Definitions

Definitions and Terms Associated with Alzheimer's Disease

Alzheimer's disease: A progressive neurologic disease of the brain that leads to the irreversible loss of neurons and dementia. The clinical hallmarks of Alzheimer's disease are progressive impairment in memory, judgment, decision making, orientation to physical surroundings, and language. A working diagnosis of Alzheimer disease is usually made on the basis of the neurologic examination. A definitive diagnosis can be made only at autopsy. On a cellular level, Alzheimer's disease is characterized by unusual helical protein filaments in nerve cells (neurons) of the brain. These odd twisted filaments are called neurofibrillary tangles. On a functional level, there is degeneration of the cortical regions, especially the frontal and temporal lobes, of the brain.

 Apraxia - A severe speech disorder characterized by inability to speak, or a severe struggle to speak clearly. Apraxia of speech occurs when the oral- motor muscles do not or cannot obey commands from the brain, or when the brain cannot reliably send those commands.

Aphasia -  A disorder that results from damage to portions of the brain that are responsible for language. For most people, these are areas on 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, an infection, or dementia. The disorder impairs 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.

Delusions - Delusional disorder, previously called paranoid disorder, is a type of serious mental illness called a "psychosis" in which a person cannot tell what is real from what is imagined. The main feature of this disorder is the presence of delusions, which are unshakable beliefs in something untrue. People with delusional disorder experience non-bizarre delusions, which involve situations that could occur in real life, such as being followed, poisoned, deceived, conspired against, or loved from a distance. These delusions usually involve the misinterpretation of perceptions or experiences. In reality, however, the situations are either not true at all or highly exaggerated

Dementia -  Significant loss of intellectual abilities such as memory capacity, severe enough to interfere with social or occupational functioning.
Criteria for the diagnosis of dementia include impairment of attention, orientation, memory, judgment, language, motor and spatial skills, and function. By definition, dementia is not due to major dementia or schezophrenia.

Dysarthria -  Speech that is characteristically slurred, slow, and difficult to produce (difficult to understand). The person with dysarthria may also have problems controlling the pitch, loudness, rhythm, and voice qualities of their speech.

Hallucination -  A false perception of objects or events involving the senses. When individuals with Alzheimer’s disease have a hallucination, they see, hear, smell, taste or feel something that isn’t there.