Reply to Daly, J.J. Comment on "Chow, J.W.; Stokic, D.S. Longitudinal Changes in Temporospatial Gait Characteristics...

Spinal cord injury progresses through two interconnected phases: primary injury and secondary injury.Primary InjuryPrimary injury happens at the moment of trauma and involves immediate mechanical damage to the spinal cord.Compression happens when broken vertebrae, herniated discs, or accumulating blood (such as a hematoma) press directly against the spinal cord, distorting its normal shape and function. In cases of contusion, the cord is bruised by a blunt force (like penetrating injuries or...

Parkinson disease (PD) is a progressive neurodegenerative disorder primarily affecting movement, with additional non-motor features. Its pathophysiology involves complex interactions among genetic susceptibility, environmental exposures, and cellular dysfunction, including dopaminergic neuron loss, protein aggregation, and mitochondrial impairment.Selective NeurodegenerationA key feature is the degeneration of dopaminergic neurons in the substantia nigra pars compacta, leading to reduced...

Early Ischemia and Ionic ImbalanceWithin minutes of spinal cord injury, a secondary cascade begins, progressing over hours to weeks. Vascular damage reduces blood flow, causing ischemia and mitochondrial dysfunction. ATP depletion leads to ion pump failure, membrane depolarization, sodium influx, potassium efflux, and water accumulation, resulting in cellular swelling. Increased intracellular calcium further disrupts mitochondria and accelerates cellular injury.Excitotoxicity and Neuronal...