Hourglass-like Fascicular Constriction Research Articles

Hourglass-like fascicular constriction of the median nerve: case series

Background. The anterior interosseus nerve (AIN) syndrome is a rare pathology, with cause is discussed. The findings in isolated AIN patients are in the main trunk of median nerve. It is confirmed by neuroimaging data and intraoperative picture in the form of the construction of fascicles in the nerve.Aim. To describe the clinical and instrumental characteristics of patients with isolated non-traumatic lesion of AIN.Materials and methods. The clinical, electrophysiological and neuroimaging data of 7 patients with isolated nontraumatic lesion of AIN were retrospectively analyzed, three of whom underwent surgical treatment.Results. All patients complained of neuropathic pain in the affected upper limb, with an average intensity of 8 points according to visual analog scale and a duration of 1.5 to 4 weeks. Weakness of the flexor pollicis longus from 1 to 3 points on the MRC (Medical Research Council Weakness) scale was observed in all cases, weakness of flexion of the distal phalanx of the index finger in 6 patients from 1 to 3 points, which indicated an isolated lesion of the anterior interosseous nerve.Needle electromyogram revealed denervation in c in all cases, 5 patients – in the pronator teres.The fascicular constriction from 1 or 2 sections of the median nerve were detected at the shoulder level on the affected side by ultrasound in 6 patients. An increase in the cross-sectional area of the median nerve at the shoulder level in 2 cases we observed, in one case the changes were o bilateral and asymmetric. In 2 cases, an increase in cross-sectional area of С5 root was noted on the affected side by no more than 23 % of the normal value. A change in echogenicity and size decrease of the pronator quadratus, when compared with the opposite side, was noted in all cases.Conclusion. Patients with isolated AIN syndrome needs intensive evaluation to identify the localization of the level of damage to the median nerve.

Surgical Indications for Spontaneous Radial Nerve Palsy with Hourglass-like Fascicular Constriction

Surgical Indications for Spontaneous Radial Nerve Palsy with Hourglass-like Fascicular Constriction

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

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

Spontaneous peripheral nerve palsy with hourglass-like fascicular constriction in the upper extremity.

Spontaneous paralysis from hourglass-like fascicular constriction of peripheral nerves is rare, its clinical manifestations are not well documented, and its pathogenesis remains unknown. The unclear origin of this disorder and difficulty in diagnosis result in its uncertain management. The authors sought to gain a more thorough understanding of this condition through describing the anatomy, clinical features, etiology, and treatment of hourglass-like constriction. The authors retrospectively reviewed 20 patients (22 nerves) with hourglass-like constriction. The patients' clinical information was reviewed. Preoperative sonographic assessment and electrophysiological examination of involved nerves were performed. Surgical treatments included interfascicular neurolysis and neurorrhaphy. Samples of tissue subjected to resected constriction were sent for pathological analysis. The patients had regular face-to-face follow-up visits. Acute pain was always the first symptom and was followed by paralysis. Paralysis progression was rapid and serious. Surgical exploration indicated an hourglass-like constricted segment completely unrelated to the compressive structures. Electrophysiological analysis showed severe denervation, and histopathological examination showed inflammatory cell infiltration, demyelination, and reduction of nerve fibers. Hourglass-like fascicular constrictive neuropathy has an integrative effect from multiple different mechanisms. Surgical intervention is beneficial for selected patients who do not recover in a timely fashion and have hourglass-like lesions confirmed by preoperative ultrasound imaging. The authors recommend that early surgical intervention of the nerve be offered to patients who do not show any signs of recovery 3 months after onset. Both interfascicular neurolysis and neurorrhaphy are effective treatment methods. Mild to moderate constriction can usually be treated successfully by interfascicular neurolysis alone, whereas more advanced lesions with loss of fascicle continuity (severe constriction) may be best treated with resection and direct neurorrhaphy.

The first case of hourglass-like constriction neuropathy of a digital nerve

Neuropathies of digital nerves are an infrequent phenomenon and their causes are most often mechanical. A rare cause of acute neuropathy is hourglass-like fascicular constriction of a nerve due to torsion. Although several cases of hourglass-like constriction have been described in the literature, none to our knowledge involved digital nerves. In this report, we present the first case of hourglass-like constriction of a digital nerve.

Correlation between "hourglass-like fascicular constriction" and idiopathic anterior interosseous nerve palsy.

In recent operative cases of anterior interosseous nerve palsy (AINP), hourglass-like fascicular constrictions have been reported. We prospectively investigated the ultrasonographic history of these lesions to better understand the role of this lesion in AINP. Seven patients who were diagnosed with idiopathic AINP based on classic clinical findings and had hourglass-like fascicular constrictions found on ultrasonography were included. All but 1 patient selected surgery, and we followed up all patients clinically and with ultrasonography. In the 5 patients treated surgically in whom paralysis recovered to a level greater than M4, postoperative ultrasonography revealed less constriction. The other patient experienced little recovery after surgery, and the severe constriction remained. In a conservatively treated patient, the paralysis recovered completely, and upon ultrasonography, the constriction had lessened. Although the mechanism is still unknown, hourglass-like fascicular constriction lessened with relief of motor weakness both in operatively and conservatively treated patients. Muscle Nerve 55: 508-512, 2017.

Relationship Between the Idiopathic Anterior Interosseous Nerve Palsy and “Hourglass-like Fascicular Constriction”: Level 4 Evidence

An hourglass-like fascicular constriction, which is a focal fascicular lesion observed at one or a few places in one or a few fascicles of a peripheral nerve trunk, and usually affects the anterior interosseous nerve (AIN) or posterior interosseous nerve, is improved with the relief of symptom. Seven consecutive patients who were diagnosed with idiopathic AIN palsy based on clinical findings and had hourglass-like fascicular constrictions in the AIN revealed by the ultrasonographic examination were included. We used the high-resolution device with a 14-6 MHz linear probe, and observed nerve fascicles in the median nerve trunk in a transverse and longitudinal fashions around the site of tenderness at the elbow joint level confirming the presence of fascicular constriction. The age at the time of diagnosis ranged from 19 to 56 years old. The duration between onset of symptoms and ultrasonographic examination ranged from 7 days to 8 months, and the duration between examination and operation ranged from 3 days to 1 month. All but one case took interfascicular neurolysis, and we followed up all cases clinically and ultrasonographically every one month. At the time of examination, we calculated constriction ratio, which was obtained by the division of the involved fascicular diameter at the constriction by that at the proximal non-constricted site. The number of constrictions ranged from one to eight, and all constrictions revealed ultrasonographically were confirmed intraoperatively. In the five cases with the operative treatment, recovery from paralysis began from 3 weeks to four months after surgery, and was completed (M0 to M4 or M5) five to seven months after surgery. Postoperative ultrasonography revealed the constrictions subsided. The other one treated operatively got little recovery (M0 to M2) at 10 months after surgery, and the severe constriction still remained. In the one conservative treated case, the paralysis began to recover at 9 months and recovered completely (M0 to M5) at 14 months after the onset. On the ultrasonographic examination, its constriction incompletely subsided. The hourglass-like fascicular constriction subsided with the relief of the paralysis both in the operatively and conservatively treated cases. The cause of constricitons is still unknown, however, it may play a significant role on this type of paralysis.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Surgical and conservative treatments of complete spontaneous posterior interosseous nerve palsy with hourglass-like fascicular constrictions: a retrospective study of 41 cases.

The surgical treatment of spontaneous posterior interosseous nerve (PIN) palsy with hourglass-like fascicular constriction (HLFC) remains controversial. To review 41 patients with complete spontaneous PIN palsy with HLFC to clarify the necessity and choice of surgery. Interfascicular neurolysis (NY), neurorrhaphy, and autografting were performed on 10, 8, and 6 patients, respectively. The thinning extent of a nerve fasciculus ≤0.25, 0.25 to 0.75, and ≥0.75 was defined as mild, moderate, and severe constriction, respectively. Final British Medical Research Council muscle power grade ≥4 was defined as good recovery. Ultrasound showed the number, location, and thinning extent of HLFC of PIN well, with results that were highly consistent with intraoperative measurements. Of the 17 conservatively treated patients, 13 recovered well. Of the 24 surgically treated patients, 20 recovered well. For NY, 8 patients with mild to moderate PIN constriction recovered well, but 2 patients with severe PIN constriction recovered poorly. For 16 patients with severe HLFC, 12 of 14 patients who underwent neurorrhaphy or autografting recovered well; the surgical effects were much better than those of 2 patients who had undergone NY. Ultrasound is a helpful diagnostic technique for spontaneous PIN palsy with HLFC. Surgery is necessary for PIN constriction if conservative treatments fail. Surgical choices depend largely on the thinning extent of the PIN constriction and the age of the patients. The outcomes of patients aged ≥50 years were much worse. We suggest NY for mild to moderate, and neurorrhaphy or autografting for severe PIN constriction.

High-Resolution Ultrasonographic Evaluation of “Hourglass-like Fascicular Constriction” in Peripheral Nerves: A Preliminary Report

An hourglass-like constriction is a focal fascicular lesion observed in one or a few places in one or a few fascicles of a peripheral nerve trunk, and usually affects the anterior interosseous (AIN) or posterior interosseous (PIN) nerve. Constrictions have previously been discovered only by surgical exploration, and have been unable to be recognized on pre-operative imaging. We encountered some cases in which the lesion was able to be diagnosed pre-operatively by high-resolution ultrasonography; these findings were then confirmed intra-operatively. Five consecutive cases were included in this study. In three cases with constrictions revealed on pre-operative ultrasound, the findings were confirmed intra-operatively. In the remaining two cases in which no constrictions were detected pre-operatively, no constriction was revealed intra-operatively. High-resolution ultrasonography may play a significant role in the diagnosis of hourglass-like constrictions, and may thus lead to significant changes in treatment strategies for AIN and PIN palsy.

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We report a case of simultaneous anterior and posterior interosseous nerve syndrome in association with shoulder arthroscopy. Shoulder arthroscopy was performed in a 45-year-old male patient with left shoulder instability. In the right lateral decubitus position, under general anesthesia, traction was applied with elbow extension for 2 hours. One week after surgery, the patient revisited the clinic for weakness of the flexor of the thumb, index finger, and extensor of the fingers. Recovery was not achieved after four months of observation. Therefore, nerve exploration was performed in the anterior and posterior interosseous nerve and hourglass-like fascicular constriction was detected in the posterior interosseous nerve. The area of constriction was removed and epineural neurorrhaphy was performed. Three months after exploration, the extension function of the fingers was recovered. Recovery was achieved gradually, and, five months after nerve exploration, the symptoms were completely recovered. Simultaneous anterior and posterior interosseous nerve syndrome following shoulder arthroscopy is rare. However, it could occur due to the traction and position of the patient. Thus, the operator should be careful of traction and position of the patient.

Posterior interosseous nerve syndrome with hourglass-like fascicular constriction of the nerve

We describe a case of the posterior interosseous nerve (PIN) syndrome in a patient with gout. Exploration of the PIN revealed multiple hourglass-like constriction of the PIN, which did not correspond to any extrinsic compressing structures. Hourglass-like constrictions of the PIN is one of the causes of the painful PIN syndrome.

Spontaneous anterior interosseous nerve palsy with hourglass-like fascicular constriction within the main trunk of the median nerve

Interfascicular neurolysis was performed in nine patients with spontaneous anterior interosseous nerve palsy. In eight of these patients, an hourglass-like constriction in the fascicles forming the anterior interosseous nerve was found within the main trunk of the median nerve at 2-7.5 cm above the medial epicondyle. The clinical signs and symptoms of these eight patients were similar to those that have been described to isolated neuritis. While the etiology remains unknown, when spontaneous anterior interosseous nerve palsy is suspected to be caused by isolated neuritis, interfascicular neurolysis should be performed to confirm the lesion and to discover whether fascicular constriction is present.