| Possible Causes of ALS | Factors Examined | sALS vs. controls |
| Oxidative stress | Urinary 8-OxodG | ↑ 8-OxodG |
| Urinary 15- isoprostane (IsoP) | ↑ IsoP | |
| Mitochondrial dysfunction | Oxidized CoQ10 levels in CSF | ↑ Oxidized CoQ10 |
| 8-OHdG levels in CSF | ↑ 8-OHdG | |
| Glutamate toxicity | Glutamate levels in CSF | ↑ Glutamate |
| Toxin exposure | Cigarette smoking | ↑ ALS risk |
| Cyanobacteria (BMAA levels) | ↑BMAA (not found in controls) | |
| Genetic mutations | TDP-43 TARBDP | ↑ Missense mutations |