AANN Core Curriculum, 7th Edition, Ch. 9 Consciousness: Digital Version-Chapter 9

Chapter 9

Pdf Summary

The chapter reviews disorders of consciousness (DOC), delirium, and dementia as distinct clinical conditions.

<strong>Severe DOCs</strong> reflect impaired wakefulness, awareness, or both. In <strong>coma</strong>, patients are neither awake nor aware: their eyes do not open spontaneously, and they cannot be aroused. In <strong>unresponsive wakefulness syndrome (vegetative state)</strong>, sleep–wake cycles and arousal are preserved, but there is no behavioral evidence of awareness. In a <strong>minimally conscious state</strong>, patients show limited but definite, sometimes inconsistent, signs of awareness, such as visual pursuit, purposeful reaching, or words. Standardized, repeated assessments help reduce misdiagnosis.

<strong>Delirium</strong> is an acute, fluctuating disturbance of attention and cognition. Its motor subtypes are <strong>hyperactive</strong>, <strong>hypoactive</strong> (often the most common in hospitalized older adults), and <strong>mixed</strong>; nonmotor delirium is also recognized. Risk factors include older age, dementia, severe illness, surgery or trauma, sedatives and other medications, infection, metabolic abnormalities, transfusions, substance use, constipation, sleep loss, malnutrition, sensory impairment, and lack of environmental cues. Prevention emphasizes treating underlying causes and multicomponent, nonpharmacologic care: orientation, mobility, support for hearing and vision, hydration, and sleep. The adult ABCDEF bundle also addresses pain, sedation, breathing trials, delirium, exercise, and family engagement.

<strong>Dementia</strong> causes cognitive decline that interferes with daily or social functioning. Alzheimer disease, the most common type, involves amyloid plaques, neurofibrillary tangles, and progressive brain atrophy. Vascular dementia results from cerebrovascular disease and often prominently affects executive function. Lewy body dementia commonly features fluctuating cognition and visual hallucinations. Frontotemporal dementia involves frontal and temporal lobe degeneration, often causing changes in personality, emotion, or speech. Parkinson disease dementia is associated with Lewy bodies and may include hallucinations.

Dementia management combines appropriate medication with practical support: use simple, reassuring communication, routines, memory aids, and meaningful activities; assess behavioral changes for causes such as pain or unmet needs; and address safety, nutrition, hydration, and daily care. Caregiver education, respite, and community support are important.

Keywords

disorders of consciousness

coma

unresponsive wakefulness syndrome

minimally conscious state

delirium

hypoactive delirium

dementia

Alzheimer disease

Lewy body dementia

frontotemporal dementia