Isolated spontaneous posterior interosseous nerve palsy: a review of aetiology and management

Posterior interosseous nerve lesion due to lipoma. Review of the literature and rare case presentation

BACKGROUND

Posterior interosseous nerve lesion is a rare mononeuropathy of the upper limb. Atraumatic posterior interosseous nerve lesions are commonly caused by lipomas of the forearm, manifesting as slow-progressing wrist and finger drop.

PATIENTS AND METHODS

In this review and case report study, we present a systematic review of the literature for patients presenting with posterior interosseous palsy due to lipomas and a rare case of patient with acute posterior interosseous nerve lesion caused by a lipoma. Our primary interest was in the timing of clinical presentation. For the review process, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

RESULTS

After reviewing the literature, we identified thirty patients with posterior interosseous nerve lesions caused by lipomas. In 28 patients, the symptoms presented progressively, ranging from 1 month to a maximum of 240 months. We found only one case of a patient with acute presentation and another patient with acute worsening of chronic weakness due to trauma.

CONCLUSIONS

Atraumatic posterior interosseous nerve lesions are frequently secondary to forearm lipomas. In the majority of cases, the symptoms will develope progressively. However, in this study, we also report a rare case of a patient presenting with acute posterior interosseous nerve lesion due to a lipoma.

Superficial branch of the radial nerve passing through the supinator canal, emerging between the extensor digitorum and abductor pollicis longus muscles and consequently supplying the second finger and radial portion of the third finger: a case report and clinical implications

Awareness of unique path of the superficial branch of the radial nerve and its unusual sensory distribution can help avoid potential diagnostic confusion. We present a unique case encountered during a routine dissection of a Central European male cadaver. An unusual course of the superficial branch of the radial nerve was found in the right forearm, where the superficial branch of the radial nerve originated from the radial nerve distally, within the supinator canal, emerged between the extensor digitorum and abductor pollicis longus muscles and supplied the second and a radial half of the third digit, featuring communications with the lateral antebrachial cutaneous nerve and the dorsal branch of the ulnar nerve. Due to dorsal emerging of the superficial branch of the radial nerve the dorsal aspect of the thumb was innervated by the lateral antebrachial cutaneous nerve. To our best knowledge such variation of the superficial branch of the radial nerve has never been reported before. This variation dramatically changes aetiology and manifestation of possible entrapment syndromes which clinicians should be aware of.

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.

Drop finger caused by lung cancer metastasis

Skeletal muscle metastasis of lung cancer is rare. However, clinicians should be aware that tumour-induced nerve compression symptoms may develop.

Spontaneous radial nerve palsy with hourglass-like constriction

Hourglass-like constriction (HLC) is an uncommon spontaneous mononeuropathy that is typically characterised by a sudden onset of pain followed by palsy, affecting branches of the radial (posterior interosseous nerve) and median nerves (anterior interosseous nerve). HLC of the radial nerve (RN) is rare, with only a few reported cases. Here, we report a case of a man who presented with acute wrist and finger drop due to the HLC of the RN. Surgery was recommended 5 months after clinical observation, when the lesion was resected and primarily repaired, resulting in satisfactory recovery. There is still much that remains unknown about HLC, especially for RN. The current understanding points out an inflammatory disease that should be treated conservatively for 3-7 months. The surgical technique depends mostly on the severity and extent of constriction; however, considering only RN constrictions, primary repair by neurorrhaphy or nerve grafts resulted in better functional outcomes.

Nerve Torsion as a Pattern of Parsonage-Turner Syndrome: Literature Review and Two Representative Cases

(1) Background: Parsonage-Turner Syndrome (PTS) is a rare peripheral nerve disease characterized by different degrees of nerve impairment. The recent development of nerve ultrasound has enabled the use of new data in the diagnosis of the disease. The aim of this study is to conduct a literature review about the ultrasound evaluation of PTS and present two clinical cases that are characteristic of the disease. (2) Methods: A review of the literature from the last 10 years on the topic containing data regarding nerve ultrasound was performed. In addition, two cases of patients on whom nerve ultrasound was performed at the first evaluation and at follow-up after the indicated treatment were described. (3) Results: The results of our review show that although it is defined as plexopathy, PTS is most often a form of multifocal neuropathy. We also report the most frequently used ultrasound classification and possible prognostic correlations and report our experience with the description of two paradigmatic clinical cases. (4) Conclusions: Further studies are needed to understand the true prognostic power of each degree of nerve impairment and the possible implications in clinical practice regarding treatment indications.

A Case of Posterior Interosseous Nerve Palsy Associated With Robotic Low Anterior Resection

A peripheral nerve compression injury associated with surgical positioning is an important complication that might compromise quality of life. We report a rare case of posterior interosseous nerve (PIN) palsy after robotic rectal cancer surgery. A 79-year-old male with rectal cancer underwent robotic low anterior resection in a modified lithotomy position with both arms tucked at his sides with bed sheets. Following surgery, he felt difficulty moving his right wrist and fingers. A neurological examination revealed muscle weakness in the area innervated by the PIN alone without sensory disturbance, and he was diagnosed with PIN palsy. The symptoms improved with conservative treatment in about a month. The PIN is a branch of the radial nerve and controls dorsiflexion of the fingers, and intraoperative continuous pressure on the upper arm by right lateral rotation position or by the robot arm was considered to be the cause.

Radial nerve compression: anatomical perspective and clinical consequences

The radial nerve is the biggest branch of the posterior cord of the brachial plexus and one of its five terminal branches. Entrapment of the radial nerve at the elbow is the third most common compressive neuropathy of the upper limb after carpal tunnel and cubital tunnel syndromes. Because the incidence is relatively low and many agents can compress it along its whole course, entrapment of the radial nerve or its branches can pose a considerable clinical challenge. Several of these agents are related to normal or variant anatomy. The most common of the compressive neuropathies related to the radial nerve is the posterior interosseus nerve syndrome. Appropriate treatment requires familiarity with the anatomical traits influencing the presenting symptoms and the related prognoses. The aim of this study is to describe the compressive neuropathies of the radial nerve, emphasizing the anatomical perspective and highlighting the traps awaiting physicians evaluating these entrapments.

Some Misconceptions in the Treatment of Cubital Tunnel Syndrome, Radial Tunnel Syndrome, and Median Nerve Compression in the Forearm

This article discusses ulnar, median, and radial nerve compression in the proximal forearm and elbow and some possible common misconceptions. In particular, the ligament of Struthers extremely rarely causes ulnar neuropathy. Lacertus syndrome and flexor superficialis-pronator syndrome can be diagnosed separately. Surgical release can be through a small incision. Acronyms for compression to radial nerve in proximal forearm can be simplified to radial tunnel syndrome, which includes a mild type (classical radial tunnel syndrome) and a severe type (posterior interosseous nerve (PIN) compression).

Posterior Interosseous Nerve Palsy Associated with Multiple Epiphyseal Dysplasia

Multiple epiphyseal dysplasia is a condition that courses with a retarded epiphyseal development and may cause joint dysmorphia. We report a case of posterior interosseous nerve palsy in a child with dysplasia. After a physical examination and complementary diagnostic tests that revealed posterior interosseous nerve compression neuropathy, surgical neurolysis og the posterior interosseous nerve was performed at level of the the arcade of Frohse. The satisfactory evolution of the patient confirmed our diagnosis. Attention must be paid to the onset of signs or symptoms of nerve compression in these patients.

Palsy of the posterior interosseous nerve treated by targeted ultrasound-guided perineural hydrodissection

Perineural hydrodissection is a minimally invasive technique using an injection of fluid to dissect the perineural plane and tissue space. This report describes a case of palsy of the descending branch of the posterior interosseous nerve (PIN) which was recovered by targeted ultrasound-guided perineural hydrodissection. Ultrasonographic examination was performed, and multiple stenotic lesions interrupted by hyperechoic bands within the fascicles of the PIN were found. Using ultrasonography, perineural hydrodissection was performed four times every other week. Fifteen weeks after the first hydrodissection, there was no restriction in the patient’s thumb and fingers movement, and ultrasonography revealed that multiple stenotic lesions had improved. Today, surgical treatment is recommended for patients with complete nerve constriction. However, there is no standardized approach for patients with incomplete or without nerve constriction. Ultrasound-guided perineural hydrodissection is a noninvasive and easy method. This procedure could be a useful diagnostic and therapeutic modality for the management of the disease.

Posterior interosseous neuropathy: distinguishing from a proximal radial neuropathy

The posterior interosseous nerve is the terminal motor branch of the radial nerve that innervates the extensor carpi ulnaris and the extensors of the thumb and fingers. We describe a case of a posterior interosseous neuropathy presenting with the typical 'finger drop' and partial 'wrist drop'. We focus on the clinical signs that distinguish it from a more proximal radial neuropathy, clarified by nerve conduction studies and needle electromyography. Multimodal imaging of the forearm did not identify a compressive lesion. Persistent symptoms prompted surgical exploration 5 years after initial onset. It identified compression of the posterior interosseous nerve in the region of the arcade of Frohse and leash of Henry. The sites were decompressed and concurrent salvage secondary reconstructive tendon transfers were required in view of the severe axonal loss with minimal chance of functional reinnervation.

Postoperative rehabilitation in elbow surgery

Postoperative rehabilitation plays a crucial role in the treatment of elbow pathology. Depending on the type of surgery, the elbow may need to be protected. As a general rule, the elbow should not be immobilized for a prolonged period after surgery. A removable splint can be used to protect the soft-tissues immediately postoperative and the patient is encouraged to remove the splint several times daily to mobilize the elbow. Dynamic articulated braces can be used to encourage movement while ligament or tendon repairs are being protected. Literature on postoperative elbow rehab is scarce. In this paper we provide practical guidelines for specific surgical procedures.

Pathological Findings of Hourglass-Like Constriction in Spontaneous Posterior Interosseous Nerve Palsy

We report the pathological findings of hourglass-like fascicular constriction (HLFC) under optical and electron microscopy. A 24-year-old man with spontaneous posterior interosseous nerve palsy was treated by interfascicular neurolysis at 29 weeks after onset. One fascicle in the radial nerve presented severe HLFC with torsion at 5 cm proximal to the elbow. Functional recovery was achieved by resection of the enlarged fascicle including HLFC and sural nerve grafting. Proximal to the HLFC, the endoneurium was filled with clusters of regenerating nerve fibers. At the level of the HLFC, a complete loss of myelinated nerve fibers and vascular occlusion of endo- and perineurial vessels were found. Few regenerating nerve fibers were observed. Distal to the HLFC, severe endoneurial edema, a complete loss of myelinated and unmyelinated nerve fibers, and bands of Büngner were noted. These electron microscopic findings demonstrated a detailed pathology of the nerve around the HLFC.

Diagnosis of Hourglass-Like Constriction Neuropathy of the Radial Nerve Using High-Resolution Magnetic Resonance Neurography: A Report of Two Cases

Hourglass-like constriction neuropathy is a neurological condition caused by fascicular constriction of one or more peripheral nerves, unrelated to intrinsic or extrinsic compression. It is often neglected in clinical practice, and its diagnosis is challenging. Here, we report two cases of hourglass-like constriction neuropathy in the radial nerve diagnosed using high-resolution magnetic resonance neurography (MRN). Two men, aged 47 and 19 years, developed sudden weakness in the left wrist and finger extensors. They were diagnosed with radial neuropathy between the left mid-humerus level and the elbow joint, using the electrodiagnostic test. To evaluate the cause of the nerve lesion and the lesion location, high-resolution MRN was performed. Patient 1 showed an hourglass-like constriction of the left posterior interosseous nerve within the epineurium of the left radial nerve, 8.9 cm proximal to the lateral epicondyle. Patient 2 showed two focal constrictions of the left radial nerve, 8.0 and 6.9 cm proximal to the lateral epicondyle, respectively, and distal to the radial groove. Additionally, bull’s eye signs were observed juxta-proximal to constrictions of the left radial nerve. The findings were indicative of hourglass-like constriction neuropathy. Both of the patients underwent surgery. However, at the 6-month follow-up, their motor weakness showed no improvement. MRN can be beneficial for diagnosing hourglass-like constriction neuropathy and locating the lesion.