Causes of imbalance and abnormal gait that may be misdiagnosed.

Disorders of gait and balance are common in medicine and often lead to referral for neurologic evaluation. Because the maintenance of balance and normal gait are mediated by complex neurologic pathways as well as musculoskeletal, metabolic, and behavioral considerations, the list of possible contributing causes is very large. Much of the time, the history and neurologic examination reveal the underlying cause or causes. There are instances, however, when there are limited neurologic findings, as well as no structural abnormalities on brain or spine magnetic resonance imaging studies to explain the imbalance or gait difficulty. In this article, selected disorders that may be overlooked in the neurologic examination and imaging studies are reviewed. Possible causes of imbalance include occult drug-induced ataxia, autoimmune ataxia, ataxia associated with tremor, bilateral vestibular hypofunction, and spastic or dystonic gait disorders with normal imaging.