What is Differentiating Delirium Versus Dementia in the Elderly?
Changes in mental state are common in elderly people, usually associated with the ‘3 Ds’ – delirium, dementia, and depression. Out of these, delirium and dementia are observed most often. Often these two terms are used interchangeably, which can lead to confusion. It’s vital to realize that delirium and dementia are separate conditions, each with their own prognosis and treatment methods.
Generally speaking, if someone’s state of confusion develops quickly over days or weeks and fluctuates, it’s likely to be delirium. However, if someone’s confusion is persistent and worsens over time, it’s more likely to be dementia. Distinguishing between these conditions can often be complicated when dealing with persistent delirium and reversible dementia. A person’s cognitive ability is evaluated in six areas: memory and learning, language, executive functioning, complex attention, perceptual-motor, and social cognition.
Delirium is defined by a sudden change in awareness, primarily affecting attention. Dementia, on the other hand, is a cognitive decline that interferes with one or more cognitive domains. Delirium usually involves a sudden onset of disorientation or lack of awareness, while dementia is a slower, gradual process that leads to cognitive impairment, with attention being affected later in the disease’s progress.
Usually, dementia is a brain disease observed in old age and it comes in various subtypes, with the onset age depending on the subtype. Delirium, however, is not tied to any specific age and is more common in older people. It can occur under different circumstances and typically develops over hours to days compared to dementia, which is a slow, gradual process that takes months to years. The two diseases often coexist in elderly people, which sometimes makes them difficult to differentiate, especially if dementia progresses rapidly. It’s essential to identify whether a patient has dementia, delirium, or both. If delirium is added to pre-existing dementia (this is often called delirium superimposed dementia or DSD), it can lead to a longer hospital stay, faster cognitive and functional decline, higher healthcare costs, and increased risk of death.
What Causes Differentiating Delirium Versus Dementia in the Elderly?
Delirium is a condition that can be caused by various factors. It is more common in people over 70, men, and individuals with dementia. Certain things are known to trigger it, including medications, sudden illness, infections, and the worsening of ongoing health problems.
Dementia, on the other hand, is a brain disorder that happens due to the buildup of certain proteins or ongoing damage to the brain. It usually happens naturally over time, but can sometimes be due to genetics, like in Alzheimer’s disease. In rare cases, it could be due to infections caused by malformed proteins, like in Creutzfeldt-Jakob disease. Research has shown that delirium is a potential risk factor for developing dementia.
Risk Factors and Frequency for Differentiating Delirium Versus Dementia in the Elderly
Delirium becomes more common as people age. For people living in their own homes, the occurrence is low, at about 1% to 2%. But, it goes up to 8% to 17% for older individuals who show up at the emergency room. It’s even higher, at about 40%, for people living in nursing homes. Alzheimer’s Disease (AD) is the most common kind of dementia, followed by vascular and Lewy body dementia (LBD). For people under the age of 65, the second most common type of dementia is the Frontotemporal type. Another condition, DSD, can occur in 22% to 89% of people in hospitals and living in communities. But it’s often not diagnosed properly. A study found that only 21% of nursing staff could recognize one type of delirium, called hypoactive delirium.
Signs and Symptoms of Differentiating Delirium Versus Dementia in the Elderly
The process of diagnosing conditions like delirium and dementia usually involves a medical history and physical examination. It’s essential to gain insights from both the patient and their family members about the patient’s mental and physical health before they started showing symptoms. This gives the professionals a solid reference point to start from. Next, the rapidity of symptom onset and the progression timeline are determined. Once these details are available, the doctor performs a brief cognitive screening using tools like the Mini-Cog and the Short Portable Mental Status Questionnaire.
According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the criteria for diagnosing delirium are:
- Sudden development of disturbances in attention and awareness that vary in intensity
- At least one more cognitive disturbance
- Disturbances cannot be attributed to a pre-existing case of dementia
- Disturbances are not happening concurrently with a severely reduced level of consciousness or coma
- There are indications of an organic cause or causes underlying the symptoms
The DSM-5 also lists the following criteria for diagnosing dementia:
- A significant drop in cognitive abilities from the baseline, involving one or more cognitive domains. This can be based on the patient’s report, the caregiver’s account, or the results of neuropsychological testing
- The cognitive impairment is clearly affecting the patient’s ability to carry out their daily routines
- The cognitive decline isn’t happening exclusively during an episode of delirium
- The cognitive decline cannot be explained away by any other medical or psychiatric condition
Testing for Differentiating Delirium Versus Dementia in the Elderly
Delirium, sometimes called “acute brain failure,” needs quick assessment, while dementia is a slower-onset condition that requires a more detailed evaluation over time. To confirm delirium, you need to see evidence of a change in the person’s mental state. This evidence could come from their history, a physical exam, medical results, or lab tests. This change should be a direct result of an underlying health issue, a reaction to a substance or medication, or a mix of these issues.
A significant sign to look for in diagnosing delirium is the sudden change and fluctuation in the person’s mental condition compared to their usual state. The Confusion Assessment Method (CAM) algorithm is often used in diagnosing delirium. This CAM algorithm looks for features like sudden and fluctuating symptoms, lack of attention, and disorganized thinking or confused state of mind. Another quick method, called the 3-Minute Diagnostic Assessment (3D-CAM), that includes 20 items to check, has a high rate of accuracy when compared with standard ratings in a study of hospitalized patients.
A skilled professional must conduct a cognitive test to reach a more clear diagnosis. To assess for delirium, the doctor should use the CAM algorithm and check for any organic causes or contributors to the delirium. A detailed workup, including scans and tests, might need to cover toxic, metabolic, and infectious conditions. Somewhat rarely, we might use a procedure called a lumbar puncture if there’s concern about an inflammation in the brain. Inflammation is believed to be a significant contributor to delirium, but no inflammation markers have been validated for use in diagnosing delirium so far.
On the other hand, when a possibility of a quick-onset condition like delirium has been excluded, patients who are suspected of having dementia should be examined thoroughly by a neurologist. This examination should include neurocognitive testing and brain imaging studies to help make a more accurate diagnosis. Brain imaging could include techniques like magnetic resonance imaging (MRI) and others to find patterns of brain degradation and identify low-functioning brain areas. Some other diagnostic techniques might be used for specific conditions, and very occasionally, genetic testing might be done for cases with a potential genetic cause.
Treatment Options for Differentiating Delirium Versus Dementia in the Elderly
Once the cause or causes of delirium are found, the main course of treatment is non-drug related. This often means reducing or cutting out medications that can impact the brain’s functioning or induce chemical imbalance, helping the patient become familiar with their surroundings, and creating a peaceful, comforting environment. If the patient has hyperactive delirium, medications might be necessary. The American Geriatrics Society has released guidelines for preventing and treating delirium after surgery. For those with Alzheimer’s disease, medications that help with memory and cognition, such as galantamines, donepezil, rivastigmine, and memantine, may be used for moderate to severe dementia. The remaining treatment involves supportive care, which focuses on maintaining comfort and quality of life.
What else can Differentiating Delirium Versus Dementia in the Elderly be?
When diagnosing a patient, doctors typically consider several illnesses that might display similar symptoms. For instance, if a patient is showing signs of confusion or forgetfulness, physicians might examine the possibility of:
- Dementia
- Depression
- Psychosis
- Vitamin B1 and B12 deficiency
- Thyroid disorders
- Infections like HIV and neurosyphilis
These are just a few potential conditions. It’s essential for doctors to thoroughly examine a patient’s symptoms and medical history to make an accurate diagnosis.
What to expect with Differentiating Delirium Versus Dementia in the Elderly
It’s not only important to tell the difference between delirium and dementia, but also to spot when a patient with dementia also develops delirium. This is because the situation can lead to longer hospital stays, a quicker decline in cognitive and physical abilities, higher healthcare costs, and sadly, in some cases, death. Generally, the outlook for patients with delirium isn’t very positive. However, it can be prevented in around 30% of cases.
Research has shown that patients who develop delirium in intensive care units have up to two to four times the usual risk of dying. Similarly, there’s up to a 1.5 times higher risk of death within a year after hospitalization for those admitted to general medical services, geriatric services, and nursing home residents who have other serious health issues like stroke or dementia.