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

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.

Arm Function After Arthroscopic Decompression of the Suprascapular Nerve at the Spinoglenoid Notch and Suprascapular Notch in Volleyball Players

Background

Suprascapular nerve (SSN) entrapment in volleyball players leads to infraspinatus (ISP) muscle atrophy and weakness of abduction and external rotation (ER) of the shoulder.

Purpose

To assess functional outcome after arthroscopic extended decompression of SSN in the spinoglenoid notch and suprascapular notch in a group of volleyball athletes.

Study Design

Case series; Level of evidence, 4.

Methods

Volleyballers who underwent arthroscopic SSN decompression were analyzed retrospectively. Assessment tools consisted of range of motion and ER strength on Lovett scale and postoperative ER strength measured by dynamometer, Constant-Murley score (CMS), and visual evaluation of ISP muscle recovery by assessing muscle bulk.

Results

The study included 10 patients (9 male and 1 female). The mean age was 25.9 years (range, 19-33) and mean follow-up was 77.9 months (range, 7-123). The mean range of postoperative ER at 90° of abduction (ER2) was 105.6° (88°-126°) and 108.5° (93°-124°) for the contralateral side, while ER2 strength was 8 ± 2.6 and 12.65 ± 2.8 kg (P < .01) respectively. Mean CMS was 89.9 (84-100). In 5 cases, there was complete recovery of ISP muscle atrophy whereas 2 patients had partial recovery and 3 had none.

Conclusion

Arthroscopic SSN decompression in volleyball players improves shoulder function, but results of ISP recovery and ER strength are variable.

The role of ultrasonography in diagnosing hourglass-like fascicular constriction(s) of the anterior interosseous nerve

BACKGROUND

In the past, the diagnosis of hourglass-like fascicular constriction(s) of the anterior interosseous nerve mostly depended on electrophysiological examination, by which the location could not be diagnosed. There are few studies on the evaluation of hourglass-like fascicular constriction(s) by ultrasonography.

PURPOSE

To evaluate the role of ultrasonography in the diagnosis of hourglass-like fascicular constriction(s) of the anterior interosseous nerve.

MATERIAL AND METHODS

A retrospective analysis of 12 patients with hourglass-like fascicular constriction(s) of the anterior interosseous nerve was carried out, and the characteristics of the high-frequency ultrasonographic images were summarized and compared with surgical exploration.

RESULTS

The 12 cases of hourglass-like fascicular constriction(s) of the anterior interosseous nerve were all located in the median nerve of the distal upper arm, including nine cases of single hourglass-like fascicular constriction and three cases of multiple hourglass-like fascicular constrictions. High-frequency ultrasonography can accurately locate the hourglass-like fascicular constriction(s) of the anterior interosseous nerve and the extent of neuropathy. The ultrasonographic images of hourglass-like fascicular constriction(s) of the anterior interosseous nerve showed single or multiple hourglass-like change(s) in the median nerve of the distal upper arm. The nerve fascicles on both sides of the affected nerve with hourglass-like change thickened.

CONCLUSIONS

High-frequency ultrasonography could be a reliable, convenient, and non-invasive diagnostic imaging method for hourglass-like fascicular constriction(s) of the anterior interosseous nerve.

Vascular compromise in a torsed transposed ulnar nerve case in support of intravenous contrast administration

Nerve torsion is a recognized etiology in brachial and peripheral neuropathy. Vascular compromise of peripheral nerves is uncommon given their unique vascular supply. Preoperative imaging diagnosis of nerve torsion and vascular compromise can be made in some cases, which impacts treatment. We present a previously unreported case of long segment torsion and vascular compromise of the ulnar nerve following anterior subcutaneous transposition with a description of the imaging findings based on the unique structure of the nerve and the presence of a blood nerve barrier (BNB) and a discussion of the potential vulnerability of a transposed and torsed nerve.

Neuralgic amyotrophy: a paradigm shift in diagnosis and treatment

Neuralgic amyotrophy (NA), also known as Parsonage-Turner syndrome, is characterised by sudden pain attacks, followed by patchy muscle paresis in the upper extremity. Recent reports have shown that incidence is much higher than previously assumed and that the majority of patients never achieve full recovery. Traditionally, the diagnosis was mainly based on clinical observations and treatment options were confined to application of corticosteroids and symptomatic management, without proven positive effects on long-term outcomes. These views, however, have been challenged in the last years. Improved imaging methods in MRI and high-resolution ultrasound have led to the identification of structural peripheral nerve pathologies in NA, most notably hourglass-like constrictions. These pathognomonic findings have paved the way for more accurate diagnosis through high-resolution imaging. Furthermore, surgery has shown to improve clinical outcomes in such cases, indicating the viability of peripheral nerve surgery as a valuable treatment option in NA. In this review, we present an update on the current knowledge on this disease, including pathophysiology and clinical presentation, moving on to diagnostic and treatment paradigms with a focus on recent radiological findings and surgical reports. Finally, we present a surgical treatment algorithm to support clinical decision making, with the aim to encourage translation into day-to-day practice.

"Isolated" Suprascapular Neuropathy: Compression, Traction, or Inflammation?

BACKGROUND

Several hypotheses have been proposed for the pathophysiology of suprascapular nerve (SSN) palsy, including compression, traction, and nerve inflammation.

OBJECTIVE

To provide insight into the pathophysiology of isolated nontraumatic SSN palsy by performing critical reinterpretations of electrodiagnostic (EDX) studies and magnetic resonance (MR) images of patients with such diagnosis.

METHODS

We retrospectively reviewed all patients referred to our institution for the past 20 yr with a diagnosis of nontraumatic isolated suprascapular neuropathy who had an upper extremity EDX study and a shoulder or brachial plexus MR scan. Patient charts were reviewed to analyze their initial clinical examination, and their original EDX study and MR images were reinterpreted by an experienced neurologist and a musculoskeletal radiologist, respectively, both blinded from the authors' hypothesis and from each other's findings.

RESULTS

Fifty-nine patients were included. Fifty of them (85%) presented with at least 1 finding that was inconsistent with an isolated SSN palsy. Forty patients (68%) had signs on physical examination beyond the SSN distribution. Thirty-one patients (53%) had abnormalities on their EDX studies not related to the SSN. Twenty-two patients (37%) had denervation atrophy in other muscles than the spinati, or neural hyperintensity in other nerves than the SSN on their MR scans, without any evidence of SSN extrinsic compression.

CONCLUSION

The great majority of patients with presumed isolated SSN palsy had clinical, electrophysiological, and/or imaging evidence of a more diffuse pattern of neuromuscular involvement. These data strongly support an inflammatory pathophysiology in many cases of "isolated" SSN palsy.

Hourglass-like constriction neuropathy of the suprascapular nerve detected by high-resolution magnetic resonance neurography: report of three patients

Hourglass-like constriction neuropathy is a neurological condition caused by non-traumatic, non-compressive fascicular constrictions of one or more individual peripheral nerves. Based on clinical manifestations, it is very difficult to differentiate hourglass-like constriction neuropathy from idiopathic neuralgic amyotrophy. Focal hourglass-like constriction neuropathy may be erroneously diagnosed as idiopathic neuralgic amyotrophy. Previous studies demonstrated hourglass-like constrictions of peripheral nerves in the surgical exploration of patients diagnosed with idiopathic neuralgic amyotrophy. Recently, high-resolution ultrasound or magnetic resonance neurography (MRN) have been introduced to detect focal hourglass-like constrictions of peripheral nerves in spontaneous nerve palsy. We present a series of three cases in which the suprascapular nerve was affected by hourglass-like constrictions, which were visualized by high-solution MRN, including a nerve-selective morphological MR pulse sequence with strong fat- and water-signal suppression.