Anterior interosseous nerve syndrome: literature review and report of 11 cases

The anterior interosseous nerve syndrome (AINS) is characterized by weakness of the flexor pollicis longus and the flexor digitorum profundus of the index finger. The orthopedic literature suggests that this syndrome is caused by mechanical compression of the nerve (an entrapment neuropathy) and that decompression should take place after an observational period of 6 to 12 weeks. The neurological literature suggests that AINS is a form of neuralgic amyotrophy and that it is safe to treat patients with AINS nonoperatively to obtain good results. With this controversy in mind, a retrospective follow-up study of 11 patients with this syndrome was conducted. Eight patients were operated on and three patients were treated conservatively. The question whether a patient should be operated on or not, cannot easily be answered. It is recommended that spontaneous recovery should be awaited in patients having other neurological symptoms in combination with AINS. In patients with symptoms caused by AINS only, the observation period should be 8 to 12 months.