts Conclusions The factors of cubital tunnel syndrome include either the common factors reported or the rare factors, such as the venous plexus, thick vein and cysts. The tests of motor conduction velocity at different sites along the ulnar nerve should be helpful in diagnosis of cubital tunnel syndrome, especially the slowing velocity of MCV across the elbow segment.