Pronator Syndrome and Anterior Interosseous Nerve Syndrome

Abstract

Dysfunction of the median nerve at the elbow or proximal forearm can characterize two distinct clinical entities: pronator syndrome (PS) or anterior interosseous nerve (AIN) syndrome. PS is characterized by vague volar forearm pain, with median nerve paresthesias and minimal motor findings. AIN syndrome is a pure motor palsy of any or all of the muscles innervated by that nerve: the flexor pollicis longus, the flexor digitorum profundus of the index and middle fingers, and the pronator quadratus. The sites of anatomic compression are essentially the same for both disorders. Typically, the findings of electrodiagnostic studies are normal in patients with PS and abnormal in those with AIN syndrome. PS is a controversial diagnosis and is typically treated nonsurgically. AIN syndrome is increasingly thought to be neuritis and it often resolves spontaneously following prolonged observation. Surgical indications for nerve decompression include persistent symptoms for >6 months in patients with PS or for a minimum of 12 months with no signs of motor improvement in those with AIN syndrome.

Síndrome do pronador redondo associada à síndrome do nervo interósseo anterior: relato de caso

“…[8][9][10] Não há alterações da sensibilidade, embora na associação com a SPR alguma alteração sensitiva possa estar presente. 4 Kiloh e Nevin 3 descreveram dois casos clínicos de comprometimento do NIA; no primeiro havia paralisia do flexor longo do polegar e dos flexores profundos dos dedos indicador e médio; no segundo caso, apenas o flexor longo do polegar estava paralisado. Dellon e Mackinnon 5 relataram que o músculo de Gantzer hipertrofiado pode comprimir o NIA e causar paralisia completa ou incompleta dos músculos inervados por ele.…”

“…Por estar situado profundamente, o NIA está protegido por diversas estruturas que fazem com que suas lesões sejam raras, mas que ao mesmo tempo podem ser causadoras da compressão nervosa. 4 O objetivo deste estudo foi relatar o caso clínico da associação da SPR à SNIA. Trata-se de uma ocorrência rara, causada por uma variação anatômica.…”

Morphometry of the anterior interosseous nerve: a cadaveric study

“…[3,4] The patients can usually reach spontaneous recovery by conservative treatment methods in one year. [7] Before surgical treatment, they can be followed with conservative treatments such as injections, electrical stimulation and strengthening of the remaining muscles from 3 months to 1 year. [7][8][9] While a compressive lesion or a precise compression level are found by magnetic resonance imaging and electroneuromyography, corticosteroid or anesthetic injections can be applied to the injury level on the purpose of treatment or to diagnose the accurate surgery level.…”

“…[7] Before surgical treatment, they can be followed with conservative treatments such as injections, electrical stimulation and strengthening of the remaining muscles from 3 months to 1 year. [7][8][9] While a compressive lesion or a precise compression level are found by magnetic resonance imaging and electroneuromyography, corticosteroid or anesthetic injections can be applied to the injury level on the purpose of treatment or to diagnose the accurate surgery level. The corticosteroid and local anesthetic injections to the proximal side of the injury level of the nerve are effective treat-ment options to relieve peripheral nerve neuropathy.…”

Ultrasound‐Guided Perineural Injection for Pronator Syndrome Caused by Median Nerve Entrapment

“…Initial management may include a trial of oral anti‐inflammatory agents, immobilization, trigger point injections into the muscle, and lifestyle modifications for a minimum of 6 months. At that point, surgical interventions such as neural decompression may be indicated . However, minimally invasive techniques such as ultrasound (US)‐guided neural hydrodissection are also available and are increasingly playing a role in treatment algorithms for this condition.…”