Unusual Parsonage–Turner syndrome with relapses and bilateral simultaneous anterior interosseous neuropathy

Parsonage-Turner Syndrome With an Uncommon Trigger: A Case Study and Literature Review

Patients with Parsonage-Turner syndrome (PTS) are often misdiagnosed due to overlapping symptoms with other conditions and coinciding procedures. Because it is most commonly seen following viral infection, it is often not considered in other cases. We present a rare case in which a 79-year-old female, with no significant past medical history, was diagnosed with PTS two months after a biopsy of the right levator scapulae muscle. Forty-eight hours after the procedure, she developed sudden-onset pain and weakness in the right scapulae and neck, followed by worsened weakness. This case report highlights the importance of considering PTS before proceeding with treatment. Patients with suspected PTS should undergo electromyography (EMG) to confirm diagnosis and monitor disease progression and resolution.

Clinical Spectrum of Postsurgical Parsonage-Turner Syndrome: A Perspective From an Electrodiagnostic Laboratory

BACKGROUND

Parsonage-Turner syndrome (PTS) is an underdiagnosed disorder characterized by the acute onset of severe pain in the shoulder/scapula/arm followed by muscle weakness/numbness in the distribution of nerves derived from the brachial plexus (BP). Surgical procedures are one of several antecedent events of PTS. This study describes the clinical spectrum of postsurgical Parsonage-Turner syndrome (PSPTS) in a large cohort of patients.

MATERIALS AND METHODS

Charts of patients diagnosed with PTS during a 16-year (2006-2022) retrospective review were analyzed to identify cases of PSPTS. The clinical criteria for PSPTS included the new onset of severe pain two days to four weeks after a surgical procedure followed by weakness of muscles innervated by one or more nerves arising from the BP. EDX criteria consist of denervation localized to branches of the BP. PSPTS cases were subdivided into two categories: definite PSPTS (surgery at a remote site) and probable PSPTS (surgery of the ipsilateral upper extremity or the cervical spine).

RESULTS

Of 202 patients (204 episodes) diagnosed with PTS, 111 (54%) were idiopathic and 61 (30%) were PSPTS. Of the 61 PSPTS episodes, 26 were definite and 35 were probable PSPTS. The anterior interosseous nerve (AIN) was most affected, followed by the posterior interosseous (PIN), and suprascapular nerve.

CONCLUSION

In this series, surgery was the most commonly recognized antecedent event for PTS, and the AIN and PIN were the most frequent nerves affected. Surgeons should consider PTS in patients who develop postoperative severe shoulder pain and weakness of muscles innervated by the BP.

Inclusion Body Myositis Mimicking Bilateral Anterior Interosseous Neuropathies

Anterior interosseous neuropathy is a rare cause of weakness of flexion of the thumb interphalangeal and index and middle finger distal interphalangeal joints, most commonly caused by trauma, compression, or inflammation. Bilateral anterior interosseous nerve palsies are rare, and other neuromuscular disorders may present with a similar pattern of weakness. We describe 2 patients who initially presented for orthopedic evaluation for suspected anterior interosseous neuropathy and were subsequently diagnosed with inclusion body myositis, an uncommon inflammatory myopathy affecting adults, with a predilection for finger and thumb flexor muscles. Electromyography, serologic and radiographic studies, and muscle biopsy can aid in diagnosis and help to distinguish inclusion body myositis from an anterior interosseous neuropathy.

Bilateral idiopathic neuralgic amyotrophy involving selective branches of peripheral nerves with a stepwise progression: A case report

RATIONALE

This is a report about a rare case of idiopathic neuralgic amyotrophy (INA) involving selective peripheral nerve branches of bilateral upper extremities, which exhibited a stepwise progression.

PATIENT CONCERN

A 66-year-old woman presented with paresis of selective branches of bilateral median nerves, followed by paresis of bilateral posterior interosseous nerve (PIN) 8 weeks later.

DIAGNOSES

We diagnosed it as INA involving the selective motor branches of bilateral median nerves and bilateral PINs. Forearm magnetic resonance imaging combined with electrodiagnostic testing helped accurately identify the affected regions, and ultrasonography demonstrated a severe constriction of the left PIN.

INTERVENTIONS

Intravenous methylprednisolone partially relieved the pain and paralysis. Surgical neurolysis of the constricted left PIN was done for persistent paralysis.

OUTCOMES

The muscle power of the bilateral median nerve territories was recovered to nearly normal, but the muscle power of the left PIN territories remained at grade 1.

LESSONS

This case indicates that INA can manifest as a multiple mononeuropathy involving individual fascicular levels of peripheral nerve branches with focal constriction, and electrodiagnostic study combined with forearm MRI and ultrasonography can help in identifying affected lesion and predicting the prognosis.

Neuralgic amyotrophy (Parsonage-Turner syndrome)

Neuralgic amyotrophy (Parsonage-Turner syndrome or brachial plexus neuritis) is an uncommon syndrome whose cause is unknown. The suprascapular and axillary nerves and corresponding muscles are affected most frequently. The disorder exhibits a broad range of clinical manifestations, and patients frequently present to physicians of different subspecialties. Accurate diagnosis can be challenging and requires a thorough history and physical examination. Nerve conduction velocity and imaging studies assist in the evaluation. Treatment consists of symptomatic management. Symptoms can persist for more than than a year, but most patients note resolution of symptoms over time.