Cueing for people with Parkinson's disease with freezing of gait: A narrative review of the state-of-the-art and novel perspectives.

Freezing, which manifests during gait and other movements, is an incapacitating motor symptom experienced by many patients with Parkinson's disease (PD). In rehabilitation, auditory and visual cueing methods are commonly applied to evoke a more goal-directed type of motor control and, as such, reduce freezing severity in patients with PD. In this narrative review, we summarize the current evidence regarding the effects of external cueing in patients with PD with freezing of gait (FOG) and provide suggestions on how to further improve cueing effectiveness with emerging technological developments. For this paper, we reviewed 24 articles describing the assessment of the effects of cues in patients with FOG (n=354). Because these studies mostly involved quasi-experimental designs, no methodological analysis was undertaken. In general, the evidence suggests that cue-augmented training can reduce FOG severity, improve gait parameters and improve upper-limb movements immediately after training. However, findings were not univocal, and long-term consolidation and transfer of the effects appear to be hampered specifically in this subgroup. With the increasing use of wearable technology, new possibilities are allowing for adapting the cue type, cue content and dose of cues to the needs of individual patients, which may boost the clinical use and efficiency of cued training in PD patients with FOG.

The relation between cognitive and motor dysfunction and motor imagery ability in patients with multiple sclerosis.

BACKGROUND: Motor imagery (MI) was recently shown to be a promising tool in neurorehabilitation. The ability to perform MI, however, may be impaired in some patients with neurological dysfunction. OBJECTIVE: The objective was to assess the relation between cognitive and motor dysfunction and MI ability in patients with multiple sclerosis (MS). METHODS: Thirty patients with MS underwent cognitive and motor screening, and also performed a composite test battery to assess their MI ability. This test battery consisted of a questionnaire, a hand rotation task and a test based on mental chronometry. Patients' MI ability was compared with the MI ability of age-matched healthy controls. Moreover, their MI scores were compared between body sides and were correlated with their scores on tests of motor and cognitive functioning. RESULTS: The average accuracy and temporal organization of MI significantly differed between MS patients and controls. Patients' MI accuracy significantly correlated with impairments in cognitive functioning, but was independent of motor functioning. MI duration, on the other hand, was independent of cognitive performance, but differed between the patients' most and least affected side. CONCLUSION: These findings are of use when considering the application of MI practice in MS patients' rehabilitation.

External cueing improves motor imagery quality in patients with Parkinson disease.

BACKGROUND: Patients with Parkinson disease (PD) are often profoundly slow in their performance of physical tasks, as well as in motor imagery (MI). This may limit the implementation and potential benefits of MI practice during rehabilitation. OBJECTIVE: The authors investigated whether the quality of MI could be improved by external cueing. METHODS: Fourteen patients with PD and 14 healthy controls physically executed and visually imagined a goal-directed aiming task and a box-and-block task, both in the presence and absence of visual and auditory cues. Mental chronometry and eye movement recording allowed objective evaluation of the temporal and spatial characteristics of MI when compared with physical execution. Visual analogue scales were used to assess imagery vividness. RESULTS: The presence of visual cues significantly reduced the patients' bradykinesia during MI and increased their imagery vividness. CONCLUSIONS: Visual cueing optimizes MI quality for PD patients and is a potential tool to increase the efficacy of MI practice in PD rehabilitation.

Motor imagery ability in patients with early- and mid-stage Parkinson disease.

BACKGROUND: Motor imagery has recently gained attention as a promising new rehabilitation method for patients with neurological disorders. Up to now, however, it has been unclear whether this practice method can also be successfully applied in the rehabilitation of patients with Parkinson disease (PD). OBJECTIVE: This study aimed to investigate whether the motor imagery ability of patients with PD is still intact despite basal ganglia dysfunctioning. METHODS: A total of 14 patients with early- and mid-stage PD (Hoehn and Yahr 1-3) and 14 healthy controls were evaluated by means of an extensive imagery ability assessment battery, consisting of 2 questionnaires, the Chaotic Motor Imagery Assessment battery, and a test based on mental chronometry. RESULTS: PD patients performed the imagery tasks more slowly than controls, but the motor imagery vividness and accuracy of most patients were well preserved. CONCLUSIONS: These results are promising regarding the potential use of motor imagery practice in the rehabilitation of patients with PD.

Facilitation of motor imagery through movement-related cueing.

In the past few years, the use of motor imagery as an adjunct to other forms of training has been studied extensively. However, very little attention has been paid to how imagery could be used to greatest effect. It is well known that the provision of external cues has a beneficial effect on motor skill acquisition and performance during physical practice. Since physical execution and mental imagery share several common mechanisms, we hypothesized that motor imagery might be affected by external cues in a similar way. To examine this, we compared the motor imagery performance of three groups of 15 healthy participants who either physically performed or imagined performing a goal-directed cyclical wrist movement in the presence or the absence of visual and/or auditory external cues. As outcome measures, the participants' imagery vividness scores and eye movements were measured during all conditions. We found that visual movement-related cues improved the spatial accuracy of the participants' eye movements during imagery, while auditory cues specifically enhanced their temporal accuracy. Furthermore, both types of cues significantly improved the participants' imagery vividness. These findings indicate that subjects may imagine a movement in a better way when provided with external movement-related stimuli, which may possibly be useful with regard to the efficiency of mental practice in (clinical) training protocols.