Échographie des nerfs périphériques — Deuxième partie : membre inférieur

[Schwannoma of the sciatic nerve: a case report]

Les schwannomes du nerf sciatique sont des tumeurs rares. Elles se manifestent essentiellement par des névralgies sciatiques plutôt que par des déficits sensitivo-moteurs. Nous rapportons le cas d´une patiente de 30 ans présentant une douleur de la fesse droite depuis 1 an. La palpation a révélé un signe de Tinel positif. Une imagerie par résonnance magnétique (IRM) a été réalisée qui a objectivé une masse grossièrement arrondie, régulière de 2 cm de diamètre en contact intime avec le nerf grand sciatique. Une exérèse complète de la tumeur a été réalisée. Cette exérèse a permis la disparition de la douleur et l´examen anatomopathologique a conclu à un schwannome plexiforme.

Ultrasound Imaging of Disorders of Small Nerves of the Extremities: Less Recognized Locations

Ultrasound is a well-proven imaging modality for showing peripheral nerve disorders and guiding perineural injections. The aim of this review is to focus on small peripheral nerve abnormalities, which are usually not recognized by sonologists. In fact, most of these small nerves have a tiny diameter (<2 mm), and their anatomy is less familiar. We describe the most common causes of small peripheral nerve disorders, providing an accurate description of their anatomic locations and relationships with adjacent structures; we also focus on technical hints that may help in their evaluation.

Partial anterior tunnel syndrome: a retrospective analysis of ultrasound findings in four surgically proven cases

We present the cases of four patients (two men and two women, mean age of 48.5 years) with surgically confirmed partial anterior tarsal syndrome, diagnosed by ultrasound. All patients reported pain in the dorsal aspect of the forefoot radiating to the first intermetatarsal space. Ultrasound showed compression of the medial branch of the deep fibular nerve by the extensor hallucis brevis tendon at the level of the Lisfranc joint, associated with a hypoechoic neuroma. The ultrasound allowed a correct diagnosis to be obtained, which was not evident from clinical examination or by standard radiographs (four patients) or MRI (three patients). Surgery confirmed the sonographic findings, and all patients showed complete recovery.

Ultrasonography of the Sural Nerve: Normal and Pathologic Appearances

Ultrasonography (US) of peripheral nerves has gained wide popularity because of the increased definition of modern high-frequency electronic transducers, as well as the well-known advantages of US, which include easy availability, low cost, and the possibility of realizing a dynamic examination. Traditionally, US has been deployed to assess the major nerves of the limbs. More recently, US has also been used to assess the normal appearance and pathologic changes of smaller subcutaneous nerves. The sural nerve is a small sensory nerve in the subcutaneous tissues of the calf that can be affected by a variety of disorders. This pictorial essay illustrates the normal anatomy of the sural nerve, the technique for its examination by US, as well as the US appearance of its main pathologic changes.

Sciatic nerve schwannoma: a case report

We report on a 46-year-old woman with a sciatic nerve schwannoma. Magnetic resonance imaging revealed a well-defined, lobulated, intensely enhancing mass posterior to the left hip joint along the left sciatic nerve suggestive of neurogenic tumour. The Tinnel sign was positive on the posterior aspect of the left thigh. The tumour was excised without neural damage. Postoperatively, the patient showed no signs of any neurological deficit, and recovery was uneventful.

A rare cause of chronic sciatic pain: Schwannoma of the sciatic nerve

Schwannomas are common, benign tumors of the shelth of peripheral nerves. Sciatic schwannomas are rare. Their symptomatology usually mimics sciatic pain due to a herniated disc, which can delay the diagnosis. If there is no lumbar pain and lumbar MRI is normal, the sciatic nerve must be clinically and radiologically examined all along its course. We report a case of sciatic nerve schwannoma presenting with chronic sciatica which was diagnosed and monitored radiologically for several years before successful surgical resection.

A rare cause of non discal sciatica: schwannoma of the sciatic nerve

Schwannomas are peripheral nerve sheath tumors. Schwannomas arising in the sciatic nerve are considered a rare condition. Their symptomatology usually mimics sciatic pain due to a herniated disc, which can delay the diagnosis. We report the case of a patient with chronic sciatica in whom Magnetic Resonance Imaging (MRI) examination of the right thigh revealed a tumor of the sciatic nerve. Excision of the tumor was easily performed without neural lesioning. Histopathological examination revealed the tumor to be a schwannoma. No neurologic deficit was noted postoperatively which confirms the good prognosis of this tumor.

[Contribution of neuroradiology to the evaluation of peripheral nerves]

The evaluation of peripheral nerve impairment can use echography, MRI and CT. The alteration of the nerves in tunnel syndromes, especially if symptoms are not sufficiently contributive, is clearly visualized with MRI. Echography is very useful in the diagnosis of nerve tumors and neuromas. Plexus brachial palsies need to be evaluated using MRI. Progress in neuroimaging has improved clinical practice so that the most relevant treatment can be chosen for some pathologies such as infiltration performed under CT scanner guidance. The authors report which exam to use and the results to be expected for each pathology.