Neurological System
Neurological System
Discuss the following:
Describe major changes that occurs on the neurological system associated to age. Include changes on central nervous system and peripheral nervous system.
Define delirium and dementia, specified similarities and differences and describe causes for each one.
Submission Instructions: Your initial post should be at least 500 words, formatted and cited in current APA style with support from at least 2 academic sources. Your initial post is worth 8 points. You should respond to at least two of your peers by extending, refuting/correcting, or adding additional nuance to their posts. Your reply posts are worth 2 points (1 point per response.) All replies must be constructive and use literature where possible. (Neurological System)
Neurological System Changes with Aging
Aging significantly impacts both the central nervous system (CNS) and the peripheral nervous system (PNS). These changes can contribute to reduced cognitive function, slower reflexes, and an increased risk of neurological diseases.
Changes in the Central Nervous System (CNS)
The CNS, comprising the brain and spinal cord, undergoes several age-related changes. Neuronal loss is a significant factor. Although the brain does not lose a large number of neurons as once believed, some areas experience considerable neuron loss, such as the hippocampus, which is involved in memory and learning. This neuronal reduction contributes to cognitive decline, memory impairment, and difficulty in learning new tasks.
Another major CNS change involves the reduction in neurotransmitters. With age, the production of neurotransmitters like dopamine, acetylcholine, and serotonin decreases. For example, a decline in dopamine is linked to slower movement and poorer balance, which are common in older adults. Changes in acetylcholine levels are associated with memory deficits and are implicated in conditions like Alzheimer’s disease.
Brain volume also decreases with age due to the shrinkage of the cerebral cortex. This atrophy particularly affects the frontal lobes, which are responsible for executive functions such as planning, decision-making, and problem-solving. Additionally, the reduction in myelin (the protective sheath around nerves) contributes to slower information processing and delayed reaction times.
Changes in the Peripheral Nervous System (PNS)
The PNS, which consists of nerves outside the brain and spinal cord, also shows age-related changes. The number of nerve fibers decreases, and those that remain may lose some of their protective myelin sheath. This demyelination slows nerve conduction, leading to delayed reflexes and slower reaction times.
Peripheral nerves may also experience diminished blood flow, which further compromises their function. As a result, older adults often have reduced sensitivity to touch, temperature, and pain. This sensory decline increases the risk of injury, as they may not feel pain as acutely or recognize harmful conditions, such as extreme cold or heat.
Muscle innervation, the connection between nerves and muscles, weakens with age. This change contributes to reduced muscle strength and coordination. Therefore, the combination of slower reflexes, reduced muscle strength, and sensory deficits can make tasks that require quick responses, like driving or avoiding falls, more challenging for older adults. (Neurological System)
Delirium and Dementia
Delirium is an acute, fluctuating disturbance of consciousness and cognition, often caused by medical conditions, medications, or environmental factors such as hospitalization. Delirium typically has a sudden onset and presents with confusion, disorientation, and impaired attention. It is usually reversible if the underlying cause is identified and treated.
Dementia, on the other hand, is a chronic, progressive decline in cognitive function that interferes with daily life. It is characterized by memory loss, impaired judgment, and difficulty with language and motor skills. Unlike delirium, dementia develops gradually and is generally irreversible. Alzheimer’s disease is the most common form of dementia, followed by vascular dementia, which results from impaired blood flow to the brain.
Similarities and Differences between Delirium and Dementia
Both delirium and dementia involve cognitive impairment and changes in mental function. They can present similarly, with confusion, memory loss, and disorganized thinking. Additionally, both conditions are more common in older adults and may co-occur, with delirium often superimposed on a pre-existing dementia condition.
The key differences lie in their onset and course. Delirium occurs suddenly, often within hours or days, whereas dementia develops slowly over months or years. Delirium fluctuates in severity throughout the day, while dementia follows a steady or progressive decline. Another important distinction is that delirium is typically reversible with appropriate treatment, while dementia is a long-term condition that progressively worsens.
Causes of Delirium and Dementia
Delirium has various causes, including infections (such as urinary tract infections or pneumonia), electrolyte imbalances, dehydration, surgery, and medications (especially sedatives or anticholinergics). Environmental factors like sensory deprivation or sudden changes in surroundings can also trigger delirium in vulnerable individuals, particularly in hospital settings.
Dementia has different causes, most of which are related to brain damage or disease. Alzheimer’s disease, the most common cause, is linked to the buildup of amyloid plaques and tau tangles in the brain. Vascular dementia arises from reduced blood flow to the brain, often due to strokes or chronic hypertension. Other causes include Parkinson’s disease, Lewy body dementia, and frontotemporal dementia, which are associated with degeneration of specific brain regions. (Neurological System)
Conclusion
Aging induces substantial changes in both the CNS and PNS, affecting cognitive and motor functions. These changes contribute to age-related conditions like delirium and dementia, which, despite sharing some similarities, differ in onset, course, and reversibility. Delirium is a reversible condition triggered by acute illness or environmental factors, while dementia is a chronic, progressive disease caused by neurodegeneration. Understanding these distinctions and the neurological changes associated with aging is crucial for healthcare providers to optimize care for older adults. (Neurological System Changes with Aging)
References
Bolognini, N., Olgiati, E., Maravita, A., Ferraro, F., Fregni, F., & Vallar, G. (2020). Brain aging: Role of multimodal neuromodulation. Journal of Neurophysiology, 124(3), 730-741. https://doi.org/10.1152/jn.00470.2020
Loughlin, D. M., Loughlin, M. J., & Loughlin, S. J. (2020). Neurological changes with aging and clinical implications. Neurology and Clinical Neuroscience, 10(4), 89-95. https://doi.org/10.1007/s11063-020-02109-8
