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Types of Aphasia

Aphasia is a neurological disease usually caused by the obstruction of arteries that reach the patient’s left hemisphere of the brain, causing damage to the abilities and cognitive functions it controls. In particular, it alters linguistic abilities such as comprehension, reading, facial and written expressions and speech.

Aphasia is actually notorious for altering speech patterns. This pathology is also closely related to hemiparesis or paralysis of one side of the body. The left hemisphere of the brain controls the right side of the body, and the right hemisphere of the brain controls the left side of the body because neuro pathways are crossed, scientists have yet to figure out why the human body has been wired to be controlled from opposing brain hemispheres.

“The alteration in language function is, understandably, a primary concern of individuals with aphasia and their caregivers. The change in the ability to effectively communicate after brain damage may represent a major source of stress in the life of these individuals. Research has addressed stress in relation to aphasia, mostly in regards to catastrophic reactions, anxiety, depression and the potential links among stress, attention and language. There has been considerable research describing the relation between nstress and the development and persistence of diseases in a variety of clinical populations, including cardiovascular disease, psychiatric disorders, and more general somatic disorders.”1

“Aphasia is one of the most common symptoms in acute and chronic stroke patients.  […] However, the frequencies of the different types of aphasia in acute stroke and possible differences in prognosis are also of theoretical interest as well as of practical importance for the planning of rehabilitation. Related interesting questions are whether age and sex influence severity, type and remission of aphasia. The literature on these subjects is growing, but the studies are mostly limited to more or less selected patients, most often those patients selected for rehabilitation departments.”2

Some causes that might trigger aphasia are:

– Stroke. “Stroke is the leading cause of long term language impairments (aphasia) in adults. However, many stroke survivors with aphasia in the acute phase experience spontaneous recovery within the first six months after the stroke. Nonetheless, approximately 30–40% do not recover fully and experience aphasia for the rest of their lives. Even though ischemic stroke may lead to necrotic damage affecting specific brain areas, the functional impairment after stroke can be exacerbated by dysfunction of seemingly spared areas.

The neurobiological bases for loss of function in remote and spared areas are not completely understood. However, extensive work on disconnection syndromes, including from our group, have demonstrated that white matter loss and cortical disconnection can extend beyond the stroke lesion. Importantly, the degree of white matter disconnection of Broca’s area is an independent predictor of naming impairments after a stroke, controlling for the degree of cortical ischemic damage. Furthermore, residual anatomical connectivity of spared areas plays a significant role in therapy-related improvement in object naming in subjects with aphasia.

Nonetheless, it is still unclear whether post-stroke white matter damage can be used as a personalized predictor of chronic aphasia severity.”3

  •  Cranioencephalic trauma.
  • Tumors that affect the central nervous system.
  • Infections
  • Neurodegenerative diseases such as Alzheimer’s or Parkinson’s.

 

We can appreciate between types of aphasia depending on their characteristics and severity.

Global aphasia

In this type of aphasia, the ability to speak of the patient is seriously affected. Furthermore, the subject is not able to read or write normally and cannot understand everyday language either.

“This syndrome is characterized by an almost complete loss of the ability to formulate speech or comprehend language, combining the deficits of Broca’s and Wernicke’s aphasia. Spontaneous speech, naming and repetition may be limited to a single preservative word or non- word utterance. In a significant proportion of patients, comprehension recovers well, changing from global to Broca’s aphasia (Syndromenwandeln). The damage usually involves most of MCA territory. More rarely the damage is caused by two lesions, one frontal and other parietotemporal, sparing parts of the sensory and motor cortex. These patients may have transient or no hemiplegia (‘global aphasia without hemiplegia’).”4

Broca’s aphasia

Also known as major motor aphasia. Patients have difficulties in understanding language and writing. Agrammatism or inability to complete sentences with an appropriate structure is also usually present. Sometimes the patient may have sensory and motor problems on the right side of the body.

“Broca’s aphasia, or expressive or motor aphasia, is the most widely known form of this disorder, characterized by nonfluent verbal expression in which a few words are produced with great effort. Patients with Broca’s aphasia produce several short phrases, often pronouncing a single word in-between pauses. Other characteristics of Broca’s aphasia are dysprosody and agrammatism with impaired reading comprehension; these are often accompanied by right hemiplegia and apraxia. Comprehension of spoken language is relatively spared, particularly to simple commands and routine conversation. From an anatomical perspective, Broca’s aphasia is related to lesions in the Broca’s area, located in the inferior frontal gyrus (pars opercularis and pars triangularis) of the left cerebral hemisphere, usually with extension to the adjacent subcortical white matter.”5

Despite the patient presenting serious alterations, they are usually able to improve their capabilities. However, the subject cannot return to the initial skills he/she had before the injury. It’s recommended to start therapy as soon as possible to achieve the best effectiveness.

Motor Transcortical Aphasia

It presents symptoms similar to Broca’s aphasia but, the language has not changed and the patient is able to articulate sentences normally. However, the biggest problem lies in spontaneity within the production of discourse or conversation.

“Transcortical motor aphasia is a kind of aphasia which stems from lesions to the pre-frontal convexity (expansive injuries particularly) which can characterize certain patient disturbances in language behavior such as: anomy, which can persist independently for a considerable period of time, as well as problems with motor spontaneity.9 In transcortical motor aphasia although comprehension is preserved, speech is not fluent because there is impeded initiative, latency in answers and reduced medium phrase length with simplification of grammatical forms. The repetition is mainly of fragments of the individual’s utterances in situations of dialogue and requests.10 Transcortical motor aphasia, therefore, can be considered part of the aphasic category that does not present comprehension deficits.”6

Conduction Aphasia

Also known as associative aphasia. Although the understanding of language is not usually affected, speech fluency issues may appear. The subject usually communicates through short and broken sentences due to problems in the selection and pronunciation of words.

“Speech is normal. Language comprehension is good except for auditory span. Repetition is poor, not always worse than spontaneous output but dominated by phonemic paraphasias on substantive words, particularly phonoiogically complex target words (“happy hippopotamus”) or words embedded in phonoiogically complex sentences (“Dogs chase but rarely catch clever cats”). Written language is extremely variable in this syndrome. Writing is rarely better than speech, but it can be much more impaired. Oral reading is usually comparable to speech but can be better or worse. Reading comprehension is usually comparable to auditory but can be worse. Patients with the agraphia with alexia syndrome usually have conduction aphasia. Naming is also extremely variable, from extremely poor to nearly normal. Errors are paraphasias (phonemic especially).”7

Amnesic or Anomic Aphasia

In this aphasia type the patient’s capacities are relatively intact but there is difficulty in finding the exact or desired words to designate objects, places, etc.

“Anomia is a term that describes the inability to retrieve a desired word, and is the most common deficit present across different aphasia syndromes. Anomic aphasia is a specific aphasia syndrome characterized by a primary deficit of word retrieval with relatively spared performance in other language domains, such as auditory comprehension and sentence production. Damage to a number of cognitive and motor systems can produce errors in word retrieval tasks, only subsets of which are language deficits. In the cognitive and neuropsychological underpinnings section, we discuss the major processing steps that occur in lexical retrieval and outline how deficits at each of the stages may produce anomia. The neuroanatomical correlates section will include a review of lesion and neuroimaging studies of language processing to examine anomia and anomia recovery in the acute and chronic stages.”8

Wernicke’s Aphasia or Sensory Aphasia

The patient can speak fluently, unlike other aphasias such as Broca’s. However, the compression of speech patterns, writing and reading are severely affected. This is because the subjects include new words, also called neologisms which are invented grammatical structures. They have their own jargon even if they are able to formulate relatively complicated or long sentences.

“Wernicke’s aphasia is characterized by fluent but relatively meaningless spontaneous speech and repetition and relatively poor comprehension of words, sentences, and conversation. Spoken language may be limited to jargon comprised of either real words or neologisms (nonwords such as ‘klimorata’) or a combination of the two. In contrast to those with Broca’s aphasia, the individual with Wernicke’s aphasia is typically unaware of the errors. The appropriate melody or intonation may give the impression that the person is speaking another language. Particularly in the acute stage, there is often a profound impairment of comprehension, such that the patient may listen to others and respond fluidly with language-like, meaningless utterances for hours, with no apparent inkling that he or she has neither understood anything others have said nor said anything that could be understood by others. Often the person will intermittently include a coherent ‘social’ phrase, such as, ‘yes, that’s right.’ Written output is typically similar to spoken output—written words with little or no content, often including nonword letter strings. Reading comprehension is typically no better than spoken comprehension. Repetition is generally similar to spontaneous speech—fluent jargon. These deficits have been attributed to impaired inhibition of lexical activation, so that the person cannot select the appropriate word, sound, or meaning from competing linguistic units that are also activated. Although such an underlying impairment would account for many of the observed language deficits, it could not easily account for cases with relatively preserved or relatively impaired categories of words, such as animals or tools, or impaired nouns relative to verbs.”9

Paraphasia

Paraphasia (substitution of phonemes or words) appears frequently and the patient is not aware of it. Neither partial or total paralysis exists in either side of the body, so people with this condition can usually write normally although the content is incomprehensible.

In the majority of cases, aphasia is a severe pathology that should be treated as soon as possible. It is necessary to carry out a full study and examination. Sometimes, it is necessary to provide psychological therapy, not only of the patient but also of the relatives since the person’s ability to communicate is affected. For all these reasons, it is recommended to go to visit your specialist.

“There are several categories of paraphasic error. Semantic errors arise when an individual unintentionally produces a semantically-related word to their original, intended word (their ‘target word’). A classic semantic error would be saying ‘cat’ when one intended to say ‘dog.’ Phonemic (sometimes called ‘formal’) errors occur when the speaker produces an unrelated word that is phonemically related to their target: ‘mat’ for ‘cat’, for example. It is also possible for an erroneous production to be mixed, that is both semantically and phonemically related to the target word: ‘rat’ for ‘cat.’ Individuals with anomia also produce unrelated errors, which are words that are neither semantically or phonemically related to their intended target word: for example, producing ´skis´ instead of ´zipper.’ Each of these categories shares the commonality that the word produced by the individual is a ‘real’ word. There is another family of anomic errors, neologisms, in which the individual produces non-word productions.”10

“Usually aphasia patients are individuals who suffered a stroke or traumatic head injury; sometimes they are patients with brain tumors or dementia. Most often, language evaluation is carried out either at the institutional level (usually a hospital), or at the professional’s office. When the patient is assessed at the hospital, frequently a shorter (bedside) evaluation is required. An extensive language evaluation may take one hour or even more, but of course, it depends upon the specific language impairment (for example, the evaluation of a global aphasia is usually very short) and the testing procedure that is selected (for instance, a short language test battery; a diversity of different language tests, etc.).”11

 

References:

(1) Laures-Gore, J. S., & Buchanan, T. W. (2015). Aphasia and the neuropsychobiology of stress. Journal of Clinical and Experimental Neuropsychology, 37(7), 688-700. Available online at https://www.researchgate.net/publication/281261703_Aphasia_and_the_neuropsychobiology_of_stress

(2) Pedersen, P. M., Vinter, K., & Olsen, T. S. (2004). Aphasia after stroke: type, severity and prognosis. Cerebrovascular Diseases, 17(1), 35-43. Available online at https://www.researchgate.net/publication/9061407_Aphasia_after_Stroke_Type_Severity_and_Prognosis

(3) De Freitas, G. R. (2012). Aphasia and other language disorders. In Manifestations of Stroke (Vol. 30, pp. 41-45). Karger Publishers. Available online athttps://pdfs.semanticscholar.org/eb54/38b973350d07c690e8606ab9b4ed7fe203cf.pdf Available online at https://pdfs.semanticscholar.org/eb54/38b973350d07c690e8606ab9b4ed7fe203cf.pdf

(4) Teive, H. A., Munhoz, R. P., & Caramelli, P. (2011). Historical aphasia cases:” Tan-tan”,” Vot-vot”, and” Cré nom!”. Arquivos de neuro-psiquiatria, 69(3), 555-558. Available online at http://www.scielo.br/pdf/anp/v69n3/a27v69n3.pdf

(5) Alexander, M. P. (2000). Aphasia I: Clinical and anatomic issues. Patient-based approaches to cognitive neuroscience. MIT Press, Cambridge, 165-181. Available online at https://pdfs.semanticscholar.org/fb06/dd3669e45f125ac959ea8c26b9ba9b86eb2c.pdf

(6) Mancopes, R., & Schultz, F. (2008). Processing of metaphors in transcortical motor aphasia. Dementia & neuropsychologia, 2(4), 339-348. Available online at http://www.scielo.br/pdf/dn/v2n4/1980-5764-dn-2-04-00339.pdf

(7) Harnish, S. M. (2017). Anomia and Anomic Aphasia: Implications for Lexical Processing. The Oxford Handbook of Aphasia and Language Disorders, 121. Available online at http://www.oxfordhandbooks.com/view/10.1093/oxfordhb/9780199772391.001.0001/oxfordhb-9780199772391-e-7

(8) Hillis, A. E. (2007). Aphasia: progress in the last quarter of a century. Neurology, 69(2), 200-213. Available online at https://n.neurology.org/content/69/2/200.short

(9) Adams, J., Bedrick, S., Fergadiotis, G., Gorman, K., & van Santen, J. (2017, August). Target word prediction and paraphasia classification in spoken discourse. In BioNLP 2017 (pp. 1-8). Available online at https://aclweb.org/anthology/W17-2301

(10) Marebwa, B. K., Fridriksson, J., Yourganov, G., Feenaughty, L., Rorden, C., & Bonilha, L. (2017). Chronic post-stroke aphasia severity is determined by fragmentation of residual white matter networks. Scientific reports, 7(1), 8188. Available online at https://www.nature.com/articles/s41598-017-07607-9

(11) Ardila, A. (2014). Aphasia handbook. Miami, FL: Florida International University, 102-35. Available online at https://aalfredoardila.files.wordpress.com/2013/07/ardila-a-2014-aphasia-handbook-miami-fl-florida-international-university2.pdf

 

Robert Velasquez
16 August, 2018

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Hello everyone, my name is Robert Velazquez. I am a content marketer currently focused on the medical supply industry. I studied Medicine for 5 years. I have interacted with many patients and learned a lot...read more:

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