It’s not all Alzheimer’s
Dementia is an umbrella term for cluster of symptoms. Alzheimer’s is an example of one type of dementia, and is a specific disease. Below are some other examples of specific diseases that fall under the category of dementia.
- Today, approximately 5.3 million people suffer from Alzheimer’s disease. Visuospatial skills tend to deteriorate earlier than vocabulary and motor function, which are not usually affected until later in the disease process. Since individuals with Alzheimer’s disease suffer from memory loss and other cognitive deficits, they frequently lack insight into the severity of their disease. This leads to issues with driving safety, among other things. A person usually will have a normal neurological examination early in the disease but will develop muscular weakness later. They often die when the muscles used to swallow no longer function. Patients with Alzheimer’s disease also have an increased risk of seizures.
- Alzheimer’s disease is conceptualized as being composed of a number of stages. The first stage typically is not associated with any measurable cognitive decline. In later stages of disease progression, behavioral symptoms often are accompanied by agitation. Patients with Alzheimer’s disease can suffer delusions, but hallucinations are not considered to be a classic sign of Alzheimer’s and would be considered fairly unusual.
- People with Alzheimer’s can be lost in time. In the absence of something familiar to orient them or resonate with them, it can be shocking how lost people can become. Physicians who treat patients with Alzheimer’s have witnessed many cases of patients who have regressed to childhood and have begun to speak with certainty about long-dead parents, as if the parents were still alive and about to come home at any minute.
Early Onset Alzheimer’s Disease also known as young onset Alzheimer’s disease
- Alzheimer’s is not just a disease of old age. Younger-onset (also known as early-onset) Alzheimer’s affects people younger than age 65.
- Early onset Alzheimer’s disease often is confused with early-stage Alzheimer’s disease which is an entirely different disease. The difference is that early onset affects people younger than age 65. Early-stage simply means that it is the beginning stages of Alzheimer’s disease which usually affects older adults.
- It’s often quite difficult to get an accurate diagnosis of young onset Alzheimer’s disease. Very often, people are misdiagnosed with stress, depression, or multiple conflicting diagnoses. Getting a diagnosis is made even more difficult because of the individual variations of the disease. If you suspect you or your loved one has young onset Alzheimer’s disease, you should reach out to a neurologist to specializes in memory disorders. And, you should bring a list of symptoms, even if they seem unrelated, so that the doctor can have the most information available.
- There are a few genetic variations of young onset Alzheimer’s disease. Many of the varieties can be traced to a few hundred families throughout the world. For more information check out https://dian.wustl.edu/.
- There’s a clear correlation between cardiovascular disease and dementia. Prevention, maintaining a heart-healthy lifestyle, and early identification of cardiac disease are critical for mitigating your risk for vascular dementia and other insults to the brain such as stroke.
- Vascular dementia can vary widely from person to person because the clinical presentation depends on the part of the person’s brain that was affected by the stroke. Even when the same part is affected, there always are individual differences in presentation.
- Vascular dementia frequently presents after a stroke, but it is not always true that a clear cerebral event predates the development of vascular dementia. Often, a clinician might notice other signs of vascular disease to help make this diagnosis. Keep in mind that vascular dementia can develop suddenly following an obvious large stroke or it can develop silently through small “silent” brain infarctions. This type of dementia frequently coexists with Alzheimer’s disease, as they share most of the same risk factors.
Lewy Body Dementia
- Lewy body dementia is a serious disease in its own right, but the presence of Lewy bodies does not necessarily mean that a person has Lewy body dementia. Many scientists consider Lewy body dementia and Parkinson’s disease to fall on a spectrum because there is a presence of Lewy bodies in both diseases. However, there are clinical and practical differences in the way the diseases manifest and progress.
- Sometimes, people with Lewy body dementia are misdiagnosed with diseases such as. Atypical Alzheimer’s disease with Parkinsonism, or Frontotemporal dementia. Commonly, however, people with Lewy body dementia have prominent complex hallucinations, difficulty judging distances, confusion between reality and TV, and intermittent periods of lucidity.
- One of the telltale signs of Lewy body dementia is a very poor reaction to antipsychotic medications like Haldol. These medications, when administered to a person with Lewy body dementia, can leave them very subdued and “locked” into one position for days, drooling and unable to move his body at all. This type of reaction to an antipsychotic medication is virtually diagnostic of Lewy body dementia and separates it from all other types of dementia.
- Fluctuating cognition and visual hallucinations are a hallmark of Lewy body dementia. Signs and symptoms can be consistent with Parkinson’s disease, such as tremors, a shuffling gait, and falls.
- Visual hallucinations occur in two-thirds of patients with Lewy body dementia, but they are very rare in patients with Alzheimer’s disease. In fact, visual hallucinations in dementia have an 83 percent positive predictive value for Lewy body. REM sleep behavior disorder is another strange but intriguing manifestation. A person with a healthy brain will not move very much during REM sleep, but a person with Lewy body dementia might kick, punch, or thrash about the bed, much to the consternation of his or her partner.
- Lewy body dementia can look a lot like Parkinson’s disease. Imaging studies are not usually very helpful in making the diagnosis, even with identification of Lewy bodies. Lewy bodies are found in Parkinson’s disease, Lewy body dementia, supranuclear palsy, Parkinson’s disease with dementia, and multiple system atrophy.
Parkinson’s Disease Dementia
- Parkinson’s disease (PD) is a neurodegenerative disease resulting in the loss of dopamine-producing cells in a region of the brain called the substantia nigra. To have a diagnosis of Parkinson’s disease a patient needs to have a tremor, rigidity, or slow movement (bradykinesia). A clinical response to the medication L-dopa also is strongly supportive of the diagnosis. Atypical Parkinson’s disease can be a challenge to diagnose and manage, but it can be helpful to know that there is a wide variety of clinical presentations possible with Parkinson’s disease. Parkinson’s disease often evolves into Parkinson’s disease dementia, as cognitive dysfunction is common in many patients with Parkinson’s disease.
- Parkinson’s disease and Parkinson’s disease dementia both require regular dosing of dopamine to account for the loss of dopamine-producing cells.
- Parkinson’s disease is not a risk factor for Alzheimer’s disease per se, but it can coexist with Alzheimer’s disease. It also is important to note that although a resting tremor is a classic feature of Parkinson’s disease, a tremor alone is not necessarily indicative of that disease. The degree to which a patient can control the tremor can help clarify. For example, if a patient is able to steady his hand when his attention is drawn to the tremor, this is often indicative of Parkinson’s disease. However, if the tremor worsens when the patient’s attention is drawn to it, then the tremor is likely to be benign and not from Parkinson’s disease.
Frontotemporal Dementia (Pick’s Disease)
Frontotemporal dementia usually will have frontal and temporal lobe atrophy visible on brain imaging and can be seen by CT, MRI, or PET scan. PET scans also show decreased function of the frontal and temporal lobes. Patients with FTD tend to be younger, often in their late 40s or 50s. They also tend to exhibit very poor judgment, socially inappropriate behavior, and very poor executive functions. There are three common and distinct presentations:
- Behavioral variant FTD (bv FTD)—50 percent of FTD cases.
- Primary progressive aphasia (PPA)—nonfluent variant
- Primary progressive aphasia (PPA)—semantic variant
Behavioral variant frontotemporal dementia is the most common subtype and is responsible for about half of the cases of FTD. The hallmark of this subtype is a change in personality and behavior. Symptoms include disinhibition, apathy, loss of empathy, a compulsive change in diet, and compulsive behaviors. Patients with primary progressive aphasia present with a type of language impairment. In the nonfluent variety of frontotemporal dementia, a patient has difficulty making sounds with their mouth. In the semantic variant, a patient will be able to form sounds but will lose the ability to comprehend single words.
- Alcohol is its own independent risk factor for dementia, with more than half of chronic alcohol abusers suffering a measurable cognitive deficit on neuropsychological testing. Structurally, there is evidence that chronic alcohol abuse is associated with degeneration of several different anatomical areas, but nutritional deficiencies also generally play a role. Researchers have been unable to prove that alcohol alone causes nerve degeneration.
- Often, people have more than one type of dementia. There are multiple interrelated causes. This often is called mixed dementia or dementia-other. Mixed dementia has a higher incidence of depression than AD.
Chronic Traumatic Encephalopathy
- A patient sustaining multiple concussions can develop what is called chronic traumatic encephalopathy (CTE), which can lead to cognitive impairment, personality changes, depression, behavior changes, and even suicidal or homicidal thoughts.
- Patients sometimes also exhibit Parkinsonism, a term used to refer to a condition that mimics the features of Parkinson’s disease, including abnormalities of speech and gait.
- With repeated concussions, the brain is damaged.
- Tau protein and neurofibrillary tangles can develop in the brains of CTE patients, but they collect in a different pattern than what is seen in other dementias. One big difference is that the neurofibrillary tangles observed in patients with CTE are seen in the superficial cortical layers on the periphery of the brain, as opposed to within deeper structures as seen with other dementias that also involve tau. These differences help to separate CTE from the other dementing illnesses on autopsy.