[Freezing of gait : phenomenology, pathophysiology, and therapeutic approaches]

Freezing of gait (FOG) is a common disturbance in Parkinson's disease (PD) and other higher-level gait disorders. It appears most often during the later stages of PD but is seen also during the initial phases before oral substitution of levodopa has started. The disorder has its own pathophysiology and differs from bradykinesia. It can occur both on and off medication. It interferes with activities of daily life, reduces mobility, and is an important risk factor for falling. While patients with FOG during medication do not reliably respond to pharmacotherapy or deep brain stimulation, external cues have been demonstrated that influence FOG effectively. They are applied as auditory, visual, tactile, or mental cues. This article discusses available pharmacological and physiotherapeutic approaches to the treatment of FOG.