Diagnosis:
The diagnosis is confirmed by isolation of the causative neoplasm and electrophysiological and clinical findings
Clinical features:
Painful,
Features of brachial plexopathy or those of lumbosacral plexopathy:
- Weakness in lower plexus C8, T1 distribution +atrophy
- Associated with Horner’s syndrome
- Asymmetric leg weakness, reduced reflexes
Findings on investigations:
NCS/EMG:
- Denervation (fibrillations and positive sharp waves PSW) in affected muscles (usually lower plexus)
- Decreased recruitment (Neurogenic recruitment)
- SNAP Abnormal conduction velocities in ulnar and median or radial nerves is common
- CMAP Abnormal conduction velocities in ulnar and median or radial nerves is common
MRI brachial plexus, infiltration by cancer or lumboscaral plexus infiltration by cancer
CT: lung cancer, retroperitoneal tumor
Mammography and breast exam: breast cancer