Practical approach to freezing of gait in Parkinson's disease.

Freezing of gait in Parkinson's disease and related disorders is common and very disabling. It usually occurs in the advanced stages, although mild forms may develop earlier. Freezing can occur on turning, in narrow spaces, immediately before reaching a destination, and in stressful situations. Dual tasking (motor or cognitive load) aggravates the problem. Freezing of gait in Parkinson's disease usually occurs in the 'off' rather than in the 'on' state. It is, therefore, not entirely drug-resistant; the first step in medical treatment is to ensure adequate dopaminergic stimulation to reduce the 'off' state. There is no good evidence for any specific drug to alleviate freezing. Visual or auditory cues are very helpful as behavioural therapy. Assistive devices, such as a wheeled walker sometimes help. Deep brain stimulation of the subthalamic nucleus may alleviate freezing in the 'off' state. Because of the complexity of freezing, individual patients need a careful assessment-particularly in relation to motor fluctuation-to optimise their treatment.