How tandem gait stumbled into the neurological exam: a review.

Tandem gait testing is an integral part of the neurological exam. It is informative in a wide variety of disorders ranging from cerebellar disease to vestibular and peripheral neuropathies, parkinsonism, and other neurodegenerative conditions. We discuss the history and development of tandem gait testing as well as its technique, utility, and limitations in the assessment of neurological conditions. Tandem gait has emerged as a tool in the assessment of cerebellar disease, Huntington disease, idiopathic Parkinson's disease, atypical parkinsonism, peripheral neuropathies, and vestibulopathies. Its origin can be deduced from experimental observation and clinical experience as far back as the early nineteenth century. Despite the long history and ubiquitous performance of tandem gait testing, there is no standardized, guideline-based protocol to model for more homogenous research and clinical practices. Such a protocol should be developed using historical texts and manuscripts as well as the consensus of the medical research community. With standard protocols, further studies could define the sensitivity of abnormal tandem gait testing in cerebellar disorders, more diffuse neurodegeneration, and peripheral pathologies. Tandem gait can be a useful marker of dysfunction in neurologic conditions whose pathologies extend beyond the vermis or vestibulocerebellar module to include interconnected networks throughout the nervous system.