f The Stroke o f God's hand.'
Bamford, (1991 a) It is thought that the word stroke comes from this original medical use of the word at a time when knowledge of the underlying causes of disease were totally unknown, when affliction was beyond earthly comprehension (Bamford, 1991a).
With the advent of modem technology and the development of medical science, our understanding of causative factors and the pathophysiology of stroke has moved forward from this early concept of divine intervention. However, a problem still exists for the
clinician in the ability to classify the pathological characteristics underlying a diagnosis of stroke.
'While it is easy for both laymen and doctors to reach a general diagnosis o f stroke it is often impossible to characterise the pathology underlying the stroke
with the degree o f precision necessary> to develop strategies fo r prevention,
treatment and rehabilitation.'
Royal College of Physicians Report (1989) Initially, the International Classification of stroke appears to be quite simple: ’a sudden
neurological deficit o f presumed vascular origin', however, it is the nature of the
vascular origin and the subsequent clinical presentation that require further identification. Once conditions that simulate stroke have been eliminated, a CVA can be divided into two pathological categories, cerebral infarction, a cerebral artery becoming blocked preventing oxygen and nutrient getting to the brain, and cerebral haemorrhage where there is a leakage of blood within or around the brain (Royal College of Physicians,
1989; Scottish Health Service Advisory Council, 1993).
Although the incidence of these categories can vary internationally, data provided by the Oxford Community Stroke project (Bamford et al., 1986) indicate that approximately 85% of strokes are the result of a cerebral infarction and 15% either intracerebral or subarachnoid haemorrhage. (Bamford et al., 1986).
As the literature suggests (Bamford et al., 1986), that the largest category of stroke patients are those who have had a cerebral infarction (Cl) this category will be further classified into anatomical site of infarction. Sterman (1987) suggests, that a lack of identification or relevant subgroups may have, hindered the development and testing of new therapeutic processes. Bamford (1991a) further suggests that knowledge of pathophysiological mechanisms may enable more accurate prognosis for survival and functional recovery.
As physiotherapists are primarily involved in resolving impairments in order to improve functional ability, accurate identification of subgroups and prediction of outcome are an important issues. Physiotherapists need to have knowledge of potential recovery processes in order to prioritise treatment input, select appropriate treatment models and provide evidence of effective interventions. Physiotherapists also require this knowledge to enable the identification and validation of theoretical models that may form the basis of their clinical practise.
A report by the National Institute of Neurological Disorders and Stroke (NINDS, 1990) identifies three methods of subclassifying the largest category, cerebral infarction and is included in table 4.
TABLE 4
Anatomical Classification of Cerebral Infarction (NINDS) Site of occlusion
• Internal carotid artery • Middle cerebral artery • Anterior cerebral artery • Vertebral artery
• Basilar artery
• Posterior cerebral artery
However, as Bamford states this anatomical classification has one main drawback, being based on the site of the infarction. It would require invasive vascular studies to obtain information to classify all strokes and for the rehabilitation team, in some clinical settings, this would not be feasible. Of more value to the practitioner, would be a classification system that associated the site of the infarction, with the signs or neurological impairments resulting from the cerebral infarction.
A system used in a number of epidemiological studies (Bamford, 1991 b) and based on the clinical findings at the time of maximal deficit from the stroke is presented in Table 5.
TABLE 5
Subdivision of Subtypes of Cerebral Infarction according to site and clinical presentation.
• Total anterior circulation infarction
motor and sensory deficit, ipsilateral haemianopia and new disturbance o f higher cerebral function • Partial anterior circulatory infarction
any two o f the above
or isolated disturbance o f higher cerebralfunction • Posterior circulatory infarction
unequivocal signs o f brainstem disturbance or isolated haemianopia
• Lacunar infarction
pure motor stroke or pure sensory stroke or pure sensory motor stroke or ataxic hemiparesis
Adapted from Bamford (1991b)
Whilst this method of subclassification incorporating clinical signs improves the clinicians’ ability to manage the rehabilitation process, it is of limited use to physiotherapists. Physiotherapists require a means of identifying and recording the signs of the stroke, such as motor and sensory deficit, rather than the level or extent of the pathology. Of greater importance to the physiotherapist, is how these signs relate to the patients’ symptoms and how these in turn affect the patients' ability to function.
The problem for physiotherapists, who need to assess and measure how stroke pathology affects individual stroke patients, is deciding on an inclusive framework for classification. Wade (1992b) states that, this is a particular problem in stroke rehabilitation because the
nervous system has many functions and therefore damage to that system can result in a large number of deficits, which may or may not respond to physiotherapy interventions. This problem was partially alleviated by the World Health Organisation’s model for the classification of diseases (WHO, ICIDH, 1980). Badley (1993) states, that the purpose of this concept in classification was to enable a better understanding of the consequences of disease. The concept attempting to describe a disease, such as stroke, in terms of the impact on body mechanisms, the person themselves, and the person as a social being (Badley, 1993). These three aspects of the disease are defined as being the impairment, the disability and the handicap.
Badley suggests, that this theoretical framework enables the clinician to determine the interrelationship between impairment, disability and handicap and to develop indicators of need or outcome. To evaluate physiotherapy intervention in stroke rehabilitation, what is required is not a pathological diagnosis, but indicators of the impact of the stroke on the individual in order to determine how the intervention has altered the consequences of the disease.
The problem for physiotherapist in stroke rehabilitation are therefore two fold. Firstly, the nature of the disease and the system which it afreets result in a variety of pathological categories each with their own clinical presentations or levels of impairment. Secondly, to evaluate the effects of interv ention, a measurement is required of the impact of the stroke at the levels of impairment, disability and handicap.
Wade (1992c) suggests, that the problem is further complicated by the need to be clinically relevant to the individual, to their abilities and their level of independence. This question of measurement in stroke rehabilitation will be developed further in the literature review on health care measurement and the needs of the physiotherapy profession.
1.3 Organisation of Stroke Services