Échographie des nerfs périphériques

Sonographic short-term follow-up after surgical decompression of the median nerve at the carpal tunnel: a single-center prospective observational study

OBJECT

Carpal tunnel syndrome causes increased cross-sectional area (CSA) of the median nerve, which can be assessed by high-definition ultrasonography. It is unclear today, however, whether high-definition ultrasonography may play a role in the postoperative period. This prospective study aimed to determine the natural history of the morphology of the median nerve at the carpal tunnel after surgical decompression assessed by high-definition ultrasonography.

METHODS

Between October and December 2014, patients with suspected carpal tunnel syndrome who were referred to the authors’ center for peripheral neurosurgery were prospectively enrolled and underwent pre- and postoperative (3 months) high-definition ultrasonography, electrophysiology, and clinical testing.

RESULTS

Eighty-one patients were enrolled in the study, and 100% were clinically better at the 3-month follow-up. The mean CSA decreased from 14.7 ± 4.9 mm2 to 12.4 ± 3.4 mm2 (mean ± SD, p < 0.0001). The mean distal motor latency decreased from 6.6 ± 2.4 msec to 4.8 ± 1.0 msec (mean ± SD, p < 0.0001). Ninety-eight percent of patients who were available for electrodiagnostic follow-up showed an improvement of the distal motor latency; only 80% had a reduction in the CSA.

CONCLUSIONS

The authors present the second-largest series of patients with sonographic follow-up after surgical decompression of the carpal tunnel reported in the literature so far. This study, which showed a decrease in size of the median nerve after surgical decompression, suggests that the preoperative increase in median nerve CSA at the carpal tunnel may be due to compression and that enlargement of the median nerve is (partially) reversible.

Newer management options in leprosy

Newer management options are needed for leprosy control even at present, as it is predicted that new cases of leprosy will continue to appear for many more years in future. This article detail newer methods of clinical grading of peripheral nerve involvement (thickening, tenderness and nerve pain which are subjective in nature) and the advances made in the use of Ultrasonography and Colour Doppler as an objective imaging tool for nerves in leprosy. It also briefly discusses the newer drugs and alternative regimens as therapeutic management options which hold promise for leprosy in future.

Contribution of ultrasound in the assessment of nerve diseases

BACKGROUND AND PURPOSE

Recently, ultrasound (US) has been used to assess the peripheral nervous system; however, there is no real study about its possible significant role in routine practice. Our study aims to assess the contribution of US as a routine tool in a neurophysiological laboratory.

METHODS

The study assesses 130 patients who presented clinical suspicion of peripheral nerve diseases, excluding motor neuron disease, radiculopathy, hereditary and acquired polyneuropathy. All patients were clinically, neurophysiologically and sonographically assessed in the same session by the same neurologist/neurophysiologist. To avoid interpretation bias, two independent and blinded clinicians, different than the examiners performing electrodiagnosis and US, reviewed clinical, neurophysiological and US findings (also data about follow-up, when available) and classified the contribution of US as follows: Contributive (US had influence on the diagnostic and therapeutic strategies), Confirming (US confirmed the clinical and neurophysiological diagnosis), Non-Confirming (US findings were normal) and Incorrect (US findings led to incorrect diagnosis).

RESULTS

US impacted, namely modified the diagnostic and therapeutic path in 42.3% of cases (55 patients); US had a confirmatory role in 40% (52 patients); US did not confirm clinical and neurophysiological diagnosis in 17.7% (23 cases); no incorrect US findings were observed.

CONCLUSION

US complements neurophysiological assessment even in routine practice, and this confirms the increasing interest in US for a multidimensional evaluation of peripheral nerve system diseases.

[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.

High-resolution ultrasonography in evaluating peripheral nerve entrapment and trauma

High-resolution ultrasonography is a noninvasive, readily applicable imaging modality, capable of depicting real-time static and dynamic morphological information concerning the peripheral nerves and their surrounding tissues. Continuous progress in ultrasonographic technology results in highly improved spatial and contrast resolution. Therefore, nerve imaging is possible to a fascicular level, and most peripheral nerves can now be depicted along their entire anatomical course. An increasing number of publications have evaluated the role of high-resolution ultrasonography in peripheral nerve diseases, especially in peripheral nerve entrapment.

Ultrasonography has been shown to be a precious complementary tool for assessing peripheral nerve lesions with respect to their exact location, course, continuity, and extent in traumatic nerve lesions, and for assessing nerve entrapment and tumors. In this article, the authors discuss the basic technical considerations for using ultrasoniography in peripheral nerve assessment, and some of the clinical applications are illustrated.

Ultrasound of the nerves of the knee region: Technique of examination and normal US appearance

The diagnosis of disorders of the peripheral nerves (PN) has traditionally been based on clinical and electrophysiological data since nerve tissue cannot be visualized on standard radiographs. More recently, however, nerve structures have been evaluated with magnetic resonance imaging (MRI) and ultrasound (US). The former modality is expensive and not available in all institutions. There are also some contraindications to its use, and the assessment of long nerves can be time-consuming since different coils must be used. Thanks to recent advances in sonographic software and hardware, US can now be used for in-depth assessment of the PN of the upper and lower limbs.Most knee disorders involve lesions to the cruciate ligaments and/or the menisci, which are difficult to evaluate with US. However, similar symptoms may be caused by compression of one or more nerves in the knee region or intrinsic disorders involving these structures. Because of their superficial positions, the nerves around the knee can be clearly visualized with US. A thorough knowledge of the normal anatomy of this region and a careful scanning technique are essential for a successful diagnostic US examination. In this article, we will review the normal gross and microscopic anatomy of the nerves in the knee region, the US technique used for their examination, and their normal US appearance.

Contribution of ultrasound in a neurophysiological lab in diagnosing nerve impairment: A one-year systematic assessment

OBJECTIVE

To evaluate the usefulness of a combination of electromyography (EMG) and ultrasound (US) assessments in diagnosing nerve trunk involvement. We hypothesised that in some cases, when the clinical or neurophysiological picture is unclear, the simultaneous study of the peripheral nervous system through both US and EMG may provide pathologic information not obtainable through EMG alone, and this may influence therapeutic decisions.

METHODS

In 2005, we performed a prospective study in 77 consecutive patients with involvement of a single nerve trunk, using a combination of EMG and US in the same session. We divided the diagnostic contribution of US into four categories: diagnostic, confirming, inconclusive and misdiagnostic.

RESULTS

In about a quarter of the patients, US provided results confirming the clinical neurophysiological diagnosis. In another quarter of the cases, US was very helpful in modifying diagnosis and therapy. In most of these cases, the contribution of US was important for the detection of tumors or cysts, thus showing the cause of nerve involvement. In half of the cases the US results were inconclusive, and in one case US was misdiagnostic.

CONCLUSIONS

The combination of EMG and US performed in the same session (or in collaboration with an ultrasound examiner) may be useful for diagnosis and determination of appropriate therapy.

SIGNIFICANCE

Diagnosis of mononeuropathies is improved through a combined functional and morphological evaluation of the nerve by using EMG and US.

Échographie des nerfs périphériques — Deuxième partie : membre inférieur

On sonographic images, the peripheral nerves have a fibrillary structure, ribboned on longitudinal images and ovoid on cross-section images. The nerves travel between the muscle groups, often with blood vessels, or in canals. Recently improved ultrasound devices are able to investigate the peripheral nerves along their entire length, as far as the sonographer has thorough anatomical knowledge, rigorous technique, and, when searching for pathology, good clinical notions. As in Part I on sonography of the peripheral nerves of the upper limbs, published in this journal, the objective of this general review is to present normal and pathological echoanatomy of the peripheral nerves of the lower limbs in an educational way.

Musculoskeletal Sonography: A Dynamic Tool for Usual and Unusual Disorders

OBJECTIVE

The purpose of this study is to illustrate a wide variety of musculoskeletal disorders that can be diagnosed with dynamic sonography.

CONCLUSION

Dynamic sonography is a useful tool for the evaluation of a variety of musculoskeletal disorders. Many of these disorders cannot be diagnosed by any other imaging method.

Régression du névrome de Morton après infiltration de corticostéroïdes

Morton neuroma is a non neoplastic lesion corresponding to perineural fibrosis encircling the common interdigital plantar nerve. Several therapeutic approaches are possible: conservative treatment or surgery. We report a case treated by local steroid injection where follow-up MR showed near complete regression of the lesion. Although local injection of steroid is a classical treatment, it is the first time to our knowledge that resolution or such a striking diminution of size is reported after infiltration.