Neuroradiologic and neurophysiologic findings of neuralgic amyotrophy

Parsonage-Turner Syndrome and SARS-CoV-2 Infection: A Literature Review With Case Presentation

Neuralgic amyotrophy, also known as Parsonage-Turner syndrome (PTS), is characterized by severe pain and muscle wasting affecting the anterior body, including the head, shoulder, upper limb, and chest wall. Often triggered by an antecedent event, such as infection, PTS encompasses various conditions historically identified as separate entities. In 1948, Parsonage and Turner unified these conditions under the term neuralgic amyotrophy based on shared features of intense pain and muscular atrophy. Recent studies have highlighted PTS as a spectrum disorder with diverse manifestations, including pure sensory neuropathy, extensive neuropathy, spinal accessory nerve involvement, and diaphragmatic palsy. We reviewed 26 documented cases of PTS following SARS-CoV-2 infection, emphasizing the importance of considering PTS in individuals with a history of COVID-19 due to varied clinical presentations. Standardized diagnostic methods and comprehensive evaluations are crucial for accurate diagnosis and management. Future research should focus on consistent evaluation methods and employing a comprehensive differential diagnosis approach.

Neuralgic amyotrophy: sensitivity and specificity of magnetic resonance neurography in diagnosis: A retrospective study

BACKGROUND

Neuralgic amyotrophy (NA) is a clinically acute or subacute disease. To study the characteristics of brachial plexus magnetic resonance neurography (MRN) in patients with NA, and to explore the clinical application value of MRN combined with electromyography (EMG) in the diagnosis of NA.

METHODS

Brachial plexus MRN images of 32 patients with NA were retrospectively analyzed, and their characteristics were investigated. The accuracy, sensitivity and specificity of MRN, EMG, and the combination of the 2 methods for NA diagnosis were compared.

RESULTS

Among the 32 patients with NA, 28 (87.5%) cases of unilateral brachial plexus involvement, 18 (56.3%) cases of multiple nerve roots involvement. In 10 cases, C5 nerve roots were involved alone, and in 9 cases, C5 to C6 nerve roots were involved together. The T2 signal intensity of the affected nerve increased, and 19 cases showed thickened and smooth nerve root edges. Twelve cases showed uneven thickening and segmental stenosis of the involved nerve roots. The diagnostic accuracy, sensitivity, and specificity of MRN for NA were higher than those of EMG. Combining MRN and EMG could improve the sensitivity and specificity of diagnosis.

CONCLUSION

The main feature of MRN in patients with NA was that it was unilateral brachial plexus asymmetric involvement. The diagnostic effect of MRN was better than that of EMG. The combined diagnosis of MRN and EMG can help clinicians diagnose NA accurately.

MR neurography in Parsonage-Turner syndrome

Background and Aims:

Parsonage Turner Syndrome is a well known clinical entity. Several excellent articles have succinctly described Magnetic Resonance Imaging (MRI) findings in PTS. However, these articles have inferred neural involvement in PTS based on the patterns of denervation of muscles in the shoulder region. The aim of this study is to directly visualize the distribution and extent of abnormality in MR Neurography (MRN) of the brachial plexus in known cases of brachial plexus neuritis or Parsonage-Turner Syndrome (PTS).

Methods:

15 patients who were diagnosed with PTS based on clinical and electrophysiological findings participated in the study. MRN of the brachial plexus was done in a 1.5T system using a combination of T1W (T1-weighted), T2W (T2-weighted) fat-saturated, STIR (Short Tau Inversion Recovery), 3D STIR SPACE (Sampling Perfection with Application Optimized Contrasts) and 3D T2W SPACE sequences. Findings were recorded and assessed.

Results:

The age range of our patients was 7-65 years (mean 37.87 years). Most of the patients had unilateral symptoms. All patients had weakness in shoulder abduction. Other common associated complaints included pain in the shoulder/neck/arm and preceding fever. MRN revealed the percentage of involvement of roots, trunks, cords and terminal branches was 53.3%, 46.7%, 40% and 13.3% respectively. Evidence of muscle denervation in the form of edema, fatty infiltration and atrophy was noted in 8 (53.3%) patients.

Conclusion:

Most of the patients in this study had unilateral involvement on MRN. The roots were the commonest site of involvement followed by the trunks, cords and terminal branches. C5 was the most commonly involved root.

Neuralgic Amyotrophy with Cervical Root and Cranial Nerves Involvement in a Child

Idiopathic neuralgic amyotrophy (INA) is a disorder presented with acute severe pain in the upper extremity, followed by muscle weakness, paralysis and atrophy. INA is rare in children and few reports are found in the literature. Here, we report a case of INA in an 8-yr old boy from Iran following pharyngitis.

Neuralgic Amyotrophy Manifesting as Mimicking Posterior Interosseous Nerve Palsy

The upper trunk of the brachial plexus is the most common area affected by neuralgic amyotrophy (NA), and paresis of the shoulder girdle muscle is the most prevalent manifestation. Posterior interosseous nerve palsy is a rare presentation in patients with NA. It results in dropped finger on the affected side and may be misdiagnosed as entrapment syndrome or compressive neuropathy. We report an unusual case of NA manifested as PIN palsy and suggest that knowledge of clinical NA phenotypes is crucial for early diagnosis of peripheral nerve palsies.

Spinal Cord Stimulation for Refractory Neuropathic Pain of Neuralgic Amyotrophy

The aim of this paper was to report the effect of temporary and chronic spinal cord stimulation for refractory neuropathic pain in neuralgic amyotrophy (NA). A 35-year-old female presented with two-months history of a severe, relentless neuropathic pain of the left shoulder, forearm, palm, and fingers. The neuropathic pain was refractory to various medical treatments, including nonsteroidal anti-inflammatory drugs, opiates, epidural and stellate ganglion blocks, and typically unrelenting. The diagnosis of NA was made with the characteristic clinical history and magnetic resonance imaging. The patient underwent a temporary spinal cord stimulation to achieve an adequate pain relief because her pain was notoriously difficult to control and lasted longer than the average duration (about 4 weeks on average) of a painful phase of NA. Permanent stimulation was given with paddle lead. The neuropathic pain in her NA persisted and she continued using the spinal cord stimulation with 12 months after development of NA. The temporary spinal cord stimulation was effective in a patient with an extraordinary prolonged, acute painful phase of NA attack, and the subsequent chronic stimulation was also useful in achieving an adequate analgesia during the chronic phase of NA.