Dementia is a broad term used to describe a decline in mental ability that impacts daily life. There are many different types of dementia, with Alzheimer’s disease being the most common. As dementia progresses, it leads to a gradual loss of cognitive skills like memory, communication, and focus. In addition to these changes, many dementia patients also experience physical symptoms like decreased mobility and trouble walking. Difficulty with walking can stem from a variety of factors related to the type and stage of dementia. Understanding why dementia patients struggle with walking can help caregivers find solutions to keep their loved ones safe and mobile for as long as possible.
What parts of the brain impact motor skills and mobility?
To understand why dementia leads to trouble walking, it helps to first review what parts of the brain control motor skills and mobility. There are several key regions involved:
- The motor cortex – This strip running along the top of the brain initiates signals to start muscle movements like walking.
- The basal ganglia – Clusters of neurons that help regulate motor control and learned motor skills like coordinating steps.
- The cerebellum – Located at the base of the brain, this region fine tunes body movements and balance.
- The sensory cortex – Receives touch signals from the body to provide position sense and spatial awareness.
In addition, various neurotransmitters like dopamine and acetylcholine play roles in smooth, coordinated muscle movements. When these areas of the brain become damaged due to dementia, it disrupts normal signaling between neurons and impacts motor function.
How do different types of dementia affect mobility and walking?
The way that dementia impacts walking ability often depends on the specific type of dementia:
Alzheimer’s disease
Alzheimer’s disease leads to progressive damage and death of neurons in parts of the brain involved in memory, cognition, and motor control. As Alzheimer’s spreads, the accumulation of abnormal proteins called beta-amyloid plaques and tau tangles interfere with communication between neurons in the motor cortex, basal ganglia, cerebellum and sensory cortex. This slow disruption in signaling pathways gradually degrades mobility skills. Walking abnormalities tend to arise later in the Alzheimer’s disease process.
Vascular dementia
Vascular dementia is caused by impaired blood flow to the brain, often due to strokes or small vessel disease. Depending on the location and severity of vascular damage, key areas involved in motor control can be affected. If stroke occurs in the motor cortex, basal ganglia, cerebellum or sensory cortex, it can directly impact signals involved in walking and coordination on one or both sides of the body. Mobility issues may arise earlier in vascular dementia.
Lewy body dementia
Abnormal protein deposits called Lewy bodies form in regions of the brain that produce key neurotransmitters like dopamine and acetylcholine. This leads to motor symptoms similar to Parkinson’s disease including slow, shuffled walking with small steps, balance issues, and falling. Mobility problems tend to arise earlier in Lewy body dementia.
Frontotemporal dementia
In frontotemporal dementia, progressive cell loss occurs in the frontal and temporal lobes of the brain. Though the regions impacted are not directly involved in motor control, damage to nerve cell networks can still disrupt signaling to parts of the brain that coordinate movement. Walking abnormalities tend to occur later in frontotemporal dementia.
How do these brain changes impair walking ability?
The accumulation of damage in motor control areas of the brain has many consequences that make walking more difficult for dementia patients:
Weakened motor signals
With the deterioration of neurons in the motor cortex, the brain has trouble generating strong initial signals to initiate normal gait and stride. Steps become slower and more tentative.
Loss of motor programming
The basal ganglia help coordinate learned sequences of steps for steady walking. Dementia disrupts these programmed motion patterns, leading to more random, variable movements.
Deteriorating balance
The cerebellum integrates input from the vestibular system, vision, proprioception and motor cortex to fine tune balance during locomotion. Dementia-related damage leads to loss of coordination.
Impaired spatial awareness
The sensory cortex provides updated information from receptors in the feet, legs and spine to sense the body’s position in space. Declining sensory input reduces this spatial awareness during walking.
Stiffness and slowness
Degeneration in substantia nigra neurons that supply dopamine to the basal ganglia causes increased stiffness and slowed movements seen in Parkinsonian disorders.
Jerky or shuffling gait
Disruption in the timing and length of steps results in abnormal gaits. Steps may become very short and variable, leading to shuffling. Or steps can alternate between big and small, producing a lurching, jerky gait.
How do memory and attention issues impact walking?
In addition to declining motor control, the memory and attention deficits commonly seen in dementia can also contribute to mobility impairment:
- Forgetting learned motor programs for coordinated steps.
- Inability to pay attention to walking surfaces leading to tripping.
- Distractedness while walking resulting in veering or imbalance.
- Disorientation and confusion about intended direction.
- Wandering behaviors that increase fatigue and instability.
These cognitive challenges make it even harder for dementia patients to navigate walking successfully.
How does dementia walking impairment progress?
Like other dementia symptoms, mobility problems tend to worsen gradually over the course of the disease. Some general patterns in this progression include:
- Mild dementia – Walking abnormalities may be subtle. Steps seem more cautious and tentative. Balance might be slightly impaired when making turns.
- Moderate dementia – More noticeable shuffling or unsteady walking. Steps become smaller. Trouble initiating walking motion. Some falls possible.
- Severe dementia – Extremely slowed pace with severe shuffle or lurching gait. Steps are very small and stance is very wide. Falls are frequent. May eventually lead to inability to walk.
Of course, the rate and specifics of this decline depend on the individual. Understanding how mobility loss typically advances can help caregivers anticipate and address emerging needs.
What are some solutions to help dementia patients with walking?
While it’s not possible to fully restore normal motor function, there are many strategies that can maximize mobility and safety for dementia patients struggling to walk:
Medication therapies
Medications that boost acetylcholine or dopamine may provide some improvement in gait and balance symptoms. These include drugs like cholinesterase inhibitors and l-dopa.
Assistive devices
Walkers, canes and other aids provide physical support and stability for balance issues. Manual or motorized wheelchairs help conserve energy and prevent falls.
Home modifications
Railings on walls, grab bars in bathrooms, improved lighting, and clutter-free hallways create a safer environment for walking inside the home.
Physical therapy
Exercises focused on strength, range of motion and coordination can help maintain mobility. Balance training is especially valuable.
External cueing
Visual cues like tape lines on the floor or auditory cues like metronome beats can provide external rhythm to stabilize gait.
Assisted mobility
Walk alongside the person and provide verbal guidance, gentle steering at the shoulders or hands-on assistance for severely impaired patients. Don’t pull on arms.
Seeking solutions tailored to the individual’s needs and abilities can help people with dementia retain mobility and independence as long as possible. Staying active also has benefits for physical and mental health.
Conclusion
Difficulty with walking and mobility is a common symptom as dementia damages areas of the brain involved in movement and motor control. Depending on the type of dementia, symptoms may include slow, stiff, unsteady, shuffling or jerky gaits and increased risk of imbalance or falls. Cognitive issues like memory loss and poor concentration further hamper walking ability. With a thorough understanding of the motor and neurological impairments behind these mobility changes, caregivers can access medical therapies, assistive equipment, home modifications, exercise programs and hands-on assistance to help dementia patients stay safely on their feet for as long as possible. Promoting physical activity improves quality of life and helps delay loss of function. There are many creative solutions that can preserve mobility and independence even in the face of progressive neurological decline.