The Mighty Vestibular System: Balance and Beyond
It’s well known that balance requires sensory input from the vestibular, visual, and proprioceptive systems, but how do these systems work together to create balance? With which other systems does the vestibular system interact? How does the interaction between the vestibular system and other neurological systems affect our ability to function in the environment?
The vestibular system can impact arousal, attention, emotional regulation, movement, communication, motor planning, vision, posture, spatial and temporal functions, coordination, sensory regulation, and executive functions. After all, it is a mighty vestibular system!
The 6 Systems of Interaction
The vestibular system interacts with six neurological areas, and each of these interactions impacts our ability to function. Integration of vestibular input is essential for balance, posture, smooth coordinated movement, and an awareness of space and self.
1. Brainstem
The vestibular system, via cranial nerve VIII, connects to the brainstem. Along with input from the visual system, this results in the vestibular ocular reflex, allowing for clear vision through gaze stabilization and coordinated eye and head movements. The brainstem, with input from the vestibular system, integrates and sorts sensory information and then relays that information to the cerebral cortex.
2. Reticular activating system
Through connections to the reticular activating system and then anteriorly to the hypothalamus and posteriorly to the thalamus, the vestibular system assists with regulation of arousal, attention, and sense of self, place, and safety.
3. Cerebellum
The vestibular system also connects to the vestibular nuclei in the cerebellum. The connection to the cerebellum, along with input from the visual and proprioceptive systems, results in fluid, smooth, and accurate movement, posture, and balance.
4. Parietal lobes
The vestibular system connects to the parietal lobes, which enhance upper and lower extremity control, helping us maintain an upright position against gravity and prepare to engage in functional activities. Connections to the parietal lobes also provide communication that assists with processing of motor, spatial, and temporal information.
5. Limbic
The vestibular system also connects to the limbic system to provide stability of sensory input and sensory discrimination to help regulate emotions. This input helps us gather, process, and respond appropriately to information in social situations.
6. Frontal lobes
With input via other systems such as the brainstem and parietal lobes, the vestibular system assists us in understanding space and time, grounds us in a sense of self, assists with sensory regulation, and enhances sensory discrimination to improve motor planning.
Adaptive Functions
In her MedBridge course, “The Mighty Vestibular System,” Tracy Stackhouse, MA, OTR/L, quotes Aristotle: “Life requires movement.” The vestibular system is essential to our ability to move.
Many aspects of brain function are impacted by the mighty vestibular system. Through these myriad connections, the vestibular system enhances our ability to explore and interact with the environment, which results in learning and adaptation. These functions produce changes in behavior that increase survival and enhance our ability to interact and adapt to the world.
Assessment and Treatment
The course referenced above provides more insight into how to assess vestibular function through clinical observation, standardized testing, and multidisciplinary collaboration, while also discussing treatment of deficits in the vestibular system. While the course focuses on the pediatric population, don’t let that deter those of you who work with adults. This information is relevant and essential to all populations with whom you work.
