Depending on the exact cause of the dementia the presenting signs and symptoms may vary. Short-term memory loss is common as evidence by forgetting recent events. The early stages of dementia are characterized by forgetting where items were placed, asking questions repeatedly, and having difficulty learning new information.
It is at times difficult to differentiate between normal aging and dementia. Normal aging is characterized by slowness in the retrieval of information. Those with dementia have difficult time recording new information. For example, the aged individual may have a hard time recalling the name of a friend they have not seen in a long-time. Those with dementia can be told something and not recall it. A husband may tell his wife (who has dementia) that friends are coming over for dinner and the wife will not remember this fact when the friends arrive.
Using words incorrectly, difficulty finding the right word or using general words to describe a specific item is a trait of dementia. A demented person uses the word "thing" to describe many items. Personality changes, making poor decisions, and mood swings are common symptoms of early dementia. Increased confusion at night, also known as sun-downing, is a common feature of early dementia.
Patients with early dementia are able to compensate well when they are in familiar environments. Problems are often first noticed when one gets out of his or her routine such as going on vacation or entering the hospital. Patients often become very anxious, depressed, scared, or have emotionally liable moods. These moods are often the direct results of the patient being aware of the progressive dementia.
As the disease progresses the patient has difficulty carrying out tasks of daily living such as bathing, handling finances, grooming, dressing, and preparing meals. This is the point at which independence is significantly impaired and a patient will need to adjust their living environment.
Those with advanced dementia are dependent on others for care. They have a very limited memory and usually are not oriented to place, time, and often name. Patients with “advanced dementia” may not know the name of his or her spouse or children.
Loss of the swallowing reflex is a common complication of advanced dementia, which leads to medical complications such as malnutrition and aspiration pneumonia. It has not been found that feeding tubes reduce the rates of aspiration pneumonia in the demented patient.
Malnutrition decreases the ability to fight off infection and increases the risk of death from infection. Loss of the swallowing reflex increases the risk of dehydration. Patients with advanced dementia have more seizures.
Behavioral changes are more common as dementia advances. Mood swings, with the patient going from calm and pleasant to completely out of control within minutes can occur. Personality changes are seen in dementia with the demented patient showing an increased incidence of irritability, suspiciousness, and fearfulness. Hallucinations and delusions are hallmarks of advancing dementia. Hallucinations are misinterpretation of sensory stimulus. They can include seeing things that are not there such as dead relatives or hearing voices when there are none. Delusions are fixed, false beliefs. Common delusions include thinking people are out to get them, thinking that someone is trying to poison them, or believing they are God.
Clinical history and exam can help differentiate between some of the different types of dementia. Alzheimer’s is the most common dementia and therefore the most likely diagnosis when a dementia presents. Some salient features of Alzheimer’s include: early memory loss with cognitive impairment and at least one other area deficit such as language dysfunction, agnosia, apraxia, visuospatial disorder, and executive dysfunction. It typically has an insidious onset and a progressive course. Memory impairment is highlighted by a storage deficit; patients are not able to recall something with a clue. For example, if you are performing the mini-mental status exam (MMSE) and the patient is asked to recall three items after five minutes, the patient will not be able to recall them even after you give them a clue. As the disease progresses long-term memory becomes impaired. Later changes also include seizures, apathy, aggression, wandering, agitation, depression, and anxiety.
Vascular dementia can have either an abrupt or insidious onset and the progression can be stepwise, fluctuating, or a continuous decline. Patients with vascular dementia typically have cardiovascular risk factors such as hypertension, hyperlipidemia, and diabetes. Focal neurological deficits are common in those with vascular dementia. Memory impairment is not as pronounced in the early stage, whereas “executive function” (concentration, decision making, and higher-order problem solving) is impaired early.
Dementia with Lewy bodies (DLB) accounts for 10-15% of cases. DLB typically presents with memory loss. It is difficult to differentiate between DLB and Parkinson's disease with dementia. If the onset of dementia is within one year of Parkinson's disease than the most likely diagnosis is DLB. If the onset of dementia is greater than one year from the onset of Parkinson's disease, than the likely diagnosis is Parkinson's disease with dementia. DLB is more associated with the Parkinson's symptoms of masked faces and postural instability as opposed to tremor. Other features noticed with DLB are a fluctuating cognitive course, early impairment of executive function, more problems in attention, visuospatial function and constructional abilities when compared to AD and more autonomic involvement. Patients typically have “recurrent visual hallucinations”. There is often repeated falls and occasional syncope.
Frontotemporal dementia (FTD), characterized by a shrinking of the frontal and temporal anterior lobes of the brain, often presents with personality and behavioral changes over memory loss, at least early on. This disease runs in families. Symptoms of FTD fall into two clinical patterns that involve either changes in behavior or problems with language. Patients are typically impulsive, act socially unacceptable, disinhibited, lack insight, and are agitated or socially withdrawn. Those with language disturbance have difficulty speaking or understanding speech. Frontotemporal dementia occurs at a younger age than does Alzheimer’s, typically between the ages of 40 and 70.
The need to evaluate for dementia can be picked up during a routine examination, from patient or family concern or from routine screening. The work-up includes performing a mental status examination. Standardized tests can be used to document mental decline, monitor decline and help make the diagnosis. Mental status examinations test the patient's memory and intellectual function. These tests look for memory impairment, language disturbance, ability to carry out purposeful movements, and ability to recognize objects. Mental status exams ask the patient to report the date and location, recall lists of items, write sentences, follow written commands, name objects, and copy diagrams. The American Academy of Neurology recommends the use of the mini-mental state exam (MMSE) or the memory impairment screen as tools to screen for dementia. However, the MMSE offers no suggestions as to how much assistance the person might need in daily life, nor does it try to apply the deficit in a cognitive area to practical living.
Scores on the MMSE range from 0 to 30, with scores of 25 or higher being traditionally considered normal. Scores less than 10 generally indicate severe impairment, while scores between 10 and 19 indicate moderate dementia. Those with Alzheimer’shave on average a decline in the MMSE score. The MMSE of 3-4 points per year occurs if they go untreated. It is important to note that one needs an IQ of about 90 to get a normal score on the MMSE.2
The MMSE takes about 10 minutes to complete, It measures aspects of cognition that include orientation, word recall, attention and calculation, language abilities, and visual construction. Scores may need to be adjusted or interpreted differently to account for a person's age, educational level, and ethnicity/race.
Other testing is often employed. Early changes in mental decline are often not picked up on the MMSE. If the spouse or caregiver notices changes and the MMSE is normal, more sensitive testing may need to be employed. If the diagnosis is in doubt then more extensive testing, known as neuropsychological testing, typically done by a specialist, is performed.
Neuropsychological testing is a more comprehensive method for the evaluation of mental status. Testing is done by a neurologist, psychiatrist, or psychologist. It looks at higher cognitive functions including but not limited to abstract, logical, and conceptual reasoning, visuospatial orientation, memory, verbal fluency and reasoning. The test identifies cognitive impairment in patients with higher baseline cognitive abilities and determines if dementia is present in its milder stages. It is more sensitive than other types of testing and can differentiate between mild cognitive impairment and dementia. The test is helpful for those who do not speak English as their native language and those with limited education. It also can help pick up anxiety and depression.
The work up of dementia rules out other causes of mental decline and consists of imaging and laboratory evaluation. The two most highly recommended tests include a vitamin 12 level and a thyroid test. Other testing is up to the individual health care provider and may include a complete blood count, glucose, kidney function test, electrolyte tests, and liver function tests. Other tests can be performed if the patient is deemed at high risk and the clinician has reason to suspect a rarer cause of dementia including: serology for syphilis, HIV testing, genetic testing, Lyme disease titers, testing for heavy metals, urinalysis, erythrocyte sedimentation rate, and serum folic acid. A lumbar puncture is sometimes performed if cerebral Lyme disease, cerebral vasculitis, neurosyphilis, or HIV is suspected as a cause of the dementia.
Testing for depression is critical as memory loss can be one of the manifestations of depression. Depression can present with memory loss and memory loss can reverse with treatment of depression. In addition, depression complicates the course of dementia if they both exist.
Many patients with dementia undergo an imaging examination to rule out other causes of disease. Its ability to identify a reversible cause of dementia is low but non-contrast computed tomography or magnetic resonance imaging is recommended as part of the initial evaluation of a patient with dementia. The use of Neuro –imaging in dementia is most likely helpful in a 61 year-old woman with an MMSE score of 20 and a history of breast cancer. Imaging can rule out brain tumors, subdural hematomas, stroke, or normal-pressure hydrocephalus. Those who are younger than 60, had recent head trauma, a history of cancer, gait disturbance, urinary incontinence, localized neurologic signs or symptoms, or those with a rapid or atypical course of dementia have the greatest chance of having a diagnostic yield from imaging studies. The only way to confirm the diagnosis is to perform a brain biopsy, which is rarely done or necessary.
More advanced testing includes photon emission tomography (PET) scans or single photon emission computed tomography (SPECT) scans. These tests are not routinely done but are often done in research settings to help distinguish between different types of dementia. Current guidelines do not recommend their routine use.
Case 1 - Alzheimer’s
John P is a 73 year-old man with a with a four-year history of memory impairment. His short-term memory is affected the most and needs to be reminded of appointments. He no longer drives after he got lost coming home from the mall 4 months ago. His wife recently took over doing the bills after he neglected to pay a number of bills, a task, which he did without error his whole life. His physical exam was negative, and he scored a 21/30 on the MMSE.
Case 2 - Vascular Dementia
Steve S is a 60 year-old man with history of two heart attacks, hypertension, diabetes and smoking. Seven months ago, he had a stroke and shortly after he was unable to remember phone numbers he had known for years. His wife also noticed he would not call their friends by their names. He later admitted he could not remember their names. He could not operate the riding lawn mower or work the remote control to the television. His examination revealed weakness in this left arm.
Case 3 - Dementia with Lewy Bodies
Mary L is a 74 year-old woman who present to the emergency room after a fall. The emergency room determines that Mary fell when she went to answer the door and saw three children with bloody heads. This was a visual hallucination. Her daughter reports that she has been experiencing slowing down in her thinking and movements over the last few months. Her exam reveals a bruised right knee from the fall. In addition, the physician notices bradykinesis.
Case 4 - Frontotemporal Dementia
Liz F is a 52 year-old woman who has been acting “strange” over the past few months. She was fired from her job because of socially unacceptable remarks and not completing her work. Her exam reveals a woman with poor hygiene and an MMSE of 28/30.