Spinal cord injury is the most common cause of hyperreflexia.[citation needed] Standard stimuli, such as the filling of the bladder, can cause excessive responses from the nervous system. The causes of hyperreflexia are not known.[citation needed]
Hyperreflexia also has many other causes, including the side effects of drugs (e.g., stimulants), hyperthyroidism, electrolyte imbalance, serotonin syndrome, severe brain trauma, multiple sclerosis, Reye syndrome, and pre-eclampsia.[citation needed]
Recovery from hyperreflexia can occur several hours to several months after a spinal cord injury; the phase of recovery is likely to occur in stages rather than on a continuum.[1] The late stage is between two weeks and several months.[1] Patients with a severe spinal cord injury mainly present with a later stage of recovery because during the early stages they present with spinal shock.[1] Reflex and motor recovery can sometimes occur simultaneously.[1]
↑ 1.01.11.21.3Little, J., Ditunno, J. F., Stien, S., A., Harris, R. M. (1999). "Incomplete spinal cord injury: Neuronal mechanisms of motor recovery and hyperreflexia. Archives of Physical Medicine and Rehabilitation 80 (5): 587-599.
