Review: Aphasia, an acquired language disorderAphasia, an acquired language disorder Schoeman R, MBChB, MSocSc, FCPsych, MMed Van der Merwe G, BRek, BComptHons Department of Psychology, Stellenbosch University, South Africa Correspondence to: Dr Renata Schoeman, e-mail:
[email protected] Keywords: aphasia; language disorder; approach; Broca; Wernicke Abstract Affecting an estimated one in every 272 South Africans, or 0.37% of the population, aphasia is a neurological condition described as “any disturbance in the comprehension or expression of language caused by a brain lesion”. Despite extensive debate throughout the history of neuropsychology there is no universal agreement on the classification of aphasia subtypes. The original localisationist model attempts to classify aphasia in terms of major characteristics, and then to link these to areas of the brain in which the damage has been caused. These initial two categories, namely fluent and non-fluent aphasia, encompass eight different subtypes of aphasia. Aphasia occurs mostly in those of middle age and older, with males and females being affected equally. As the general practitioner is likely to have first contact with affected patients, it is important to be aware of aphasia and to diagnose and refer patients in an appropriate and expeditious manner. In this article we will review the types of aphasia, an approach to its diagnosis, aphasia subtypes, rehabilitation and prognosis. Peer reviewed. (Submitted: 2009-10-11, Accepted: 2010-01-10). © SAAFP SA Fam Pract 2010;52(4):308-311 Introduction dominance for language,4 as was first observed by the neurologist Broca (Broca’s area) in 1861, and affirmed by Aphasia is a neurological condition affecting an estimated Wernicke (Wernicke’s area) in 1874.5 To understand aphasia one in every 272 South Africans.1 Aphasia seldom occurs as an isolated symptom, but typically with other symptoms, it is important to acquire an insight into the anatomy of indicators and risk factors that are suggestive of the the language areas, including those for comprehension, underlying cause. As the general practitioner is likely to production of speech, and speech fluency (see Figure 1). have first contact with affected patients, it is important to Broca’s area (Brodmann areas 44 and 45) is located in be aware of aphasia and to diagnose and refer patients in the posterior portion of the frontal lobe and is regarded an appropriate and expeditious manner. as the syntactic-articulatory pole of the language system, Described as “any disturbance in the comprehension, or associated with speech production and articulation.6 expression, of language caused by a brain lesion”,2 aphasia Wernicke’s area (Brodmann area 22) is located in the mostly occurs in those of middle age and older, with males superior posterior temporal lobe and is associated with and females being affected equally. However, children can also be affected.3 Aphasia is caused by any brain injury language processing in both the written and spoken forms.6 such as a cerebrovascular accident (stroke), trauma, a brain It connects with Broca’s area via a neural pathway, the tumour, a degenerative process such as dementia, or as a arcuate fasciculus. sequelae of infections such as meningitis.3 The angular gyrus (Brodman area 39) is located at the Language demonstrates a hemispheric localisation of junction of the temporal, occipital and parietal lobes, and function, with 90% of individuals having left hemispheric is involved in the processing of auditory and visual input.7 SA Fam Pract 2010 308 Vol 52 No 4 the area damaged. or speech include the cause of the brain damage. In these cases. oftentimes of speech are the motor cortex. with Once the underlying condition has been treated. or Given the wide range of variables associated with the a foreign language background. but with patients. has been caused. In diagnosis) these instances. such as the use of incorrect words. observed and reported behaviour (i. Non-fluent aphasias. Other areas involved in the comprehension and production whereas non-fluent speech is effortful. Review: Aphasia. appears to be unrelated to concentration the extent of the injury. • Comprehension of spoken language with verbal There is no universal agreement on the classification of responses to ‘yes/no’ questions and response to verbal aphasia subtypes. phrases. usually and words in nonsensical combinations (paraphasia). psychiatric conditions (such as psychosis). cortex. in the motor cortex Wernicke’s area right half of the body. medical records and case history) of the patient should be conducted before any formal. and • Writing words and sentences to dictation and sentences then link these to the areas of the brain in which the damage on command. objects and stimuli familiar to the and Broca respectively. but with difficulties in the output focus shifts to rehabilitation. also known as receptive aphasias. Consequently. despite extensive debate throughout commands. naming of colours. however. conversational speech and speech fluency. precisely. The duration of recovery typically spans a two-year period. an acquired language disorder with complaints of sensory changes.10-13 Fluent aphasias. following a transient ischaemic attack. the history of neuropsychology.21 or attention deficits. spontaneous. patient has been stabilised and referred appropriately.9 These initial two categories. visual cortex and auditory distorted. and poorly articulated.20 Factors influencing recovery whenever a patient’s difficulty in speech. Normal speech should be produced Figure 1: Language areas of the brain easily. such as: auditory cortex • Expressive. speech-language therapy is often helpful. sentences and Types of aphasia tongue-twisters. For most characterised by effortful and non-fluent speech. which is indicative of damage to the angular gyrus left cerebral hemisphere. and the difficulties either in auditory comprehension or in repetition.19. articulately and typically remain consistent with normal. also called expressive aphasias.8. responses. rehabilitation should be approached as a a patient for the presence of aphasia when he/she presents process of patient management. namely fluent and non-fluent aphasia. are Management impairments related to the reception of language. or weakness.8 and encompass the eight different patient should be employed in order to elicit accurate subtypes of aphasia.8. loss of hearing. Broca’s area and should probe several different aspects (see Figure 2).9 Although premorbid proficiency in communication may be Assessing aphasia (an approach to re-attained. Bedside testing. the Speech is easy and fluent. were devised by Wernicke In assessing aphasia. physical speech impairment. numbers and letters. conversational dialogue. or sounds full recovery from aphasia without rehabilitation.8 One popular school of • Reading text aloud and explaining an understanding thought subscribes to the original localisationist model that thereof.e.10 It is important to assess condition.11 visual Bedside testing allows for the informal appraisal of language cortex and differential diagnoses of aphasia subtype (see Table I). relatively good auditory comprehension. • Repetition of words. are language abilities may return in a few hours or days. and the patient’s age and health. recovery is not as quick or as complete. A patient will occasionally enjoy of language. most patients do not recover completely. A high index of suspicion of aphasia should be present with few gains thereafter. behavioural observations. the process SA Fam Pract 2010 309 Vol 52 No 4 . test- based assessment. comprehension. and attempts to classify aphasia by major characteristics. 8.14 The least common of the transcortical aphasias. Comprehension is intact and writing is impaired. articulately and prosaically intact. but incoherent. Right-sided hemiplegia may be present.12. Spontaneous speech production is relatively normal. but understand little of what they repeat or read. Language comprehension is intact. this form combines both the motor and sensory elements common of the Mixed transcortical transcortical aphasias.17 Classical non-fluent. with fluent. Is comprehension intact? Is comprehension intact? Yes No Yes No Is repetition Is repetition Is repetition Is repetition intact? intact? intact? intact? Yes No Yes No Yes No Yes No Transcortical Transcortical Mixed Anomic Conduction Wernicke’s Broca’s Global sensory motor transcortical Figure 2: Aphasia flowchart Table I: Aphasia subtypes in brief Considered the most common of the disorders.18 Presents with near complete loss of ability to formulate verbal communication. Patients cannot write and have severe speaking and comprehension impairment.15 Transcortical Similar to Wernicke’s aphasia. well articulated and grammatically correct.2.12. speech being present. - Speech impairment.8 It is defined when there is a disturbance in or loss of speech. - Loss of hearing. although minor Conduction phonemic paraphasias may be introduced. Is it fluent? - Language background.14 SA Fam Pract 2010 310 Vol 52 No 4 . Speech is non-fluent and reduced to a few words. but speech is non-fluent. the exception being that repetition is intact.16 Wernicke’s Patients are usually unaware that their speech is unintelligible. In severe Transcortical motor cases a patient’s speech is virtually absent. but with unaffected repetition.8 A comparatively rare form of aphasia. troubled by phonemic and global paraphasias and without connective words. Patients have fluent and paraphasic speech and can sensory repeat verbatim. Repetition is intact. spontaneous.11 Patients struggle to repeat verbatim. Review: Aphasia. Speech output is fluent. an acquired language disorder Is it aphasia? No Differential diagnosis Yes - Attention deficit. - Psychosis.2.14.14. yet difficulty in Anomic naming objects does have a limited effect on speech output. and most generally recognised. Global with impairment of language and auditory comprehension.14 Characterised by a severe deficit in auditory comprehension. fluent and correct. and repetition is normal. form of aphasia. and most will fail to repeat anything when function words are requested. Speech produced easily. Broca’s but with good comprehension of spoken language. Assessment neurological examination 20. Available from http://thebrain. New York. of aphasia.gov/health/ voice/aphasia. of his or her quality of life. San Diego: Academic Press. Individual therapy focuses on the 2.19 The acceptance of a condition such as aphasia Oxford University Press. Neuroanatomical correlates of the aphasias: acquired aphasia. frustration 11. Schoeman R. Neuropsychological assessment versus general practitioner (see Table II). Neuroanatomical correlates of the aphasias. Philadelphia: Lippincott Williams & Wilkens.wikipedia.nih. Clinician’s guide to neuropsychological assessment. Available from http://en.17(1):386–93. New York. org/wiki/Transcortical_motor_aphasia (Accessed 04/09/2009). Prognostic factors in aphasia.wikipedia.cureresearch. 1996. Sarno JE. 8.com. expression. Vanderploeg RD. Kaplan and Sadock’s synopsis of specific needs of the person. Introduction to neurospychology. Aphasia: a clinical perspective. language assessment South Africa. Howieson DB. Aphasiology early referral to neurologist 1992. Medical Technology SA 2003.19 Disorders. UCSF Memory and Ageing Centre. National Institute on Deafness and Other Communication setting. New York: and anger. Table II: Practical considerations 13. Aphasia therapy aims to improve a patient’s capacity to communicate by focusing on the use of the References remaining language abilities. Kolb B. Englewood Cliffs: Prentice Hall.org/wiki/ management of a patient should go beyond the aim of Angular gyrus (Accessed 16/08/2009).wikipedia. It is therefore imperative to diagnose and refer 16/08/2009). Oxford University Press: 1998. psychiatric conditions (such as psychosis) org/wiki/Mixed_transcortical_aphasia (Accessed 04/09/2009). Gainotti G. 4th ed. sense of well- 9. and the presence of adequate familial involvement 5th ed. and support. and learning alternative com/a/aphasia/stats-country. Nevid JS. Damasio H. 2003.nidcd. abilities as much as possible. while group therapy facilitates psychiatry: behavioural sciences. and often not achievable.wikipedia. functional communication. New York: Oxford University Press. Fundamentals of human neuropsychology. Aphasia is a common symptom in patients assessed by the 5. 2nd ed. 10th ed. Lezak MD. Transcortical motor aphasia. Conclusion 4. Sadock BJ. 2007.htm#who (Accessed 19/08/2009). Worth. Louw D. CureResearch. 2000. The time between onset. Exclude physical speech impediment 18. 2nd ed. The 7. CT/MRI brain Management facilitate prompt rehabilitation. neuro-imaging in the diagnosis of cerebral lesions: an explorative diagnosis and the initiation of therapy. restoring these language 1. University of Cape Town.html (Accessed recovery. therapy all affect the eventual outcome of the degree of 6.mcgill. communicative methods.html (Accessed 19/08/2009). Mahwah: Lawrence Erlbaum. weakness 16.org/wiki/ unilateral (right-sided) sensory changes or Conduction_aphasia (Accessed 04/09/2009). 3rd ed. manage treatable causes and risk factors 21. Review: Aphasia. Available from http://en. the opportunity to use new communication skills in a group 3. Mixed transcortical aphasia. Unpublished master’s thesis. Timol RSH. Risser AH. Basso A. and the intensity of study. Abnormal psychology in a concentration or attention deficits changing world. Angular gyrus. patients tend to recover skills in language assistance with the preparation of the manuscript and the comprehension more completely than those skills involving language editing. Loring DW. 2008. Greene BA. 2nd ed. Available from http:// memory. 1998. From thought to language. The authors are grateful to Mr Heath Jones. clinical psychiatry. emotional state. Conduction aphasia. 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