Parkinson’s Disease Dementia

A disease that begins with degeneration of the cells that produce dopamine in the brain, Parkinson’s is the most common of movement disorders. In fact, for the longest time, it’s been considered only a movement disorder, but the dementia associated with it has become more and more common.

Parkinson’s disease dementia (PDD) contributes considerably to the degree of illness and eventually to the end of life, of Parkinson’s patients. PDD has its own list of symptoms and progression, that’s different than Alzheimer’s.

Parkinson’s and PDD are both associated with environmental and genetic factors. One example is a study conducted in 2003 that demonstrated that certain gene mutations were associated with vulnerability to damage by pesticides, which led to Parkinson’s symptoms.

In addition, coffee and cigarette smoke have been studied and seem to delay or prevent the onset of Parkinson’s. (Is there actually something good that comes from smoking?) Plus inherited cases of Parkinson’s seem to be related to mutations in one of several specific genes, and even those that seem to be spontaneous seem to be a result of one of these mutations.

The short answer is that most neuroscientists believe it’s a complex combination of genetics and environment. They’re still seeking answers but don’t have them yet.

The most common symptoms of Parkinson’s disease are the tremors in the hand, leg, foot, jaw, on one side of the body. There’s rigidity of the trunk and limbs that make it hard to balance and move. As a result, falls are common.

And there are other symptoms, like the characteristic shuffling walk, difficulty with speaking, expressionless facial features (they call this facial masking), difficulty swallowing and a stooped posture.

In Parkinson’s disease, the most troubling and unmistakable symptoms that require attention are associated with movement: shuffling gait, tremor, rigidity, postural instability, bradykinesia, and fine motor dexterity.

• Shuffling gait in Parkinson’s looks like the person is dragging their feet, and the steps may be shorter in stride than when the person walked normally. In addition, they typically hold their arms still by their sides.
• Freezing gait is a hesitation before stepping forward. It may be temporary, and the person may return to a normal walking gait soon afterward. It may happen when the individual is about to cross a street, or change directions, or when getting up from a chair. Some say that it feels as if their feet are glued to the floor. This is change tends to contribute to more falls.
• Festinating gait is a shortening and quickening of a normal walking gait. Even though the steps are quicker, the stride is so short that it prevents the individual from making very fast progress. This is often very frustrating for the person with Parkinson’s.
• Tremors is a shaking of the hands, arms, or legs, or jaw, when at rest. Often occurs on one side of the body at the start and may begin with even a single finger before it progresses.
• Rigidity shows up as an abnormal stiffness in one of the limbs or a specific part of the body
• Postural instability refers to difficulty with balance when standing or walking. An example might be stumbling on an uneven sidewalk…this may lead to a fall, since the individual’s ability to right himself is impaired.
• Bradykinesia – “brady” means “abnormally slow” and “kinesia” refers to voluntary movement, so bradykinesia describes the slowed spontaneous movement of someone with Parkinson’s.
• Unwanted Acceleration means that there is speech or movement that’s much quicker than normal, and cannot be slowed down
• Changes in speech such as slowed speech or slurring, and voice softness
• Dystonia is prolonged contractions of muscles that can cause repetitive movements and twisting of the affected body parts
• Impaired dexterity is difficulty with using the fingers. A test for this is
• Restlessness or restless movement: the muscles appear to be jumpy or fidgety
• Difficulty swallowing which can also cause drooling or excessive salivating
• Micrographia is a characteristic “shrinking” of the size of script when writing by hand

All of these symptoms tend to get worse as the years go by. And in some cases, as the symptoms worsen, dementia develops.

Impaired Cognition

Over time, as Parkinson’s advances, depression, anxiety, sleep disturbances, personality and behavior changes as well as sexual problems can develop. But these symptoms don’t necessarily signal dementia.

Parkinson’s disease, of itself, doesn’t interfere or impair the person’s ability to think, make decisions, learn or reason, or remember.

However, in some people with Parkinson’s, one or more of these abilities are affected. When that happens, IF it’s severe enough to interfere with daily living and activities, then it’s diagnosed as dementia.

Thankfully, Parkinson’s disease leads to dementia in only about 20% of cases. When it does develop, it’s ten or fifteen years after the original diagnosis of Parkinson’s. Since Parkinson’s is usually diagnosed in people over 60, dementia emerges in the later years of life. In fact, most of the time when dementia develops, it happens in those who weren’t diagnosed with Parkinson’s until they were 70 or older.

Early Onset Parkinson’s Disease

Even though Parkinson’s disease is usually diagnosed in people who are 60 or older, it doesn’t always happen that way. If someone between the ages of 21-50 is diagnosed with Parkinson’s disease, it’s called Early Onset Parkinson’s. In this younger group, dementia is rare.

The progression of the disease is much slower, too, because these younger people are usually healthy and stronger, and can benefit far more from physical therapy.

Michael J. Fox is a beloved celebrity who was diagnosed with early-onset Parkinson’s disease when he was only 29 years old.

Parkinson’s Disease Dementia Symptoms

But for those who are diagnosed at the age of 70 or older, the disease progression is crueler.

• As the cognitive symptoms develop, you may find it more and more difficult to make decisions. In fact, you may become indecisive…even passive.
• You may find it increasingly difficult to adapt to change and you may seem stubborn about adapting to others, but it’s because the change makes you feel confused
• When you’re in a new place, with unfamiliar surroundings, you may feel confused and disoriented… maybe even agitated
• When you’re trying to learn something new, it is likely to be difficult for you
• You may also find it extremely difficult to concentrate
• Your long-term memory, as well as your short-term memory, will slowly disappear. You can see how the loss of memory would make it hard for you to accurately put a sequence of events in the correct order… you need a working memory to do that. You’ll need people to talk with you in simple sentences, using simple words, because complex language becomes impossible to understand.

There are medications that can help to slow the progression of this PDD, and to lessen the symptoms. But there is no cure yet.

So What Causes Parkinson’s Disease Dementia?

So far, it’s believed that 10% of the cause of PDD is genetic. However, the causes are still a mystery regarding the other 90%. One thing is certain, groups of brain cells in the midbrain change – then die – over a period of time. The result is that the dopamine-making cells are destroyed, so dopamine is no longer produced. Now here’s the problem with that.

Brain cells (neurons) in the substantia nigra segment of the midbrain connect with brain cells in the basal ganglia within which the substantia nigra is located, by releasing dopamine (a neurotransmitter).
When that happens, dopamine, which is a neurotransmitter, helps fine-tune that person’s movements

So you can see, when dopamine-producing cells are destroyed by Parkinson’s disease, movement control is lost. In addition to movement, other functions are lost also that are controlled in this segment of the midbrain. Certain behaviors, learning, and emotion are managed in this part of the brain also.

Loss of cells in the area can result in loss of emotion, the ability to learn, and some behavior control is lost, too.

Lewy bodies

Then, there are the Lewy bodies. Protein compounds – alpha-synuclein – inside the neuron that clump up near the synapse and block function.

Lewy bodies can’t be visualized while you’re living. It’s only during autopsy that they can be identified under microscope.

Robin Williams, the comedian who amazed us for a generation, had been diagnosed with Parkinson’s disease, and suffered from that as well as… and committed suicide. During the autopsy, Lewy bodies were found in high numbers in his brain. You can learn more about Lewy body dementia here.

At ProTem, we love helping you make the most of your life. We have the caregivers and methods to treat you as your loving family would…in fact, you become our family when joining us here.

If you’ve experienced a shuffle when you walk, a tremor on one side in your hand, jaw, arm, or foot… or have a loved one who has…call your doctor.