Nominal aphasia
Encyclopedia
Nominal aphasia is a severe problem with recalling words or names.
Dysnomia refers to a less severe form of this word-recall dysfunction. Learning disabilities caused by name-recall problems are usually diagnosed as dysnomia rather than anomia.
characterized by problems recalling words or names. Subjects often use circumlocution
s (speaking in a roundabout way) in order to express a certain word for which they cannot remember the name. Sometimes the subject can recall the name when given clues. Sufferers are often frustrated when they know that they know the name, but cannot produce it. However, the person is able to speak with correct grammar, but the main problem is finding appropriate words to identify or describe an object or person.
Sometimes subjects may know what to do with an object, but still not be able to give a name to the object. For example, if a subject is shown an orange, and asked what it is called, the subject may be well aware that the object can be peeled and eaten, and may be able to demonstrate this by actions or even verbal responses. However, whether such a subject could name the "color" of the orange is unknown.
. Although people suffering from averbia cannot recall or produce action words, they also have problems naming objects as well.
Alexia is another form of anomic aphasia when the person has trouble reading in their head, reading aloud, and reading comprehension. Lesions in alexia patients are in the left posterior inferior temporal area.
Another type of anomia is color anomia, where the patient can distinguish between colors but cannot identify them by name or name the color of an object. They can separate colors into categories, but they cannot name them.
or the temporal lobe
of the brain
. These damages can be brain trauma, such as an accident, stroke
, or tumor
. This type of phenomenon can be quite complex, and usually involves a breakdown in one or more pathways between various regions in the brain.
Although the main causes are not specifically known, many researchers have found contributing factors to anomic aphasia. It is known that people with damage to the left hemisphere of the brain are more likely to have anomic aphasia. Broca’s area, the speech production center in the brain, was linked to being the source for speech execution problems, and with the use of functional magnetic resonance imaging
(fMRI), Broca’s area was connected with speech repetition problems, which is commonly used to study anomic patients. Other experts believe that damage to Wernicke's area
, which is the speech comprehension area of the brain, is connected to anomia because the patients cannot comprehend the words that they are hearing.
Although many experts have believed that damage to Broca’s area or Wernicke's area
are the main causes of anomia, current studies have shown that damage in the left parietal lobe
is the epicenter of anomic aphasia. One study was conducted using a word repetition test as well as magnetic resonance imaging
(MRI) in order to see the highest level of activity as well as where the lesions are in the brain tissue. Fridrikkson, et al. saw that damage to neither Broca’s area nor Wernicke's area
were the sole sources of anomia in the subjects. Therefore, the original model, which showed that damage occurred on the surface of the brain on the grey matter
for anomia, was debunked and it was found that the damage was done in the white matter
deeper in the brain on the left hemisphere. More specifically, the damage was done to a part of the nerve tract called the arcuate fasciculus
, which the mechanism of action is unknown but it is shown to connect the posterior (back) of the brain to the anterior (front) and vice versa.
New data has shown that although the arcuate fasciculus
’s main function does not include connecting Wernicke's area
and Broca’s area, damage to the tract does create speech problems because the speech comprehension and speech production areas are connected by this tract. Some studies have found that in right-handed people the language center is 99% in the left hemisphere; therefore, anomic aphasia almost exclusively occurs with damage to the left hemisphere. However, in left-handed people the language center is about 60% in the left hemisphere; thus, anomic aphasia can occur with damage to the right hemisphere in left-handed people. Therefore, the specific cause of anomia is unknown; however, research is bringing the answer into focus.
.
However, it is also important to do a hearing test in case that the patient cannot hear the words or sentences needed in the speech repetition test. In the speech tests, the person is asked to repeat a sentence with common words and if the person cannot identify the word but he or she can describe it then the person is highly likely to have anomic aphasia. However, to be completely sure, the test is given as a person is in an MRI and the exact location of the lesions and areas activated by speech are pinpointed. Although no simpler or cheaper option is available as of now, lesion mapping and speech repetition tests are the main ways of diagnosing anomic aphasia.
Although there are not many literary cases about anomic aphasia, there are many books out there about life with aphasia
. One of the most notable books on aphasia is The Man Who Lost His Language by Sheila Hale. It is the story of Sheila Hale’s husband, John Hale
, who was a very prestigious scholar who suffered a stroke and lost speech formation abilities. Sheila Hale does a great job explaining the symptoms and mechanics behind aphasia and speech formation. She also adds in the emotional components of dealing with a person with aphasia and how to be patient with the speech and communication.
.
Dysnomia refers to a less severe form of this word-recall dysfunction. Learning disabilities caused by name-recall problems are usually diagnosed as dysnomia rather than anomia.
Overview
Anomic aphasia (anomia) is a type of aphasiaAphasia
Aphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....
characterized by problems recalling words or names. Subjects often use circumlocution
Circumlocution
Circumlocution is an ambiguous or roundabout figure of speech...
s (speaking in a roundabout way) in order to express a certain word for which they cannot remember the name. Sometimes the subject can recall the name when given clues. Sufferers are often frustrated when they know that they know the name, but cannot produce it. However, the person is able to speak with correct grammar, but the main problem is finding appropriate words to identify or describe an object or person.
Sometimes subjects may know what to do with an object, but still not be able to give a name to the object. For example, if a subject is shown an orange, and asked what it is called, the subject may be well aware that the object can be peeled and eaten, and may be able to demonstrate this by actions or even verbal responses. However, whether such a subject could name the "color" of the orange is unknown.
Types of Anomic Aphasia
Averbia is a specific type of anomic aphasia in which the person has trouble remembering only verbs. This is caused by damage to the frontal cortex, in or near Broca's areaBroca's area
Broca's area is a region of the hominid brain with functions linked to speech production.The production of language has been linked to the Broca’s area since Pierre Paul Broca reported impairments in two patients. They had lost the ability to speak after injury to the posterior inferior frontal...
. Although people suffering from averbia cannot recall or produce action words, they also have problems naming objects as well.
Alexia is another form of anomic aphasia when the person has trouble reading in their head, reading aloud, and reading comprehension. Lesions in alexia patients are in the left posterior inferior temporal area.
Another type of anomia is color anomia, where the patient can distinguish between colors but cannot identify them by name or name the color of an object. They can separate colors into categories, but they cannot name them.
Causes
Anomia is caused by damage to various parts of the parietal lobeParietal lobe
The parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the...
or the temporal lobe
Temporal lobe
The temporal lobe is a region of the cerebral cortex that is located beneath the Sylvian fissure on both cerebral hemispheres of the mammalian brain....
of the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
. These damages can be brain trauma, such as an accident, stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
, or tumor
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...
. This type of phenomenon can be quite complex, and usually involves a breakdown in one or more pathways between various regions in the brain.
Although the main causes are not specifically known, many researchers have found contributing factors to anomic aphasia. It is known that people with damage to the left hemisphere of the brain are more likely to have anomic aphasia. Broca’s area, the speech production center in the brain, was linked to being the source for speech execution problems, and with the use of functional magnetic resonance imaging
Functional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI is a type of specialized MRI scan used to measure the hemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
(fMRI), Broca’s area was connected with speech repetition problems, which is commonly used to study anomic patients. Other experts believe that damage to Wernicke's area
Wernicke's area
Wernicke's area is one of the two parts of the cerebral cortex linked since the late nineteenth century to speech . It is involved in the understanding of written and spoken language...
, which is the speech comprehension area of the brain, is connected to anomia because the patients cannot comprehend the words that they are hearing.
Although many experts have believed that damage to Broca’s area or Wernicke's area
Wernicke's area
Wernicke's area is one of the two parts of the cerebral cortex linked since the late nineteenth century to speech . It is involved in the understanding of written and spoken language...
are the main causes of anomia, current studies have shown that damage in the left parietal lobe
Parietal lobe
The parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the...
is the epicenter of anomic aphasia. One study was conducted using a word repetition test as well as magnetic resonance imaging
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
(MRI) in order to see the highest level of activity as well as where the lesions are in the brain tissue. Fridrikkson, et al. saw that damage to neither Broca’s area nor Wernicke's area
Wernicke's area
Wernicke's area is one of the two parts of the cerebral cortex linked since the late nineteenth century to speech . It is involved in the understanding of written and spoken language...
were the sole sources of anomia in the subjects. Therefore, the original model, which showed that damage occurred on the surface of the brain on the grey matter
Grey matter
Grey matter is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil , glial cells and capillaries. Grey matter contains neural cell bodies, in contrast to white matter, which does not and mostly contains myelinated axon tracts...
for anomia, was debunked and it was found that the damage was done in the white matter
White matter
White matter is one of the two components of the central nervous system and consists mostly of myelinated axons. White matter tissue of the freshly cut brain appears pinkish white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries. Its white color is due to...
deeper in the brain on the left hemisphere. More specifically, the damage was done to a part of the nerve tract called the arcuate fasciculus
Arcuate fasciculus
The arcuate fasciculus is the neural pathway connecting the posterior part of the temporoparietal junction with the frontal cortex in the brain and is now considered as part of the superior longitudinal fasciculus..-Neuroanatomy:...
, which the mechanism of action is unknown but it is shown to connect the posterior (back) of the brain to the anterior (front) and vice versa.
New data has shown that although the arcuate fasciculus
Arcuate fasciculus
The arcuate fasciculus is the neural pathway connecting the posterior part of the temporoparietal junction with the frontal cortex in the brain and is now considered as part of the superior longitudinal fasciculus..-Neuroanatomy:...
’s main function does not include connecting Wernicke's area
Wernicke's area
Wernicke's area is one of the two parts of the cerebral cortex linked since the late nineteenth century to speech . It is involved in the understanding of written and spoken language...
and Broca’s area, damage to the tract does create speech problems because the speech comprehension and speech production areas are connected by this tract. Some studies have found that in right-handed people the language center is 99% in the left hemisphere; therefore, anomic aphasia almost exclusively occurs with damage to the left hemisphere. However, in left-handed people the language center is about 60% in the left hemisphere; thus, anomic aphasia can occur with damage to the right hemisphere in left-handed people. Therefore, the specific cause of anomia is unknown; however, research is bringing the answer into focus.
Diagnosis
The best way to see if anomic aphasia has developed is by using verbal as well as imaging tests. The combination of the two tests seem to be most effective. Either test done alone will give false positives or false negatives. For example, the verbal test is used to see if there is a speech disorder and whether it is a problem in speech production or comprehension. However, patients with Alzheimer’s disease have speech problems that are linked to dementia rather than anomia. The imaging test, mostly MRI, is ideal for lesion mapping or viewing deterioration in the brain. However, imaging cannot diagnose anomia on its own because the lesions may not be located deep enough to damage the white matter or damaging the arcuate fasciculus. However, anomic aphasia is the most difficult to associate with a specific lesion location in the brain. Therefore the combination of speech tests and imaging tests has the highest sensitivity and specificitySensitivity and specificity
Sensitivity and specificity are statistical measures of the performance of a binary classification test, also known in statistics as classification function. Sensitivity measures the proportion of actual positives which are correctly identified as such Sensitivity and specificity are statistical...
.
However, it is also important to do a hearing test in case that the patient cannot hear the words or sentences needed in the speech repetition test. In the speech tests, the person is asked to repeat a sentence with common words and if the person cannot identify the word but he or she can describe it then the person is highly likely to have anomic aphasia. However, to be completely sure, the test is given as a person is in an MRI and the exact location of the lesions and areas activated by speech are pinpointed. Although no simpler or cheaper option is available as of now, lesion mapping and speech repetition tests are the main ways of diagnosing anomic aphasia.
Treatment
Unfortunately, there is no method available to completely cure the anomic aphasia. However, there are treatments that help improve word-finding skills. Although a person with anomia may find it difficult to recall many types of words such as common nouns, proper nouns, verbs, etc., many studies have shown that treatment for object words, or nouns, have shown promise in rehabilitation research. The treatment includes visual aid, such as pictures, and the patient is asked to identify the object or activity. However, if that is not possible, then the patient is shown the same picture surrounded by words associated with the object or activity. Throughout the process positive encouragement is provided. The treatment shows an increase in word-finding during treatment; however, word identifying decreased two weeks after the rehabilitation period. Therefore, it shows that rehabilitation needs to be continuous for word-finding abilities to improve from the baseline. The studies show that verbs are harder to recall or repeat even with rehabilitation.Life with Anomic Aphasia
This disorder may be extremely frustrating for people with and without the disorder. Although the person with anomic aphasia may know the specific word, they may not be able to recall it and this can be very difficult for everyone in the conversation. However, it is important to be patient and work with the person so that he or she gains confidence with his or her speech. Positive reinforcements are helpful.Although there are not many literary cases about anomic aphasia, there are many books out there about life with aphasia
Aphasia
Aphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....
. One of the most notable books on aphasia is The Man Who Lost His Language by Sheila Hale. It is the story of Sheila Hale’s husband, John Hale
John Rigby Hale
Sir John Rigby Hale was a British Renaissance historian, translator, editor, and university professor.John Rigby Hale was born September 17, 1923, in Ashford, Kent, in the United Kingdom. He was educated at Jesus College, Oxford . He also attended Johns Hopkins University and Harvard University...
, who was a very prestigious scholar who suffered a stroke and lost speech formation abilities. Sheila Hale does a great job explaining the symptoms and mechanics behind aphasia and speech formation. She also adds in the emotional components of dealing with a person with aphasia and how to be patient with the speech and communication.
Current Research
There are many institutes and universities that are working to gain a better understanding of anomic aphasia so that people suffering from anomia have more information on their disorder. One of the leading departments in the United States is the Department of Aphasia in the University of South Carolina. The lead researcher, Dr. Julius Fridrikkson, has done extensive research on aphasia and other communication disorders using neuroimagingSee also
- AphasiaAphasiaAphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....
- Broca’s area
- Wernicke's areaWernicke's areaWernicke's area is one of the two parts of the cerebral cortex linked since the late nineteenth century to speech . It is involved in the understanding of written and spoken language...
- Broca's aphasia
- Wernicke's aphasia
- Paul BrocaPaul BrocaPierre Paul Broca was a French physician, surgeon, anatomist, and anthropologist. He was born in Sainte-Foy-la-Grande, Gironde. He is best known for his research on Broca's area, a region of the frontal lobe that has been named after him. Broca’s Area is responsible for articulated language...
- Karl WernickeKarl WernickeCarl Wernicke was a German physician, anatomist, psychiatrist and neuropathologist. He earned his medical degree at the University of Breslau...