James McLoughlin

Association of Postural Sway with Disability Status and Cerebellar Dysfunction in People with Multiple Sclerosis: A Preliminary Study.

BACKGROUND The aims of this study were 1) to examine postural sway in the eyes open (EO) and eyes closed (EC) conditions in people with multiple sclerosis (MS) with moderate levels of disability compared with controls and 2) to examine relationships between postural sway and total Expanded Disability Status Scale (EDSS) scores, functional system subscores, and clinical measures of strength and spasticity in the MS group. METHODS Thirty-four people with moderate MS and ten matched controls completed measures of postural sway with EO and EC, knee extension and ankle dorsiflexion isometric strength, EDSS total score and subscores, and spasticity levels. RESULTS Participants with MS swayed significantly more with EO and EC and had reduced knee extension and ankle dorsiflexion strength compared with controls (P < .001). In the MS group, increased sway was associated with higher total EDSS scores and cerebellar function subscores, whereas increased sway ratio (EC/EO) was associated with reduced sensory function subscores. Postural sway was not significantly associated with strength or spasticity. CONCLUSIONS Participants with MS swayed more and were significantly weaker than controls. Cerebellar dysfunction was identified as the EDSS domain most strongly associated with increased sway, and sensory loss was associated with a relatively greater dependence on vision for balance control. These findings suggest that exercise interventions targeting sensory integration and cerebellar ataxia may be beneficial for enhancing balance control in people with MS.

Six minutes of walking leads to reduced lower limb strength and increased postural sway in people with Multiple Sclerosis

BACKGROUND Fatigue, lower limb weakness and poor balance can significantly limit safe mobility in people with Multiple Sclerosis (MS). Further research is required to elucidate relationships among these factors. OBJECTIVE To investigate the effect of walking-induced fatigue on lower limb strength and postural sway in people with moderately disabling MS. METHODS Thirty-four people (26 female) with moderate MS (mean Expanded Disability Status Scale of 3.7 ± 0.7) underwent assessments of acute fatigue, postural sway and lower limb strength before and after six-minute conditions of seated rest and walking. A matched sample of 10 healthy controls also undertook identical assessments before and after a six-minute walk. RESULTS Significant time by condition effects for all assessment measures indicated the six-minute walk induced fatigue with associated increases in postural sway and reductions in lower limb strength in people with MS. Increases in sway with eyes closed correlated with increases in acute fatigue and self-reported impact of fatigue on physical and psychological functioning. No changes were observed in healthy controls. CONCLUSION People with MS show signs of fatigue after 6 minutes of walking, including strength and balance deficits. These findings have implications for both mobility and fall risk in this group.

Fatigue induced changes to kinematic and kinetic gait parameters following six minutes of walking in people with multiple sclerosis

Abstract Purpose: The aim of this study was to examine the effect of 6 min of walking on fatigue, exertion and spatiotemporal, kinematic and kinetic gait parameters in people with multiple sclerosis (MS). Methods: Thirty-four people with MS with moderate levels of disability completed measures of fatigue, exertion and instrumented gait analysis before and after 6-min trials of rest and walking (using a modified 6-min walk test, m6MWT). Ten age- and gender-matched healthy controls completed analysis before and after the m6MWT. Results: The MS group had a significant increase in self-reported fatigue following the m6MWT; however, there was no effect on spatiotemporal gait parameters. During stance on the more affected side ankle dorsiflexion at initial contact decreased, while knee and hip flexor moments and hip power absorption increased. On the less affected side ankle and knee power absorption, and hip extensor moment all increased. Healthy controls showed increases in joint kinetics likely due to increased walking speeds following m6MWT. Conclusion: For people with MS, ankle dorsiflexion angle reduces at initial contact following walking induced fatigue, while increased power absorption at the hip, knee and ankle indicate gait inefficiencies that may contribute to higher levels of fatigue and exertion. Implications for Rehabilitation The modified 6-min walk test (m6MWT) leads to significant increases in self-reported fatigue and exertion in people with MS. Following the m6MWT, there is significantly reduced ankle dorsiflexion angle at initial contact in the more affected leg in people with MS. This reveals an important walking-induced kinematic change that should be the target of future orthotic and strengthening interventions. In people with MS, increased power absorption primarily during the stance phase of gait following the m6MWT reveals important walking-induced muscle weakness that should also be monitored in future strengthening and gait retraining interventions.

Effect of wearing a dorsiflexion assist orthosis on mobility, perceived fatigue and exertion during the six-minute walk test in people with multiple sclerosis: a randomised cross-over protocol.

BackgroundFatigue in combination with gait and balance impairments can severely limit daily activities in people with multiple sclerosis (PWMS). Generalised fatigue has a major impact on walking ability, with moderately disabled PWMS experiencing difficulty in walking extended distances. Localised motor fatigue in the ankle dorsiflexors can lead to foot drop, further reducing functional ambulation. The aim of this study is to evaluate the effect of a simple dynamic dorsiflexion assist orthosis on walking-induced fatigue, gait, balance and functional mobility in PWMS.MethodsA randomised cross-over trial will be conducted with 40 community dwelling PWMS with mild to moderate mobility disability. Participants will initially be screened for disease severity, balance, strength, depression and fatigue at the South Australian Motion Analysis Centre. On two non-consecutive occasions, within two weeks, participants will undergo either the 6-minute walk test (6MWT) or the 6MWT while wearing a dorsiflexion ankle orthosis (with a randomised condition order). Distance walked, perceived exertion, perceived fatigue and the physiological cost of walking (the primary outcome measures) will be compared between the two walking conditions. Additional pre- and post-6MWT assessments for the two conditions will include tests of strength, reaction time, gait and balance.DiscussionThis study will increase our understanding of motor fatigue on gait and balance control in PWMS and elucidate the effect of a Dynamic Ankle Orthosis on fatigue-related balance and gait in PWMS. It will also examine relationships between mobility and balance performance with perceived fatigue levels in this group.Trial Registration NumberACTRN12612000218897

Orthotic and therapeutic effect of functional electrical stimulation on fatigue induced gait patterns in people with multiple sclerosis

Abstract Purpose: To assess the orthotic and therapeutic effects of prolonged use of functional electrical stimulation (FES) on fatigue induced gait patterns in people with Multiple Sclerosis (MS). Method: Thirteen people with MS completed 3D gait analysis with FES off and on, before and after a fatiguing 6-minute walk, at baseline and after 8 weeks of use of FES. Results: Eleven participants completed all testing. An orthotic effect on gait was not evident on first use of FES. However, therapeutic effects on gait after 8 weeks use were generally positive, including increases in walking speed due to improved neuromuscular control and power generated at the hip and ankle of the more affected limb. The action of FES alone was not sufficient to overcome all fatigue related deficits in gait but there was evidence 8 weeks use of FES can ameliorate some fatigue effects on lower limb kinetics, including benefits to ankle mechanics involved in generating power around push-off during stance. Conclusions: Eight-weeks of FES can benefit the gait pattern of people with MS under non-fatigued and fatigued conditions. Implications for rehabilitation In some people with MS prolonged use of FES may be necessary before observing positive orthotic effects. Improvements in the neuromuscular control of the more affected lower limb may develop with prolonged use of FES in people with MS. Only some therapeutic benefits of FES are maintained during fatigued walking in people with MS. FES may be considered as a gait retraining device as well as an orthotic intervention for people with MS.

Dorsiflexion Assist Orthosis Reduces the Physiological Cost and Mitigates Deterioration in Strength and Balance Associated With Walking in People With Multiple Sclerosis

OBJECTIVE To evaluate the effect of wearing a dorsiflexion assist orthosis (DAO) on walking distance, physiological cost, fatigue, and strength and balance measures after a modified 6-minute walk test (6MWT) in people with multiple sclerosis (MS). DESIGN Randomized crossover trial. SETTING Hospital Movement Laboratory. PARTICIPANTS People with moderate MS and Expanded Disability Status Scale score of 3.7±0.7 (N=34; 26 women). INTERVENTIONS Modified 6MWT with and without a DAO worn on the weaker leg. MAIN OUTCOME MEASURES Distance walked, perceived fatigue, and the physiological cost of walking were compared between walking conditions. Pre- and postwalk changes in knee extensor and ankle dorsiflexor isometric strength and standing postural sway with eyes open and closed were compared between walking conditions. RESULTS There were no differences in distance walked or perceived fatigue between the 2 walking conditions. However, there was a reduced physiological cost of walking (P<.05), a smaller reduction in knee extensor strength (P<.05), and a smaller increase in standing postural sway with eyes open (P<.01) after walking while wearing the DAO compared with walking without wearing the DAO. CONCLUSIONS Despite not increasing walking distance or reducing perceived fatigue, the DAO reduced the physiological cost of walking and maintained knee strength and standing balance, which may have important implications for physical rehabilitation in people with MS. Further trials are required to determine whether the beneficial effects of wearing a DAO found here are maintained for longer periods.

Walking for six minutes increases both simple reaction time and stepping reaction time in moderately disabled people with Multiple Sclerosis

BACKGROUND Walking ability and fatigue are often reported as the most disabling symptoms in Multiple Sclerosis (MS). Motor fatigue may contribute to reduced mobility, and is likely caused by both central and peripheral deterioration in neuromuscular function. Simple and choice stepping reaction time (RT) measures have the potential to detect walking induced changes in motor impairment. OBJECTIVES The aim of this study was to assess the effect of six minutes of walking on simple and choice stepping RT in people with MS. METHODS 31 people with moderate walking disability and a diagnosis of MS completed simple and choice stepping RT tasks, and rated their levels of fatigue on a 100mm visual analogue scale before and after a modified six minute walk test. RESULTS Subjects walked an average of 368(±110)m in six minutes. Perceived fatigue increased following the six minute walk, as indicated by a 25(±19.7)mm increase on the 100mm visual analogue scale (p<0.001). There was a significant increase in both hand (p=0.003) and foot (p=0.006) simple RT following the six minute walk. For choice stepping RT, response time was significantly slower (p=0.006) following the six minute walk, while movement time was unchanged (p=0.506). CONCLUSION Simple and choice stepping reaction times are slower following six minutes of walking in people with MS. These findings suggest that walking-induced fatigue might lead to central slowing and slowed stepping performance. Further studies are needed to investigate the clinical relevance of these RT measures in relation to fall risk and therapeutic interventions to improve mobility and manage fatigue in people with MS.

The effectiveness of allied health therapy in the symptomatic management of progressive supranuclear palsy: a systematic review protocol

Review question/objective The objective of this review is to present the best available evidence related to allied health therapy in the symptomatic management of progressive supranuclear palsy (PSP). More specifically, the review question to be addressed is: • What are effective physiotherapy, occupational therapy and speech therapy techniques used in the symptomatic management of PSP? Background Progressive supranuclear palsy, or sometimes known as Steele‐Richardson‐Olsewski syndrome, is a rapidly degenerative neurological disorder. The average age of onset is 60‐65 years with a life expectancy of six to seven years following diagnosis.1 The main symptoms of PSP typically include vertical gaze palsy (difficulty looking up or down), postural imbalance and falls, dysphagia (difficulty eating or drinking) and/or dysarthria (speech disorder).2 Progressive supranuclear palsy belongs to the class of neurodegenerative conditions called tauopathies. Aggregation of the protein tau in neurons can lead to damage in both cortical and subcortical areas of the brain.3 Progressive supranuclear palsy is a severe disorder that is under recognized and underdiagnosed.4 It is an insidious condition with devastating impacts on individuals, their families, and the health resources of the broader community.5 This review will focus solely on PSP; however, in order to understand this seemingly obscure condition, it is important to first discuss the class of neurological conditions to which it belongs and the trends in prevalence of these conditions. Progressive supranuclear palsy is a Parkinsonian condition, more specifically an atypical Parkinsonian condition. Parkinsonian conditions are a class of neurological disorders characterized by parkinsonism type symptoms such as slowness of movement, difficulty initiating movement, and rigidity with or without resting tremor.6 Parkinsons disease is the most common type. There is also a collection of conditions that may initially present similar symptoms to Parkinsons disease, but as the disease progresses they evolve in a critically different way to Parkinsons disease.6 These conditions have been named atypical Parkinsonian or Parkinsons plus syndromes. As mentioned, PSP is one type of atypical Parkinsonian conditions, others include multiple system strophy (MSA) and dementia with Lewy bodies.6 The key differences between Parkinsons disease and atypical Parkinsonian conditions have been summarized in Table 1 taken from Litvan.6 Table 1: Differential diagnosis of Parkinsons disease modified from Litvan The similarities and differences of Parkinsons disease and atypical Parkinsonian conditions begin to illustrate the complexities of PSP. People with Parkinsons disease and PSP all present with parkinsonism symptoms. Unlike most presentations of typical Parkinsons disease, people with PSP experience rapid progression of their disorder, early instability or falls, early dysphagia and/or dysarthria without the alleviating benefits of levodopa6 or an alternative effective medication.7 They experience an economic burden of disease high above that reported for Parkinsons disease,5 and may remain undiagnosed for approximately half of the natural history of their disease.8 As mentioned previously, PSP is a seemingly obscure disorder. To appreciate the true scale of the disorder it is necessary to explore the difficulties in defining, diagnosing and therefore ascertaining the actual prevalence of PSP. These difficulties, against the backdrop of a recent generalized trend of increasing prevalence of all neurodegenerative disorders14, paint a different picture. It is interesting to consider that the prevalence of PSP has been estimated to be 6.5 per 100,000,8 similar to the prevalence of motor neuron disease (MND),1 a far more well‐known neurodegenerative disorder. Six of the seven states in Australia have their own MND Association, while there is only one PSP Association.9 The difference in the level of services and awareness of two conditions with a similar prevalence may be related to how easily they can be defined. Historically, MND was more readily accepted as a separate morbid entity due to a distinctive clinical and pathological presentation in comparison to PSP.1 Diagnosis of PSP continues to be a complex process, as demonstrated by a 41% misdiagnosis rate.8 Progressive supranuclear palsy is difficult to discern from Parkinsons disease due to an overlap in presenting symptoms.6,8 It is also commonly misdiagnosed as stroke.8 Autopsy continues to be the gold standard in the diagnosis of PSP.7 The National Institute of Neurological Disorders and Stroke (NINDS) and the Society for PSP (SPSP) have developed criteria to assist the clinical diagnosis of PSP10 which has been summarized in Table 2. Clinical diagnosis utilizing the NINDS‐SPSP criteria is frequently used in studies researching PSP, presumably due to the difficulties obtaining autopsy results from participants. A recent study11 comparing the diagnostic accuracy of NINDS‐SPSP against the gold standard of autopsy identified that NINDS‐SPSPs probable criteria is appropriate for recruitment into clinical trials where an early and specific diagnosis is important.11 In the case of routine care where high sensitivity is crucial, a combination of NINDS‐SPSPs possible and probable criteria is more suitable.11 The NINDS‐SPSP criteria was first published in July 1996, therefore clinical studies completed prior to this time would not have had access to an appropriate recruitment method. Table 2: Summary of Litvan et al.s10 NINDS‐SPSP clinical criteria for the diagnosis of PSP Mandatory exclusion criteria: Recent history of encephalitis Alien limb syndrome, cortical sensory deficits, focal frontal or temporoparietal atrophy Hallucinations/delusions unrelated to dopaminergic therapy Cortical dementia of Alzheimers type Prominent early cerebellar symptoms Prominent, early unexplained autonomic dysfunction Severe asymmetric Parkinsonian signs Neuroradiologic evidence of relevant structural abnormality i.e. basal ganglia or brainstem infarcts Whipples Disease The NINDS‐SPSP clinical diagnosis criteria have been utilized in the prevalence study by Nath et al.8, which estimated the crude prevalence of PSP to be 6.5 per 100,000. A recent publication has suggested that the prevalence of PSP has been radically underestimated in clinical studies.12 Kovacs et al.13 identified two cases of pathologically confirmed PSP in their community drawn autopsy population (n=233) with a further five cases of anatomically restricted forms of PSP. In their study, 3% of their population had confirmed PSP or anatomically restricted forms of PSP. The radical difference in the number of people identified with PSP may be in part attributed to the diagnostic method used, with autopsy being the gold standard. The study by Kovacs et al.13 was published 12 years after the study by Nath et al.8 It is possible that the population studied by Kovacs et al.13 inherently had a higher prevalence of PSP than the population by Nath et al.8 due to an ageing population and an increase in possible environmental triggers, as will now be explored. More broadly, there is an increase in prevalence of all types of neurodegenerative conditions. This is in part attributed to an ageing population with more people living long enough to acquire disorders that occur later in life.14 An increase in neurological deaths (deaths due to an underlying pathology such as Parkinsons disease and MND) has also been observed in younger age ‐groups and females from 1979 to 2010.15 The possibility of modern environmental factors (increased population, pollution and exposure to electro‐magnetic fields) triggering existing underlying genetic predispositions has also been raised.15 This increase in prevalence of neurodegenerative disorders is a major public health problem14,15 and raises serious implications on families and health and social care services15 as in the case of Parkinsons disease. In the United States of America (USA), the economic burden of Parkinsons disease was 14.4 billion (USD) for the year of 2010. The projected prevalence of Parkinsons disease, and therefore associated cost, is expected to double by 2040.16 No such study has been completed for PSP; however, it is known that per person, the economic burden of disease for PSP is high above reports for Parkinsons disease.5 If the prevalence of PSP doubles in line with the expected trend of Parkinsons disease, the future economic burden of the disorder will be significant. There is an acute need for further evaluation of the economic impact of PSP. Symptoms and current approaches to the management of PSP People with PSP experience a range of symptoms2 that reduce quality of life across mobility, self‐care, usual activities, pain/discomfort and anxiety/depression domains.17 Mobility problems, visual symptoms, speech and swallowing problems are most commonly experienced.2 Symptoms of PSP continue to be defined and studies have since explored cognitive disturbances further18,19. A summary of the main symptoms experienced by people with PSP has been developed from a preliminary search of the literature and from publications from PSP associations including CurePSP (USA),20 the PSP Association (UK)21 and PSP Australia9 (see Table 3). Table 3: Summary of the main symptoms experienced by people with PSP Progressive supranuclear palsy is challenging to treat due to the widespread involvement of both dopaminergic and nondopaminergic systems.10 Currently, there are no curative treatments available.7 A multidisciplinary team is considered to be integral to the symptomatic management of PSP.24 In practice, there are a number of therapies used.4, 20, 22, 25, 26 This systematic review will focus on the interventions that can be delivered by the following three disciplines: physiotherapy/physical therapy, occupational therapy, and speech therapy/speec

Effect of walking on sand on gait kinematics in individuals with multiple sclerosis

BACKGROUND Walking in the real-world involves negotiating challenging or uneven surfaces, including sand. This can be challenging for people with Multiple Sclerosis (PWMS) due to motor deficits affecting the lower extremities. The study objective was to characterise kinematic gait adaptations made by PWMS when walking on sand and describe any immediate post-adaptation effects. METHODS 17 PWMS (mean age 51.4 ± 5.5, Disease Steps 2.4 ± 1.0), and 14 age-and gender matched healthy adults (HA) took part in a case-control study. 3D gait analysis was conducted using an eight-camera Vicon motion capture system. Each participant completed walking trials over level ground (baseline), sand (gait adaptation response), and again level ground (post-adaptation). Spatiotemporal data and kinematic data for the hip knee and ankle were recorded. RESULTS At baseline PWMS showed significantly less total lower limb flexion (p<0.05) compared to HA. PWMS adapted to walking on sand by significantly increasing hip and knee flexion and ankle dorsiflexion (p<0.05) during swing, resulting in an overall 23° greater total lower limb flexion (p<0.05), reaching values within normal range. During the return to level ground walking values of temporal-spatial and kinematic parameters returned towards baseline values. CONCLUSIONS PWMS adapted to walking on sand by increasing lower limb flexion during swing, and returned to their gait pattern to near baseline levels, in a manner similar to but with values not equalling HA. Further work is required to determine whether this mode of walking has potential to act as a gait retraining strategy to increase flexion of the lower limb.

Visual field dependence is associated with reduced postural sway, dizziness and falls in older people attending a falls clinic

Moving visual fields can have strong destabilising effects on balance, particularly when visually perceived motion does not correspond to postural movements. This study investigated relationships between visual field dependence (VFD), as assessed using the roll vection test, and reported dizziness, falls and sway under eyes open, eyes closed and optokinetic conditions. Ninety five falls clinic attendees undertook the roll vection test (i.e. attempted to align a rod to the vertical while exposed to a rotating visual field). Sway was assessed under different visual conditions by centre of pressure movement. Participants also completed questionnaires on space and motion discomfort, fear of falling, depression and anxiety. Thirty four (35.8%) participants exhibited VFD, i.e. had an error >6.5º in the roll vection test. Compared to participants without VFD, participants with VFD demonstrated less movement of the centre of pressure across all visual conditions, were more likely to report space and motion discomfort and to have suffered more multiple falls in the past year. VFD was independent of fear of falling, anxiety and depression. VFD in a falls clinic population is associated with reduced sway possibly due to a stiffening strategy to maintain stance, dizziness symptoms and an increased risk of falls.