Dementia symptoms related to cognitive processes (like memory and judgment) are usually given the most attention in public discussions. However, dementia is also often associated with severe impairments in motor skills.
These dysfunctions in movement are most common (and severe) in the later stages, but problems may appear earlier, depending on the underlying cause. In some dementia cases, the limitations imposed by disordered movement can be more debilitating than the cognitive toll.
Movement Impairment by Dementia Type
Until recently, it was thought that the ability to control movement remained relatively unaffected by
Alzheimer’s disease until the
later stages, at which point it is known to rapidly decline.
Newer studies suggest that movement is actually affected very early in the development of the disease, well before a diagnosis is possible by
current standards. Researchers are now investigating the possibility of identifying Alzheimer’s disease in its earliest stages by detecting these sometimes subtle impairments.
Vascular Dementia
Dementia caused by vascular damage can have a
wide range of symptoms, based on the area(s) affected within the brain. For example, a stroke that disrupts blood flow to a key part of the brain related to movement (like the
cerebellum or motor
cortex) would likely cause immediate and lasting movement dysfunctions.
In contrast,
vascular dementia due to isolated oxygen restriction in another part of the brain could feature no movement symptoms at all. Alternatively, impairments in movement could gradually appear over time in a case of vascular dementia caused by protein deposits.
Lewy Body Dementia
Movement problems are a primary symptom of
Lewy body dementia, but they
may not appear for several years after diagnosis. Once they arrive, these issues can quickly become severe and debilitating.
Some of the motor impairments associated with this condition are very similar to those seen in Parkinson’s disease and are described collectively as “parkinsonism”. They include:
Frontotemporal Dementia
There are many types of underlying conditions that can cause
frontotemporal dementia, so it can be expected that the range of symptoms will be highly variable on a case to case basis. Still, movement disorders are a
common feature among several forms of frontotemporal dementia.
Like in Lewy body dementia, some frontotemporal types can meet the criteria for parkinsonism. Other forms result in motor impairments that make speech difficult or impossible, suppress facial expressions, and immobilize the eyes.
Dementia is About More Than Just Memory
Popular culture promotes the false idea that dementia is primarily a memory-related condition. The truth is that dementia affects many parts of the brain and body, resulting in a variety of impairments to multiple cognitive functions (not just memory) and, often, movement problems. By giving more attention to these less popular symptoms, researchers are now developing better ways to diagnose and treat the underlying disorders.
Current diagnostic methods for Alzheimer’s disease and other causes of dementia focus on more than just memory. They are designed to take a wide range of cognitive abilities into account, as are competent self-assessment tools like the BrainTest® app. Perhaps, in the future and with enough research, motor function analysis will become a key part of early dementia detection.
