Is Freezing of Gait in Parkinson's Disease a Result of Multiple Gait Impairments? Implications for Treatment
Figure 3
Intervening to improve overall gait performance and to reduce the FOG burden. (a) Improving gait performance in general, for example, by maintaining a sustained effective therapeutic effect on multiple gait features associated with FOG (recall Figure 1(a)) is a target for therapy that will likely reduce the FOG burden (see text). The black arrows reflect two instances where FOG might normally occur when the patient is OFF anti-parkinsonian medications. This might represent some diversion or divided attention that increase the likelihood of FOG. In the ON medication condition, when the overall performance is further away from the FOG threshold (horizontal line), attention still has a negative effect, but it is no longer sufficient to cause FOG. In general, one way of reducing the likelihood of FOG is to move the overall gait performance further away from this threshold. (b) Online intervention may reduce the duration of FOG episodes (see text). Key: Gait performance OFF—gait during the “off” medication periods. Gait performance ON—gait during the “on” medication periods.
