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Postural Instability (postural + instability)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Postural stability of Parkinson's disease patients is improved by decreasing rigidity

EUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2005
A. Bartoli
Postural instability has a big impact on the quality of life of patients with Parkinson's disease (PD) as it often leads to an insecure stance and fall. We investigated if postural stability in these patients improves by decreasing rigidity with a dopaminergic agonist. In our study, we tested eight PD patients with no concomitant diseases. Their age was 61 ± 2 years (mean ± SE) and their Hoehn-Yahr score was 3 ± 0.1. The patients were evaluated according to the Unified Parkinson's Disease Rating Scale for motor function (mUPDRS) and with stabilometric measurements of forward,backward and side-to-side body oscillations during free stance with eyes open. Both evaluations were performed in an ,off' state and in an apomorphine-induced ,on' state. As expected, the mUPDRS score was significantly decreased in the ,on' state with posture being improved in six patients, gait in eight patients and postural stability in seven of eight patients. In addition, apomorphine caused a significant reduction of the relative amplitude of lower frequencies and an increase of the relative amplitude of higher frequencies of forward,backward body oscillations. The results of stabilometry and mUPDRS evaluations are in agreement with the effect of apomorphine on rigidity, indicating that postural stability of PD patients is improved by decreasing rigidity. [source]

Effects of stereotactic neurosurgery on postural instability and gait in Parkinson's disease

MOVEMENT DISORDERS, Issue 9 2004
Maaike Bakker MSc
Abstract Postural instability and gait disability (PIGD) are disabling signs of Parkinson's disease. Stereotactic surgery aimed at the internal globus pallidus (GPi) or subthalamic nucleus (STN) might improve PIGD, but the precise effects remain unclear. We performed a systematic review of studies that examined the effects of GPi or STN surgery on PIGD. Most studies examined the effects of bilateral GPi stimulation, bilateral STN stimulation, and unilateral pallidotomy; we, therefore, only performed a meta-analysis on these studies. Bilateral GPi stimulation, bilateral STN stimulation, and to a lesser extent, unilateral pallidotomy significantly improved PIGD, and more so during the ON phase than during the OFF phase. © 2004 Movement Disorder Society [source]

Postural instability during reaching tasks in Parkinson's disease

PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 3 2005
Dr Emma Stack
Abstract Background and Purpose. Reaching, like turning and rising from sitting, is an activity commonly associated with falls by people with Parkinson's disease. We set out to: (a) identify how people with moderate and severe Parkinson's disease performed high and low reaches and (b) to explore in detail the standard functional reach (functional reach) test and the fall histories of those who appeared unstable when reaching. Method. In this cross-sectional study, people with moderate or severe Parkinson's disease (Hoehn and Yahr Grade III or IV) were video-recorded at home, reaching above shoulder height and below knee level. Blinded observers rated stability, alignment, foot position, floor contact, use of support and reach type. Functional reach was also measured and participants were interviewed about falls. Results. Of 51 participants, 33 (65%) had moderate Parkinson's disease and 18 (35%) severe. A greater proportion of the latter used support when reaching high (p = 0.029) and aligned forward when reaching low (p = 0.015); otherwise, strategies were similar across groups. Six people (all with severe Parkinson's disease) appeared unstable when reaching: they had a shorter functional reach than the others (median 10 cm versus 18 cm; p = 0.042) and had fallen frequently (median five falls in a year), although rarely when reaching. Conclusions. Reaching tasks challenge postural stability in severe Parkinson's disease. People who appear unstable when reaching are likely to be repeat-fallers and at risk of further falls during more demanding activities. Research should address whether discouraging potentially destabilizing manoeuvres (such as squatting and toe-standing) and promoting safety-enhancing strategies (such as using support and facing forward), with or without balance retraining, reduces the risk of falling among people with severe Parkinson's disease. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Mechanisms of Postural Control in Alcoholic Men and Women: Biomechanical Analysis of Musculoskeletal Coordination During Quiet Standing

ALCOHOLISM, Issue 3 2010
Edith V. Sullivan
Background:, Excessive sway during quiet standing is a common sequela of chronic alcoholism even with prolonged sobriety. Whether alcoholic men and women who have remained abstinent from alcohol for weeks to months differ from each other in the degree of residual postural instability and biomechanical control mechanisms has not been directly tested. Method:, We used a force platform to characterize center-of-pressure biomechanical features of postural sway, with and without stabilizing conditions from touch, vision, and stance, in 34 alcoholic men, 15 alcoholic women, 22 control men, and 29 control women. Groups were matched in age (49.4 years), general intelligence, socioeconomic status, and handedness. Each alcoholic group was sober for an average of 75 days. Results:, Analysis of postural sway when using all 3 stabilizing conditions versus none revealed diagnosis and sex differences in ability to balance. Alcoholics had significantly longer sway paths, especially in the anterior,posterior direction, than controls when maintaining erect posture without balance aids. With stabilizing conditions the sway paths of all groups shortened significantly, especially those of alcoholic men, who demonstrated a 3.1-fold improvement in sway path difference between the easiest and most challenging conditions; the remaining 3 groups, each showed a ,2.4-fold improvement. Application of a mechanical model to partition sway paths into open-loop and closed-loop postural control systems revealed that the sway paths of the alcoholic men but not alcoholic women were characterized by greater short-term (open-loop) diffusion coefficients without aids, often associated with muscle stiffening response. With stabilizing factors, all 4 groups showed similar long-term (closed loop) postural control. Correlations between cognitive abilities and closed-loop sway indices were more robust in alcoholic men than alcoholic women. Conclusions:, Reduction in sway and closed-loop activity during quiet standing with stabilizing factors shows some differential expression in men and women with histories of alcohol dependence. Nonetheless, enduring deficits in postural instability of both alcoholic men and alcoholic women suggest persisting liability for falling. [source]

REM sleep behavior disorder is not linked to postural instability and gait dysfunction in Parkinson,

MOVEMENT DISORDERS, Issue 11 2010
David H. Benninger MD
Abstract To evaluate a potential association of REM-sleep behavior disorder (RBD) with gait and postural impairment in Parkinson's disease (PD). Gait difficulties and postural impairment are frequent in PD and are a major cause of disability. Animal studies indicate a key role of the pedunculopontine nucleus (PPN) in gait, postural control, and REM sleep, and also in the pathophysiology of RBD. In humans, such an association has not been investigated. Twenty-six patients with mild-to-moderate PD (13 with polysomnography confirmed and 13 with excluded RBD), and 20 age-matched healthy controls were prospectively investigated. Gait assessment on a treadmill, and static and dynamic posturography were performed. PD patients with RBD do not differ from those without RBD in gait and postural control. Greater severity of PD or prevalence of gait and postural disturbances in the presence of RBD were not found. RBD was not associated with any particular motor phenotype. We found no association of RBD with gait disturbances and postural impairment. Human gait and postural control and RBD appear to depend upon different neuronal circuits. © 2010 Movement Disorder Society [source]

Differentiating vascular parkinsonism from idiopathic Parkinson's disease: A systematic review,,

MOVEMENT DISORDERS, Issue 2 2010
Seema Kalra MRCP
Abstract Vascular parkinsonism (VP) remains a loose constellation of various clinical features. We systematically reviewed studies comparing clinical, neuroimaging and other investigations that might distinguish VP from idiopathic Parkinson's disease (PD). Medline, Embase, Cinahl (R), and PsycINFO were searched by querying appropriate key words. Reports were included if the study population contained comparative findings between patients with VP and PD. Twenty-five articles fulfilled the selection criteria. Patients with VP were older, with a shorter duration of illness, presented with symmetrical gait difficulties, were less responsive to levodopa, and were more prone to postural instability, falls, and dementia. Pyramidal signs, pseudobulbar palsy, and incontinence were more common in VP. Tremor was not a main feature of VP. Structural neuroimaging was more likely to be abnormal in VP (90,100% of cases) than in PD (12,43% of cases), but there was no specific abnormal structural imaging pattern for VP. Two studies of presynaptic striatal dopamine transporters (using single photon emission computed tomography) showed a significant reduction in striatal uptake ratios in PD but not in VP, whereas another study found that only the mean asymmetry index was significantly lower in VP. Various other investigations, including alternative imaging techniques, electrophysiological, and neuropsychological studies, are reported, but the diverse diagnostic criteria used makes it difficult to reach any firm conclusions. The development of accepted international diagnostic criteria for VP is urgently needed to facilitate further studies. © 2010 Movement Disorder Society [source]

Clinical measures of progression in Parkinson's disease,

MOVEMENT DISORDERS, Issue S2 2009
Werner Poewe MD
Abstract Despite all recent advances in symptomatic therapy Parkinson's disease (PD) continues to be a relentlessly progressive neurodegenerative disorder. Therefore therapies that will slow or hold disease progression are a major medical unmet need in PD. Clinical measures of disease progression that have been used in disease modification trials so far have focused on indices of progression of cardinal motor features like bradykinesia, rigidity, and tremor as captured by the UPDRS and the emerging need for effective dopaminergic symptomatic therapy. Progression of global disability in PD, however, is driven by additional factors beyond progressive nigrostriatal denervation leading to increasing severity of cardinal motor features. Progressive pathology in extranigral sites in the brain or peripheral autonomic nervous system contribute to poorly levodopa responsive motor symptoms like postural instability, freezing and falls or nonmotor symptoms. In addition treatment-induced motor complications also impact on PD disability. Although it is widely accepted that clinical progression of PD is multidimensional and in addition includes effects of aging, there is no consensus how to best implement more clinically meaningful endpoints for disease progression trials that would reflect these complex interactions impacting on the evolution of global disability in PD. There is an urgent need for biomarkers for disease progression that would faithfully reflect advancing neurodegeneration and resulted clinical disability in PD and that could be used in shorter term clinical trials testing putative disease modifying agents. © 2009 Movement Disorder Society [source]

Motor patterns in Parkinson's disease: A data-driven approach,

MOVEMENT DISORDERS, Issue 7 2009
Stephanie M. van Rooden MSc
Abstract To identify patterns of motor disturbances in Parkinson's disease (PD) and evaluate their relation with other PD domains. A cohort of 399 PD patients was randomly divided into two samples. Factors within the motor section of the SPES/SCOPA were identified by exploratory factor analysis on data from the first sample and next tested by confirmatory factor analysis in the second sample. Relations with other PD domains were evaluated by regression analyses. A four factor model was found to be valid. This included a tremor, a bradykinetic-rigid, and two axial factors. One axial factor ("rise", "gait", "postural instability") was associated with age and cognition, while the other axial factor ("freezing", "speech", "swallowing") was related to dopaminergic medication and complications of therapy. Both other factors showed no relevant associations with demographic and clinical characteristics. The identification of motor factors and their relation with other domains of the disease may help to elucidate the mechanisms responsible for these associations and provide an objective base for further research on subtypes in PD. © 2009 Movement Disorder Society [source]

The clinical spectrum of freezing of gait in atypical parkinsonism,

MOVEMENT DISORDERS, Issue S2 2008
Stewart A. Factor DO
Abstract Freezing of gait (FOG), commonly seen in advanced Parkinson's disease (PD), has been classified as its fifth cardinal feature. However, its presence frequently leads to a misdiagnosis of PD. FOG is actually more common in atypical parkinsonism (AP): including vascular Parkinsonism (VP), progressive supranuclear palsy (PSP), multiple system atrophy (MSA), corticobasal degeneration (CBD), dementia with Lewy bodies (DLB), and higher level gait disorders (HLGDs). VP is the result of multiple small vessel infarcts (lacunar state or Binswanger's disease), particularly involving the frontal, parietal, and basal ganglia regions. Approximately 50% have FOG (often referred to as lower body parkinsonism). FOG is also common in neurodegenerative forms of AP, present in 45,57%. Of these, FOG is present in 53% of PSP, 54% MSA, 54% DLB, 25% CBD, and 40% HLGD. It is generally seen in the late stages. There are two syndromes closely associated with AP that are dominated by FOG; pure akinesia (PA) and primary progressive freezing gait (PPFG). PA is characterized by akinesia of gait (including FOG), writing, and speech. Tremor, rigidity, dementia, and response to levodopa are notably absent. PPFG is defined by early FOG (often the initial feature) that progresses to include postural instability. It is accompanied by bradykinesia, rigidity, postural tremor, dementia, and levodopa unresponsiveness. Both syndromes are heterogeneous but PSP seems to be the most common cause. CBD and DLB can also present as PPFG. FOG is a common feature of AP and although typically occurring late in disease may also be an early symptom. © 2008 Movement Disorder Society [source]

Coupling between limb tremor and postural sway in Parkinson's disease

MOVEMENT DISORDERS, Issue 3 2008
Graham Kerr BSc, MPhED
Abstract Increased tremor and postural instability are motor problems commonly associated with Parkinson's disease (PD). Despite the similarity between these oscillatory forms, little is known about the relation between them, especially for individuals with enhanced tremor. This study was designed to examine the nature of any relation between center of pressure (COP) excursions and postural/resting limb tremor of young, older individuals, and Parkinsonian participants in their different medication states. The resting and postural tremor for the PD participants was characterized by a single, prominent peak frequency between 4 and 7 Hz. The postural tremor for young/older participants contained smaller peaks between 1 to 4 and 7 to 12 Hz although no prominent peak was seen in their resting tremor. The AP and ML COP dynamics of all participants was characterized by a major peak between 0.1 and 0.5 Hz. An additional peak was observed in the COP output of the PD participants between 4 and 7 Hz. While no tremor-COP coupling was observed for the young/old groups, coherence analysis revealed a significant degree of coupling between COP motion and tremor between 4 and 7 Hz for PD participants. These results highlight that the amplified tremor in PD can manifest itself in COP dynamics. This finding may have implications for postural stability for this patient group. © 2007 Movement Disorder Society [source]

Manganic encephalopathy due to "ephedrone" abuse

MOVEMENT DISORDERS, Issue 9 2007
Yanush Sanotsky MD
Abstract We describe the clinical and neuroimaging features of 6 drug-abuse patients with self-inflicted manganese poisoning. The patients injected a home-brewed mixture called "ephedrone" (slang term) that contained manganese to produce an amphetamine-like euphoria. The desired chemical product, phenylpropanoneamine (also called methcathinone), was synthesized from a common-cold,remedy compound using permanganate as the catalyst. Manganese was a by-product in the ephedrone mixture. After months of self-injections, a clinical picture emerged, consisting of apathy, bradykinesia, gait disorder with postural instability, and spastic-hypokinetic dysarthria. There was no response to levodopa. The MRI revealed symmetric hyperintense T1-weighted signals in the basal ganglia, typical of manganese accumulation. © 2007 Movement Disorder Society [source]

Changes in motor subtype and risk for incident dementia in Parkinson's disease

MOVEMENT DISORDERS, Issue 8 2006
Guido Alves MD
Abstract The objective of this study was to assess the temporal relationship between changes in predominant motor symptoms and incident dementia in Parkinson's disease (PD). A community-based sample of 171 nondemented patients with PD was followed prospectively and examined at baseline and after 4 and 8 years. The motor subtype of Parkinsonism was classified into tremor-dominant (TD), indeterminate, or postural instability gait difficulty (PIGD) subtype at each visit, based on defined items in the Unified Parkinson's Disease Rating Scale, subscales II and III. Dementia was diagnosed according to DSM-III-R criteria, based on clinical interview, cognitive rating scales, and neuropsychological examination. Logistic regression was used to analyze the relationship between subtype of Parkinsonism and dementia. Transition from TD to PIGD subtype was associated with a more than threefold increase in the rate of Mini-Mental State Examination decline. Compared to patients with persistent TD or indeterminate subtype, the odds ratio for dementia was 56.7 (95% CI: 4.0,808.4; P = 0.003) for patients changing from TD or indeterminate subtype to PIGD subtype, and 80.0 (95% CI: 4.6,1400.1; P = 0.003) for patients with persistent PIGD subtype. Patients with TD subtype at baseline did not become demented until they developed PIGD subtype, and dementia did not occur among patients with persistent TD subtype of Parkinsonism. In a substantial proportion of PD patients who develop postural instability and gait disorder during the course of the disease, this transition is associated with accelerated cognitive decline and highly increased risk for subsequent dementia. These findings raise the question whether PIGD and dementia share common or parallel neuropathology. © 2006 Movement Disorder Society [source]

The pull test: A history

MOVEMENT DISORDERS, Issue 7 2006
Ann L. Hunt DO
Abstract The pull test (PT) is used as a measure of postural instability in Parkinson's disease (PD) and other movement disorders. In 1987, it was incorporated into the Unified Parkinson's Disease Rating Scale (UPDRS), a scale used to measure the severity and treatment response in PD both in research studies and in clinical practice. However, the origins of the observation of postural instability in movement disorders and the attempt to quantify it are much older. Here, we trace the history of postural instability first described as a feature of PD by Romberg in 1853. Attempts to evaluate postural instability began with the first measurement by Charcot in the 1880s by pulling the clothes of patients and progressed to the push on the sternum by Hoehn and Yahr in the 1960s. Eventually, this evolved into the formal PT proposed by Fahn in the 1980s. Despite the widespread use of the PT as part of the UPDRS, variability exists in its execution. Recommendations have been made for training of examiners in clinical trials to improve its accuracy in assessing postural instability. We agree with improving PT technique for clinical trials and advocate for its routine use in clinical practice when diagnosing and treating movement disorders. Further, we propose the name "Fahn pull test" for the maneuver based on his significant contribution to its development. © 2006 Movement Disorder Society [source]

Effects of stereotactic neurosurgery on postural instability and gait in Parkinson's disease

Do fall predictors in middle aged and older adults predict fall status in persons 50+ with fibromyalgia?

RESEARCH IN NURSING & HEALTH, Issue 3 2010
An exploratory study
Abstract We explored potential predictors of fall status in 70 community-dwelling persons ,50 years of age with fibromyalgia (FM). Over 40% of the sample reported one or more falls in the year prior to the study. A logistic regression model using 10 variables known to predict falls in middle aged and older persons predicted 45% of the variance in fall status. Three variables offered significant independent contributions to the overall model predicting fall status: perception of postural instability, balance performance, and executive function processing speed. The results support prior work in both nonclinical and clinical populations of middle aged and older adults indicating that falls are associated with multiple risk factors. Prospective designs with larger samples are needed to (a) validate and extend these findings, and (b) identify risk factors related to fall status that are unique to persons with FM. © 2010 Wiley Periodicals, Inc. Res Nurs Health 33:192,206, 2010 [source]

Mal de Debarquement and Posture: Reduced Reliance on Vestibular and Visual Cues

THE LARYNGOSCOPE, Issue 3 2004
Zohar Nachum MD
Abstract Objective The neural mismatch theory assumes that the intersensory conflicts leading to motion sickness are resolved by changes in the relative weighting of the various senses that contribute to orientation. If this sensory rearrangement persists after disembarkment, it might result in mal de debarquement (MD): ataxia and a rocking sensation sometimes felt after landing. The objective of the present study was to examine possible changes in sensory organization in naval crew members with differing susceptibility to MD with computerized dynamic posturography (CDP). Study Design Cross-sectional parallel-group design. Methods Seventeen subjects susceptible to MD (SMD) and 17 subjects nonsusceptible to MD (NSMD) (healthy male volunteers aged 18,22) participated in the study. CDP was performed twice with each subject, before and immediately after sailing, using the EquiTest system (NeuroCom, Inc., Clackamas, OR). Results The SMD group showed a significant reduction in their scores on sensory organization tests 3, 4, and 5 after sailing. Sensory pattern analysis revealed reduced use of inputs from the vestibular and visual systems to maintain balance. Prolonged latencies of the motor responses to unexpected pitch perturbations were also recorded in the postsailing CDP of the SMD group. Reduced performance on the presailing CDP task, which presents the greatest challenge to the vestibular system, was found to control for the presence of MD postsailing. Conclusions The results show that MD is associated with postural instability, slower motor reflexes, and larger sways in response to abrupt changes in the body's center of gravity. These findings may be explained by under reliance on vestibular and visual inputs and increased dependence on the somatosensory system for the maintenance of balance. [source]

Parkinsonian signs and substantia nigra neuron density in decendents elders without PD,

ANNALS OF NEUROLOGY, Issue 4 2004
G. Webster Ross MD
Substantia nigra (SN) neurons were counted on single, transverse caudal midbrain sections from 217 male participants in the Honolulu-Asia Aging Study, aged 74,97 years at death. Quadrants areas within the SN were determined with a planimeter and neuronal density was expressed as neurons/mm2 for 10 Parkinson's disease (PD) cases, 29 incidental Lewy body cases, and 178 controls with neither condition. Mean densities in all quadrants were significantly lower in the PD group compared with the other groups (p = 0.006). This relationship was strongest in the ventrolateral quadrant. In a subgroup of 50 controls who were examined with the Unified Parkinson's Disease Rating Scale an average of 2.1 years prior to death, there was an association of stooped posture (p = 0.009), postural instability (p = 0.013), body bradykinesia (p = 0.048), and gait disturbance (p = 0.05) with neuron density in the dorsolateral quadrant; and impaired speech (p = 0.014), abnormal facial expression (p = 0.022), and difficulty rising from a chair (p = 0.032) with neuron density in the dorsomedial quadrant. There was a significant association of increasing number of signs present with decreasing neuron density in both quadrants (p = 0.001 for trend). Low SN neuron density may be the basis for parkinsonian signs in the elderly without PD. Ann Neurol 2004 [source]

Are dysautonomic and sensory symptoms present in early Parkinson's disease?

ACTA NEUROLOGICA SCANDINAVICA, Issue 2010
O.-B. Tysnes
Tysnes O-B, Müller B, Larsen JP. Are dysautonomic and sensory symptoms present in early Parkinson's disease? Acta Neurol Scand: 2010: 122 (Suppl. 190): 72,77. © 2010 John Wiley & Sons A/S. Parkinson's disease (PD) occurs with an annual incidence of 13/100.000, is slightly more frequent in men and is characterized by the motor symptoms tremor, rigidity, bradykinesia and postural instability. In addition, non-motor symptoms have been increasingly connected to the disease although already described in James Parkinson's ,Essay on the shaking palsy' from 1817. The motor symptoms in PD are related to the degeneration of dopaminergic cells in the substantia nigra (SN). These symptoms respond well to dopaminergic substitution. It is much more unclear whether non-motor symptoms like dysautonomia, insomnia, day-time sleepiness, fatigue, pain and neuropsychiatric symptoms respond to levodopa. Autonomic symptoms include dizziness because of orthostatic hypotension, constipation, nausea, voiding symptoms and increased sweating. Such symptoms as well as sensory symptoms like hyposmia and pain are very frequently reported in PD and seem to occur early in the disease process. Braak proposed a sequential model of neuropathology in PD starting with affection of the olfactory bulb and the autonomic innervation of the heart and gut. Affection of SN is seen from Braak stage 3, and limbic and cortical structures are affected in the later stages of the disease. Currently, the evidence for sensory and autonomic involvement in PD is reviewed with special focus on the early phase of the disease. [source]