An overview of the clinical management of spasticity

1 An overview of the clinical management of spasticity Michael P. Barnes Spasticity can cause significant problems with activ- ity and participation in people with a variety of neu- rological disorders. It can represent a major chal- lenge to the rehabilitation team. However, modern approaches to management, making the best use of new drugs and new techniques, can produce signif- icant benefits for the disabled person. The details of these techniques are outlined in later chapters and each chapter has a thorough reference list. The pur- pose of this initial chapter is to provide a general overview of spasticity management, and it attempts to put the later chapters into a coherent context. Definitions of spasticity and the upper motor neurone syndrome Spasticity has been given a fairly strict and nar- row physiologically based definition, which is now widely accepted (Lance, 1980): Spasticity is motor disorder characterised by a veloc- ity dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks, resulting from hyper- excitability of the stretch reflex, as one component of the upper motor neurone syndrome. This definition emphasizes the fact that spasticity is only one of the many different features of the upper motor neurone (UMN) syndrome. The UMN syn- drome is a somewhat vague but nevertheless useful concept. Many of the features of the UMN syndrome are actually more responsible for disability, and con- sequent problems of participation, than the more narrowly defined spasticity itself. The UMN syn- drome can occur following any lesion affecting some or all of the descending motor pathways. The clini- cal features of the UMN syndrome can be divided into two broad groups – negative phenomena and positive phenomena (Table 1.1). Negative phenomena of the UMN syndrome The negative features of the UMN syndrome are characterized by a reduction in motor activity. Obvi- ously this can cause weakness, loss of dexterity and easy fatiguability. It is often these features that are actually associated with moredisabilitythanthepos- itive features. Regrettably the negative phenomena are also much less easy to alleviate by any rehabili- tation strategy. Positive phenomena of the UMN syndrome These features can also be disabling but neverthe- less are somewhat more amenable to active inter- vention. At the physiological level thereareincreased tendon reflexes, often with reflex spread. There is usually a positive Babinski sign and clonus may be elicited. These may be important diagnostic signs for the physician but are of little relevance with regard to the disability. The exception is sometimes the presence of troublesome clonus. This can be trig- gered during normal walking, such as when stepping off a kerb, or can occasionally occur with no obvi- ous trigger, such as in bed. In these circumstances clonus can sometimes be a significant disability and 1 2 Michael P. Barnes Table 1.1. Features of the upper motor neurone syndrome Negative Positive r Muscle weakness r Increased tendon reflexes with radiation r Loss of dexterity r Clonus r Fatiguability r Positive Babinski sign r Spasticity r Extensor spasms r Flexor spasms r Mass reflex r Dyssynergic patterns of cocontraction during movement r Associated reactions and other dyssynergic and stereotypical spastic dystonias occasionally needs treatment in its own right. The other positive features of the UMN syndrome cause more obvious disability. Spasticity A characteristic feature of spasticity is that the hyper- tonia is dependent upon the velocity of the muscle stretch – in other words, greater resistance is felt with faster stretches (this results in the clinical sign of a ‘spastic catch’). Thus, spasticity resists muscle stretch and lengthening. This has two significant consequences. First, the muscle has a tendency to remain in a shortened position for prolonged peri- ods, which in turn may result in soft tissue changes and eventually contractures (Goldspink & Williams, 1990). The second consequence is that attempted movements are obviously restricted. If, for exam- ple, the individual attempts to extend the elbow by activation of the triceps, this will stretch the biceps, which in turn will induce an increase in resistance and indeed may prevent full extension of the elbow. However, it is worth emphasizing that the situa- tion is usually more complex. In the above example, relief of the spasticity in the biceps may not lead to improvement in the function of the arm, as other features of the UMN syndrome, particularly muscle weakness, may have a part to play. Soft tissue changes and contractures Restriction of the range of movement is not always simply due to increase of tone and spasticity in the relevant muscles. The surrounding soft tissues, including tendons, ligaments and the joints them- selves, can develop changes resulting in decreased compliance. It is likely that such contractures and changes in the soft tissues arise from the muscle being maintained in a shortened position. It is pos- sible, but not absolutely proven, that maintaining a joint through a full range of movement may prevent the longer-term development of soft tissue contrac- tures. The frequency of the stretch, either actively or passively, that is required to prevent contractures is unknown. However, it is important to emphasize good posture and seating such that the muscles, as far as possible, are maintained at full stretch for at least some of every day. The recommendation is that muscles be put through a full stretch for 2 hours in every 24 hours (Medical Disability Society, 1988). However, more research is needed in this field to determine the degree and frequency of stretch with more certainty. Thus, hypertonia often has both a neural com- ponent (secondary to the spasticity) and a biome- chanical component (secondary to the soft tissue changes). Obviously biomechanical hypertonia is not velocity dependent and restricts movements even at slow velocities. Furthermore, biomechanical hypertonia will not respond to antispastic agents; the only treatment possibilities relate to physiotherapy, stretching, good positioning, splinting and casting. Ultimately surgery may be needed to relieve advanc- ing and disabling soft tissue contracture. In practical terms there is often a mixture of neural and biome- chanical hypertonia, and it is very difficult clinically to determine the relative contribution of each of the components. Thus, active intervention for spastic- ity (e.g. by antispastic medication or local treatment such as phenol block or botulinum toxin injection) An overview of the clinical management of spasticity 3 is worth undertaking simply to be sure of alleviat- ing at least the neural component of the hypertonia. Thereis often a gratifying response even in limbs that appear to have fixed contractures. In advanced spasticity, it is often the soft tissue changes that contribute most to the disability and are resistant to treatment. Increasing deformity of the limbs will clearly lead to rapidly decreasing function and often result in problems with regard to hygiene, positioning, transferring and feeding and make the individual more prone to pressure sores (O’Dwyer et al., 1996). Flexor and extensor spasms Severe muscle spasms are often found in UMN syn- drome. These can be in either a flexor pattern or an extensor pattern. The commonest pattern of flexor spasm is flexion of the hip, knee and ankle. The spasms can some- times occur spontaneously or, more commonly, in response to stimulation, are often mild. Sim- ple movement of the legs or adjusting position in a chair can be enough to induce the spasm. The spasms themselves can be painful and are some- times so frequent and severe that a permanent state of flexion is produced. If spasms worsen suddenly, it is worth looking for aggravating factors such as pressure sores, bladder infections, irritation from a catheter or even such apparently mild stimulants suchasanill-fittingorthosisoratight-fittingcatheter leg bag. Occasionally constipation or bladder reten- tion can also produce a flexor spasm, which can then be associated with a reflex emptying (mass reflex) of the bowel or bladder. Similar problems can occur with extensor spasms, which are commonest in the leg and involve exten- sion of the hip and knee with plantar flexion and usually inversion of the ankle. Once again, such spasms can be triggered by a variety of stimuli and sometimes can be so severe as to produce a perma- nent extensor position. Extensor spasms are proba- bly more common than flexor spasms in incomplete spinal cord lesions and cerebral lesions, but there is no clear association with any particular pathology. Occasionally a spasm can be useful from a functional point of view. Placing pressure on the base of the foot in order to stand can sometimes produce a strong extensor spasm of the leg, effectively turning it into a rigid splint, which, in turn, aids walking. Occasion- ally individuals can make positiveuseofself-induced spasms, such as for putting on trousers. This empha- sizes the importance of detailed discussion with the disabled person and his or her carer before assuming that the spasm will need treatment. Finally, extensor and flexor spasms can be extremely painful; even if not causing undue functional disturbance, they can need treatment in an attempt to relieve the associ- ated acute pain. Spastic dystonia and associated reactions Most of the previously described positive phenom- ena of the UMN syndrome can occur at rest. Another range of problems can occur on movement. For example, there is the classic hemiplegic posture, commonly occurring in stroke, that often occurs when the individual tries to walk. This posture con- sists of a flexed, adducted, internally rotated arm with pronated forearm and flexed wrist and fin- gers. The leg is extended, internally rotated and adducted, and the ankle is plantar flexed and inverted, often with toe flexion. Other patterns occurring on movement are sometimes called spas- tic dystonias (Denny-Brown, 1966). This is a term that probably ought to be avoided, given the poten- tial confusion with extrapyramidal disease. Other problems that occur on movement or attempted movement involve co-contraction of the agonist and antagonists. Simultaneous contraction of agonist and antagonist muscles is a normal motor phenomenon and is required for the smooth move- ment of the limb. However, in the UMN syndrome, agonist and antagonist muscles may co-contract inappropriately and thus disrupt normal smooth limb movement (Fellows et al., 1994). Sometimes involuntarily activation of muscles remote from the muscles involved in a particular task also contract. For example, if the individual attempts to move an arm, then a leg may extend or flex. Conversely the 4 Michael P. Barnes arm can flex when attempting to walk (Dickstein et al., 1996). These ‘associated reactions’ (Walshe, 1923) can interfere with walking by unbalancing the individual or, for example, making it impossi- ble to do any task with the arms while standing. Various other patterns of dyssynergic and stereo- typical contractions have been described, such as extensor thrust (Dimitrijevic et al., 1981). However, the labelling of these problems is less helpful than a prolonged period of observation and discussion with the disabled person, the family and the person’s car- ers. Simple bedside testing is usually inadequate to determine an overall treatment strategy. The pattern of spasticity and the functional consequences dur- ing attempted movement as well as at rest all need careful assessment, often over prolonged periods of time. Reports from a well-educated disabled person who can describe the problems in different circum- stances are of far more value than a single examina- tion in the outpatient clinic. Clinical consequences The above description of the different patterns of the UMN syndrome make it clear that there is a poten- tially wide range of functional problems. In order to draw the discussion together, the major conse- quences can be annotated as follow. Mobility Probably the most common consequence of the UMN syndrome is difficulty walking. The gait can be clumsy and uncoordinated, and falling can become a common event. Eventually walking may become impossible owing to a combination of soft tissue con- tractures, flexor or extensor spasms and unhelpful associated reactions. It is also worth bearing in mind that individuals with UMN syndrome may often have a whole variety of other neurological problems, such as cerebellar ataxia or proprioceptive distur- bance, which further compounds the problem. Even if the individual cannot walk, the UMN syndrome can cause further problems with regard to difficulty maintaining a suitable seating posture. Spasticity may make it difficult to self-propel a wheelchair. Extensor spasms may constantly thrust the individ- ual forward while sitting in the chair, giving rise to an increased risk of shear forces that can cause pres- sure sores. Seating will often require a considerable range of bracing, supports and adjustments in order to allow the person to maintain a useful and com- fortable position. Loss of dexterity Inthe arm, the UMN syndrome can cause further dif- ficulties with, for example, feeding, writing, personal care and self-catheterization. Mobility in bed may be hampered and loss of dexterity in the arm may make it difficult to self-ambulate in a wheelchair. All these problems can slowly lead to decreased inde- pendence and a consequent increased reliance on a third party. Bulbar and trunk problems Although most of the functional consequences of spasticity occur in the arm or leg, it is worth remem- bering that truncal spasticity can cause problems with seating and maintaining an upright posture – necessary for feeding and communication. Bulbar problems can give rise to difficulty swallowing, with consequent risk of aspiration or pneumonia. Further problems can arise with communication, secondary not only to inappropriate posture but also to spastic forms of dysarthria. Pain It is not widely recognized that spasticity and the other forms of UMN syndrome can be extremely painful. This is particularly the case with flexor and extensor spasms, and sometimes treatment is needed simply for analgesia rather than improve- ment of function. Abnormal postures can also give rise to an increased risk of musculoskeletal prob- lems and osteoarthritic change in the joints. Any peripheral stimuli from problems such as ingrowing An overview of the clinical management of spasticity 5 toenails or small pressure sores can, in turn, exacer- bate the spasticity, and a vicious circle of increased pain and increased spasticity can ensue. Carers and nursing problems Spasticity is one of the unusual conditions that can sometimes require treatment of the disabled per- son for the sake of the carer. Individuals, particularly with advanced spasticity, can be extremely difficult to move and nurse. Transfers from bed to toilet or bed to wheelchair can be laborious. Hygiene can be a problem with, for example, marked adductor spas- ticity, causing problems with perineal hygiene and catheter care. Flexion of the fingers can cause partic- ular difficulties with hygiene in the palm of the hand. Thus, aggressive treatment of spasticity can some- times be a factor in reducing carer stress, which in turn can make the difference between the individual remaining at home or moving into an institution. An approach to management The previous section indicated the complexity and functional consequences of spasticity. The following chapters in the book outline the detail of the dif- ferent approaches to the management, but this sec- tion attempts to provide an overview of the process (Fig. 1.1). Aims of treatment The first question to ask is whether treatment is needed at all. The previous section has shown that occasionally a spastic pattern can be functionally useful, such as an aid to walking or dressing. Spas- ticity in the UMN syndrome may be abnormal from a neurophysiological point of view, but this does not mean that treatment is always required. The aims of treatment will always need careful annotation and discussion with the individual. The commoner aims are to improve a specific function, reduce pain, ease the task of caring or prevent long-term problems, such as soft tissue contractures. The specific aims of a particular treatment strategy always need clear explanation. This also implies that there should be an appropriate method of measuring outcome, so that one knows when the aim is fulfilled. Chapter 3 discusses the topic of measurement in spasticity. Outcomes clearly need to be geared to the aim of treatment. For example, if the aim of the treatment is to improve hand function, a simple, reproducible and valid test of hand function will be required. If the outcome is a reduction of pain, perhaps use of a visual analogue scale will be helpful. The use of a global disability or activities of daily living (ADL) scale is usually inappropriate, as subtle treatment effects may be masked. It is important, particularly in people needing long-term treatment, that the aims and purposes of treatment be reviewed regularly and new goals set or old goals adjusted. This is particularly the case with the use of long-term antispastic medication when the side effects of treatment may at some point out- weigh its benefits (see Chapter 7). Self-management Education of the disabled person and his or her family is vital, as in all rehabilitation management. Spasticity and the UMN syndrome involve complex phenomena. The individual needs to be aware of some of the factors that may aggravate the prob- lem, such as inappropriate positioning, tight-fitting shoes, or even heavy bedclothes. A detailed appraisal of the pattern of spasticity may enable the individ- ual to relieve many of the functional problems. Both the clinician and the individual should be aware of potential aggravating factors, such as the worsening effect on spasticity of bladder infection or constipa- tion. The physiotherapist and the orthotist The early involvement of an experienced physio- therapist is invaluable. There are many potential interventions, ranging from simple passive range-of- motion exercises to more complex antispastic phys- iotherapy approaches (see Chapters 4 and 5). The physiotherapist can also administer symptomatic 6 Michael P. Barnes Spasticity and UMN syndrome present? Does it interfere with function, care or cause pain? Identify goals Is the individual educated about spasticity? Might treatment be needed to reduce the risk of longer- term complications? • No treatment needed • Monitor Initiate self-awareness programme Are there treatable aggravating factors? Remove Involve physiotherapist (± orthotist) for posturing/seating/splinting/ orthosis/exercise programme etc. Is spasticity still a problem? Yes Consider oral medication Is spasticity still a problem? (medication insufficient or not tolerated) Consider focal techniques (phenol blocks/botulinum/ intrathecal baclofen) Consider surgery Is spasticity still a problem? Is spasticity still a problem? Monitor YesNo No Yes seYoN No Yes No Monitor No Yes Yes Yes Figure 1.1. Flowchart outlining the approach to the overall management of spasticity. An overview of the clinical management of spasticity 7 treatment such as heat and advice on the use of hydrotherapy as well as the prescription of splints and casts. At this point the input of an orthotist is essential, as many situations are helped by the judi- cious application of a suitable orthotic device (see Chapter 6). Much can be achieved by these nonin- vasive techniques before resorting to medication or invasive focal treatments. Oral medication Chapter 7 outlines the various pharmacological possibilities of antispastic medication. Medication should rarely be used in isolation but usually is just part of a whole treatment strategy. Medication can provide a useful background effect, which makes, for example, the fitting of an orthosis or positioning in a chair easier and more comfortable. Occasion- ally, particularly in mild spasticity, the use of anti- spastic medication can be sufficient in isolation to reduce a functional problem, such as troublesome clonus. The problem with medication is that it is often associated with side effects. These particularly focus around increased weakness and fatigueability. Spasticity is often a focal problem, and medication will clearly give a systemic effect. Thus, muscles that are not troublesome can be inappropriately weak- ened and the overall functional effect can be made worse. Medication may reduce some of the positive effects of the UMN syndrome but at the same time make some of the negative effects worse. The pur- poses and goals of medication need to be care- fully annotated and the use of medication constantly reviewed. Focal techniques The need for intervention in spasticity is often con- centrated on one or a few muscle groups. Thus, a focal approach is often more appropriate than the systemic effect induced by oral medication. In recent years increasing value has been placed on focal tech- niques such as phenol and alcohol nerve blocks (see Chapter 8) and the use of botulinum toxin (see Chapter 9). The latter, in particular, is a remarkably safe and useful technique, but once again it is impor- tant to emphasize that it is not often used in isola- tion but rather as part of an overall treatment pack- age. For example, the use of botulinum can facilitate positioning in physiotherapy or ease the fitting of an orthosis. Fortunately, the effect of botulinum toxin is reversible over a period of 2 to 3 months, which enables reappraisal and reassessment on a regular basis. Phenol nerve blocks are equally efficacious but more difficult to administer, and there is the risk of a permanent effect. However, phenol is very sig- nificantly cheaper than botulinum toxin and thus is more relevant and practical in developing countries. Intrathecal and surgical techniques Occasionally spasticity is very resistant to interven- tion and further invasive techniques need to be con- sidered. Intrathecal baclofen (see Chapter 10) is now a well-recognized and relatively safe procedure. In some centres, it is used in preference to other focal techniques, such as botulinum toxin. The technique isgenerallysafe,althoughitcanoccasionallybe asso- ciated with unwanted complications such as pump failure, infection or movement of the catheter tip. Finally, there is the possibility of surgical interven- tion (see Chapter 11). There are some surgical tech- niques, such as rhizotomy, that relieve spasticity in their own right, but surgery is now often reserved for the unwanted complications of spasticity, particu- larly soft tissue contracture. If soft tissue contracture is advanced and disabling, there is often no option but to resort to surgical release and repositioning of the limb. However, it is probably true that if spasticity is treated appropriately and actively at the outset, it is only the very rare individual who will need surgery. Overall, we hope that this book gives a practical andstraightforward account ofthe various treatment approaches to spasticity as well as emphasizing the importance of setting clear goals with clear outcome measures. We trust the book makes it clear that spas- ticity is a highly variable and dynamic phenomenon. Treatment needs careful planning, careful monitor- ing and above all the input and involvement not only 8 Michael P. Barnes of the physician, physiotherapist and orthotist but also of the person with the spasticity and his or her carer. REFERENCES Denny-Brown, D. (1966). The Cerebral Control of Movement. Liverpool: Liverpool University Press, pp. 170–84. Dickstein, R., Heffes, Y. & Abulaffio, N. (1996). Electromyo- graphic and positional changes in the elbows of spastic hemiparetic patients during walking. Electroenceph Clin Neurophysiol, 101: 491–6. Dimitrijevic, M. R., Faganel, J., Sherwood, A. M. & McKay, W. B. (1981). Activation of paralysed leg flexors and exten- sors during gait in patients after stroke. Scand J Rehab Med, 13: 109–15. Fellows, S. J., Klaus, C., Ross, H. F. & Thilmann, A. F. (1994). Agonists and antagonist EMG activation during isometric torque development at the elbow in spastic hemiparesis. Electroenceph Clin Neurophysiol, 93: 106–12. Goldspink, G. & Williams, P. E. (1990). Muscle fibre and con- nective tissue changes associated with use and disuse. In: Ada, A. & Canning, C. (eds), Foundations for Practice. Top- ics in Neurological Physiotherapy. Heinemann, London, pp. 197–218. Lance, J. W. (1980). Symposium synopsis. In: Feldman, R. G., Young, R. R. & Koella, W. P. (eds), Spasticity: Disorder of Motor Control. Year Book Medical Publishers, Chicago, pp. 485–94. MedicalDisability Society. (1988). The Management of Trau- matic Brain Injury. Development Trust for the Young Dis- abled, London. O’Dwyer, N. J., Ada, L. & Neilson, P. D. (1996). Spasticity and muscle contracture following stroke. Brain, 119: 1737–49. Walshe, F. M. R. (1923). On certain tonic or postural reflexes inhemiplegia withspecial reference tothe so-called‘asso- ciated movements’. Brain, 46: 1–37. . outlining the approach to the overall management of spasticity. An overview of the clinical management of spasticity 7 treatment such as heat and advice on the. 1 An overview of the clinical management of spasticity Michael P. Barnes Spasticity can cause significant problems with activ- ity and participation