Conditions affecting the brain, spinal cord, nerves
Epilepsy, ALS, stroke complications, Parkinsonian syndrome, multiple sclerosis, cerebral palsy, spinal cord injury, traumatic brain injury, coma, neurological conditions causing problems with movement, communication, or mental functioning (like early-onset Alzheimer's).
Medical evidence (exams, imaging, labs) confirming the diagnosis. Evidence of severe limitation in physical abilities (like standing, walking, using hands/arms) OR communication OR mental functioning (understanding, interacting, concentrating, managing oneself). For some conditions (like epilepsy), you must show the limitations persist for at least 3 months despite following treatment.