Prompt interfascicular neurolysis for the successful treatment of hourglass-like fascicular nerve compression

Neuralgic Amyotrophy and Hourglass Nerve Constriction/Nerve Torsion: Two Sides of the Same Coin? A Clinical Review

Neuralgic amyotrophy, also called Parsonage-Turner syndrome, in its classic presentation is a brachial plexopathy or a multifocal neuropathy, involving mainly motor nerves of the upper limb with a monophasic course. Recently, a new radiological entity was described, the hourglass constriction, which is characterized by a very focal constriction of a nerve, or part of it, usually associated with nerve thickening proximally and distally to the constriction. Another condition, which is similar from a radiological point of view to hourglass constriction, is nerve torsion. The pathophysiology of neuralgic amyotrophy, hourglass constriction and nerve torsion is still poorly understood, and a generic role of inflammation is proposed for all these conditions. It is now widely accepted that nerve imaging is necessary in identifying hourglass constrictions/nerve torsion pre-surgically in patients with an acute mononeuropathy/plexopathy. Ultrasound and MRI are useful tools for diagnosis, and they are consistent with intraoperative findings. The prognosis is generally favorable after surgery, with a high rate of good motor recovery.

Hourglass-like constriction of the anterior interosseous nerve in the left forearm: A case report

BACKGROUND

Hourglass-like constriction neuropathy is a rare neurological disorder. The main clinical manifestation is peripheral nerve injury with no apparent cause, and the pathomorphological change is an unexplained narrowing of the diseased nerve. The diagnosis and treatment of the disease are challenging and there is no accepted diagnostic or therapeutic approach.

CASE SUMMARY

This report describes a rare hourglass constriction of the anterior interosseous nerve in the left forearm in a 47-year-old healthy male who was treated surgically and gradually recovered function over a 6-mo follow-up period.

CONCLUSION

Hourglass-like constriction neuropathy is a rare disorder. With the development of medical technology, more examinations are now available for diagnosis. This case aims to highlight the rare manifestations of Hourglass-like constriction neuropathy and provides a reference for enriching the clinical diagnosis and treatment experience.

[Sonographic characteristics of non-traumatic focal hourglass-like nerve constriction]

AIM

To describe the sonographic phenomenon of the focal 'hourglass-like constriction' of the peripheral nerves (FCPN).

MATERIAL AND METHODS

The authors described 7 patients meeting the criteria for the diagnosis of neuralgic amyotrophy with unilateral FCPN identified with ultrasound in 4 cases and detected intraoperatively in 3 cases (preliminary ultrasound was not performed). The US scanner Sonoscape Pro mode gray scale in the transverse and longitudinal scanning, linear probe 8-15 MHz and Logiq9 scanner with elastography were used.

RESULTS

FCPN was detected in the single nerve in 4 patients, in two nerves in 2 patients and in 3 nerves in one patient. Among all the nerves involved in the pathological process, the radial nerve and its branches were affected in 73% (8 nerves); the ulnar nerve was involved in 18% (2 nerves) and the musculo-cutaneous nerve in 9%. The length of the constriction of the peripheral nerve did not exceed 1.7 mm. The deformation coefficient (DC) of constriction area was 3.8 to .,9; the change in the elasticity in the form of an increase of DC to 5.9 when compared to the intact portion of the nerve and a decrease in echogenicity were observed in one patient.

CONCLUSION

High-resolution ultrasound of the nerve can be an informative method for the diagnosis of idiopathic non-traumatic FCPN mononeuropathy.

Hourglass-like constriction of the suprascapular nerve: a contraindication for minimally invasive surgery

BACKGROUND

Suprascapular nerve (SSN) entrapment is usually ascribed to static or dynamic compression. When no cause of compression is found, SSN entrapment is defined as idiopathic. Focal hourglass-like constriction (H-LC) of the SSN that results in muscle paralysis represents an unusual condition that may be misinterpreted and erroneously diagnosed as SSN entrapment or as neuralgic amyotrophy.

METHODS

With the aim of finding clinical and surgical clues that could differentiate the traditional form of idiopathic SSN entrapment from the rare H-LC, a series of 6 cases of SSN palsy caused by H-LC is presented.

RESULTS

All but 1 supraspinatus muscle recovered M5 muscle strength. The Constant shoulder score was excellent in 3 patients, good in 1, fair in 1, and poor in 1.

DISCUSSION

If a diagnosis is not made in time, H-LC may evolve from mild to severe nerve torsion that may require a shift in surgical procedure from epineurotomy and external neurolysis to focal resection and suture. If an incorrect therapy is chosen, the chance of recovery might be definitively compromised with the persistence of muscle palsy. Conversely, when SSN palsy persists despite notch decompression, especially when it is performed with a limited open approach or arthroscopically, concerns about the real etiology and location of nerve compression responsible for the nerve palsy may arise.

CONCLUSION

When approaching SSN pathology, H-LC should be considered as a potential cause of nerve palsy, as it may represent a contraindication for a limited open approach or arthroscopic decompression.

Ultrasonographic identification of nerve pathology in neuralgic amyotrophy: Enlargement, constriction, fascicular entwinement, and torsion

INTRODUCTION

The aim of this study was to characterize the ultrasonographic findings on nerves in neuralgic amyotrophy.

METHODS

Fourteen patients with neuralgic amyotrophy were examined using high-resolution ultrasound.

RESULTS

Four types of abnormalities were found: (1) focal or diffuse nerve/fascicle enlargement (57%); (2) incomplete nerve constriction (36%); (3) complete nerve constriction with torsion (50%; hourglass-like appearance); and (4) fascicular entwinement (28%). Torsions were confirmed intraoperatively and were seen on the radial nerve in 85% of patients. A significant correlation was found between no spontaneous recovery of nerve function and constriction/torsion/fascicular entwinement (P = 0.007).

CONCLUSION

Ultrasonographic nerve pathology in neuralgic amyotrophy varies in order of severity from nerve enlargement to constriction to nerve torsion, with treatment ranging from conservative to surgical. We postulate that the constriction caused by inflammation is the precursor of torsion and that development of nerve torsion is facilitated by the rotational movements of limbs.

Hourglass-Like Constrictions of Peripheral Nerve in the Upper Extremity

BACKGROUND:

The development of an hourglass-like constriction in the nerve is rare, and its origin is unknown. Its clinical manifestations are not well documented, and the treatment protocol has not been established.

OBJECTIVE:

To identify the cause, presentation, and possible treatment for patients with nerve palsies secondary to an hourglass-like constriction in the affected nerves.

METHODS:

Patients presenting with peripheral nerve palsy caused by an hourglass-like constriction of nerves were retrospectively investigated in 2 hand centers. The patients' presentation and neurological findings were reviewed, and the immunohistochemistry of excised specimens was studied.

RESULTS:

Forty-two patients who presented with 47 nerve palsies were examined. Forty-one patients experienced a sudden onset of pain in the upper limb, followed by flaccid paralysis in the affected muscles. Ten patients had multiple nerve involvement. Surgical exploration found 1 or more hourglass-like constrictions in the nerve. The treatments included internal neurolysis, neurorrhaphy, and nerve grafting. Thirty-one of 42 patients (36 nerves) were followed up for a mean of 48 months (range, 8–157 months). Fifteen of 16 nerves treated by neurolysis, 10 of 13 nerves treated by neurorrhaphy, and 4 of 7 nerves treated by nerve grafting had good recovery. CD8-positive T-lymphocyte infiltration was observed in all the excised specimens.

CONCLUSION:

The clinical presentation of patients with hourglass-like constrictions in their nerves is similar to that of patients with neuralgic amyotrophy. Histochemical analysis suggests that the pathogenesis may be immunological in origin. The role of surgery in this condition is uncertain.

Typical brachial neuritis (Parsonage-Turner syndrome) with hourglass-like constrictions in the affected nerves

PURPOSE

To report on 5 patients who had acute brachial neuritis (Parsonage-Turner syndrome) with hourglass-like constriction in the affected nerves.

METHODS

We retrospectively reviewed 5 patients who were treated in our department from December 2003 to December 2008. Acute, intense pain around the shoulder girdle and upper arm was the first symptom and was followed by muscle weakness and atrophy. Clinical and EMG examinations showed involvement of 2 or more nerves in the affected extremity. Those severely affected nerves that had no response to conservative treatment were explored, and an hourglass-like constriction was identified. Neurolysis was performed at the sites of constrictions in 2 radial nerves and 1 median nerve. The constricted portion was resected, and direct coaptation was performed in 1 radial nerve and 1 musculocutaneous nerve. The constricted portion was resected, and nerve graft was performed in 2 radial nerves and 1 median nerve.

RESULTS

All patients were followed up for 24 to 84 months after surgery. Of 3 nerves treated with external neurolysis, all attained full recovery. Of 2 nerves treated with resection and neurorrhaphy, 1 attained full recovery, and the other had an incomplete recovery. Of 3 nerves treated with resection and nerve graft, 1 (4-cm nerve graft) attained full recovery, and 2 (4-cm and 13-cm nerve graft, respectively) had incomplete recovery.

CONCLUSIONS

The site of nerve lesion of brachial neuritis was not necessarily within the brachial plexus. Our finding of hourglass-like constrictions in individual peripheral nerves suggest that multifocal involvement of terminal branch lesions may underlie the complex patterns of paralysis often encountered clinically.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Homolateral hourglass-like constrictions of the axillary and suprascapular nerves: case report

In contrast with previous research, it was recently demonstrated that hourglass-like constriction is not exclusive to the elbow region. We present a report of a patient who had an axillary nerve and a suprascapular nerve hourglass-like constriction, found 7 years apart.