Yoost Ch. 31 Cognition

Normal structure and function of brain and body regions involved in cognitive sensation 

  • Cognition  

  • Knowling influenced by awareness and judgement; comprised of skills such as language, calculation, memory, reasoning, learning, etc. 

  • Lobes of cerebrum 

  • Frontal – voluntary motor function, short-term memory, goal-oriented behaviors, and eye movements 

  • Parietal - receiving, analyzing, and responding to somatic sensory input from different parts of the body. 

  • Temporal - auditory stimuli, as well as long-term memory, balance, taste, and smell 

  • Occipital – visual info 

  • Sensation  

  • A feeling, within or outside the body, of conditions resulting from stimulation of sensory receptors.  

  • Reticular activating system (RAS) - area of brain that controls alertness and attention 

  • General senses – touch, pressure, pain, heat, cold 

  • Special senses – smell, taste, hearing, equilibrium, vision 

  • Decussate – when sensory impulses cross over (in spinal cord?) to the other side of the body before reaching the brain 

  • General senses of touch, pressure, temp, pain 

  • Tactile (touch and pressure) receptors, or those detectable by touch, are located in the dermis and subcutaneous tissue. 

  • Warm vs cold receptors 

  • Warm: skin receptors respond to moderately warm (more than 25° C [77° F] but less than 46° C [114° F]) temperature changes. When the warm receptors in the dermis are exposed to a temperature above 48° C (118° F), the body senses burning pain. 

  • Cold: Cold receptors deep in the epidermis react when the body is exposed to temperatures between 10° C (50° F) and 40° C (104° F). When the external temperature gets too cold, freezing pain is sensed. 

  • At moderate temperatures, both warm and cold receptors send input to the brain 

  • Special senses of smell, taste, hearing, equilibrium, vision 

  • Sense of taste (gustation) - chemoreceptors must come in direct contact with stimulus – on taste buds, roof of mouth, and throat 

  • Right and left seventh cranial nerves and right and left ninth cranial nerves transfer taste information to the brain, where it is analyzed 

  • Hearing  

  • Inner and middle ear 

  • Auricle – eardrum – ossicles (3 bones) middle ear – oval window – fluid of inner ear – labyrinths – left/right CN8 (vestibulocochlear nerves) 

  • Semicircular canal (2nd set of labyrinths in inner ear) - equilibrium  

  • Eyes  

  • Rode – vision in the periphery and dim light 

  • Cones – color and detail  

  • Left/right CN2, optic nerves, and occipital lobes of cerebrum 

Alterations in structure and function associated with impaired cognition and sensation 

  • intro 

  • # of neurons dec w age causing gradual decline in ability to interpret sensory stimuli in the brain causing change in tactile and special senses 

  • Affects cognition, causing slower response time 

  • Doesn't affect judgement, language, or independence  

  • Cognitive Alteration 

  • Cognitive impairment: disorientation, loss of language and/or simple arithmetic skills, poor judgment, and memory loss 

  • Not normal part of aging 

  • Delirium – a reversible state of acute confusion 

  • Disturbance in consciousness or change in cognition developing over 1-2 days caused by medical condition 

  • s/s: Fluctuating awareness, impairment of memory and attention, disorganized thinking, hallucinations, and disturbances of sleep-wake cycles 

  • Causes: sensory overload, drug or alcohol use, the side effects of medication, infections, fluid and electrolyte imbalances, low oxygen level, and pain 

  • Depression 

  • mood disorder characterized by a sense of hopelessness and persistent unhappiness.  

  • Signs and symptoms: loss of interest, sadness for an extended period of time, decreased self-esteem, sleeping too much or insomnia, and changes in eating patterns.  

  • Major depression is characterized by symptoms on most days for 2 weeks. This type of depression is often triggered by a life situation.  

  • Persistent depressive disorder is when symptoms are present for at least 2 years, but might vary in severity. With both types of depression, the symptoms interfere with daily living 

  • Dementia  

  • permanent decline in mental function, has a subtle onset.  

  • characterized by the decline in many cognitive abilities, including reasoning, use of language, memory, computation, judgment, and learning. 

  • Alzheimer's – most common type of dementia 

  • Degenerative, pathologic changes occur in the brain 

  • amyloid plaques - protein fragments that build up between the nerve cells of the brain, blocking electrical impulses and chemical connections between neurons.  

  • Development of neurofibrillary tangles - which are twisted fragments of protein within the cells that clog nerve cells and interrupt nutrient delivery to the brain cells.  

  • Brain shows marked cerebral atrophy, a decrease in the size of the brain 

  • Lewy body dementia, which includes Parkinson’s disease dementia and dementia with Lewy bodies 

  • 2nd most common type 

  • Behavioral problems that arise in dementia patients include wandering, agitation, repetitive behaviors, sundowning (worsening of agitation and confusion in the evening; Box 31.2), and verbal or physical outbursts. These behaviors can result from frustration, confusion, fear, anxiety, or lack of control. 

  • Sundowning  

  • Several factors may contribute to increased confusion and behavior problems that occur in many Alzheimer’s patients later in the day and into the night: 

  • • Brain changes causing a mix-up between day and night 

  • • Exhaustion at the end of the day of both the patient and the caregiver 

  • • Reduced ability to see due to dim lighting 

  • • Inability to distinguish between dreams and reality 

  • Strategies to deal with sundowning: 

  • • Keep the home well lit during awake hours. 

  • • Keep on a consistent schedule. 

  • • Avoid alcohol, caffeine, and nicotine. 

  • • Approach the patient in a calm, reassuring manner. 

  • • Anticipate needs (toileting, thirst, etc.). 

  • • Reorient the patient to person, place, and time of day. 

  • Strokes AKA cerebrovascular accident (CVA) occurs when an area of the brain is deprived of blood flow. 

  • two types: (1) ischemic stroke caused by narrowing of a vessel or embolism (blood clot) blocking a vessel; and (2) hemorrhagic stroke caused by bleeding in the brain from a burst aneurysm or traumatic injury. 

  • FAST (face, arm, speech, time) early on with acute ischemic stroke 

  • Loss of balance/coordination on opposite side of the body from the side of the brain damage 

  • Sensory deficits  

  • Tactile  

  • may not be able to feel sharp objects or discern extreme hot and cold temperatures, leaving them vulnerable to injury. Peripheral neuropathy occurs in patients with diabetes mellitus and renal disease. 

  • Arms and legs 

  • Smell  

  • Anosmia is the complete loss of the sense of smell. 

  • Taste  

  • Age cause taste bud decline 

  • Hearing  

  • Presbycusis  

  • Genetics. Other causes of congenital hearing loss are maternal diseases, such as rubella or diabetes, and lack of oxygen at birth. 

  • Vision  

  • Myopia – near sightedness 

  • Presbyopia – farsightedness 

  • Cataracts – cloudiness in eye, cause blurring of vision and usually occur with aging 

  • Glaucoma - pressure on the optic nerve, leading to loss of peripheral visual fields and possibly blindness 

  • Diabetic retinopathy - a complication of diabetes mellitus in which the blood vessels of the retina become damaged 

  • Macular degeneration - the leading cause of visual defects in the United States, affects central vision 

Assessment  

  • Health history – cognitive and sensory focus 

  • Effects of lifestyle on sensory and cognition 

  • Effects of environment  

  • Damage to special sense organs 

  • Effects of medical conditions 

  • Effects of meds 

  • Aspirin can cause tinnitus 

  • Physical assessment 

  • Vital signs 

  • Neuro assessment 

  • Lab tests 

  • Hypocalcemia - tingling and numbness around the mouth and in the fingers – tactile disturbances 

  • hypoglycemia - irritability and have difficulty concentrating. If the level of glucose in the blood becomes extremely low, loss of consciousness, coma, and even death can occur.  

  • If glucose levels are extremely high, diabetic ketoacidosis or diabetic coma may develop. Hyperglycemia  

  • Complications of hyperglycemia that may contribute to cognitive and sensory deficits, such as diabetic retinopathy, peripheral neuropathy, and stroke. 

  • Effects of Age, Illness, Stress, and Trauma on Cognition and Sensation 

  • Mental status and cognitive function 

  • Aging causes loss of neurons. 

  • decreased ability to identify sensations such as pain, touch, pressure, and postural changes.  

  • As aging occurs, reflexes decrease; muscles atrophy; taste, smell, and vision decline; neuromuscular control of gait and posture decreases; and memory and cognitive impairment may occur.  

  • All of these changes may impair cognitive abilities and the person’s response to sensory stimuli 

  • Ability to communicate 

  • Hearing, Vision, Touch, Smell, and Taste 

  • Ability to perform ADL 

Nursing diagnosis 

  • Chronic Confusion 

  • Supporting Data: Alert and oriented to person only; unable to express his needs but repeats questions asked, or responds with unrelated comments; wife states patient wanders frequently 

  • Impaired Verbal Communication 

  • Supporting Data: Alterations of the central nervous system, cerebrovascular accident (CVA), inability to recognize words or understand questions 

  • Risk for Social Isolation 

  • Supporting Data: Alterations in mental status, dementia, sad affect, states “I feel so alone” 

Planning  

  • Patient will continue to respond to his name over the next 48 hours. 

  • Patient will communicate basic needs through the use of photos within 1 week. 

  • Patient will interact with other nursing home residents during planned activities 

Implementation and evaluation  

  • Dynamic  

  • Interventions  

  • Patients w visual alterations 

  • The patient with a visual alteration is oriented to the placement of items in the hospital room. It is best to limit the amount of change in the environment. Furniture is kept in the same place so that the patient can memorize its position. Items that the patient needs are left within easy reach and the nurse confirms that the patient knows the location. The call light is placed within reach so that the patient can call for assistance with ambulation, especially in the first few days of hospitalization. If eyeglasses or other visual assistive devices (such as contact lenses) are used, they should be kept in good working order and be available on the bedside table. Adequate lighting without glare is provided if the patient needs to read print 

  • Evaluation  

Chapter summary  

  • LO 31.1 Describe the normal structure and function of brain and body regions involved in cognition and sensation: Cognitive abilities and nervous system interpretation of sensory input enable individuals to respond to their environment. 

  • LO 31.2 Identify how alterations in structure and function associated with impaired cognition and sensation affect patients’ abilities: Illness, trauma, stress, and aging may cause alterations in cognitive and sensory function. When alterations occur, thought processes may be affected and sensory loss may occur. 

  • LO 31.3 Perform assessments of patients’ cognitive and sensory function: A thorough assessment is crucial for all patients at risk for or experiencing cognitive or sensory alterations. 

  • LO 31.4 Choose nursing diagnoses after analysis of data for patients who need assistance or modifications in care because of cognitive or sensory deficits: Nursing diagnoses are based on the specific deficit and may include Chronic Confusion, Impaired Verbal Communication, and Risk for Social Isolation. 

  • LO 31.5 Generate goals for patients with cognitive or sensory alterations: When planning care for patients with cognitive or sensory alterations, the nurse generates goals that are aimed at patients reaching their full potential. The patient’s abilities and specific deficits are taken into consideration when the nurse establishes outcome criteria. 

  • LO 31.6 Carry out actions to enhance patients’ cognitive and sensory function that can be evaluated after implementation: Nursing care plans are individualized for patients with specific cognitive or sensory alterations to maximize each patient’s capabilities. Evaluation of the plan of care is ongoing.