Anterior Interosseous Nerve Syndrome: Characteristic Magnetic Resonance Findings and Applications

CY Chu, JCK Lee, JLY Leung, CS Cheng

Hong Kong J Radiol 2011;14:93-6

Anterior interosseous nerve syndrome, also known as Kiloh-Nevin syndrome, is characterised by weakness of the muscles supplied by the anterior interosseous nerve, a branch of the median nerve that innervates the flexor pollicis longus, the flexor digitorum profundus of the index finger and middle finger, and the pronator quadratus. Clinically, patients have weakness in the involved muscles and are unable to form an ‘O’ with the thumb and index finger. Traditionally, the diagnosis relies on a clinical history, physical examination, and electrodiagnostic testing. Although magnetic resonance imaging may not visualise the anterior interosseous nerve, it aids the diagnosis of anterior interosseous nerve syndrome by recognising altered signals related to denervation of the relevant muscles and detecting any underlying mass causing nerve compression. Most patients with anterior interosseous nerve syndrome improve without any surgical intervention. During the period of conservative treatment, patients can also be monitored by magnetic resonance imaging. Controversy still exists about the treatment of anterior interosseous nerve syndrome and the optimal timing of surgical intervention. We present a patient with anterior interosseous nerve syndrome, who had characteristic clinical and magnetic resonance imaging findings.

中文摘要

前骨間神經綜合症：典型的磁共振表現及應用

朱志揚、李仲啟、梁禮賢、鄭志成

前骨間神經綜合症又稱Kiloh-Nevin綜合症，表現為前骨間神經支配著的肌肉無力；前骨間神經是正 中神經的一個分支，支配拇長屈肌、食指和中指的指深屈肌以及旋前方肌。臨床方面，患者受影響 部位的肌力減弱，拇指與食指不能捏成「O」字。傳統上，病症診斷視乎臨床病歷、體檢及電學診 斷檢查。雖然磁共振不能清楚顯示前骨間神經，但可以辨認去神經後有關肌肉的信號改變，以及偵 測是否有腫塊病灶壓迫神經，幫助前骨間神經綜合症的確診。大部分前骨間神經綜合症患者無需接 受手術也可以病情好轉。在保守治療期間，可用磁共振監察患者的情況。有關前骨間神經綜合症的 治療方法及進行手術的最佳時機現仍存有爭議。本文報告一名前骨間神經綜合症患者的臨床及磁共 振典型特徵。