Training Based On Declarative Memory Cues Improved Gait In Patients With Parkinson's Disease

Improvement In Gait Performance After Training Based On Declarative Memory Cues In Patients With Parkinson's Disease: A Randomized Clinical Trial

Deficits in automatic motor control, characteristic of Parkinson's disease (PD), contribute to progressive impairment in gait performance. The use of declarative memory cues in order to promote the engagement of attention and activation of the next movement in gait may minimize the consequences of lack of automatic control. The purpose of this study is to verify the long-term efficiency of a new strategy based on declarative memory cue to improve the gait performance and independence in daily life activities (DLA) in patients with PD.

Background: Deficits in automatic motor control, characteristic of Parkinson's disease (PD), contribute to progressive impairment in gait performance. The use of declarative memory cues in order to promote the engagement of attention and activation of the next movement in gait may minimize the consequences of lack of automatic control. Objectives: To verify the long-term efficiency of a new strategy based on declarative memory cue to improve the gait performance and independence in daily life activities (DLA) in patients with PD. Design: Parallel prospective, single blind, randomized clinical trial. Setting: Brazilian Parkinson Association. Participants: Forty-four patients with PD in stages 2-3 of disease evolution according to Hoehn and Yahr Classification Interventions: The experimental training (ET) consisted of eight gait training sessions, twice a week, using the declarative memory cues strategy (DMCS). The control training (CT) consisted of a similar gait training without DMCS. Primary outcome measure: Gait performance in terms of speed and stride length. Secondary outcome measure: Independence in DLA according to Section II of the Unified Parkinson's Disease Rating Scale. Randomization: Participants were randomized into a control group (CG), which performed the CT, and an experimental group (EG), which performed the ET, through blinded drawing of names. Statistical analysis: The gait performance and ADL independence before, 2 and 60 days after the end of training were compared for CG and EG using Repeated-measures analysis of variance (RM-ANOVA).

The experimental training (ET) consisted of eight gait training sessions, twice a week, using the declarative memory cues strategy (DMCS).

The ET consisted of 3 phases being that the first one (Phase 1) was done only in the first session. Phase 1: patients received a short and simple explanation about the deficiency in automatic movement resulting from PD. Following explanation, the patient memorized a sequence of declarative cues. Phase 2: the patient organized a sequence of cues using cards illustrating the subcomponent movements (key movement) involved in taking steps. Phase 3: the patient had to train using declarative cues as a gait performance aid through 8 sets follow the instruction "Walk in your ordinary speed. Use the key movements and going to saying each of them while you make them. The declarative cues had to be evoked verbally by the patients themselves, during gait, triggering the corresponding movement.

The CT consisted of 3 phases, being the first one (Phase 1) was done only in the first session of training, and the other two (Phase 2 and 3) were repeated at each of the 8 sessions. Phase 1: Patients received a short and simple explanation about the deficiency in automatic movement resulting from PD. Phase 2: Patients received a general verbal attentional instruction of "pay attention to your steps and try to walk as better as you can", before starting the walk. Phase 3: motor training of gait, where the patient had to perform 8 sets, following the instruction "Walk in your ordinary speed, paying attention to your steps" in the identical trajectories of ET. Additional instructions or cues were not provided.

The first primary outcome was the gait speed (m/s). Patients were asked to walk in a straight trajectory of 20 meter following the sole instruction "upon the go signal, walk as fast as possible at the line and stop". The speed was calculated based on the time to walk 20 meters timed using a digital chronometer.

The second primary outcome was the stride length (cm) on gait. Patients were asked to walk in a straight trajectory of 20 meter following the sole instruction "upon the go signal, walk as fast as possible at the line and stop". The number of steps was measured using a pedometer.

The secondary outcome was independence in activities of daily living (ADL), assessed by Section II of the Unified Parkinson Disease Rating Scale (UPDRS-II). This section includes 12 questions (items 5 to 16) on patient's performance in ADL. Among these questions, two investigate gait performance (frequent fall due to freezing; inability to walk ), with scores ranging from zero (normal) to 4.

Inclusion Criteria: diagnosis of idiopathic Parkinson's disease according to the UK Brain Bank criteria; in stage 2-3 of the disease evolution according to the Hoehn and Yahr; treated with levodopa or its synergists; capable to ambulate independently indoors without aid; referring 5 to 15 years of education; good visual and auditory acuity. Exclusion Criteria: presence of other neurological (excluding PD), orthopedic or cardiopulmonary problems; visual and auditory deficiency; dementia [assessed by the Mini Mental State Examination (MMSE), cut-off 23]; depression [according to the Geriatric Depression Scale (GDS-15), cut-off 6] participation in other physical therapy training.

Department of Physiotherapy, Communication Science & Disorders, Occupational Therapy, School of Medicine, University of São Paulo

Department of Physiotherapy, Communication Science & Disorders, Occupational Therapy, School of Medicine, University of São Paulo