Bizarre Mental Case Studies : Brain and Language Connections

split brain

In 1861, the French surgeon, Pierre Paul Broca, described his  patients who had lost the ability to speak after injury to the posterior inferior frontal gyrus of the brain. Since that time, an infinite number of clinical and functional imaging studies have relied on this brain^behaviour relationship as their anchor for the localization of speech functions. Clinical studies of Broca’s aphasia often assume that the deficits in these patients are due entirely to dysfunction in Broca’s area, thereby attributing all aspects of the disorder to this one brain region.
Moreover, functional imaging studies often rely on activation in Broca’s area as verification that tasks have successfully tapped speech centres. Despite these strong assumptions, the range of locations ascribed to Broca’s area varies broadly across studies.

Here are two mental case studies that proves Speech functions can be damaged whenever Broca brain part, or Broca’s Aphasia is affected.  Take the first case study named  PETER. 

Location of Damage: Corpus Callosum :

Peter began to suffer from complex partial seizures at the age of 8. His seizures were severe, despite taking antiepileptic medication; so, at the age of 20, after struggling with his condition for over 12 years, he and his doctors agreed to have him undergo a commissurotomy.

The commissurotomy involved a surgical incision of Peter’s corpus callosum. The corpus callosum is the major cerebral nerve tract that connects the brain’s right and left cerebral hemispheres together; and therefore, serves as the major communication pathway for intrahemispheric signals. Removal or damage to one’s corpus callosum would result in impaired communication between the two sides of the brain.

On one hand, Peter’s surgery was a success, as it did end up attenuating the magnitude of his seizures. On the other hand, however, Peter was left much different than before. For example, he was not able to respond with the left side of his body to verbal input. If asked to “Stand like a Boxer,” his left side would sag and appear lackluster, while his right side would behave appropriately.

Because his brain had, literally, been split into two separate pieces, his left and right sides were often behaving like two separate people.

  • He complained that his left hand would turn off television shows that he was enjoying,
  • that his left leg would not always walk in the intended direction, and
  • that his left arm would occasionally begin to fight with the right side of his body.

It is clear from Peter’s case that the brain works best when it is capable of functioning as a single, cohesive unit,
as opposed to multiple ones.

Brains’ Lateralization: 

The left and right brains are connected by an intricate network of nerve fibres called the corpus callosum. It was the ancient Egyptians who first noticed that the left brain tends to control the right side of the body and the right brain tends to control the left side of the body. Although each hemisphere is almost identical in terms of structure, each hemisphere operates in an entirely different way and are associated with very different activities. This is known as specialization or lateralization.

LEFT HEMISPHERE
The left brain is the logical brain responsible for words, logic, numbers, analysis, lists, linearity and sequence. It controls the right side of your body.
RIGHT HEMISPHERE
The right brain is the creative brain and is responsible for rhythm, spatial awareness, colour, imagination, daydreaming, holistic awareness and dimension. It controls the left side of your body.
CORPUS CALLOSUM
The corpus callosum is a thick band of nerve fibres which connect the brain cells in one hemisphere to those in the other hemisphere. The two hemispheres keep up a continuous conversation via this neural bridge.

brain lateralization

Case study No 2: N.I.
The Woman Who Read With Her Right Hemisphere

woman who reads

Location of Damage: Complete Removal of Left Hemisphere

Before contracting her illness, N.I. was a perfectly normal girl. Unfortunately, at the age of 13, she began to experience convulsions, along with deteriorated speech and motor abilities. CT scans revealed ischemic (lack of blood flow) brain damage to her left hemisphere. N.I. was still experiencing symptoms two years after the onset of her illness, and her right limbs had become paralyzed. In an attempt to relieve these symptoms, a total left hemispherectomy (removal of a hemisphere in the brain) was performed.

Following this procedure, her seizures subsided completely. Sadly, however, her surgery had taken away her ability to read correctly. (Most people, including N.I., use their left hemispheres for language related tasks)Post surgery, N.I. was able to recognize letters, but was totally incapable of translating them into sounds. She could read concrete familiar words (ie: fan), but could not pronounce even simple nonsense words (ie: neg). Her reading errors indicate that she reads on the basis of meaning and appearance of words rather than by translating the individual letters into sounds. For instance, when shown the word “fruit” she would respond by saying: “juice.”

Her responses are similar to people with a disorder known as ‘deep dyslexia’, which is an inability to apply rules of pronunciation while reading. Deep dyslexics can still pronounce familiar words based on their specific memories of them, but similar to N.I., they cannot pronounce nonsensical words, or words they are unfamiliar with

source :  Bizarre mental cases/listverse.com

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Aphasia : A Language Disorder after a Stroke

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What is Aphasia?

Aphasia often arises as a result of damage to Broca’s area or Wernicke’s area.

Aphasia is a language disorder that results from damage to portions of the brain that are responsible for language. For most people, these are parts of the left side (hemisphere) of the brain. Aphasia usually occurs suddenly, often as the result of a stroke or head injury, but it may also develop slowly, as in the case of a brain tumor. The disorder impairs both the expression and understanding of language as well as reading and writing. Aphasia may co-occur with speech disorders such as dysarthria or apraxia of speech, which also result from brain damage.

Who has aphasia?
Anyone can acquire aphasia, but most people who have aphasia are in their middle to late years. Men and women are equally affected. It is estimated that approximately 80,000 individuals acquire aphasia each year. About one million persons in the United States currently have aphasia.

What causes aphasia?
Aphasia is caused by damage to one or more of the language areas of the brain. Many times, the cause of the brain injury is a stroke. A stroke occurs when blood is unable to reach a part of the brain. Brain cells die when they do not receive their normal supply of blood, which carries oxygen and important nutrients. Other causes of brain injury are severe blows to the head, brain tumors, brain infections, and other conditions of the brain.

Individuals with Broca’s aphasia have damage to the frontal lobe of the brain. These individuals frequently speak in short, meaningful phrases that are produced with great effort. Broca’s aphasia is thus characterized as a nonfluent aphasia. Affected people often omit small words such as “is,” “and,” and “the.” For example, a person with Broca’s aphasia may say, “Walk dog” meaning, “I will take the dog for a walk.” The same sentence could also mean “You take the dog for a walk,” or “The dog walked out of the yard,” depending on the circumstances. Individuals with Broca’s aphasia are able to understand the speech of others to varying degrees. Because of this, they are often aware of their difficulties and can become easily frustrated by their speaking problems. Individuals with Broca’s aphasia often have right-sided weakness or paralysis of the arm and leg because the frontal lobe is also important for body movement.

In contrast to Broca’s aphasia, damage to the temporal lobe may result in a fluent aphasia that is called Wernicke’s aphasia. Individuals with Wernicke’s aphasia may speak in long sentences that have no meaning, add unnecessary words, and even create new “words.” For example, someone with Wernicke’s aphasia may say, “You know that smoodle pinkered and that I want to get him round and take care of him like you want before,” meaning “The dog needs to go out so I will take him for a walk.” Individuals with Wernicke’s aphasia usually have great difficulty understanding speech and are therefore often unaware of their mistakes. These individuals usually have no body weakness because their brain injury is not near the parts of the brain that control movement.

A third type of aphasia, global aphasia, results from damage to extensive portions of the language areas of the brain. Individuals with global aphasia have severe communication difficulties and may be extremely limited in their ability to speak or comprehend language.

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How is aphasia diagnosed?

Aphasia is usually first recognized by the physician who treats the individual for his or her brain injury, usually a neurologist. The physician typically performs tests that require the individual to follow commands, answer questions, name objects, and converse. If the physician suspects aphasia, the individual is often referred to a speech-language pathologist, who performs a comprehensive examination of the person’s ability to understand, speak, read, and write.

How is aphasia treated?
In some instances, an individual will completely recover from aphasia without treatment. This type of “spontaneous recovery” usually occurs following a transient ischemic attack (TIA), a kind of stroke in which the blood flow to the brain is temporarily interrupted but quickly restored. In these circumstances, language abilities may return in a few hours or a few days. For most cases of aphasia, however, language recovery is not as quick or as complete. While many individuals with aphasia also experience a period of partial spontaneous recovery (in which some language abilities return over a period of a few days to a month after the brain injury), some amount of aphasia typically remains. In these instances, speech-language therapy is often helpful. Recovery usually continues over a 2-year period. Most people believe that the most effective treatment begins early in the recovery process. Some of the factors that influence the amount of improvement include the cause of the brain damage, the area of the brain that was damaged, the extent of the brain injury, and the age and health of the individual. Additional factors include motivation, handedness, and educational level.

Aphasia therapy strives to improve an individual’s ability to communicate by helping the person to use remaining abilities, to restore language abilities as much as possible, to compensate for language problems, and to learn other methods of communicating. Treatment may be offered in individual or group settings. Individual therapy focuses on the specific needs of the person. Group therapy offers the opportunity to use new communication skills in a comfortable setting. Stroke clubs, which are regional support groups formed by individuals who have had a stroke, are available in most major cities. These clubs also offer the opportunity for individuals with aphasia to try new communication skills. In addition, stroke clubs can help the individual and his or her family adjust to the life changes that accompany stroke and aphasia. Family involvement is often a crucial component of aphasia treatment so that family members can learn the best way to communicate with their loved one.

Family members are encouraged to:

  • Simplify language by using short, uncomplicated sentences.
  • Repeat the content words or write down key words to clarify meaning as needed.
  • Maintain a natural conversational manner appropriate for an adult.
  • Minimize distractions, such as a blaring radio, whenever possible.
  • Include the person with aphasia in conversations.
  • Ask for and value the opinion of the person with aphasia, especially regarding family matters.
  • Encourage any type of communication, whether it is speech, gesture, pointing, or drawing.
  • Avoid correcting the individual’s speech.
  • Allow the individual plenty of time to talk.
  • Help the individual become involved outside the home. Seek out support groups such as stroke clubs.

What are researchers investigating about aphasia?
Aphasia research is exploring new ways to evaluate and treat aphasia as well as to further understand the function of the brain. Brain imaging techniques are helping to define brain function, determine the severity of brain damage, and predict the severity of the aphasia. These procedures include PET (positron emission tomography), CT (computed tomography), and MRI (magnetic resonance imaging) as well as the new functional magnetic resonance (fMRI), which identifies areas of the brain that are used during activities such as speaking or listening. In-depth testing of the language ability of individuals with the various aphasic syndromes is helping to design effective treatment strategies. The use of computers in aphasia treatment is also being studied. Promising new drugs administered shortly after some types of stroke are being investigated as ways to reduce the severity of aphasia.

source : http://www.strokecenter.org/