Prevalence of Delirium After Abdominal Surgery and Association With Ketamine: A Retrospective, Propensity-Matched Cohort Study.

IMPORTANCE: Delirium is a common postoperative complication for older patients in the ICU. Ketamine, used primarily as an analgesic, has been thought to prevent delirium. OBJECTIVE: Determine the prevalence and association of delirium with low-dose ketamine use in ICU patients after abdominal surgery. DESIGN: Single-center, retrospective, propensity-matched cohort study. SETTING: Eight hospital academic medical center. PATIENTS: Cohort comprising 1836 patients admitted to the ICU after abdominal surgery between June 23, 2018 and September 1, 2022. MAIN OUTCOMES AND MEASURES: Propensity score matching (PSM) with a 3:1 ratio between no-ketamine use and ketamine use was performed through a greedy algorithm (caliper of 0.005). Outcomes of interest included: delirium (assessed by Confusion Assessment Method-ICU), mean pain score (Numeric Pain Scale or Critical Care Pain Observation Tool score as available), mean opioid consumption (morphine milligram equivalents), length of stay (d), and mortality. RESULTS: Prevalence of delirium was 47.71% (95% CI, 45.41-50.03%) in the cohort. Of 1836 patients, 120 (6.54%) used low-dose ketamine infusion. After PSM, the prevalence of delirium was 56.02% (95% CI, 51.05-60.91%) in all abdominal surgery patients. The ketamine group had 41% less odds of delirium (odds ratio [OR] = 0.59; 95% CI, 0.37-0.94; p = 0.026) than patients with no-ketamine use. Patients with ketamine use had higher mean pain scores (3.57 ± 2.86 vs. 2.21 ± 2.09, p < 0.001). In the subgroup analysis, patients in the ketamine-use group 60 years old or younger had 64% less odds of delirium (OR = 0.36; 95% CI, 0.13-0.95; p = 0.039). The mean pain scores were higher in the ketamine group for patients 60 years old or older. There was no significant difference in mortality and opioid consumption. CONCLUSIONS AND RELEVANCE: Low-dose ketamine infusion was associated with lower prevalence of delirium in ICU patients following abdominal surgery. Prospective studies should further evaluate ketamine use and delirium.

Performing Dynamic Weight-Shifting Balance Exercises With a Smartphone-Based Wearable Telerehabilitation System for Home Use by Individuals With Parkinson's Disease: A Proof-of-Concept Study.

Telerehabilitation technology often helps individuals with Parkinson's disease (PD) to control their balance and improve postural stability. This proof-of-concept study describes the redesign of a smartphone-based wearable balance rehabilitation system, or Smarter Balance System (SBS) intended for in-home use, and determines the number of exercise sessions required to achieve steady-state balance exercise performance by people with PD who performed 6 weeks of in-home dynamic weight-shifting balance exercises. The redesigned SBS supplied real-time multimodal (visual and vibrotactile) biofeedback during dynamic weight-shifting balance exercises (WSBEs). A Technology Acceptance Model (TAM) questionnaire completed by participants validated its acceptability and use. The results of regression analyses of participants' balance exercise performance, based on the average cross-correlations and absolute position errors between the target motion and the exerciser's motion, showed exponential trends, a performance plateau after 3 weeks, and a quasi-steady state performance by the end of 6 consecutive weeks.

Risk factors and machine learning model for predicting hospitalization outcomes in geriatric patients with dementia.

Introduction: Geriatric patients with dementia incur higher healthcare costs and longer hospital stays than other geriatric patients. We aimed to identify risk factors for hospitalization outcomes that could be mitigated early to improve outcomes and impact overall quality of life. Methods: We identified risk factors, that is, demographics, hospital complications, pre-admission, and post-admission risk factors including medical history and comorbidities, affecting hospitalization outcomes determined by hospital stays and discharge dispositions. Over 150 clinical and demographic factors of 15,678 encounters (8407 patients) were retrieved from our institution's data warehouse. We further narrowed them down to twenty factors through feature selection engineering by using analysis of variance (ANOVA) and Glmnet. We developed an explainable machine-learning model to predict hospitalization outcomes among geriatric patients with dementia. Results: Our model is based on stacking ensemble learning and achieved accuracy of 95.6% and area under the curve (AUC) of 0.757. It outperformed prevalent methods of risk assessment for encounters of patients with Alzheimer's disease dementia (ADD) (4993), vascular dementia (VD) (4173), Parkinson's disease with dementia (PDD) (3735), and other unspecified dementias (OUD) (2777). Top identified hospitalization outcome risk factors, mostly from medical history, include encephalopathy, number of medical problems at admission, pressure ulcers, urinary tract infections, falls, admission source, age, race, anemia, etc., with several overlaps in multi-dementia groups. Discussion: Our model identified several predictive factors that can be modified or intervened so that efforts can be made to prevent recurrence or mitigate their adverse effects. Knowledge of the modifiable risk factors would help guide early interventions for patients at high risk for poor hospitalization outcome as defined by hospital stays longer than seven days, undesirable discharge disposition, or both. The interventions include starting specific protocols on modifiable risk factors like encephalopathy, falls, and infections, where non-existent or not routine, to improve hospitalization outcomes of geriatric patients with dementia. Highlights: A total 15,678 encounters of Geriatrics with dementia with a final 20 risk factors.Developed a predictive model for hospitalization outcomes for multi-dementia types.Risk factors for each type were identified including those amenable to interventions.Top factors are encephalopathy, pressure ulcers, urinary tract infection (UTI), falls, and admission source.With accuracy of 95.6%, our ensemble predictive model outperforms other models.

Ex vivo expansion of dysfunctional regulatory T lymphocytes restores suppressive function in Parkinson's disease.

Inflammation is a pathological hallmark of Parkinson's disease (PD). Chronic pro-inflammatory responses contribute to the loss of neurons in the neurodegenerative process. The present study was undertaken to define the peripheral innate and adaptive immune contributions to inflammation in patients with PD. Immunophenotyping revealed a shift of peripheral myeloid and lymphoid cells towards a pro-inflammatory phenotype. Regulatory T cells (Tregs) were reduced in number, and their suppression of T responder proliferation decreased. The PD Tregs did not suppress activated pro-inflammatory myeloid cells. Ex vivo expansion of Tregs from patients with PD restored and enhanced their suppressive functions while expanded Tregs displayed increased expression of foxp3, il2ra (CD25), nt5e (CD73), il10, il13, ctla4, pdcd1 (PD1), and gzmb. Collectively, these findings documented a shift towards a pro-inflammatory peripheral immune response in patients with PD; the loss of Treg suppressive functions may contribute significantly to this response, supporting PD as a disorder with extensive systemic pro-inflammatory responses. The restoration and enhancement of Treg suppressive functions following ex vivo expansion may provide a potential cell therapeutic approach for patients with PD.

Effects of a Smartphone-Based Wearable Telerehabilitation System for In-Home Dynamic Weight-Shifting Balance Exercises by Individuals with Parkinson's Disease.

This paper describes the effects of a smartphone-based wearable telerehabilitation system (called Smarter Balance System, SBS) intended for in-home dynamic weight-shifting balance exercises (WSBEs) by individuals with Parkinson's disease (PD). Two individuals with idiopathic PD performed in-home dynamic WSBEs in anterior-posterior (A/P) and medial-lateral (M/L) directions, using the SBS 3 days per week for 6 weeks. Exercise performance was quantified by cross-correlation (XCORR) and position error (PE) analyses. Balance and gait performance and level of fear of falling were assessed by limit of stability (LOS), Sensory Organization Test (SOT), Falls Efficacy Scale (FES), Activities-specific Balance Confidence (ABC), and Dynamic Gait Index (DGI) at the pre-(beginning of week 1), post-(end of week 6), and retention-(1 month after week 6) assessments. Regression analyses found that exponential trends of the XCORR and PE described exercise performance more effectively than linear trends. Range of LOS in both A/P and M/L directions improved at the post-assessment compared to the pre-assessment, and was retained at the retention assessment. The preliminary findings emphasize the advantages of wearable balance telerehabilitation technologies when performing in-home balance rehabilitation exercises.

A new smart balance rehabilitation system technology platform: Development and preliminary assessment of the Smarter Balance System for home-based balance rehabilitation for individuals with Parkinson's disease.

Physical and balance rehabilitation programs have been shown to improve postural stability and balance performance and to be more effective than dopaminergic medication and surgical treatments for individuals with Parkinson's disease (PD). This paper describes the development and assessment of a new Smarter Balance System (SBS) intended for home-based use by individuals with PD. We report the initial results of a long-term study currently underway that quantifies the clinical impacts of using the SBS during a 6-week, home-based rehabilitation program. Preliminary results indicate that individuals with PD improved their balance and postural stability, and maintained the improvements for 1 month after completing the 6-week, homebased rehabilitation program with the SBS.

Process and Results of Implementing Disease Management Program in Patients with First-time Ischemic Stroke.

BACKGROUND: This study aimed to examine the effect of disease management program (DMP) on the patients with first-time ischemic stroke (IS). METHODS: A DMP with 4 parts of performance indicators (PIs, including outpatient, emergency department, inpatient and follow-up treatment) was implemented in patients with stroke in 2 hospitals (Hospital T and R) in Shanghai China from 2007-2010. The effect of DMP on the outcome of IS patients was analyzed according to the criteria of the National Institute of Health Stroke Scale (NIHSS). Furthermore, the total effective rate of DMP, average length of stay, hospitalization cost, and cost-effectiveness ratio (CER) between DMP and non-DMP patients were calculated, followed by the cost-effectiveness analysis. RESULTS: The total effective rate of DMP (T: 69.9%; R: 76.6%) was significantly (P<0.05) higher than that of non-DMP (T: 60.8%; R: 62.7%) group in the same hospital. In addition, a significant (P<0.05) difference in effective rate was observed between DMP and non-DMP at the NIHSS score ≥ 7. Furthermore, the average length of stay and hospitalization cost of the patients in DMP group were significantly (P<0.05) lower than those in non-DMP group. A superior CER was also found in DMP group than non-DMP group. CONCLUSION: The implementation of DMP for IS can effectively improve the treatment outcome and reduce the average length of stay and hospitalization cost.

Usability and Validation of the Smarter Balance System: An Unsupervised Dynamic Balance Exercises System for Individuals With Parkinson's Disease.

Conventional physical and balance rehabilitation programs to improve balance performance and increase postural stability are often limited due to cost, availability of physical therapists, and accessibility to rehabilitation facilities. Exercise compliance is also affected by a loss of memory and decline in motivation in prescribed home-based balance training. We have developed the smarter balance system (SBS) incorporating multimodal biofeedback (visual plus vibrotactile) intended for clinical and home-based balance rehabilitation and assessed its efficacy on physical therapists' recommended dynamic weight-shifting balance exercises (dynamic WSBE) in individuals with Parkinson's disease (PD). The SBS consists of a smartphone and custom belt housing a processing unit, miniaturized sensors, and vibrating actuators (tactors). Visual and vibrotactile biofeedback guidance during dynamic WSBE is generated by the SBS's custom app based on 90% of the user's limits of stability (LOS). Ten individuals with idiopathic PD having impaired postural stability participated in one unsupervised session comprising 24 trials of the dynamic WSBE in a laboratory setting. Participants' limits of stability (LOS) in the anterior-posterior (A/P) and medial-lateral (M/L) direction were measured at the pre- and post-session. To assess the efficacy of SBS to provide guidance during balance rehabilitation using dynamic WSBE, cross-correlation (XCOR), position error (PE), and percent of tactor activation (PTA) were measured. There was a significant increase in LOS between the pre- and post-training session in both A/P and M/L directions. The average XCOR across all participants were 0.87 (SD = 0.11) and 0.76 (SD = 0.11) for the A/P and M/L direction respectively. The average PE and PTA for the A/P direction was 1.17 deg (SD = 0.60) and 65.35% (SD = 15.1) respectively and 0.74 deg (SD = 0.28) and 31.3% (SD = 16.42) in the M/L direction respectively. There was no significant effect of trials for XCOR, PE, and PTA. Participants' LOS significantly increased after one session of the dynamic WSBE. Individuals with PD could accurately follow the target movements during the dynamic WSBE using the SBS. Future studies will assess the efficacy and acceptability of the SBS during long-term in-home rehabilitative training for balance-impaired individuals.

Post-stroke dyskinesias.

Strokes, whether ischemic or hemorrhagic, are among the most common causes of secondary movement disorders in elderly patients. Stroke-related (vascular) movement disorders, however, are uncommon complications of this relatively common disease. The spectrum of post-stroke movement disorders is broad and includes both hypo- and hyperkinetic syndromes. Post-stroke dyskinesias are involuntary hyperkinetic movements arising from cerebrovascular insults and often present with mixed phenotypes of hyperkinesia which can sometimes be difficult to classify. Nevertheless, identification of the most relevant motor phenotype, whenever possible, allows for a more specific phenomenological categorization of the dyskinesia and thus helps guide its treatment. Fortunately, post-stroke dyskinesias are usually self-limiting and resolve within 6 to 12 months of onset, but a short-term pharmacotherapy might sometimes be required for symptom control. Functional neurosurgical interventions targeting the motor thalamus or globus pallidus interna might be considered for patients with severe, disabling, and persistent dyskinesias (arbitrarily defined as duration longer than 12 months).

Comparing clinical features of young onset, middle onset and late onset Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) affects 1-2% of the population over 65 years. There is evidence that the clinical features differ with age at symptom onset, but published information is scarce. METHODS: We reviewed the charts of 593 PD patients and divided them into young onset (≤49 years), middle onset (50-69 years) and late onset (≥70 years) groups. Data collected included age at symptom onset, year of onset, family history of Parkinson's disease in first and second degree relatives, predominant first symptom, first anti parkinsonian medication prescribed, frequency of levodopa-induced dyskinesia, therapy related dystonia, therapy related gastrointestinal side effects, hallucination, dementia, depression and apathy. RESULTS: The middle onset was the largest group (51%), followed by the late onset (39%) and the young onset (10%) groups. Young onset patients had a more frequent family history of Parkinson's disease and a longer survival. Symptoms other than tremor were more frequent as the initial symptom of the young onset group, and the frequency of tremor as the first symptom increased with advancing age at onset. Depression was more frequent in the young onset group. The frequency of treatment related dyskinesia or dystonia decreased with advancing age at onset. CONCLUSION: We have identified specific clinical differences in Parkinson's disease related to the patient's age at onset and added to the existing knowledge of the variability of disease presentation. We suggest an age of onset of 49 years or less for the definition of young onset PD.

Deep brain stimulation in Parkinson's disease.

For the last 50 years, levodopa has been the cornerstone of Parkinson's disease management. However, a majority of patients develop motor complications a few years after therapy onset. Deep brain stimulation has been approved by the FDA as an adjunctive treatment in Parkinson disease, especially aimed at controlling these complications. However, the exact mechanism of action of deep brain stimulation, the best nucleus to target as well as the best timing for surgery are still debatable. We here provide an in-depth and critical review of the current literature on this topic.

Two different 18F-FDG brain PET metabolic patterns in autoimmune limbic encephalitis.

PURPOSE: Autoimmune limbic encephalitis (ALE) is a severe, but treatable, neuropsychiatric disorder that is difficult to diagnose clinically. With the goal of improving diagnosis of this disorder, we retrospectively evaluated the cerebral FDG PET pattern in a group of patients with ALE. MATERIALS AND METHODS: Nine adult patients with subacute cognitive decline were eventually diagnosed with ALE based on clinical presentation, cerebrospinal fluid inflammatory markers, and response to immunosuppressive therapy. All patients received FDG PET brain scanning during their diagnostic evaluation, which were retrospectively reviewed for this study. RESULTS: Our patients' scans fell into 2 readily separable patterns. Five younger patients had a mixed metabolic pattern most easily recognized by pronounced occipital hypometabolism, accentuated by hypermetabolism in the temporal and orbitofrontal cortex. Other, milder findings were also present. Once this unusual pattern was established as corresponding to ALE, it helped lead to the correct clinical diagnosis in the last 2 patients. Four older patients had scans that closely resembled diffuse neurodegenerative disease. CONCLUSIONS: We found 2 different PET scan patterns in patients with ALE. One is an easily recognizable mixture of hyper- and hypometabolism that has also been described in a few recent case reports and is potentially specific for ALE. The other is indistinguishable from neurodegenerative disease. We propose that awareness of these patterns may contribute to the diagnosis of this elusive, but treatable, neurologic disorder.

Randomized trial of deep brain stimulation for Parkinson disease: thirty-six-month outcomes.

OBJECTIVES: Our objective was to compare long-term outcomes of deep brain stimulation (DBS) of the globus pallidus interna (GPi) and subthalamic nucleus (STN) for patients with Parkinson disease (PD) in a multicenter randomized controlled trial. METHODS: Patients randomly assigned to GPi (n = 89) or STN DBS (n = 70) were followed for 36 months. The primary outcome was motor function on stimulation/off medication using the Unified Parkinson's Disease Rating Scale motor subscale. Secondary outcomes included quality of life and neurocognitive function. RESULTS: Motor function improved between baseline and 36 months for GPi (41.1 to 27.1; 95% confidence interval [CI] -16.4 to -10.8; p < 0.001) and STN (42.5 to 29.7; 95% CI -15.8 to -9.4; p < 0.001); improvements were similar between targets and stable over time (p = 0.59). Health-related quality of life improved at 6 months on all subscales (all p values significant), but improvement diminished over time. Mattis Dementia Rating Scale scores declined faster for STN than GPi patients (p = 0.01); other neurocognitive measures showed gradual decline overall. CONCLUSIONS: The beneficial effect of DBS on motor function was stable and comparable by target over 36 months. Slight declines in quality of life following initial gains and gradual decline in neurocognitive function likely reflect underlying disease progression and highlight the importance of nonmotor symptoms in determining quality of life. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that improvement of motor symptoms of PD by DBS remains stable over 3 years and does not differ by surgical target. Neurology® 2012;79:55-65.

An exploratory study of activity in veterans with Parkinson's disease.

Movement disorder specialists have limited information on the specifics of how patients with Parkinson's disease (PD) spend their time. We deemed it important to examine the relationships among activity and daily energy expenditure (DEE), non-motor symptoms, and body mass index in veterans with PD who were outpatients at a Veterans Affairs medical center. In this exploratory study, we mailed demographic and activity questionnaires and gathered data on 100 patients. Activity was categorized into five domains and three intensity levels, and DEE was measured in kilocalories. Light activities accounted for 64.9% of DEE (9.1 h), moderate activities for 32.9% (2.1 h), and vigorous activities for 2.2% (0.1 h) of DEE. Television viewing comprised 10.6% (2.5 h) of the day. The effects of non-motor symptoms were significantly associated with more time spent on activities of daily life (ADL). Patients rated fatigue and pain as having the greatest impact on their daily activities. The overweight/obese group of PD patients expended more overall DEE (p = 0.044) and more DEE on social activities (p = 0.024) and light intensity activities (p = 0.021) than did the underweight/normal group. Leisure activities for both groups changed from active to passive. Veterans with PD primarily expended DEE on ADL, TV viewing, and light intensity activities. Television viewing time may have been under reported. Movement disorder specialists can be more proactive in referring patients to physical therapy and encouraging their participation in community exercise and support groups.

Assessment of appropriate medication administration for hospitalized patients with Parkinson's disease.

BACKGROUND: For Parkinson's disease (PD) patients, adherence to a regular PD medication schedule is important in achieving optimal symptom control. There are few published studies quantifying PD medication administrations in hospitalized PD patients. METHODS: Hospitalization records for 100 veterans with idiopathic PD and admitted to our center were reviewed to determine the on time rate and contraindicated medication doses. A barcode based computerized medication administration system within the electronic medical record provided information of the exact time the medication was given to a patient. RESULTS: Eighty-nine idiopathic PD patients met study inclusion criteria. Among them, 87 were on levodopa monotherapy or in combination with other PD medications. Two patients were on dopamine agonists only. A total of 3873 doses of PD medications were prescribed during hospitalization. Among 675 incorrect medication administrations, 322 doses were omitted, 300 doses late by ≥ 30 min, and 53 doses given early by ≥ 30 min. Contraindicated medications were prescribed for 19 patients. The correct administration percentage was lower during the first 2 days post-admission compared to subsequent days (mean 74.6% vs. 82.8%) and higher for patients who had neurological consultations (mean 85.5% vs. 76.5%). Correct administration rates were better for patient-based medication schedules (85.6%) than with hospital-based schedules (77.5%), but did not achieve statistical significance. CONCLUSION: Adherence to regular PD medication dosing schedules during hospitalization is problematic, but improves with specialist consultation. Staff involved in the admission process for PD patients should work to safeguard against disruption of the prescribed home dosing schedule.

Gait variability in Parkinson's disease: influence of walking speed and dopaminergic treatment.

OBJECTIVES: To study the effects of levodopa and walking speed on gait variability in individuals with Parkinson's disease (PD). METHODS: Thirty-three individuals with PD were studied. Their mean age was 70.61±9.23 year. The average time since diagnosis was 9.65±5.80 year. Gait variability was studied while 'OFF' and 'ON' dopaminergic medication when the subjects walked at their usual and fastest speeds. RESULTS: Variability of step time, double support time, stride length and stride velocity decreased significantly (P=0.037; P=0.037; P=0.022; P=0.043, respectively) after dopaminergic treatment. When subjects increased walking speed, the variability of stride length and stride velocity decreased significantly (P=0.038 and P=0.004, respectively) both while 'OFF' and 'ON' levodopa. Increasing walking speed did not change the variability of step time and double support time regardless of medication status. CONCLUSIONS: Levodopa decreased gait variability in persons with PD. Stride length and stride velocity variability appeared to be speed dependent parameters, whereas, the variability of step time and double support time appeared to be speed independent measures. Levodopa had positive effects on gait stability in PD.

Feasibility of using cranial electrotherapy stimulation for pain in persons with Parkinson's disease.

Objectives. To assess the feasibility of treating musculoskeletal pain in the lower back and/or lower extremities in persons with Parkinson's disease (PD) with cranial electrotherapy stimulation (CES). Design. Randomized, controlled, double-blind trial. Setting. Veterans Affairs Medical Center, Community. Participants. Nineteen persons with PD and pain in the lower back and/or lower extremities. Thirteen provided daily pain rating data. Intervention. Of the thirteen participants who provided daily pain data, 6 were randomly provided with active CES devices and 7 with sham devices to use at home 40 minutes per day for six weeks. They recorded their pain ratings on a 0-to-10 scale immediately before and after each session. Main Outcome Measure. Average daily change in pain intensity. Results. Persons receiving active CES had, on average, a 1.14-point decrease in pain compared with a 0.23-point decrease for those receiving sham CES (Wilcoxon Z = -2.20, P = .028). Conclusion. Use of CES at home by persons with PD is feasible and may be somewhat helpful in decreasing pain. A larger study is needed to determine the characteristics of persons who may experience meaningful pain reduction with CES. Guidelines for future studies are provided.

Pallidal versus subthalamic deep-brain stimulation for Parkinson's disease.

BACKGROUND: Deep-brain stimulation is the surgical procedure of choice for patients with advanced Parkinson's disease. The globus pallidus interna and the subthalamic nucleus are accepted targets for this procedure. We compared 24-month outcomes for patients who had undergone bilateral stimulation of the globus pallidus interna (pallidal stimulation) or subthalamic nucleus (subthalamic stimulation). METHODS: At seven Veterans Affairs and six university hospitals, we randomly assigned 299 patients with idiopathic Parkinson's disease to undergo either pallidal stimulation (152 patients) or subthalamic stimulation (147 patients). The primary outcome was the change in motor function, as blindly assessed on the Unified Parkinson's Disease Rating Scale, part III (UPDRS-III), while patients were receiving stimulation but not receiving antiparkinsonian medication. Secondary outcomes included self-reported function, quality of life, neurocognitive function, and adverse events. RESULTS: Mean changes in the primary outcome did not differ significantly between the two study groups (P=0.50). There was also no significant difference in self-reported function. Patients undergoing subthalamic stimulation required a lower dose of dopaminergic agents than did those undergoing pallidal stimulation (P=0.02). One component of processing speed (visuomotor) declined more after subthalamic stimulation than after pallidal stimulation (P=0.03). The level of depression worsened after subthalamic stimulation and improved after pallidal stimulation (P=0.02). Serious adverse events occurred in 51% of patients undergoing pallidal stimulation and in 56% of those undergoing subthalamic stimulation, with no significant between-group differences at 24 months. CONCLUSIONS: Patients with Parkinson's disease had similar improvement in motor function after either pallidal or subthalamic stimulation. Nonmotor factors may reasonably be included in the selection of surgical target for deep-brain stimulation. (ClinicalTrials.gov numbers, NCT00056563 and NCT01076452.)

A pilot study: influence of visual cue color on freezing of gait in persons with Parkinson's disease.

PURPOSE: To investigate the effect of red and green light beams on gait and freezing of gait (FOG) in persons with Parkinson's disease (PD). METHODS: Seven persons with PD who experienced FOG participated in the study. Gait and turning performances were studied while walking with canes with red, green, and no light beams while "off" and "on" anti-Parkinsonian medications. Gait speed, cadence, and stride were recorded. Time and number of freezing episodes were recorded during a 50-foot walk and a 360° turn. RESULTS: During 'off' medication, compared to no light, stride length improved when using the green light, but not the red. During the 50-foot walk, freezing episodes were reduced when using the green light compared to both the red and no light. During the 360° turn, time, number of steps and number of freezing episodes were reduced using the green light compared to the red and no light. During 'on' medication, gait speed and stride length improved more with the green light compared to the red. Neither color showed any effect on cadence during either medication state. CONCLUSION: A green light improved gait and alleviate FOG in persons with PD better than a red light or no light.