The sequence effect and gait festination in Parkinson disease: Contributors to freezing of gait?

Abstract

Festination and freezing of gait (FOG) are poorly understood gait disorders that cause disability and falls in people with Parkinson disease (PD). In PD, basal ganglia malfunction leads to motor set deficits (hypokinesia), while altered motor cue production leads to a sequence effect, whereby movements becomes progressively smaller as in festination. We suggest both factors may contribute to FOG. Disturbance of set maintenance by the basal ganglia in PD has previously been examined in gait, but limited systematic evaluation of the sequence effect exists. In this study, we investigated the step-to-step amplitude relationship in 10 PD subjects with clinical evidence of festination and FOG. Four conditions were examined: off levodopa, off with attentional strategies, off with visual cues, and on levodopa. Participants demonstrated a sequence effect (F = 6.24; P = 0.001), which was reversed only by use of visual cues. In contrast, medication, attentional strategies, and visual cues all improved hypokinesia. Variability was marked both within and between participants in all conditions. The variability of FOG is suggested to relate to a combination of factors, including the sequence effect and its variability, as well as the severity of hypokinesia and its response to medications.

Rotating treadmill training reduces freezing in Parkinson disease: Preliminary observations

“…Self-reported turning difficulty is a sensitive indicator of freezing and falling [8]. On-period freezing in PD is particularly problematic because, by definition, it does not respond to medications [9]. As such, the development of novel rehabilitative interventions to address these problems is warranted.…”

“…One proposition is that freezing results from a combination of hypokinesia and the sequence effect [9]. Hypokinesia refers to the fact that steps are smaller than normal at the outset of walking and the sequence effect refers to the fact that steps become progressively smaller over the course of a walking trial.…”

A simple method to assess freezing of gait in Parkinson's disease patients

“…FOG is not necessarily a completely frozen, akinetic posture. Thus, during locomotion, different characteristics of gait disturbances may be seen: feet may be "glued" to the ground (freezing) or they may change their normal rhythm (festination) (7,(9)(10)(11). Much faster oscillations than the normal walking pattern may occur as the result of an ineffective effort to move forward.…”

“…Much faster oscillations than the normal walking pattern may occur as the result of an ineffective effort to move forward. Gait festination is highly associated with FOG (10), suggesting that the two conditions may share a common pathophysiology such as a central timing mechanism (7). While glued to the ground, the lower extremities may show signs of shaking and asynchronous movement described as "trembling in place".…”

A novel cognitive cueing approach to gait retraining in Parkinson’s disease: A pilot study

“…Fok, Farrel, McMeeken, and Kuo (2011) completed a systematic review of the literature that explored the effects of verbal instructions on gait among individuals with PD. In their review, Fok et al (2011) identified 13 studies that examined either independently or in combination one the following sets of verbal cues: (a) "walk fast" (Behrman, Teitelbaum, & Cauraugh, 1998;Ferrandez & Blin, 1991;Morris, Iansek, Matyas, & Summers, 1994), (b) "take big steps" (Baker, Rochester, & Nieuwboer, 2007Behrman et al, 1998;Canning, 2005;Iansek, Huxham, & McGinley, 2006;Lehman, Toole, Lofald, & Hirsch, 2005;Morris et al, 1996;Werner & Gentile, 2003), (c) "walk fast and take big steps" (Canning, Ada, & Woodhouse, 2008), (d) "swing arms while walking" (Werner & Gentile, 2003), and (e) "count rhythm while walking" (Behrman et al, 1998). While 11 of these studies examined the immediate effects of employing the instructional sets in a single laboratory-based testing session, Canning et al (2008) and Lehman et al (2005) investigated the effects of weekly training sessions.…”