What is Postural Instability?
Postural instability simply means you have problems keeping your balance in various situations whether moving or standing still. It often happens to people with Parkinson’s disease, which is a condition that progressively worsens over time, resulting in difficulties with movement. This happens because certain nerve cells in a particular part of the brain start to deteriorate.
There are several other symptoms of Parkinson’s disease that may occur at the same time as postural instability. These include shaking or trembling (tremor), stiffness (rigidity), slowness of movement (bradykinesia), small, cramped handwriting (micrographia), and problems with memory and thinking (dementia).
In many cases, postural instability results in falls that can lead to emergency hospital visits. Therefore, it’s crucial to understand the causes and how to diagnose postural instability. This knowledge can help manage the condition more effectively, reducing the severity of the symptoms and improving the quality of life for those affected.
What Causes Postural Instability?
Keeping a steady posture is a complex process. It involves the coordination of several aspects of our body, like movement control, sensory perception, vision, cognitive processing, and balance signals from the brain. If any of these aspects get disrupted, it can lead to instability and difficulty in maintaining balance. Understanding the exact cause of balance issues can be challenging as it involves different disorders, and there is still a lot to learn about the root causes of this condition.
In a healthy person, maintaining balance relies on vision, touch and feel perception, and balance signals from the brain. The brain collects all these sensory signals, and then generates a corrective action to maintain balance. In conditions like Parkinson’s disease, obstacles to balance can arise due to slower visual processing, problems with visual and spatial orientation, or decreased vision clarity. These all affect motor functions and the ability to maintain a stable posture. Vision isn’t the only factor; balance signals from the brain and body’s sense of its own position (proprioception) are required for standing upright. Balance receptors in our inner ear detect any changes in the position or movement of the head. In Parkinson’s, patients have issues with tilting reactions, showing that balance responses from the inner ear are also connected with areas of the brain called basal ganglia. However, problems in the balance signals from the brain alone do not seem to be the full reason behind balance issues in Parkinson’s patients with a mild to moderate degree of the disease.
The body’s touch and feel perception system also plays a vital role in maintaining balance. This system is responsible for both the conscious perception of passive or active motion and direction of movements, and for processing touch and position information from muscles, skin, and joints. It’s known that basal ganglia, different areas of the brain, play a role in processing position and motion signals for coordinating posture and movement. This proprioception, the body’s sense of its own position, plays a critical role in controlling balance reactions when faced with unexpected stimuli.
Risk Factors and Frequency for Postural Instability
Parkinson’s disease is often linked to “postural instability”, which means difficulties with balance and coordination. It’s the second most common brain disorder after Alzheimer’s disease. About 0.3% of everyone and 1% of people over 65 have Parkinson’s. Around 16% of Parkinson’s patients experience postural instability. Unfortunately, balance issues lead to falls in about 60% of these cases. As a result, three quarters of hospital stays for Parkinson’s patients worldwide are due to falls and fractures.
- Postural instability or problems with balance is a typical problem in Parkinson’s disease.
- Parkinson’s is the second most common brain disorder, following Alzheimer’s disease.
- About 0.3% of the entire population and 1% of people over 65 years old have Parkinson’s.
- Approximately 16% of Parkinson’s patients suffer from postural instability.
- Balance issues cause falls in about 60% of patients with Parkinson’s.
- Falls and related fractures are responsible for 75% of all hospitalizations of Parkinson’s patients worldwide.
Signs and Symptoms of Postural Instability
Postural instability, a condition where a person struggles to stay balanced, can be diagnosed through careful evaluation and physical examination. It is essential to understand the patient’s symptoms and risk factors, which can be both changeable and unchangeable. Changeable factors could be things like their environment, lifestyle, exposure to certain chemicals, or stress. Age, on the other hand, is an example of an unchangeable risk factor.
When assessing a patient for postural instability, it’s important to examine factors that could increase the risk for Parkinson’s disease, such as smoking, alcohol use, coffee consumption, exposure to pesticides, and living in rural areas. Certain dietary elements like DHA and vitamin D can help protect the nervous system, so testing for vitamin D deficiency could be helpful in assessing the risk of postural instability, particularly in patients with Parkinson’s disease. Always bear in mind that older age can contribute to all motor symptoms of Parkinson’s disease, including postural instability.
Patients who have balance problems might often fall when they get up from a seat, or even fall backward while sitting down. It’s crucial to ask the patients about their history of falling, how they fall, and if they express a fear of walking. An important step in the physical examination is the retropulsion test. In this test, the doctor will quickly pull the patient’s shoulders from behind. If the patient is able to maintain their balance and take no more than one step back, it means their postural reflexes are normal. If the patient takes two or more steps back to regain balance, it could mean that they have postural instability.
Besides the retropulsion test, other clinical exams to assess balance include:
- The functional reach test: the patient tries to reach as far forward as possible without moving their feet
- The timed up and go test: it measures the time it takes for the patient to stand up from a chair, walk a short distance, return, and sit down again
Testing for Postural Instability
Postural instability, or trouble maintaining balance, is diagnosed based on a doctor’s evaluation. If the cause of the balance issue is not clear, your doctor may order various tests to figure out if there are any underlying health conditions contributing to your imbalance.
If a physical examination doesn’t identify the cause of postural instability, doctors might start by performing blood tests that check for different factors. These tests can include a complete blood count, a rapid plasma reagin test (a test for syphilis), electrolyte levels, kidney function, thyroid function, blood sugar level, creatinine (a waste product removed by the kidneys), and vitamin B12 levels. All these tests can help identify any abnormalities that might be causing balance issues.
There is a link between postural instability and an increased risk of falls. Because of this, if you’re newly diagnosed with Parkinson’s disease – a condition that often causes balance issues – your doctor may advise testing your level of vitamin D, which plays a crucial role in bone health. Assessing for nutritional deficiencies and checking bone density can also be important as these risks can lead to bone loss and fractures.
Depending on your symptoms, other tests may be necessary to exclude certain neurological conditions related to your walking pattern. For example, a brain or spine MRI might be recommended if you present with weakness and spasticity in your gait, potentially indicating conditions affecting your central nervous system or spinal cord. If you have foot drop, a condition making it hard to lift the front part of your foot, a lumbosacral spine MRI or nerve conduction studies might be carried out to look for conditions such as spinal stenosis or nerve damage.
If you find it difficult to start walking, this could suggest conditions such as normal pressure hydrocephalus or neurodegenerative dementia, and an MRI may be helpful for diagnosis. On the other hand, a narrow or hurried walking pattern might suggest Parkinson’s disease, which would call for a brain MRI to confirm.
If your walking doesn’t fit into any typical patterns, this could indicate a functional gait disorder often linked to psychiatric disorders; a diagnosis here usually relies primarily on clinical assessment. If you tend to fall towards the side of an affected ear, this could reflect a vestibular gait pattern, a balance disorder stemming from the inner ear. This condition may be evaluated in part with sensorineural vestibular testing, a hearing test to check if the inner ear is causing the problem.
Treatment Options for Postural Instability
Physical therapy can help improve balance and reduce the risk of falling. While the relationship between muscle function and balance isn’t clearly established, it’s recommended to start physical therapy early to prevent muscle weakness and frailty, especially in elderly patients. Physical therapy has shown short-term benefits in Parkinson’s patients struggling with balance and walking issues. Long-term benefits, however, require patients to stick with progressive resistance and aerobic exercises. These approaches should be customized to meet the patient’s needs. Home therapy plans might be a good option, especially for frail elderly patients as they could potentially improve their quality of life. But more research is needed to ensure these unsupervised home programs are safe.
For people with a condition called progressive supranuclear palsy, often a wheelchair is needed for moving around and changing positions. Their therapy often includes learning how to fall safely and how to move about after a fall to minimize the risk of injury.
Medication can help manage most symptoms of Parkinson’s disease, but it’s not typically effective for balance issues. Research suggests that this might be due to issues in areas of the brain not affected by current Parkinson’s drugs. However, some research has suggested potential benefits from medications like donepezil and methylphenidate in reducing falls and freezing in place. It may also help to stop taking certain medications like benzodiazepines or anticholinergic drugs. Again, more research is needed.
Lastly, certain types of neurostimulation and surgical treatments have shown promise. Transcranial direct current and vagal nerve stimulation, which involve stimulating certain parts of the brain or nerves, have been used to manage balance and walking issues. Deep brain stimulation, a surgical procedure focused on specific parts of the brain, may provide some benefits for balance issues. However, these options are still being researched and are not yet widely available.
What else can Postural Instability be?
Postural instability, or difficulty in maintaining balance, can be a symptom of various health issues. It’s not unique to any single condition, and it can be caused by problems in the sensory inputs, pathways in the nervous system that deliver commands to muscles, issues with the muscles and joints, or problems with how the brain processes information.
In addition to Parkinson’s disease, there are a number of conditions that can cause postural instability. These include:
- Disorders affecting the lower motor neurons (nerve cells that control muscle activity)
- Severe spasticity (muscle stiffness or tightness)
- Normal pressure hydrocephalus (a buildup of fluid in the brain)
- Vestibular dysfunction (problems with the balance system in the inner ear)
- Atypical Parkinsonian disorders (Parkinson-like conditions)
- Orthostatic hypotension (low blood pressure upon standing up)
Distinguishing between postural instability and orthostatic hypotension is important. For instance, if symptoms of dizziness are linked to changes in position and accompanied by fainting or lightheadedness, it may suggest orthostatic hypotension. On the other hand, if dizziness occurs when a person reaches, bends, or turns, it might indicate postural instability.
Progressive supranuclear palsy, an atypical Parkinsonian disorder, often starts with symptoms of postural instability and falls. This differs from Parkinson’s disease, where postural instability typically develops in the later stages.
Patients with multiple system atrophy often show symptoms similar to Parkinson’s disease, such as slow movement, issues with body balance, and disturbances in walking. Usually, the onset of the disease is crucial for diagnosis. In multiple system atrophy, postural instability is a usual initial symptom, while in Parkinson’s disease, it tends to appear later.
Corticobasal degeneration, a condition that can mimic Parkinson’s disease, usually presents postural instability from the early stages of the disease.
Dementia with Lewy bodies might show postural instability similar to Parkinson’s disease, but symptoms like visual hallucinations and fluctuations in attention and awareness are key for the diagnosis of this disease.
Vertigo, a kind of dizziness, can also indicate postural instability. However, people with vertigo would mainly complain about feelings of dizziness. Other neurological signs like unsteady movements, speech difficulties, difficulty swallowing, or double vision can suggest that the vertigo originates from a problem in the central nervous system. On the other hand, unidirectional instability when walking along with possible hearing loss or tinnitus might suggest vertigo due to issues with the inner ear.
What to expect with Postural Instability
When a person has trouble keeping their balance, which can often lead to falls, it’s known as postural instability. This can be particularly concerning, as frequent falls might result in someone breaking a bone or needing to be hospitalized. It appears that treatments using dopamine, a chemical in the brain that helps control movement and emotional responses, have not been successful in improving this issue.
For those suffering from mild to moderate Parkinson’s disease, trouble with balance and walking can greatly impact their quality of life. In fact, this is a major factor contributing to disability among Parkinson’s disease patients.
Possible Complications When Diagnosed with Postural Instability
The symptom of postural instability, or difficulty maintaining balance, is particularly impactful for people with Parkinson’s disease. It can increase their risk of falling, which can lead to severe health issues like broken bones. Fear of falling can halt mobility, limit physical activity, and even lead to social isolation. Overall, it can truly decrease their quality of life.
Some common issues associated with postural instability include:
- Falls
- Medical complications such as fractures
- Fear of falling
- Decreased mobility
- Social isolation
- Self-restricted physical activity
- Lowered quality of life
Preventing Postural Instability
Patients can experience instability when standing or walking due to various reasons, and each person has different means to get treatment. Therefore, it’s vital to tailor the treatment depending on the personal circumstances of each patient. Many factors control a person’s ability to maintain an upright position, including control of movement, thought processing, physical limitations, movement and sensory strategies, and spatial awareness. If any of these factors become impaired, it can cause instability in specific situations.
It’s helpful for patients to be informed about the aspects they can change that might influence the development of the condition. The way the condition presents itself over time can be used to predict the future progression and to choose the best treatment options accordingly. Healthcare professionals, like physiotherapists, should teach patients about safety techniques and let them know if they might need any equipment in the future, such as wheelchairs.
It’s also crucial to address any fears of falling to reduce inactive behavior, instability when standing or walking, and the number of falls. Understanding the condition and its symptoms allows patients to actively participate in their care.
