1. Patients with a history of traumatic brain injury had more than double the risk of developing amyotrophic lateral sclerosis compared with matched controls.
2. The highest ALS risk occurred within the first 2 years after injury, suggesting a time-sensitive window for heightened surveillance.
3. The study analyzed over 340,000 adults using linked UK electronic health records, providing strong epidemiologic validity.
4. Beyond 2 years post-injury, ALS risk attenuated to rates similar to the general population.
5. Physicians managing head trauma should consider long-term neurological follow-up to identify early neurodegenerative changes.

Source: JAMA Network Open