Computerized Dynamic Posturography: Developing Vestibular Rehabilitation Programs

Following the Sensory Organization Test (SOT), rehabilitation programs can be developed using Computerized Dynamic Posturography (CDP). This video provides an overview of how to build an individualized rehabilitation program for your patients.

If you prefer reading, find the full transcript below.

SOT training

When using the CDP for rehabilitation purposes, all of the same principles and recommendations apply as when using the CDP for the assessment method, such as the sensory organization test (SOT).

The goal of rehabilitation following the SOT is to improve the patient's sensory weighting. First of all, identify which conditions on the SOT that the patient found challenging. This will typically be those that had high amounts of sway as shown by the red bars on the equilibrium score graph (Figure 1) or those that the patient fell on.

The recommendation is to start the rehabilitation process using the condition on which their balance function was reduced but starting with the highest scoring of these conditions. This will represent the least challenging of the conditions that they found difficult, which means their rehabilitation program is not starting with a scenario that is too difficult for them to complete.

Within the CDP/IVR™ software, under the training tab, identify and select the align center protocol. Within the align center protocol, you can now recreate a simplified version of the highest scoring condition which caused the patient to experience imbalance.

Altering the difficulty

Once the patient has performed this first training condition, identify whether they were able to perform the task successfully. If the patient was successful in this initial task, then you can increase the difficulty of the scenario until it becomes challenging for them. You want to gradually increase the difficulty and not reach a point where they cannot complete the task at all.

If, however, the first scenario was too difficult for the patient to perform, then simplify the difficulty level until the patient is able to perform it while still maintaining some degree of challenge. What we don't want is for the first task to be too simple, otherwise the patient will not make progress.

Continue to increase the level of difficulty of the training scenario until it becomes challenging and repeat until the patient is able to perform the task comfortably. Once this has been achieved, then you can progress the patient to another condition of the SOT where their score was poorer, and they experienced more imbalance. And then repeat the training process using the align center protocol to mimic the condition with an appropriate starting level of difficulty.

Adjusting sway gain

You can adjust the sway gain for the platform during the SOT assessment. A 1:1 ratio is used, which means the platform moves the same amount as the patient sways. In the align center protocol, it is possible to reduce this ratio to zero, which means there will be no platform movement at all, making it an easier task. Or you can increase the sway gain in increments up to two, whereby the platform will move twice as much as the patient sways, making for a much more challenging task.

Adjusting camera gain

You can also adjust the camera gain for the screen. As is the case for the platform during the SOT assessment, a 1:1 ratio is used, which means the screen moves the same amount as the patient sways. In the align center protocol, it is possible to reduce this ratio to zero, which means there will be no screen movement at all, making it a much easier task. Or you can increase this ratio in increments up to two, whereby the screen moves twice as much as the patient sways, making for a much more challenging task.

Adjusting the visual field

Furthermore, it is possible within the align center protocol to make changes to the visual field to alter the level of difficulty.

1. Change scene and complexity

You can change the type of background used to make this more or less visually complex.

2. Add or remove components

It is also possible to add target points, which can help provide a focal point for the patient. Or you can remove these, which makes the task more challenging. When considering which elements to add, remove, or alter, refer back to their SOT results and the pattern of results the patient is presenting with.

Visual field considerations

In some cases, the patient may find too much complexity overstimulating at the start of their rehabilitation process. In others, they may require the central targets to focus on in the initial stages of their training to maintain stability to complete the task successfully.

The most important element is to ensure that the patient can make progress by successfully moving on to increasingly complex conditions. It is vital not to start too hard, which can lead to a loss of confidence or to start too easy, which doesn't challenge the sensory integration process sufficiently to make progress.