J Korean Neurosurg Soc.  2015 Nov;58(5):491-493. 10.3340/jkns.2015.58.5.491.

Neuralgic Amyotrophy Manifesting as Mimicking Posterior Interosseous Nerve Palsy

• Yang JS
• Cho YJ
• Kang SH
• Choi EH

• KMID: 2191419
• DOI: http://doi.org/10.3340/jkns.2015.58.5.491

Abstract

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.

Keyword

Neuralgic amyotrophy; Brachial plexus neuritis; Posterior interosseous nerve; Entrapment syndrome; Magnetic resonance neurography

MeSH Terms

Brachial Plexus
Brachial Plexus Neuritis*
Early Diagnosis
Fingers
Humans
Paralysis*
Paresis
Peripheral Nerves
Phenotype
Shoulder

Figure

• 

  Fig. 1 On physical examination, the patient showed a complete finger drop (A) with sparing of wrist extension (B) on right side.

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  Fig. 2 Coronal short tau inversion recovery imaging at TR/TE 50000/52 demonstrated a thickening and increased signal intensity in the right C6 root of the brachial plexus (white arrow).

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