Freezing of gait and falls in Parkinson's disease.

Freezing of gait (FOG) and falls are common and disabling phenomena in Parkinson's disease (PD) and related disorders as they may lead to loss of independence. Both are usually observed in the advanced stage of the disease, although they can also be seen in the early stage. FOG and falls have similar risk factors, such as axial motor disability and cognitive impairment, and FOG is one of the most common causes of falls. The objective of this review is to address recent ideas about the underlying pathophysiology of FOG and falls, and discuss the similarities, differences, and relationships between FOG and falls. Recent advances in studies that elucidate physical and cognitive risk factors to predict future falls are also reviewed. In addition to the history of prior falls and disease severity, the presence of FOG and cognitive dysfunction are associated with falls in PD.