Introduction – time is brain

According to The Stroke Association (2010), every 5 minutes, someone in the UK has a stroke. This means that in Great Britain alone, approximately 150,000 people have a stroke every year. Stroke is the third biggest cause of death and the biggest cause of adult disability.

A stroke is a medical emergency and anyone suspected of having a stroke should be taken to Accident & Emergency immediately. The UK Stroke Association aims to raise stroke awareness and has organized the FAST campaign (Figure 2.1). FAST is an acronym standing for Face, Arm, Speech, Time to call 999. When you suspect someone is having a stroke, test facial weakness (can the person smile?), arm weakness (can the person raise both arms?) and speech problems (can the person speak clearly and understand what you say?). If the answer to any of these questions is no, the person might have a stroke so it is time to call 999 – because stroke is a medical emergency.

Figure 2.1 The FAST campaign leaflet

(origin: The Stroke Association, with permission)

Making a prognosis directly after stroke is difficult and depends on a variety of factors, which will be presented later in this chapter. Overall, approximately 20% of patients having their first stroke are dead within a month, and of those alive at 6 months approximately one-third are dependent on others for activities of daily living (Warlow, 1998).

It is important to consider that various limitations (such as motor and sensory impairments, cognitive deficits, emotional disturbances, etc.) can cause restricted activities of daily living and participation after stroke. Rehabilitation of people after stroke should address all impairments resulting in functional restrictions; however, this chapter will focus on the physical management of people after stroke.

Definitions

A stroke or cerebrovascular accident (CVA) is typically defined as an accident with ‘rapidly developing clinical signs of focal or global disturbance of cerebral function, with symptoms lasting 24 hours or longer or leading to death, with no apparent cause other than of vascular origin’ (WHO, 1988).

A transient ischaemic attack (TIA) is sometimes called a mini-stroke and patients present similar symptoms which last only minutes or hours and are gone within 24 hours.

Since the majority of strokes happen in one of the two brain hemispheres, the typical clinical sign of a person after stroke is a sensory-motor hemiparesis or hemiplegia, contralateral to the side of lesion in the brain. Hemiparesis is typically defined as weakness on one side of the body, whereas hemiplegia is total paralysis of the arm, leg and trunk on one side of the body. Of course, this focus on only motor impairment is too limited, as will become clear throughout this chapter.

Classification and aetiology of stroke

Strokes are classified into two main categories: ischaemic or haemorrhagic (Amarenco et al., 2009). An ischaemic stroke is caused by an interruption of the blood supply. A haemorrhagic stroke is caused by a ruptured blood vessel. The majority of strokes are ischaemic accidents (approximately 80%).

In an ischaemic stroke, blood supply to a certain area of the brain is decreased, which causes dysfunction of the brain area supplied by the affected blood vessel.

The main causes of ischaemic stroke are:

A haemorrhagic stroke can be an intracerebral or intracranial accident. An intracerebral haemorrhage is a stroke where blood is leaking directly into the brain tissue, building up a haematoma. An intracranial haemorrhage is the build-up of blood anywhere within the skull, typically somewhere between the skull and the meninges surrounding the brain and spinal cord. Haemorrhagic strokes are most common in small blood vessels and potential causes are hypertension, trauma, bleeding disorders, drug use and vascular malformations.

Strokes are thus typically classified as ischaemic or haemorrhagic. Ischaemic strokes are commonly further classified according to the Oxford Community Stroke Project (OCSP) classification, also known as the Oxford or Bamford classification (Bamford et al., 1991). This classification distinguishes between a:

Anatomy and pathophysiology

The arteries that supply blood to the brain are arranged in a circle called the Circle of Willis (Figure 2.2), after Thomas Willis (1621–1673), an English physician. All the principal arteries of the Circle of Willis give origin to secondary vessels which supply blood to the different areas of the brain (Figure 2.3).

Figure 2.2 Diagram of the arterial circulation at the base of the brain. A.L. Antero-lateral. A.M. Antero-medial. P.L. Postero-lateral. P.M. Posteromedial ganglionic branches.

(Origin: Henry Gray. Anatomy of the human body 1918 Fig. 519, from Bartleby.com with permission)

Figure 2.3 The arteries of the base of the brain. The temporal pole of the cerebrum and a portion of the cerebellar hemisphere have been removed on the right side.

(Origin: Henry Gray. Anatomy of the human body 1918, Fig. 516, from Bartleby.com with permission)

If a stroke occurs in one of the brain arteries, the area normally supplied by the blood will be affected. The OCSP classification proposes the following symptoms for the different types of ischaemic accident:

• TACI: all of the following:

Higher dysfunction (e.g. speech or visuospatial impairments)

Visual impairments (homonymous hemianopia) and

Severe sensory-motor deficit in face, arm, trunk and leg.

• PACI: any one of these:

Two out of three as TACI

Higher dysfunction alone or

Limited sensory-motor impairments in face, arm, trunk and leg.

• LACI: any one of these:

Pure motor impairments in face, arm, trunk and leg

Pure sensory impairments in face, arm, trunk and leg

Sensory-motor impairments in face, arm, trunk and leg or

Ataxic hemiparesis.

• POCI: any of these:

Cranial nerve palsy and sensory-motor impairments

Bilateral sensory or motor impairment

Conjugate eye movement deficit

Isolated cerebellar dysfunction or

Isolated homonymous hemianopia.

When an ischaemic stroke occurs and part of the brain suffers from lack of blood, the ischaemic cascade starts. Without blood the brain tissue is no longer supplied with oxygen and after a few hours in this situation, irreversible injury could possibly lead to tissue death. Because of the organization of the Circle of Willis, collateral circulation is possible, so there is a continuum of possible severity. Part of the brain tissue may die immediately while other parts are potentially only injured and could recover. The area of the brain where tissue might recover is called the penumbra. Ischaemia triggers pathophysiological processes which result in cellular injury and death, such as the release of glutamate or the production of oxygen free radicals. Neuroscience research is constantly studying ways to inhibit these pathophysiological processes by means of developing neuroprotective agents (Ginsberg, 2008).

A haemorrhagic stroke causes tissue injury by compression of tissue from an expanding haematoma or blood pool. This can result in tissue injury and, consequently, the increased pressure might lead to a decreased blood supply into the surrounding tissue (and eventually infarction).

Diagnosis

The diagnosis of stroke is based on a clinical assessment and imaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI) scans. For diagnosing an ischaemic stroke in the acute setting, an MRI scan is preferred, as sensitivity and specificity are higher in comparison with CT imaging (Chalela et al., 2007). For diagnosing ischaemic strokes, CT and MRI scan have comparable sensitivity and specificity.

When a stroke has been diagnosed, determining the underlying aetiology is important with regard to secondary stroke prevention. Common techniques include:

Early medical treatment

In the case of an ischaemic stroke, the more rapidly the blood flow is restored to the brain, the fewer brain cells die (Saver, 2006). Hyperacute stroke treatment is aimed at breaking down the blood clot by means of medication (thrombolysis) or mechanically removing the blood clot (thrombectomy). Other acute treatments focus on minimizing enlargement of the clot or preventing new clots from forming by means of medication such as aspirin, clopidogrel or dipyridamole. Furthermore, blood sugar levels should be controlled and the patient should be supplied with adequate oxygen and intravenous fluids.

Thrombolysis is performed with the drug tissue plasminogen activator (tPA); however, its use in acute stroke is controversial. It is a recommended treatment within 3 hours of onset of symptoms as long as there are no contraindications, such as high blood pressure or recent surgery. tPA improves the chance of a good neurological outcome (The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group, 1995). In a recent study, thrombolysis has been found beneficial even when administered 3 to 4.5 hours after stroke onset (The European Cooperative Acute Stroke Study, 2008). However, another recent study showed mortality to be higher among patients receiving tPA versus those who did not (Dubinsky & Lai, 2006).

Another intervention for acute ischaemic stroke is the mechanical removal of the blood clot. This is done by inserting a catheter into the femoral artery, which is then directed into the cerebral circulation next to the thrombus. The clot is then entrapped by the device and withdrawn from the body. Studies have shown beneficial effects of thrombectomy in restoring the blood flow in patients where thrombolysis was contraindicated or not effective (Flint et al., 2007).

In case of a haemorrhagic stroke, being able to stop the bleeding as early as possible is of paramount importance and patients sometimes do require neurosurgical intervention to achieve this. Drug interventions used in ischaemic stroke (such as anticoagulants and antithrombotics) can make bleeding worse and therefore cannot be used in haemorrhagic stroke.

Prognosis and recovery

Van Peppen and colleagues (2007) have performed a systematic review of prognostic factors of functional recovery after stroke. They investigated walking ability, activities of daily living, and hand and arm use after stroke.

Walking ability (defined as a Functional Ambulation Category (Holden et al., 1984) score ≥4) at 6 months after stroke was best predicted by initial walking ability in the first 2 weeks after stroke, degree of motor paresis of the paretic leg, homonymous hemianopia, sitting balance, urinary incontinence, older age and initial ADL functioning in the first 2 weeks after stroke (Kwakkel et al., 1996).

The Barthel Index score (Mahoney & Barthel, 1965) in the first 2 weeks after stroke appeared to be the best prognostic factor for recovery of independence in activities of daily living at 6 months after stroke. Other contributing predictors were urinary incontinence in the first 2 weeks after stroke, level of consciousness in the first 48 hours after stroke, older age, status following recurrent stroke, degree of motor paresis, sitting balance in the first 2 weeks after stroke, orientation in time and place, and level of perceived social support (Kwakkel et al.,1996; Meijer et al., 2003).

The best clinical predictor of recovery of dexterity of the paretic arm 6 months after stroke appeared to be severity of arm paresis at 4 weeks after stroke, measured by Fugl-Meyer Arm Assessment (Kwakkel et al., 2003). Other studies also identified severity of the upper extremity paresis, voluntary grip function of the hemiplegic arm, voluntary extension movements of the hemiplegic wrist and fingers within the first 4 weeks after stroke, and muscle strength of the paretic leg (Heller et al., 1987; Kwakkel et al., 2003; Sunderland et al.,1989).

Hendricks et al. (2002) conducted a systematic review of the literature of motor recovery after stroke. They concluded that approximately 65% of the hospitalized stroke survivors with initial motor deficits of the lower extremity showed some degree of motor recovery. For patients with paralysis, complete motor recovery occurred in less than 15% of cases, both for the upper and lower extremities. The recovery period in patients with severe stroke appeared twice as long as in patients with mild stroke.

There are several studies indicating that most of the overall improvement in motor function occurs within the first month after stroke, although some degree of motor recovery can continue in patients for up to 6 months after stroke. Verheyden et al. (2008) compared the recovery pattern of trunk, arm, leg and functional abilities in people after ischaemic stroke. They assessed participants at 1 week, 1 month, and 3 and 6 months after stroke. There appeared to be no difference in the recovery pattern of trunk, arm, leg and functional ability and, for all measurements, most (significant) improvement was noted between 1 week and 1 month after stroke. There was still a significant improvement between 1 month and 3 months after stroke, but between 3 and 6 months participants showed no more significant improvement. Further exploration of this latter period saw some participants stagnate in trunk, arm, leg and functional recovery and others deteriorate. Deterioration in people after stroke has been demonstrated in other (long-term) studies (van de Port et al., 2006). But despite evidence of stagnation, deterioration or a plateau phase, there is substantial secondary evidence concerning late recovery, i.e. several months after stroke, although most of these studies were in (outpatient) rehabilitation centres and thus included selected patient populations. Nevertheless, Demain et al. (2006) suggested that the notion ‘plateau’ is conceptually more complex than previously considered and that ‘plateau’ not only relates to the patients’ physical potential, but is also influenced by how recovery is measured, the intensity and type of therapy, patients’ actions and motivations, therapist values and service limitations.

Outcome measures

Milestones of stroke rehabilitation should be documented by means of standardized outcome measures (Stokes, 2009). There is an increasing number of tools available. Van Peppen et al. (2007) have performed a systematic review of outcome measures for people with stroke. They propose a core set of outcome tools based on consistency with the International Classification of Functioning, Disability and Health (WHO, 2001); high-level psychometric properties (i.e. inter- and intrarater reliability, validity and responsiveness); good clinical utility (easy and quick to administer); minimal overlap of the measures and consistency with current physiotherapy practice. The core outcome measures proposed for people with stroke based on their review were:

Van Peppen et al. (2007) also propose a set of 18 optional outcome measures, to be used to evaluate a specific function or activity in people with stroke. These optional outcome measures are:

Clinical utility of an outcome measure is probably a key aspect and often authors have neglected this area in the past. A recent study by Tyson and Connell (2009) looked at how to measure balance in clinical practice. They performed a systematic review of measures of balance activity for neurological conditions. They scored not only psychometric properties, but also clinical utility by assigning scores to the time taken to administer, analyse and interpret the test, the costs of the tool, whether the measure needs specialist equipment and training, and whether the measurement tool is portable. They evaluated 30 measures and after excluding 11 based on limited psychometric analysis or inappropriate statistical tests used, they recommended the following balance tools for people with stroke:

Principles of physical management

The aim of physical management following a stroke is to maximize the return of movement and independence in everyday life and to minimize unwanted secondary complications, in particular those that create risk of injury. Throughout the rehabilitation process, the purpose is to facilitate and encourage an individual to actively participate, to maximize their physical potential and to return to a life in the community.

A physiotherapist plays a major role in the physical management of people after a stroke. She/he will adopt several roles and requires an understanding of scientific measurement, assessment and handling techniques, and evidence-based therapy. As an assessor the therapist will utilize observational skills and scientific knowledge of recording and analysing movement and functional ability. For treatment the therapist has to be able to interpret assessments, problem solve and utilize educational skills and manual handling techniques to retrain movement. The therapist needs to be able to develop the expertise of recognizing positive and negative responses to therapeutic strategies, so that unwanted outcomes can be avoided and positive results encouraged. The personality and needs of the person with a stroke must be acknowledged, which requires a broad understanding of the psychosocial factors that influence people and their goals in life.