Regional anesthesia for acute pain management in elderly patients

Table 3 Nervous system changes in the elderly[11,13-15]

Structural changes: gross and molecular level	Neuronal axon loss and pathology (more than seen with glial cells)
	Neural cytoskeleton changes resulting in neurofibrillary tangles and neuritic plaques (induces glial cell-mediated inflammation)
	Loss of dendrite components and decrease in neural synaptic activity
	Amyloidoses due to amyloid protein accumulation
Biochemical changes	Neurotransmitter imbalance: mostly involves changes in serotonin, dopamine, norepinephrine, acetylcholine
	Circulatory changes: multi-infarct senile dementia; increased BBB permeability
	Metabolic disturbances: atherosclerosis and associated blood flow and O2 consumption decreases
Functional sequelae	Gait changes
	Sleep and wakefulness alterations and EEG changes
	Cognitive impairment
	Decreased balance stability/physical equilibrium

BBB: Blood-brain barrier; EEG: Electroencephalograph.