Dementia with Lewy bodies is a neurodegenerative disorder that results in progressive intellectual and functional deterioration. There are no known therapies to alter the course of dementia with Lewy bodies. Average survival after the time of diagnosis is about 8 years. In a retrospective analysis of 243 autopsy-confirmed cases of Lewy body dementia and Parkinson dementia, the presence of cognitive fluctuations early in the course of the disease, older age at onset, and hallucinations at onset were associated with a shorter survival time (Jellinger et al 2007).
Patients with this form of dementia often respond well to medications that may improve the cognitive and neuropsychiatric symptoms and, to a lesser extent, motor symptoms. However, approximately 50% of individuals with Lewy body dementia experience severe sensitivity to the side effects of antipsychotic medications, both traditional and atypical, as manifested by worsening parkinsonism, immobility, increased confusion, unresponsiveness, and heightened autonomic instability (McKeith et al 2005). A longitudinal study of individuals with mild dementia in western Norway found that the median time until nursing home placement of those with a diagnosis of Lewy body disease (n=43) was 663 days (range=342-984 days) (Rongve et al 2013). The use of cholinesterase inhibitors was associated with delayed institutionalization (hazard ratio [HR] 0.24 [0.70, 0.82]), whereas the use of antipsychotic medication was associated with a markedly increased rate of nursing home admission (HR 37.3 [4.35, 320,64]).
Autonomic dysfunction is also an underrecognized complication of dementia with Lewy bodies. Patients commonly complain of dizziness and will frequently be found to have orthostatic or spontaneous fluctuations in blood pressure, cardiac dysrhythmias, constipation, detrusor hyperactivity, and incontinence. Blood pressure should be carefully monitored over time and antihypertensive medication doses adjusted or discontinued as necessary.
Lewy body dementia progresses into severe dementia and ultimately eliminates a person's ability to speak or move. The most common cause of death is pneumonia or other primary infection. This is usually brought on by dysphagia, inhaling food or drink into the airway, from a catheter inserted into the body, and/or from becoming bedridden. Infection also may be introduced by a urinary catheter (urinary tract infection). As the disease advances, people may lose all ability to care for themselves. They may have difficulty eating, become incontinent, or be unable to take a walk and find their way back home. Other problems will come about by falls and related injuries. Patients may become disoriented or have tremor or gait problems. These can lead to head injuries and fractures. Surgical risks increase in the elderly, as does the risk of pulmonary embolus with prolonged immobilization.