Aphasia

Aphasia is the inability to communicate verbally or by written words. Aphasia can be usually due to brain injury or a stroke. It can also be the result of a brain tumor, Alzheimer or Encephalitis. Aphasia can be permanent or temporary (usually known as transient aphasia). Aphasia is sometimes confused with Apraxia which is a condition that affects the muscles used in speech rather than the language function.

Aphasia can be grouped as below based on the cause and the area of the brain affected:

• Global Aphasia : Occurs due to head trauma on the language areas of the brain. Language ability affected may vary based on the location and the extent of the injury.
  
  
• Wernicke's Aphasia : Partial or total loss of the ability to understand written or spoken words though the affected person may still retain the ability to speak - but with made-up words.
  
  
• Transcortical Aphasia : Partial or total loss of the ability to express verbally or by writing words although the individual may have the ability to repeat words, phrases or even sentences
  
  
• Conduction Aphasia : Affected person loses the ability to repeat words, phrases or sentences
  
  
• Subcortical Aphasia : Partial or total loss of the ability to express verbally or by using written words due to damage to the non-language dominated areas of the brain
  
  
• Anomic Aphasia : Partial or total loss of the ability to recall the names of persons or things.
  
  
• Broca's Aphasia : Hearing comprehension is not affected
  
  

As Aphasia develops following a head trauma, tumor, disease (Alzheimer's) or infection (encephalitis), the pathways for language comprehension or production are disrupted. This occurs in the left hemisphere of the brain. MRI (magnetic resonance imaging) and CT (Computed tomography) scans can show the extent of the damage and the area affected. Coupled with standardized tests like Boston Diagnostic Aphasia Examination, the Western Aphasia Battery and Porch Index of Speech Ability, can indicate the severity of Aphasia and probable course of speech therapy.

Alzheimer's disease

Alzheimer's disease is a progressive mental disorder that brings about changes in the brain slowly leading to dementia. Named after the German physician Alois Alzheimer, Alzheimer's disease has 2 characteristic neuronal changes : Loss of cholinergic cells in the basal forebrain and the development of neuritic plaques in the cerebral cortex. Neurofibrillary tangles can also occur due to Neuritic plaques.

Here the brain cells degenerate and die thus causing a decline in the mental functioning and memory of a person. Alzheimer's disease (AD) or Presenile dementia as it was earlier known as, is one of the primary causes of dementia. The levels of the brain neurotransmitters serotonin, norepinephrine and acetylcholine are found to be low in AD. This kind of brain disorder causes loss of social and intellectual skills of a person. In severe cases it interferes with the day-to-day activities of a person.

Alzheimer's disease causes

• Most scientists believe that Alzheimer's disease is caused due to increase in production and accumulation of a protein called beta-amyloid protein. The accumulation of this protein leads to nerve cell death.
  
• Environment factors that causes a change in the brain's functioning can also lead to Alzheimer's disease
  
• Genetic causes
  
• Abnormal levels of elements like aluminum and lead
  
• Chronic cerebrovascular condition resulting from high blood pressure can lead to cerebral microbleeds. These microbleeds over a long period can result in mild cognitive impairment.
  
• Head injury
  
• Some viruses
  
• Lifestyle changes that causes change in the brain's functioning can also lead to Alzheimer's disease
  
  

There are 4 major cognitive deficits arising out of AD :

1. Amnesia : Memory loss is probably the most common symptoms of Alzheimer' disease.
2. Aphasia : Loss of Language - Failure to recollect names of objects
3. Apraxia : Inability to perform voluntary movements
4. Agnosia : Inability to recognize people and places

• Forgetfulness, unusual difficulty in remembering things
  
• Mild confusion
  
• Occasional memory lapse
  
• Disorientation day, date, etc.
  
• Problem with speaking and writing
  
• Problem in thinking and reasoning
  
• Decision making problems
  
• Depression, anxiety, mood swing and many such behavioral problems
  
• Problems with cognitive skills like calculating, judgment, etc
  
  

Alzheimer's disease diagnosis

1. A physical examination and a neurological examination to check:

• Muscle tone and strength
  
• Sense of touch and sight
  
• Reflexes
  
• Balance
  
• Coordination, etc.
  

2. Brain imaging (CT scans, MRI) to check for tumors, etc.
3. Lab tests for thyroid etc so as to rule out other possibilities for memory loss

Treating Alzheimer's disease

As this disease is of degenerative nature, there is no permanent cure. Early diagnosis and changes in lifestyle can slow down its progression or improve the quality of life for the afflicted.

• Drugs to deal with cognitive changes and memory symptoms
  
• Drugs to increase acetylcholine or butylcholine levels. eg; Donepezil hydrochloride or rivastigmine, a cholinergic agonist or Cholinesterase inhibitor.
  
• Vitamin E combined with Cholinesterase inhibitors
  
• Alternate medicines like Ginkgo Biloba, Brahmi, Gotu kola, Ginseng and St. John's Wort
  
• Exercise
  
• Well balanced and nutritious food
  
• Lifestyle changes that help deal with and improve the current condition
  

Broca's area

Broca's area or convolution of Broca is that region of the brain that is linked to speech. The motor neurons that deal with speech control are located in this area of the brain and this was identified by French surgeon Paul Broca. The Broca's area plays a vital role in the development and articulation of speech, language comprehension and processing. Since this area lies in the frontal convolution, any damage to the frontal lobe can cause language disorder known as Broca aphasia.

Broca's Aphasia (also known as motor aphasia) can be complete as the affected person may become mute or may speak simple statements with a great deal of effort.