Non-vestibular dizziness and imbalance can be very frustrating to the clinician, because the symptoms are often vague and the vestibular test results are normal. This chapter discusses the more common causes of these disorders. Disuse disequilibrium with fear of fall, the most common cause of imbalance, readily responds to gait and balance therapy. Other disorders that cause imbalance are leukoaraiosis, normal-pressure hydrocephalus (NPH), progressive supranuclear palsy, Parkinson's disease, large fiber peripheral neuropathy, and cerebellar ataxia. Many of these disorders are associated with disuse disequilibrium (or deconditioning) and, therefore, respond to physical therapy (PT) to a certain extent. Some individuals with these disorders do not have disuse disequilibrium, because they are very active or are too incapacitated to perform PT. In these individuals, one must concentrate on reducing fall risk through the use of assistive devices and education. Finally, we discuss a group of disorders that are best described as dizziness in the head without severe imbalance that are triggered primarily by specific situations.
It is best to have any patient with chronic dizziness first assessed by a physician to determine the diagnosis. After this assessment, PT can be started the same day or as soon as possible. During PT, there is an initial assessment to identify the patient's specific problems. Then the patient is started on a daily home gait and balance program that is reviewed and revised by the physical therapist every week. At each visit, outcomes scores are reassessed. The patient is then reevaluated by the physical therapist, and the outcomes scores are reviewed to determine whether the patient needs more rehabilitation and/or a follow-up appointment in 6 to 12 months. The latter is especially important in patients who have progressive problems (spinocerebellar degeneration, progressive peripheral neuropathy, and progressive supranuclear palsy).
Disuse Disequilibrium (or Deconditioning) and Fear of Fall
Each year, approximately one-third of elderly individuals in the general population experience a fall.1 In elderly individuals, there is progressive decline in muscle bulk, joint range of motion, and reflex time.2 Increased exercise can reduce the rate of this decline. Many individuals stop walking and exercising because of recent surgery, fatigue, chronic illness, or a fall to the ground or a near fall. Lack of exercise in the elderly leads to disuse disequilibrium.3 Fear of fall can occur as a result of disuse disequilibrium and can also exacerbate disuse disequilibrium by reducing the patient's willingness to participate in a home exercise program.4
Figure 29.1 shows the age distribution of fear of fall and disuse disequilibrium in patients at our Dizziness and Balance Clinic. The diamonds indicate all patients seen in the clinic (left axis) based on decade of age of the patient. The squares indicate the percentage of patients seen within each decade with fear of fall (FOF) and disuse disequilibrium (DD) (right axis).