Presented by: Specialists from the Stanford Balance Center
March 17, 2011
Balance problems can stem from dizziness, light-headedness, weakness, or lack of coordination, and often can lead to falls. It’s a pervasive problem but one that has not been thoroughly studied, perhaps in part because of the difficulties in determining the cause. But studies show that 30 percent of people over age 65 fall every year, and more than half of the people over age 75 in nursing homes or care facilities are unable to live independently because of falling. And only about 20 percent of people who fall get medical attention for the problem.
To address these troubling statistics, Stanford has launched a new Balance Center, making it one of the few medical centers in the country to offer an interdisciplinary program for comprehensive testing and community outreach. A panel of experts discussed the causes and treatments for balance disorders at a presentation sponsored by the Stanford Health Library.
Normal balance requires several interconnected systems to communicate. It requires that muscle strength (the musculoskeletal system) is aligned with sensory feedback from vision, the vestibular system (a fluid-filled network in the inner ear), and sensations from the skin, muscles, and joints.
This multisystem arrangement keeps the body upright, whether the support surface is stationary and/or smooth (static balance) or moving and/or uneven (dynamic balance). The brain is involved in all systems related to balance, said Dr. Bronte-Stewart MD MSE, an associate professor of neurology and neurological sciences and director of the Stanford Movement Disorders Center.
About 5 percent of the causes are neurological; 5 percent are medical, such as high blood pressure or heart conditions like arrhythmia; 15 percent are psychological, such as from anxiety; and the remaining 25 percent are from multiple causes. When balance is caused by dizziness, more than 50 percent of the cases are related to problems with the inner ear. Diseases like Parkinson’s or multiple sclerosis also affect balance, Dr. Bronte-Stewart said, as does muscle weakness.
“Our team looked at the statistics for balance disorders and wondered why there are no standard screening protocols or diagnostic tests,” she added. “If our goal is to reduce falls, we need an evidence-based evaluation process to know what works. We can then design customized therapy for every individual.”
Diagnosing the Cause
A diagnosis of a balance problem begins with a thorough review of your medical history and a physical exam to assess muscle strength and possible cardiovascular conditions. From there, several tests can be applied to find the root cause.
The inner ears house the sensory organs of the vestibular system, the site of many balance problems. Like a carpenter’s level, liquid in the organs flows to maintain equilibrium and keep the body oriented. These organs can be affected by a variety of diseases or factors, said Gerald Popelka, PhD, a professor of otolaryngology and chief of audiology.
Assessing if there are fluid problems can help determine if more complex tests, such as magnetic resonance imaging (MRI), are needed. These assessments often involve hearing pathway tests including air pressure measurements in the ears to ensure that the fluid is responding properly to changes in position. Other tests can analyze eye movements to determine if you have a false sense of motion or spinning, or to measure minute changes in muscle contractions in reaction to sound.
“Dizziness is often a mismatch between what you see and what you feel, so we also use optical tracking to watch eye movements,” said Dr. Popelka, who also uses equipment to measure involuntary eye movements. “We look at both sides of the vestibular system since sometimes only one ear is affected. The measurements are extremely precise.”
To identify neurological causes of dizziness, Balance Center physicians may use posturography to measure your ability to maintain balance, which can determine whether you are relying on only one or all of your orientational senses. A cubicle surrounds two plates that measure the forces you exert through your feet as the plates shift. The feedback shows how well the brain adjusts to incongruent sensory feedback (such as when you try to balance in the dark walking on a thick shag carpet).
Posturography can also measure reaction time and speed in adapting to unexpected changes in balance. If reactions to any of these stimuli are slow, there is a greater risk of falling, Dr. Bronte-Stewart said.
A Physical Perspective
Additional tests look at the physical aspects of movement and gait, measuring head movement, muscle strength, and range of motion. A person with weak leg muscles may not be lifting their feet high enough when they walk or someone with poor posture may be off-balance by holding their head too far forward.
Once the source of the balance disorder is identified, the Center can provide vestibular and neurological rehabilitation to reduce falls and improve balance. Rehabilitation can improve stability, enhance eye-head-body coordination, and reduce dependence on visual cues, said Diane Pacholski, PT, a physical therapist trained in neuro- and vestibular rehabilitation.
She and her team provide customized exercises to help with postural alignment, hip and core strength, ankle motion, spinal flexibility, or eye coordination. Studies in sports medicine have shown that people benefit more from focused therapy rather than from general rehabilitation, making it vital to determine the cause of the balance problem. Therapy is custom-developed for each individual to help develop strength and balance skills that can be applied to day-to-day activities. “We continually revise the therapy as the person improves” she said.
Stanford’s Farewell to Falls program is an integral part of the Balance Center. The home-based program, free for Santa Clara and San Mateo county residents 65 and older, provides home visits from an occupational therapist, who evaluates the home for potential problems, performs a sensory-motor review, and does a health risk interview. The therapist also offers individualized suggestions and a review of medications from a pharmacist. Participants are encouraged to exercise or to receive physical therapy to help improve strength and balance.
“We’re hoping that seniors take advantage of this opportunity to participate in a program that can help them to maintain their independence,” said Ellen Corman, OT, an occupational therapist and director of the Farewell to Falls program.
About the Stanford Balance Center
The Stanford Balance Center is an interdisciplinary program designed to provide comprehensive evaluation and care for people with balance difficulties and to reduce and prevent falls in the community. Its staff comprises specialists in neurology, otolaryngology, vision, physical and occupational therapy, audiology, rehabilitation medicine, and other relevant fields, focused on refining diagnostic and therapeutic strategies for balance concerns. The Center is co-directed by Dr. Bronte-Stewart and Dr. Popelka.
For More Information:
About Dr. Bronte-Stewart
About Dr. Popelka
Stanford Department of Otolaryngology
Stanford Department of Neurology & Neurological Sciences