Clinical Features of Powered Wheelchair Users With

Clinical features of powered wheelchair users with

severely disabling multiple sclerosis

Lorraine H. De Souza PhD*, Andrew O. Frank FRCP

FromCentre for Research in Rehabilitation, School of Health Science and Social Care, Mary Seacole Building, Brunel University, Uxbridge, Middlesex, UB8 3PH, UK (De Souza) and Stanmore Specialist Wheelchair Service+, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, HA7 4LP, UK (Frank)

*Author for correspondence:

Email:

Tel: +44 (0)1895 268847

Fax: +44 (0)1895 269853

+ Stanmore Specialist Wheelchair Service has now been disbanded.

Implications for Rehabilitation

1. Those with MS needing powered mobility should have a clinical assessment of their

MS, comorbid problems and complications of disability – including risks to health

and pressure ulcers.

2. Risks for osteoporosis, thrombo-embolic disorders and cardiovascular disease should

be included.

3. Weight management is essential and could be performed using weighing equipment

based in wheelchair services.

Abstract

Purpose: To describe the provision of electric powered indoor/outdoor wheelchairs for peopleseverely disabled by multiple sclerosis and explore the complexities of comorbidities, clinicalfeatures and conditions secondary to disability influencing prescription.

Methods: Patients were recipients of electric powered indoor/outdoor wheelchairs (users)attending a specialist wheelchair service between June 2007 and September2008. Electronicand case note records were reviewed retrospectively by a consultant in rehabilitationmedicine. Data were systematically extracted under three themes; demographic, diagnosticand clinical profiles, and wheelchair factors and entered into a computer database. Furtherdata were entered from the clinical records.

Results: Twenty eight men aged 57 (range 37-78, sd 12) years and 63 women aged 57 (range35-81, sd 11) years with multiple sclerosis were reviewed a mean of 64 (range 0-131) monthsafter receiving their wheelchair. Twenty two comorbidities, 11 features of multiple sclerosisand 8 conditions related to disability were thought to influence wheelchair prescription.Fifteen users were provided with specialised seating and 40 with tilt-in-space.

Conclusions: Findings suggest that the features of severe disabling multiple sclerosis

influence the prescription of the electric powered indoor/outdoor chair more than the

comorbidities. Assessment should include a health risk assessment.

Keywords: Multiple sclerosis, wheelchairs, comorbidity, disability, mobility, seating

Introduction

Multiple Sclerosis (MS) is an incurable long term debilitating neurological conditionaffecting predominantly young adults but may present in childhood and older age [1]. Arecent report indicates that, for those with relapse-remitting MS, the median time fromdiagnosis to being wheelchair dependent (disability status scale (DSS) 8 [2]) is 28 years [3].

The most common functional consequence of MS is mobility disability which affects 50% ofthose diagnosed within 15 years of disease onset [4]. This is due to weakness, spasticity,balance problems and/or fatigue alone or in any combination [4]. However, it has beenestimated from a Canadian survey, that approximately eight percent of people with MS(PwMS) will use powered wheelchairs [5].

Electric powered indoor/outdoor powered wheelchairs (EPIOCs) have been available throughthe UK National Health Service (NHS) for PwMS and those with other disabling conditionssince 1996. Eligibility for NHS EPIOC provision requires a potential user to be able tocontrol the EPIOC safely, independently, and be unable to walk around their home or self-propel[6]. These criteria are based on functional need and the potential benefit to the user.

For PwMS, EPIOCs will benefit those who cannot self-propel due to difficulty grasping andreleasing the pushrim of a manual wheelchair, those who have asymmetry of upper limbpower and/or wheelchair users’ shoulder [7] and consequently are unable to maintain speedover even short periods of time. This effort contributes to fatigue and is thought to renderself-propulsion non-functional [8].In addition to mobility disability, PwMS frequently have comorbidities that may affecttreatment decisions [9-11]. The number of comorbid conditions are thought to increase withDSS and adversely affect health-related quality of life [12]. For example, the co-occurrenceof pain and depression is thought to be noteworthy in PwMS [13], while older PwMS areknown to be at increased risk of fracture [14]. Pain is a major problem for PwMS and achallenge for rehabilitation professionals [15] , particularly in their wheelchair use andseating [15,16].

Several symptoms characteristic of MS e.g. spasticity and fatigue are alsorelevant to wheelchair use. Studies of comorbidity in MS at onset of symptoms and atdiagnosis have been reported and may be associated with differences in clinicalcharacteristics [11]. The picture is likely to be very different in severe disabling MS due todisease progression and the impact of long-term physical and functional limitations for thosewho are wheelchair dependent. The challenge in this group of PwMS is in identifying whathealth issues are comorbidities as distinct diagnostic entities and what have arisen due to thelong term impact of the disease. Thus deep venous thromboembolism (VTE) may beconsidered a separate diagnosis; however the increased frequency in late-stage MS issuggested to be due increased risk factors such as immobility and limb paralysis [17].

Little research has been carried out into the mobility needs of those who are very severelyaffected by MS. We have found no reports of comorbidity in wheelchair dependent PwMS.The benefits of independent powered mobility (PM) include education [6,18,19] or work[6,18,19] , and a range of social activities such as shopping [6,18,19] , church going[6,18,20], socialising with family and friends [6,18,20-22] and accessing healthcare facilities[6,20,21]. In addition, the increased mobility provided by PM enhances quality of life andwellbeing [22,23].

Multidisciplinary clinical teams assessing for prescription of EPIOCs will have knowledgeand information about the potential users’ diagnoses. The important aspects of the clinical picture are those with significant implications for seating and/or the control of the EPIOC.Consideration needs to be given to the progression of the MS, the risk of potentialcomplications including the development of new comorbidities e.g. osteoporosis or pressuresores, environmental factors and active ageing.

The aim of this study is to describe the provision of EPIOCs for people severely disabled byMS. We also aim to explore the constellation, and the complexities, of comorbidities, clinicalfeatures of MS and conditions secondary to disability influencing prescription. In doing so,we aim to compare our findings of comorbidity recorded in the clinic with the classificationsused in self-report questionnaires in those mildly or moderately disabled with MS [9-11].

Methods

Potential participants were referred from their local wheelchair service. All individuals whohad been prescribed an EPIOC and were currently using their chair were of interest to thisstudy. Their electronic records were reviewed between June 2007 and September 2008 by aconsultant physician in rehabilitation medicine and data were systematically extracted andentered into a computer database for analysis. Further data were entered from the clinicalnotes (charts) and all the data anonymised. Those relevant to this research were users with adiagnosis of MS.

Data were extracted under three themes; demographic profile, clinicalprofile and wheelchair factors.Demographic profiles consisted of information on age at initial EPIOC assessment andgender. Clinical profiles included the diagnosis of MS, comorbidities (e.g. asthma or cancer),features that reflected aspects of MS (e.g. trigeminal neuralgia or spasticity) andcomplications relating to the disability (e.g. pressure sores or (kypho)scoliosis).Comorbidities included all conditions reported by Marrie et al [11] and Horton et al [9] andwere compared with Kang et al [10]. Conditions classified as comorbidities included thoseunrelated to MS but reported to have co-occurrence with the disease e.g. fractures [14] andpain [13]. Conditions classified as features of MS (e.g. trigeminal neuralgia, MS fatigue)were reported as known signs and symptoms of the disease [24]. Weakness was not recordedas it is universal in a group of EPIOC users.

Clinical features consequent to long-standing immobility and relevant to EPIOC prescription(e.g. pressure sores, shoulder pain, thrombo embolism) were classified as complications ofsevere disability. Back pain associated with kyphus or fracture was not coded as back painbut as the underlying cause. The following conditions were recorded as being probablypainful: any form of spinal pain, osteoarthritis (OA), severe pain of uncertain cause,wheelchair users shoulder (WUS), shoulder pain, irritable bowel syndrome (IBS), trigeminalneuralgia (TN), polyarthralgia and spasticity.

Wheelchairs and seating

Data relating to specialised seating (SS), defined as ‘that which is needed by people whorequire a wheelchair but due to instability or deformity need additional support in order tofunction’ [25] were recorded. Other features included tilt-in-space (TIS), complex controlse.g. central joystick / tray mounted controls, head controls, switch controls, non-standardcontrol system, interfacing with other assistive technology and cushions.

Methods of analysis

Data were analysed to describe proportions and frequencies of variables to determine therange and pattern of the wheelchair provided and medical factors recorded. Descriptivestatistics were used to analyse demographic data and to describe subgroups of interest.

This study was approved by the National Research Ethics Service.

Results

Ninety one users had a diagnosis of MS. They consisted of 28 men aged 57 (range 37-78, sd12) years and 63 women aged 57 (range 35-81, sd 11) years. Users had been with the EPIOCservice a mean of 64 (range 0-131) months at the time of review. Only partial data wereavailable on the medical profiles of 42 users whilst data on TIS was available for 82 users.

Twenty two comorbidities were identified. Of these, 12 were the same as those comorbiditiesfound by Marrie et al [11] and Horton et al [9] (Table 1) and a further 10 were notrepresented in those publications. They were: fractures (n=6), cerebrovascular disease/stroke(n=2) (a noted comorbidity of Kang et al [10]), and one each of the following - amputation,cervical cancer, hearing impairment, lymphoma, platelet disorder, polyarthralgia, radialdysplasia and weight loss of uncertain cause. In addition 11 features of MS were found and 8conditions consequent to disability (Table 2)

Thirty one users had no comorbidities, features of disabling MS or conditions consequent todisability (collectively referred to as additional clinical features – ACFs). Twenty nine usershad one ACF and 31users had two or more. A total of 41 different ACFs were noted. Thefrequency of ACFs in the remaining 60 EPIOC users totalled 108, of which 42 werecomorbidities, 28 were disabling features of MS and 38 were conditions consequent todisability (Table 2).

The most frequent comorbidities found were asthma and depression. Poorly controlledspasticity was by far the most common feature of MS noted in 10 users. Pressure soresincluding leg ulcers and low back pain were the most often found conditions consequent to disability (Table 2). Forty one painful conditions were experienced by 31 users. The mostcommon causes of pain were low back pain and spasticity.

Wheelchairs and seating

Fifteen users (eight men) were provided with SS and 40 (14 men) with TIS. Only seven userswere given both SS and TIS. Of the 15 users with SS, 11 had one or more ACFs (Table 3)and eight had painful conditions. Of these 15, three needed matrix seating systems, and theremainder had standard pressure-relieving cushions (Roho=3 [The Roho Group, Belleville,IL USA], Vicaire=3 [The Comfort Company, Bozeman, MT USA], Qbitus=3 [QbitusProducts, Halifax, UK], Jay2=2 [Sunrise Medical Limited, West Midlands, UK],TempurMed=1 [Sumed International (UK) Ltd, Glossop, UK]).

Of the 40 users with TIS, 34 had one or more ACFs (Table 3). Twenty eight had standardpressure-relieving cushions (Qbitus=15, Roho=3, Vicaire=3, Jay2 and V-Trak [Pontyclun,Rhondda Cynon Taff, UK] two each and one each of Jay-Active, Transflow [KaromedLimited, Chard, UK] and Protech [Invacare UK, Bridgend, UK]). Two users were givenmatrix seats and six had standard wheelchair seats whilst there was no data on four cushions.

Of the 31 users with problematic pain, only 14 used TIS and eight used SS.Only two users required complex controls. A 50y old woman with secondary progressive MSand hyperthyroidism had profound finger/hand weakness challenging our control system. Sheneeded a non-standard tray-mounted system that interfaced with an environmental controlunit (ECU). The other was a 62y old man with MS as the only diagnosis who needed SS andchin controls. This user was advised to have an additional control stick for carer's use.

None used wheelchair mounted ventilators. Of the 10 users with poorly controlled spasticity, sixreceived either TIS and or SS. Both users with severe MS fatigue had TIS.

Safety concerns were noted in six users. Three had suffered accidents through toppling out oftheir EPIOC (one had driven off the curb). One experienced an electric burn on the armfollowing an electrical short from the control system through the user’s metal jewellery. Theuser noted above (with carer-operated controls) was given these controls for safety reasonse.g. when the user was weaker following an infection or flare in the MS. Another had theEPIOC withdrawn following symptom progression resulting in an inability to drive safely.

Discussion

This paper reports, for the first time, the clinical features seen in EPIOC users severelydisabled by MS that are due to both the established impact of late stage MS and theaccumulative effect of long-term disability. Our results demonstrate that these features,including comorbidity, in PwMS severely affected by mobility disability are very differentwhen compared with those at diagnosis.

Comorbidities

A comparison of our results with published MS comorbidity [9-11] shows 12 conditions thathave previously been reported but 10 that are unreported in the current literature. Manypossible explanations for this discrepancy relate to the later course of the life cycle thatseverely disabled PwMS reflect, which also allows for the treatment of some of these conditions to have been completed e.g. cataracts. Other PwMS may have died at earlierstages of the disease due to related/unrelated conditions. The apparent under-reporting ofpublished MS comorbidity may be due to our smaller group of PwMS. Nonetheless comorbidities found in our group e.g. cervical cancer and lymphoma are not reported

Comorbidity is associated with increased disability in MS [11] and is also associated withdifferences in clinical characteristics of the disease [11]. It is recognised that complicationsdue to MS, or its disabling consequences e.g. thrombo-embolism or choking, and nonneurologicalcomorbidities e.g. cardio-respiratory conditions, are causes of unexpected deaths[26]. Our results include these and other potential risks of premature death. Evidence islacking to support the difficult clinical decisions needed to inform best rehabilitation practicefor those with multiple health conditions [27] but it is recommended that taking specificprecautions could prevent some deaths in MS [26].

Features of MS

Poorly controlled spasticity was the commonest MS feature found in our group. This mayreflect inadequate utilisation of specialist spasticity services available to these users. Thepresence of poorly controlled spasticity influences EPIOC prescription and predisposes tofurther complications such as pressure sores and contractures. Spasticity can be managedthrough positioning in the wheelchair, physiotherapy, medication (oral or intrathecal) or acombination of the above after the abolition of any triggers e.g. infection. EPIOC prescriptionfor 6 users was influenced by the presence of spasticity. These features are not reported bythe earlier studies of comorbidity [9-11] due to the earlier stage of disease. Later stage MSwould commonly include these conditions as recognised complications of MS [28].Other features such as swallowing and choking are often managed through posture which anEPIOC can facilitate. For those with potential bowel or bladder incontinence there are issuesregarding the cushion needed. Failed continence is not only undignified and often painful, butmay need frequent transfers out of the EPIOC which has implications for both user and carerand may need specialist intervention. For those with indwelling catheters, TIS may not beappropriate.

MS fatigue may be the primary reason for EPIOC provision when selfpropulsion is either too slow to be functional or becomes impossible [8]. More usually, it willbe managed by use of TIS as with our two users. Trigeminal neuralgia may be assisted by useof EPIOCs with good suspension, or by cushions that dampen vibration.

This study found that about one third of users had problematic painful conditions which maybe due to the underlying medical condition, the wheelchair or a combination of the two [16].Wheelchair technology e.g. TIS or back/leg rests and/or appropriate cushions can douch toameliorate problematic pain. Wheelchair providers should be more proactive inexploring thepain experiences of users and utilise existing technology appropriately, together with userfeedback [16].

Features of disability

While prevention and treatment of pressure sores is stressed in guidelines for MSmanagement [29] these guidelines do not refer to the risks of osteoporosis (although theserisks have been recognised for some time) [30], venous thromboembolism (VTE) [17,26] andcoronary heart disease [26]. It is likely that the five users reporting fractures hadundiagnosed osteoporosis. Osteoporosis is important for PwMS in view of the known risk ofaccidents such as tipping out of wheelchairs [6,18] or falls during transfers [6]. These risksare additional to the risks for osteoporosis for PwMS relating to immobility, previous steroidsand potential lack of vitamin D through being housebound [22].

Wheelchair dependency places people at risk of weight gain and obesity. Although ourfindings identified only one individual who was clinically obese, this issue should beconsidered within the overall assessment. Obesity in MS has been identified [31] and it isrecommended that investigations into weight and MS were needed to elucidate therelationship with disability [31]. Problems associated with weight gain in powered wheelchairusers relate to health and practicalities of wheelchair use. Users gaining weight may need wider chairs and eventually be unable to go through some doors at home without houseadaptations. Wheelchair services could offer regular weighing. Measurement of abdominalgirth may be taught as a self-management technique as a proxy of weight measurement forusers, or their carers, to monitor weight change.

Ambiguities of classification

Classification of clinical features is, almost by definition, complex and imprecise, yet is seento be important e.g. for ‘understanding, shaping and managing the outcomes of the provisionof AT devices’ [32]. This paper has attempted to categorise sets of clinical features into oneof three groups to clarify, potentially, the importance of these groups in EPIOC users withadvanced MS.It is hoped that, by exploring these profiles, the information gained will assist the complexand difficult decisions that rehabilitation professionals need to make when prescribingEPIOCs to severely disabled PwMS. Such decisions need to be made, not only in the bestinterests of the user but also recognising user and carer preferences. Taking into account thecomorbidity and complications of MS and disability avoids the dangers of ‘siloing’ usersinto a single diagnostic group [27] and the potential additional costs for failing to account fordisease severity [33].