| Diabetes mellitus |
| Single or multiple radiculopathies |
| Inflammatory disorders |
| Acute inflammatory demyelinating polyradiculoneuropathy (AIDP; Guillain-Barré syndrome) |
| Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) |
| Sarcoidosis |
| Infectious diseases |
| Borrelia burgdorferi (Lyme disease) |
| Cytomegalovirus |
| Epstein-Barr |
| Herpes simplex virus |
| Human immunodeficiency virus (HIV) |
| Mycobacterium |
| Mycoplasma |
| Syphilis |
| Varicella zoster virus (Herpes zoster or shingles) |
| Malignancy |
| Lymphoma |
| Metastasis |
| Multiple myeloma |
| Vascular |
| Arteriovenous malformation |
| Radiation-induced vascular occlusion |
| Vasculitis (nerve root infarction) |
