Diagnosis:
The diagnosis is made based on findings of plexopathy clinically and on imaging supported by exclusion of other causes.
Clinical features:
Exposure to radiation, exclusion of other causes
Weakness, usually painless
Clinical fasciculations and myokymia may occur
Findings on investigations:
NCS/EMG:
- Fasciculations and myokymia may occur
- SNAP and CMAP: slowed conduction velocity is common
MRI and other imaging: to rule out recurrence of tumor
Forms:
Transient brachial plexopathy: acute onset within weeks to months, numbness and weakness
Late-delayed brachial plexopathy: onset months to years, numbness and weakness, usually painless,
Lumbosacral plexopathy: slowly progressive unilateral <bilateral leg weakness and sensory symptoms with no or very little pain,
Pathology:
Fibrous encasement of brachial plexus
Axonal loss