====== Brachial plexus neuropathy ======

see also [[Idiopathic brachial plexus neuropathy]].

===== Evaluation =====

When the [[etiology]] is unclear, check [[CXR]] (with apical lordotic view), glucose, ESR, and ANA.


If no improvement by ≈ 4 weeks, obtain MRI of the plexus ([[idiopathic brachial plexitis]] will usually
start to show some improvement by this time; therefore tumor should be ruled out if no
improvement).

===== Differential diagnosis of etiologies of brachial plexopathy =====

1. Pancoast syndrome or Pancoast tumor AKA superior sulcus tumor. Clinical: various combinations
of pain in the shoulder radiating into the upper extremity in the ulnar nerve distribution
from involvement of the lower brachial plexus, atrophy of hand muscles, Horner syndrome
, UE edema. 

Etiologies:

a) neoplasms:

● most common: bronchogenic cancer, usually non-small cell (NSCLC) (squamous cell or
[[adenocarcinoma]]) arising in the pulmonary apex

● metastases

b) infections

c) inflammatory: granulomas, amyloid

2. (idiopathic) brachial plexitis AKA neuralgic amyotrophy: most commonly upper plexus or diffuse

3. cervical rib

4. viral

5. following radiation treatment: often diffuse 

see [[Radiation induced brachial plexus neuropathy]]

6. diabetes

7. vasculitis

8. inherited: dominant genetics

9. trauma