Dementia is one of the most common neurological disorders affecting millions of people living in the United States. The neurohospitalist is often consulted by medical teams to ascertain the cause of the decline in a person’s cognition. Behavioral decompensation often due to delirium complicating dementia is another common trigger for neurological consultation. Therefore, it is important to recognize the signs and symptoms of dementia in hospitalized patients, as early recognition can allow measures to prevent acute confusional states, treat underlying diseases that can induce dementia, provide symptomatic relief, and facilitate discharge planning.
Ms. JC is a 66-year-old woman who was brought to the hospital with rapidly progressive cognitive decline. She was a teacher before her retirement 2 years previously. At that time, she voluntarily stopped working due to problems with lesson preparation and self-organization. She had difficulties with decorating cakes at which she was previously adept. She also had problems with word finding. One month previously, she had travelled down to Florida. The trip was relatively uneventful except for the fact that it was pollen season in Florida and she had had an exacerbation of her allergies. She presents with signs of a confused state and complains that she cannot recognize people anymore. On the day prior to being brought to the hospital, her daughter had to drive around to find her. She had gone out to walk the dog and had gotten lost. You are asked by the hospitalist team to assess this patient. They suspect the patient has delirium superimposed on a dementing disease.
For practical purposes, dementia has four characteristics:1
Decline in more than one cognitive domain: Cognitive domains are a group of related cognitive functions that are often mediated by the same or similar networks in the brain (we will elaborate on this below). A decline in cognitive functioning often manifests itself as concerns expressed by the patients themselves or an informed care-giver who may have better insight into the patient’s functioning. The importance of collateral history cannot be overemphasized, as anosognosia (unawareness of dysfunction) is commonly associated with dementing disorders. If the patient is on their own in the hospital, it is often worthwhile to call family or the nursing home to get a more reliable and detailed account of daily functioning. Once dementia is suspected, some form of neuropsychological testing should confirm historical insights. In the hospital setting, given the lack of access to inpatient neuropsychology and coexistence of delirium with dementia, it is often not possible to do extensive formal testing. In this case, a short form such as Montreal Cognitive Assessment (www.mocatest.org) supplemented with tailored higher function testing may be useful.
Delirium by itself cannot explain all the symptoms: Whereas dementia is a chronic decline in cognition, delirium is an acute confusional state often due to systemic medical conditions, which are potentially reversible. Common causes may ...