What is Dementia?

The term “dementia” refers to a group of conditions that deteriorate the brain over time, causing changes in cognition (thinking), behavior, and physical functioning. When the symptoms are severe enough to impact a person’s ability to function independently, dementia can be diagnosed. They are now more commonly referred to as “neurodegenerative diseases” or “major neurocognitive disorders (MND).”The most common form of MND is Alzheimer’s disease, which accounts for 60-80% of all cases of dementia. Behaviorally, Alzheimer’s disease characterized by symptoms of short-term memory problems, communication, reasoning, navigating the environment, and knowing how to use objects. In the end stages, physical functioning is affected, and there may be some drastic changes in personality.

The second most common form is vascular dementia, which can occur when an individual has suffered multiple strokes. Depending on what parts of the brain were affected, the symptoms can appear to be similar to Alzheimer’s disease.

Frontotemporal dementias (FTD) are another category of conditions that are neuropathologically distinct, affecting certain parts of the frontal and temporal lobes. Some individuals with FTD might exhibit early symptoms of personality change with little to no apparent change in their memory. Others might have a marked decline in their ability to express themselves.

Parkinson’s Disease (PD) is a neurological condition affecting motor functions and causes tremors. However, the neuronal pathways affected in Parkinson’s disease can also affect cognition. In some individuals, the symptoms may be severe enough to be considered a “Parkinson’s Dementia.” Additionally, there are a number of other neurological conditions that appear similar to Parkinson’s disease, but have distinct features that indicate other parts of the brain that are not typically affected with a pure Parkinson’s condition are involved.

Lewy body dementia is a condition that has similar features to both Alzheimer’s disease and Parkinson’s disease, and often includes symptoms of psychosis.

Each form of dementia has a distinct pathology, which makes proper diagnosis important when medications are being considered. Additionally, some types of dementia may have a rapid course whereas others have a much slower progression. Knowing what type of dementia one has is important for planning important issues, such as caregiving, safety implementations, and legal matters.

Why is a Proper Diagnosis Important?

Unfortunately, there is no cure for MNDs. However, there are medications to treat specific symptoms associated with dementia. A proper diagnosis of a dementia subtype is important because some medications that may be used for one condition can actually worsen symptoms if the person actually has a different neurological condition. For example, if a person with undiagnosed Lewy body disease (LBD) who is experiencing symptoms of psychosis (delusions or hallucinations) and was misdiagnosed as schizophrenic may be given traditional antipsychotic medications, which can worsen their condition. Using the same example, this person may also have tremors and be misdiagnosed as having Parkinson’s disease, but some anticholinergic medications used to treat the tremors can worsen the symptoms of psychosis. Worsening of symptoms can lead to even more rapid decline and neurodegeneration.

A proper neuropsychological evaluation will examine the clinical history, neurologic and behavioral presentation, and use objective cognitive tests in order to arrive to the most accurate diagnosis of an MND. The neuropsychologist can then refer the patient and family members to the right doctors or organizations to help with treatment and provide support and education. Additionally, the neuropsychologist can work with caregivers to help them understand the limitations of the patient, and determine the most optimal environment to promote well-being and safety.