Symptom group | Symptom/diagnosis | Pre-ALS frequency, %† | Medicare frequency, %‡ | Prevalence ratio§ | Median time to diagnosis from first limb/bulbar symptom, years‖ |
---|---|---|---|---|---|
Nerve | Chronic inflammatory demyelinating polyneuropathy | 2 | < 1 | 30.5 | ND |
Nerve | Myopathy (including myopathy with weakness) | 8 | < 1 | 28.6 | 2.75 |
Nerve | Unspecified disease of spinal cord (including myelopathy NOS) | 5 | < 1 | 19.6 | 2.25 |
Nerve | Cervical/thoracic or lumbar spondylosis with myelopathy | 6 | 1 | 11.2 | 3.50 |
Limb | Atrophy, muscular disuse | 5 | 1 | 5.0 | 2.75 |