[Mononeuropathy of dorsal interosseous nerve: compression by return radial arteries]

Among many causes of compression neuropathies involving the radial nerve, compression of the posterior interosseous nerve (PIN) by the returning radial arteries is rare.

To describe the clinical instrumental characteristics of cases of mononeuropathy caused by compression of the return radial arteries.

Two observations with neuropathy of the deep branch of the radial nerve, manifested by weakness in the corresponding muscles, inconsistent pain syndrome with previous stereotypic (recurring) physical activity are presented.

According to the results of ultrasound examination of posterior interosseous nerve, a local hypoechogenic increase in the cross-sectional area of nerve of different lengths was revealed. During surgical decompression of the nerve, in the first case, a tight arterial loop was found around the nerve, in the second case, expanded arterial trunks, one of which, of small diameter, covered the nerve in the 'loop', and the other, larger, pierced the nerve. After the operation, regression of motor deficiency and relief of pain were noted.