12 Cranial Nerves — Functions and Mnemonics

Module overview For many people who have had a stroke, weakness or paralysis on one side – hemiparesis or hemiplegia – is the most obvious symptom. However, brain damage, including stroke, can cause a range of impairments that may be less obvious but equally devastating for people and their families. This module provides an overview of communication, movement and perception difficulties, and the strategies nurses can use to help people cope with any changes to their lives. Keywords agnosia, aphasia, apraxia, cardiovascular, cardiovascular diseases, communication, communication difficulties, nervous system diseases, neurology, stroke. Aims The aim of this module is to provide an overview of communication, movement and perception problems that may persist after a stroke. It considers the effect of these on people and their families, and some of the strategies nurses can use to help them cope with persisting disabilities. Intended learning outcomes After reading this module and completing the time out activities you should be able to: Discuss the difference between Broca’s and Wernicke’s aphasia. Consider the effect of these and other communication difficulties. Discuss possible effects of apraxia. Discuss visual problems including agnosia, hemianopia and hemispatial neglect. Recognise the effect of fatigue and depression on ability to cope with long-term disabilities. Outline ways that nurses can help people cope with long-term impairments. Introduction People can be left with complex problems after a stroke, including weakness on one side, but also other less obvious impairments in communication, perception and movement. It is the role of professionals, such as speech and language therapists, occupational therapists and specialist stroke nurses, to map out the finer points of the changes and related therapies. However, all nurses caring for older people who have had a stroke require a broad understanding so they can help individuals to make the best use of remaining abilities. What is a stroke? Definition The World Health Organization (2014) describes a stroke as an interruption of the blood supply to the brain. It is usually caused by an embolus or blood clot blocking a cerebral artery, which is termed ischaemic stroke, but can also be caused by a bleeding vessel, known as haemorrhagic stroke. The long-term effects of any damage are the same for both types of stroke. Stroke is the leading cause of complex disability in the UK (Adamson et al 2004). Stroke can result in many long-term difficulties. The best recognised of these is a problem with communication. About one third of people who have a stroke will have some initial language problems and for 30%-40% of these the difficulties will persist (Bakheit and Gatehouse 2006). Other problems include difficulties with vision, perception – recognition and interpretation of information from sensory organs – and execution of movement. About one third of people who have a stroke will have some initial language problems and for 30%-40% of these the difficulties will persist. Problems related to stroke also include difficulties with vision, perception – recognition and interpretation of information from sensory organs – and execution of movement. Learning points Nurses caring for older people who have had a stroke require a broad understanding to help individuals to make the best use of remaining abilities as they can be left with complex problems after a stroke. The World Health Organization describes a stroke as an interruption of the blood supply to the brain. It is usually caused by an embolus or blood clot blocking a cerebral artery – ischaemic stroke. It can also be caused by a bleeding vessel, in which case it is referred to as a haemorrhagic stroke. Communication Communication is a complex process that is central to our functioning as social beings. There are many different ways that it can be damaged by a stroke. Aphasia The terms aphasia and dysphasia are used interchangeably (Bakheit and Gatehouse 2006), but aphasia is more commonly used (Brady et al 2012). Definition Aphasia refers to difficulties after damage to specific language centres in the left cerebral hemisphere and can include problems with all aspects of language including speaking, listening, reading and writing (Marshall et al 2010a). In the 19th century Broca and Wernicke described different types of aphasia (Figure 1); people who had damage to more anterior parts of the brain had problems with spoken language – Broca’s aphasia, while damage to more posterior areas resulted in language that was well articulated but meaningless – Wernicke’s aphasia (Marshall et al 2010a). Broca’s aphasia: people with Broca’s aphasia are able to understand what is said to them and have more insight into the problems they face. Speech is disjointed (Marshall et al 2010a) and the normal inflections of the voice are absent. There is an impression that every word has to be searched out. Often people will present the wrong word, although they recognise the correct one if it is used by the person who is conversing with them. The effect can be one of embarrassment because they feel foolish for not being able to make their point. Nurses should give them time and encouragement to talk and help their family to do the same (Marshall et al 2010a). It is vital that people with aphasia feel that their contribution is valued. Wernicke’s aphasia: also known as fluent aphasia because words flow easily with normal tone and inflexion but, although speech sounds normal, it makes no sense (Marshall et al 2010a). These people may be unaware that they are not making sense and become angry with those who do not understand them. This can be challenging for family and caregivers and there have been reports of Wernicke’s aphasia being mistaken for psychosis (Owolabi and Yakasai 2012). However, Robson et al (2014) found that the ability to comprehend visually presented material, words and pictures may be partially preserved. This suggests that some people with Wernicke’s aphasia will be able to understand gestures and take clues from their environment. Being handed a flannel and soap is likely to be a better understood prompt to wash than verbal encouragement, for example. It is also worth trying picture and word charts as a means of communication. Conversation should be maintained because tone of voice and facial expression may be accurately interpreted even if spoken words are not, so can help to prevent a feeling of isolation (Stroke Association 2012a). Global aphasia: a combination of Broca’s and Wernicke’s aphasia. People will have severely impaired comprehension and limited speech, although they may have a single word or phrase that they use repeatedly (Hillis 2007). Conduction aphasia: Hillis (2007) also describes conduction aphasia where speech is relatively accurate and fluent, but some words are replaced by similar-sounding nonsense words. Aphasia has a significant effect on quality of life. The concept of ‘living successfully with aphasia’ encourages a focus on what the person can do rather than deficits in communication (Brown et al 2012). Brown et al’s (2012) analysis highlighted social companionship and positive interactions with others as the core to success. They found that people wanted a balance between support and independence but did not want to be pitied. A frequent complaint of people with aphasia is that they lose their friends (Northcott and Hilari 2011). There are many reasons for this, including unhelpful responses from others and an overwhelming sense of fatigue making social contact impossible. Northcott and Hilari (2011) highlight the link between loss of friends and depression. A positive approach is considered important, especially by family members, who say that early successes should be celebrated to provide confidence and hope (Brown et al 2012). Families should be seen as partners in rehabilitation so they are given information about helpful approaches and are able to contribute towards joint goals (Howe et al 2012). Learning points Aphasia refers to difficulties that occur after damage to specific language centres in the left cerebral hemisphere and can include problems with all aspects of language, including speaking, listening, reading and writing. People with Broca’s aphasia are able to understand what is said to them and have more insight into the problems they face. Nurses should give such people enough time and encouragement to avoid embarrassment to them. Wernicke’s aphasia is also known as fluent aphasia because words flow easily with normal tone and inflexion but, although speech sounds normal, it makes no sense. It is worth using gestures, trying picture and word charts as a means of communication. Global aphasia is a combination of Broca’s and Wernicke’s aphasia where people will have severely impaired comprehension and limited speech, although they may have a single word or phrase that they use repeatedly.