The effects of high frequency subthalamic stimulation on balance performance and fear of falling in patients with Parkinson's disease

Effects of deep brain stimulation on the kinematics of gait and balance in patients with idiopathic Parkinson's disease

BACKGROUND

Advanced stages of idiopathic Parkinson's disease are often characterised by gait alterations and postural instability. Despite improvements in patients' motor symptoms after deep brain stimulation of the subthalamic nucleus, its effects on gait and balance remain a matter of debate. This study investigated the effects of deep brain stimulation on balance and kinematic parameters of gait.

METHODS

The gait of 26 patients with advanced idiopathic Parkinson's disease was analysed before and after (between 3 and 6 months) after bilateral deep brain stimulation of the subthalamic nucleus. Computerised analysis was used to study cadence, number of cycles with the correct support sequence, number of cycles, duration of the cycle stages, and knee and ankle goniometry. Balance, postural instability, and mobility were assessed using the Tinetti and Timed Up and Go test.

FINDINGS

After stimulation, the following changes were significant (p < 0.01): number of cycles with the correct support sequence, number of total cycles, and foot contact. Patients improved significantly (p < 0.01) in the Tinetti and Timed Up and Go tests, the risk factors for falls changed from high (median 17) to low (median 25), and they improved from minor dependence (statistical median 14) to normality (statistical median 8.70).

INTERPRETATION

Deep brain stimulation to inhibit hyperactivity of the subthalamic nucleus was associated with an improvement in the space-time variables of gait and balance in patients with Parkinson's disease for up to 3-6 months. These results highlight the major role of the subthalamic nucleus in motor control mechanisms during locomotion and balance.

Deep brain stimulation in the subthalamic nuclei alters postural alignment and adaptation in Parkinson's disease

Parkinson’s disease (PD) can produce postural abnormalities of the standing body position such as kyphosis. We investigated the effects of PD, deep brain stimulation (DBS) in the subthalamic nucleus (STN), vision and adaptation on body position in a well-defined group of patients with PD in quiet standing and during balance perturbations. Ten patients with PD and 25 young and 17 old control participants were recruited. Body position was measured with 3D motion tracking of the ankle, knee, hip, shoulder and head. By taking the ankle as reference, we mapped the position of the joints during quiet standing and balance perturbations through repeated calf muscle vibration. We did this to explore the effect of PD, DBS in the STN, and vision on the motor learning process of adaptation in response to the repeated stimulus. We found that patients with PD adopt a different body position with DBS ON vs. DBS OFF, to young and old controls, and with eyes open vs. eyes closed. There was an altered body position in PD with greater flexion of the head, shoulder and knee (p≤0.042) and a posterior position of the hip with DBS OFF (p≤0.014). With DBS ON, body position was brought more in line with the position taken by control participants but there was still evidence of greater flexion at the head, shoulder and knee. The amplitude of movement during the vibration period decreased in controls at all measured sites with eyes open and closed (except at the head in old controls with eyes open) showing adaptation which contrasted the weaker adaptive responses in patients with PD. Our findings suggest that alterations of posture and greater forward leaning with repeated calf vibration, are independent from reduced movement amplitude changes. DBS in the STN can significantly improve body position in PD although the effects are not completely reversed. Patients with PD maintain adaptive capabilities by leaning further forward and reducing movement amplitude despite their kyphotic posture.

Strategic alterations of posture are delayed in Parkinson's disease patients during deep brain stimulation

Parkinson’s disease (PD) is characterized by rigidity, akinesia, postural instability and tremor. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) reduces tremor but the effects on postural instability are inconsistent. Another component of postural control is the postural strategy, traditionally referred to as the ankle or hip strategy, which is determined by the coupling between the joint motions of the body. We aimed to determine whether DBS STN and vision (eyes open vs. eyes closed) affect the postural strategy in PD in quiet stance or during balance perturbations. Linear motion was recorded from the knee, hip, shoulder and head in 10 patients with idiopathic PD with DBS STN (after withdrawal of other anti-PD medication), 25 younger adult controls and 17 older adult controls. Correlation analyses were performed on anterior–posterior linear motion data to determine the coupling between the four positions measured. All participants were asked to stand for a 30 s period of quiet stance and a 200 s period of calf vibration. The 200 s vibration period was subdivided into four 50 s periods to study adaptation between the first vibration period (30–80 s) and the last vibration period (180–230 s). Movement was recorded in patients with PD with DBS ON and DBS OFF, and all participants were investigated with eyes closed and eyes open. DBS settings were randomized and double-blindly programmed. Patients with PD had greater coupling of the body compared to old and young controls during balance perturbations (p ≤ 0.046). Controls adopted a strategy with greater flexibility, particularly using the knee as a point of pivot, whereas patients with PD adopted an ankle strategy, i.e., they used the ankle as the point of pivot. There was higher flexibility in patients with PD with DBS ON and eyes open compared to DBS OFF and eyes closed (p ≤ 0.011). During balance perturbations, controls quickly adopted a new strategy that they retained throughout the test, but patients with PD were slower to adapt. Patients with PD further increased the coupling between segmental movement during balance perturbations with DBS ON but retained a high level of coupling with DBS OFF throughout balance perturbations. The ankle strategy during balance perturbations in patients with PD was most evident with DBS OFF and eyes closed. The increased coupling with balance perturbations implies a mechanism to reduce complexity at a cost of exerting more energy. Strategic alterations of posture were altered by DBS in patients with PD and were delayed. Our findings therefore show that DBS does not fully compensate for disease-related effects on posture.

Spectral analysis of body movement during deep brain stimulation in Parkinson's disease

BACKGROUND

The characteristics of Parkinson's disease (PD) include postural instability and resting tremor. However, reductions of tremor amplitude do not always improve postural stability.

RESEARCH QUESTION

What is the effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) on spectral analysis of body movement in patients with PD when tested without anti-PD medication? The effect of visual cues was also studied.

METHODS

Ten patients with PD (mean age 64.3 years, range 59-69 years) and 17 control participants (mean age 71.2 years, range 65-79 years) were recruited. Spectral power following a period of quiet stance (35 s) was analysed in three different spectral power bands (0-4 Hz, 4-7 Hz and 7-25 Hz). Motion markers were secured to the head, shoulder, hip, and knee, which recorded movements in two directions, the anteroposterior and lateral.

RESULTS

DBS STN significantly changed the spectral distribution pattern across the body in the anteroposterior (p = 0.029) and lateral directions (p ≤ 0.003). DBS predominantly reduced spectral power at the head (p ≤ 0.037) and shoulder (p ≤ 0.031) in the lateral direction. The spectral power of the lower and upper body in patients with PD, with DBS ON, were more similar to the control group, than to DBS OFF. Visual cues mainly reduced spectral power in the anteroposterior direction at the shoulder (p ≤ 0.041) in controls and in patients with PD with DBS ON.

SIGNIFICANCE

There is an altered postural strategy in patients with PD with DBS ON as shown by an altered spectral power distribution pattern across body segments and a reduction of spectral power in the lateral direction at the head and shoulder. A reduction of spectral power in controls and in patients with PD with DBS ON suggests that visual cues are able to reduce spectral power to some extent, but not with DBS OFF where postural sway and power are larger.

Safety and Tolerability of Burst-Cycling Deep Brain Stimulation for Freezing of Gait in Parkinson's Disease

Background: Freezing of gait (FOG) is a common symptom in Parkinson’s disease (PD) and can be difficult to treat with dopaminergic medications or with deep brain stimulation (DBS). Novel stimulation paradigms have been proposed to address suboptimal responses to conventional DBS programming methods. Burst-cycling deep brain stimulation (BCDBS) delivers current in various frequencies of bursts (e.g., 4, 10, or 15 Hz), while maintaining an intra-burst frequency identical to conventional DBS.

Objective: To evaluate the safety and tolerability of BCDBS in PD patients with FOG.

Methods: Ten PD subjects with STN or GPi DBS and complaints of FOG were recruited for this single center, single blinded within-subject crossover study. For each subject, we compared 4, 10, and 15 Hz BCDBS to conventional DBS during the PD medication-OFF state.

Results: There were no serious adverse events with BCDBS. It was feasible and straightforward to program BCDBS in the clinic setting. The benefit was comparable to conventional DBS in measures of FOG, functional mobility and in PD motor symptoms. BCDBS had lower battery consumption when compared to conventional DBS.

Conclusions: BCDBS was feasible, safe and well tolerated and it has potential to be a viable future DBS programming strategy.

Exploring the effects of deep brain stimulation and vision on tremor in Parkinson's disease - benefits from objective methods

Background

Tremor is a cardinal symptom of Parkinson’s disease (PD) that may cause severe disability. As such, objective methods to determine the exact characteristics of the tremor may improve the evaluation of therapy. This methodology study aims to validate the utility of two objective technical methods of recording Parkinsonian tremor and evaluate their ability to determine the effects of Deep Brain Stimulation (DBS) of the subthalamic nucleus and of vision.

Methods

We studied 10 patients with idiopathic PD, who were responsive to _L-Dopa and had more than 1 year use of bilateral subthalamic nucleus stimulation. The patients did not have to display visible tremor to be included in the study. Tremor was recorded with two objective methods, a force platform and a 3 dimensional (3D) motion capture system that tracked movements in four key proximal sections of the body (knee, hip, shoulder and head). They were assessed after an overnight withdrawal of anti-PD medications with DBS ON and OFF and with eyes open and closed during unperturbed and perturbed stance with randomized calf vibration, using a randomized test order design.

Results

Tremor was detected with the Unified Parkinson’s Disease Rating Scale (UPDRS) in 6 of 10 patients but only distally (hands and feet) with DBS OFF. With the force platform and the 3D motion capture system, tremor was detected in 6 of 10 and 7 of 10 patients respectively, mostly in DBS OFF but also with DBS ON in some patients. The 3D motion capture system revealed that more than one body section was usually affected by tremor and that the tremor amplitude was non-uniform, but the frequency almost identical, across sites. DBS reduced tremor amplitude non-uniformly across the body. Visual input mostly reduced tremor amplitude with DBS ON.

Conclusions

Technical recording methods offer objective and sensitive detection of tremor that provide detailed characteristics such as peak amplitude, frequency and distribution pattern, and thus, provide information that can guide the optimization of treatments. Both methods detected the effects of DBS and visual input but the 3D motion system was more versatile in that it could detail the presence and properties of tremor at individual body sections.

Deep brain stimulation in Parkinson's disease: A multicentric, long-term, observational pilot study

BACKGROUND

The impact of deep brain stimulation (DBS) on cognitive and urinary disorders, falls, and eventually hospitalizations and mortality in Parkinson's disease (PD) is still debated.

OBJECTIVE

We compared the rates of dementia, mild cognitive impairment (MCI), urinary incontinence, nocturia, falls, hospitalizations, and mortality in a cohort of PD patients undergoing DBS with a cohort of medically-treated patients chosen as controls.

METHODS

We conducted a retrospective pilot study in six Italian DBS centers. 91 PD patients receiving DBS and 91 age- and gender-matched controls receiving the best medical treatment alone with a minimum follow-up of one year were enrolled. Clinical data were collected from baseline to the last follow-up visit using an ad-hoc developed web-based system.

RESULTS

The risk of dementia was similar in the two groups while patients in the surgical cohort had lower rates of MCI, urinary incontinence, nocturia, and falls. In contrast, the risk of hospital admissions related to PD was higher in the surgical cohort. However, when excluding hospitalizations related to DBS surgery, the difference between the two cohorts was not significant. The surgical cohort had a lower number of hospitalizations not related to PD. The risk of death was similar in the two groups.

CONCLUSION

Despite a higher risk of hospitalization, patients receiving DBS had a lower rate of MCI, urinary incontinence, nocturia and falls, without evidence of an increased risk of dementia and mortality. Although these findings need to be confirmed in prospective studies, they seem to suggest that DBS may play a significant role in the management of non-motor symptoms and common complications of advanced PD.

Deep Brain Stimulation to Alleviate Freezing of Gait and Cognitive Dysfunction in Parkinson's Disease: Update on Current Research and Future Perspectives

Freezing of gait (FOG) is a gait disorder featured by recurrent episodes of temporary gait halting and mainly found in advanced Parkinson's disease (PD). FOG has a severe impact on the quality of life of patients with PD. The pathogenesis of FOG is unclear and considered to be related to several brain areas and neural circuits. Its close connection with cognitive disorder has been proposed and some researchers explain the pathogenesis using the cognitive model theory. FOG occurs concurrently with cognitive disorder in some PD patients, who are poorly responsive to medication therapy. Deep brain stimulation (DBS) proves effective for FOG in PD patients. Cognitive impairment plays a role in the formation of FOG. Therefore, if DBS works by improving the cognitive function, both two challenging conditions can be ameliorated by DBS. We reviewed the clinical studies related to DBS for FOG in PD patients over the past decade. In spite of the varying stimulation parameters used in different studies, DBS of either subthalamic nucleus (STN) or pedunculopontine nucleus (PPN) alone or in combination can improve the symptoms of FOG. Moreover, the treatment efficacy can last for 1–2 years and DBS is generally safe. Although few studies have been conducted concerning the use of DBS for cognitive disorder in FOG patients, the existing studies seem to indicate that PPN is a potential therapeutic target to both FOG and cognitive disorder. However, most of the studies have a small sample size and involve sporadic cases, so it remains uncertain which nucleus is the optimal target of stimulation. Prospective clinical trials with a larger sample size are needed to systematically assess the efficacy of DBS for FOG and cognitive disorder.

Factors Contributing to Perceived Walking Difficulties in People with Parkinson's Disease

BACKGROUND

While walking difficulties are common in people with Parkinson's disease (PD), little is known about factors that independently contribute to their perceived walking difficulties.

OBJECTIVE

To identify factors that independently contribute to perceived walking difficulties in people with PD.

METHODS

This study involved 243 (62% men) participants; their mean (min-max) age and PD duration were 70 (45-93) and 8 (1-43) years, respectively. A postal survey preceded a home visit that included observations, clinical tests, questions and questionnaires that were administered as a structured interview. Perceived walking difficulties (dependent variable) were assessed with the self-administered generic Walk-12 (Walk-12G, scored 0-42, higher = worse). Independent variables included personal (e.g., age and general self-efficacy) and social environmental factors (e.g., social support and living situation) as well as disease-related factors including motor (e.g., freezing of gait (FOG) and postural instability) and non-motor symptoms (e.g., fatigue and orthostatic hypotension). Linear multiple regression analysis was used to identify factors that independently contributed to perceived walking difficulties.

RESULTS

Eight significant independent variables explained 56.3% of the variance in perceived walking difficulties. FOG was the strongest significant contributing factor to perceived walking difficulties, followed by general self-efficacy, fatigue, PD duration, lower extremity function, orthostatic hypotension, bradykinesia and postural instability.

CONCLUSION

Motor and non-motor symptoms as well as personal factors (i.e., general self-efficacy) seem to be of importance for perceived walking difficulties in PD. These findings might nurture future interventions that address modifiable factors in order to enhance walking ability in people with PD.

Concerns About Falling in Parkinson's Disease: Associations with Disabilities and Personal and Environmental Factors

BACKGROUND

Fear of falling can be conceptualized in different ways, e.g., as concerns about falling or low fall-related self-efficacy. It is common in people with Parkinson's disease (PD), and there is growing knowledge about its contributing factors. However, previous multivariate studies have mainly focused on fear of falling in relation to PD-related disabilities, and less is known about the associations between fear of falling and personal and environmental factors.

OBJECTIVE

To identify explanatory factors of concerns about falling in people with PD by focusing on personal and environmental factors as well as PD-related disabilities.

METHODS

Data were collected from 241 persons with PD (39% women, median age 70 years, PD duration 8 years). Concerns about falling (assessed with the Falls Efficacy Scale-International, FES-I; categorized into low, moderate, or high concerns) were used as the dependent variable in a multivariate ordinal regression analysis. Personal factors, environmental factors and PD-related disabilities constituted independent variables.

RESULTS

Low, moderate and high concerns about falling were reported by 29% , 24% and 47% of the participants, respectively. Walking difficulties, orthostatism, motor symptoms, age, and fatigue (presented in order of importance) were significant (p <  0.05) explanatory factors of concerns about falling.

CONCLUSIONS

Several factors significantly explained concerns about falling in people with PD. Walking difficulties was by far the strongest explanatory factor. This suggests that minimizing walking difficulties should be a primary target when aiming at reducing concerns about falling in people with PD.

Psychological Benefits of Nonpharmacological Methods Aimed for Improving Balance in Parkinson's Disease: A Systematic Review

Parkinson's disease (PD) is a serious condition with a major negative impact on patient's physical and mental health. Postural instability is one of the cardinal difficulties reported by patients to deal with. Neuroanatomical, animal, and clinical studies on nonparkinsonian and parkinsonian subjects suggest an important correlation between the presence of balance dysfunction and multiple mood disorders, such as anxiety, depression, and apathy. Considering that balance dysfunction is a very common symptom in PD, we can presume that by its management we could positively influence patient's state of mind too. This review is an analysis of nonpharmacological methods shown to be effective and successful for improving balance in patients suffering from PD. Strategies such as general exercise, robotic assisted training, Tai Chi, Qi Gong, Yoga, dance (such as tango or ballet), box, virtual reality-based, or neurofeedback-based techniques and so forth can significantly improve the stability in these patients. Beside this physical outcome, many methods have also shown effect on quality of life, depression level, enjoyment, and motivation to continue in practicing the method independently. The purpose of this review is to provide information about practical and creative methods designed to improve balance in PD and highlight their positive impact on patient's psychology.

The effects of brain stimulation of subthalamic nucleus surgery on gait and balance performance in Parkinson disease. A pilot study

INTRODUCTION

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by tremor, rigidity and bradykinesia. Gait and postural difficulties supersede tremor, rigidity and bradykinesia as drivers of disease burden in patients with advanced PD. The aim of this study was to describe the effects of deep brain stimulation of the subthalamic nucleus on gait ability and balance performance in patients with PD.

MATERIAL AND METHODS

We studied 19 consecutive patients who underwent bilateral stimulation of the subthalamic nucleus. Patients were evaluated preoperatively and at the 5(th) day and 6(th) month after surgery. Timed Up and Go Test, 12 m Walking Test, Chair Stand Test and Berg Balance Scale (BBS) were used to assess mobility and balance performance. Unified Parkinson's Disease Rating Scale (UPDRS III) and Hoehn and Yahr Scale were also used.

RESULTS

All the patients' mobility ability and balance performance improved after surgery (p < 0.05). At the 6th month after surgery, the Timed Up and Go Test scores were decreased from 56.05 ±42.52 to 21.47 ±20.36, the 12 m Walking Test scores were decreased from 100.44 ±66.44 to 28.84 ±19.79, the Chair Stand Test scores were increased from 4.00 ±4.66 to 11.68 ±4.43 and the BBS score was increased from 12.84 ±6.89 to 38.89 ±8.79. UPDRS total scores were significantly improved 6 months after surgery (p < 0.001). UPDRS total scores were decreased from 98.26 ±37.69 to 39.36 ±18.85. The Hoehn and Yahr Scale score was significantly decreased after surgery (p < 0.05).

CONCLUSIONS

Surgical therapy is an effective treatment to improve gait ability and balance performance in Parkinson's patients.

Home and health in people ageing with Parkinson's disease: study protocol for a prospective longitudinal cohort survey study

BACKGROUND

With an increased life expectancy for the general population as well as for those ageing with chronic diseases, there are major challenges to the affected individuals and their families, but also to health care and societal planning. Most important, an increasing proportion of older people remain living in their ordinary homes despite health decline and disability. However, little is known about the home and health situation of people ageing with Parkinson's disease (PD), and older people are often excluded from PD-research.

METHODS/DESIGN

The overall aim of the present project is to generate knowledge on home and health dynamics in people with PD, with an explicit attention to PD-specific symptomatology. We will concentrate on aspects of home and health captured by state-of-the-art methodology from gerontology as well as PD-research, health science and rehabilitation. This study protocol describes a longitudinal cohort survey study that includes a baseline data collection and a 3-year follow-up. Both data collection waves include self-administered questionnaires, structured interviews, clinical assessments and observations during home visits effectuated by research staff with project-specific training. In order to arrive at a follow-up sample of N=160, 250 participants identified by PD specialist nurses are being recruited from three hospitals in southern Sweden. With no lower or upper age limit, only those diagnosed with PD since at least one year were included. The exclusion criteria were: difficulties in understanding or speaking Swedish and/or cognitive difficulties/other reasons making the individual unable to give informed consent or to take part in the majority of the data collection. The data collection targets environmental factors such as assistive devices, social support, physical environmental barriers, accessibility problems and perceived aspects of home. A broad variety of instruments tap PD-specific problems (e.g. freezing of gait, fear of falling) and health-related issues such as general self-efficacy, body functions, activities and participation.

DISCUSSION

This project will produce knowledge to the benefit of the development of health care and societal planning that targets people ageing with PD, ultimately promoting activity and participation and an increase of the number of healthy life years for this sub-group of the population.

Subthalamic deep brain stimulation improves smooth pursuit and saccade performance in patients with Parkinson's disease

Background

Deep brain stimulation (DBS) in the subthalamic nucleus (STN) significantly reduces symptoms of Parkinson’s disease (PD) such as bradykinesia, tremor and rigidity. It also reduces the need for anti-PD medication, and thereby potential side-effects of _L-Dopa. Although DBS in the STN is a highly effective therapeutic intervention in PD, its mechanism and effects on oculomotor eye movement control and particularly smooth pursuit eye movements have to date rarely been investigated. Furthermore, previous reports provide conflicting information. The aim was to investigate how DBS in STN affected oculomotor performance in persons with PD using novel analysis techniques.

Methods

Twenty-five patients were eligible (22 males, 3 females) according to the clinical inclusion criteria: idiopathic PD responsive to _L-Dopa and having had bilateral STN stimulation for at least one year to ensure stable DBS treatment. Fifteen patients were excluded due to the strict inclusion criteria applied to avoid interacting and confounding factors when determining the effects of DBS applied alone without PD medication. One patient declined participation. Nine PD patients (median age 63, range 59–69 years) were assessed after having their PD medications withdrawn overnight. They were examined with DBS ON and OFF, with the ON/OFF order individually randomized.

Results

DBS ON increased smooth pursuit velocity accuracy (p < 0.001) and smooth pursuit gain (p = 0.005), especially for faster smooth pursuits (p = 0.034). DBS ON generally increased saccade amplitude accuracy (p = 0.007) and tended to increase peak saccade velocity also (p = 0.087), specifically both saccade velocity and amplitude accuracy for the 20 and 40 degree saccades (p < 0.05). Smooth pursuit latency tended to be longer (p = 0.090) approaching normal with DBS ON. Saccade latency was unaffected.

Conclusions

STN stimulation from DBS alone significantly improved both smooth pursuit and saccade performance in patients with PD. The STN stimulation enhancement found for oculomotor performance suggests clear positive implications for patients’ ability to perform tasks that rely on visual motor control and visual feedback. The new oculomotor analysis methods provide a sensitive vehicle to detect subtle pathological modifications from PD and the functional enhancements produced by STN stimulation from DBS alone.

Cerebral blood flow responses to dorsal and ventral STN DBS correlate with gait and balance responses in Parkinson's disease

OBJECTIVES

The effects of subthalamic nucleus (STN) deep brain stimulation (DBS) on gait and balance vary and the underlying mechanisms remain unclear. DBS location may alter motor benefit due to anatomical heterogeneity in STN. The purposes of this study were to (1) compare the effects of DBS of dorsal (D-STN) versus ventral (V-STN) regions on gait, balance and regional cerebral blood flow (rCBF) and (2) examine the relationships between changes in rCBF and changes in gait and balance induced by D-STN or V-STN DBS.

METHODS

We used a validated atlas registration to locate and stimulate through electrode contacts in D-STN and V-STN regions of 37 people with Parkinson's disease. In a within-subjects, double-blind and counterbalanced design controlled for DBS settings, we measured PET rCBF responses in a priori regions of interest and quantified gait and balance during DBS Off, unilateral D-STN DBS and unilateral V-STN DBS.

RESULTS

DBS of either site increased stride length without producing significant group-level changes in gait velocity, cadence or balance. Both sites increased rCBF in subcortical regions and produced variable changes in cortical and cerebellar regions. DBS-induced changes in gait velocity are related to premotor cortex rCBF changes during V-STN DBS (r=-0.40, p=0.03) and to rCBF changes in the cerebellum anterior lobe during D-STN DBS (r=-0.43, p=0.02).

CONCLUSIONS

DBS-induced changes in gait corresponded to rCBF responses in selected cortical and cerebellar regions. These relationships differed during D-STN versus V-STN DBS, suggesting DBS acts through distinct neuronal pathways dependent on DBS location.

Medication and subthalamic nucleus deep brain stimulation similarly improve balance and complex gait in Parkinson disease

BACKGROUND

Dopaminergic medications and subthalamic nucleus deep brain stimulation (STN-DBS) alleviate motor symptoms in Parkinson disease, but balance and gait are more variably affected. Balance reports are particularly inconsistent. Further, despite their prevalence in daily life, complex gait situations including backward and dual task gait are rarely studied. We aimed to assess how medications, STN-DBS, and both therapies combined affect balance and complex gait.

METHODS

Twelve people with Parkinson disease were evaluated OFF medication with STN-DBS OFF and ON as well as ON medication with STN-DBS OFF and ON. Motor impairment was measured with the Movement Disorder Society Unified Parkinson Disease Rating Scale motor section (MDS-UPDRS-III). The Mini-Balance Evaluations Systems Test, timed-up-and-go, and dual task timed-up-and-go measured balance and mobility. Preferred-pace forward, fast as possible forward, backward, dual task forward, and dual task backward gait were also analyzed.

RESULTS

Medication improved MDS-UPDRS-III scores, dual task timed-up-and-go, and stride length across all gait tasks. STN-DBS improved MDS-UPDRS-III scores, balance scores, dual task timed-up-and-go, and stride length and velocity across all gait tasks. Medication and STN-DBS combined did not provide additional benefits over either therapy alone.

CONCLUSIONS

Overall, dopaminergic medications and STN-DBS provided similar improvements in balance and gait tasks, although the effects of STN-DBS were stronger, potentially due to reductions in medication doses after surgery. Lack of synergistic effect of treatments may suggest both therapies improve balance and gait by influencing similar neural pathways.

Walking ability is a major contributor to fear of falling in people with Parkinson's disease: implications for rehabilitation

Although fear of falling (FOF) is common in people with Parkinson's disease (PD), there is a lack of research investigating potential predictors of FOF. This study explored the impact of motor, nonmotor, and demographic factors as well as complications of drug therapy on FOF among people with PD. Postal survey data (including the Falls Efficacy Scale, FES) from 154 nondemented people with PD were analyzed using multiple regression analyses. Five significant independent variables were identified explaining 74% of the variance in FES scores. The strongest contributing factor to FOF was walking difficulties (explaining 68%), followed by fatigue, turning hesitations, need for help in daily activities, and motor fluctuations. Exploring specific aspects of walking identified three significant variables explaining 59% of FOF: balance problems, limited ability to climb stairs, and turning hesitations. These results have implications for rehabilitation clinicians and suggest that walking ability is the primary target in order to reduce FOF. Specifically, balance, climbing stairs, and turning seem to be of particular importance.

Fear of falling and falls in people with Parkinson's disease treated with deep brain stimulation in the subthalamic nuclei

BACKGROUND

No previous study prospectively investigated the effects of subthalamic deep brain stimulation on fear of falling (FOF) and falls.

AIM

The aim was to prospectively explore whether FOF and fall rate were affected after STN stimulation in people with Parkinson's disease (PD).

METHODS

Twenty participants (mean age: 65, SD 6.4) were included. Falls and near falls were recorded (fall diary) during 3 months before and 1 year after surgery. FOF was evaluated using the Falls-Efficacy Scale, Swedish version, FES(S), and the modified Survey of Activities and Fear of Falling in the Elderly (SAFFE).

RESULTS

After surgery, the FES(S) scores of complex activities improved (P=0.026), i.e. median 34 (q1-q3, 26-50) vs 43 (32-55). SAFFE scores also improved (P=0.007): median 25 (22-30) versus 22 (18-27). The rate of near falls decreased (P=0.014). Nine participants reported no near falls. For the remaining ten participants, the median near fall rate decreased from 6 (3-17) to 2 (1-8). The rate of falls showed no significant (P>0.3) difference.

CONCLUSIONS

After surgery, fewer activities were avoided owing to the risk of falling, and fall-related self-efficacy had improved during complex activities. The rate of near falls decreased. The results cannot support any change in fall rate.