<unk> es can be penetrating, compression, or closed traction:
Supraclavicular (roots and trunks)
Infraclavicular (cords and terminal nerves)
Supraclavicular (roots and trunks)
Infraclavicular (cords and terminal nerves)
Idiopathic
Post-infectious
Viral
Epstein-Barr, CMV, influenza, parvovirus, coxsackie, HIV, Polio
Bacterial
Lyme, Leptospirosis, TB, Salmonella
Post-immunization
Compressive
Neoplasm
Pancoast tumor
Post-traumatic
Penetrating or blunt neck/shoulder trauma
Traction<unk> 
Birth trauma
Erb's palsy
Klumpke's paralysis
Connective tissue disorders
Autoimmune disorders
Lupus
Polyarteritis nodosa
Temporal arteritis
Iatrogenic
Post-surgical
Medication induced
Radiation
Hereditary Neuralgic Amyotrophy
Rotator Cuff<unk> 
Adhesive capsulitis
Calcific tendinitis
Thoracic outlet syndrome
ALS
Poliomyelitis
Parsonage-Turner syndrome
Viral
Epstein-Barr, CMV, influenza, parvovirus, coxsackie, HIV, Polio
Bacterial
Lyme, Leptospirosis, TB, Salmonella
Epstein-Barr, CMV, influenza, parvovirus, coxsackie, HIV, Polio
Lyme, Leptospirosis, TB, Salmonella
Neoplasm
Pancoast tumor
Pancoast tumor
Penetrating or blunt neck/shoulder trauma
Traction<unk> 
Birth trauma
Erb's palsy
Klumpke's paralysis
Erb's palsy
Klumpke's paralysis
Lupus
Polyarteritis nodosa
Temporal arteritis
Post-surgical
Medication induced
Radiation
Roots:
C5
C6
C7
C8
T1
Trunks:
Upper
Middle
Lower
Cords:
Lateral
Posterior
Medial
Terminal Nerves:
Musculocutaneous
Median
Axillary
Radial
Ulnar
C5
C6
C7
C8
T1
Upper
Middle
Lower
Lateral
Posterior
Medial
Musculocutaneous
Median
Axillary
Radial
Ulnar
Brachial plexus injury
Rucksack paralysis
Anterior cord syndrome
Traumatic/Acute:
Third nerve palsy
Shoulder Dislocation
Spinal cord injury
Anterior shoulder dislocation