5 A's Associated with Alzheimer's Disease

There is a lot of medical jargon and terminology used, especially when it comes to brain health. Much of it is based in Greek or Latin, but for those who never studied these languages or medical terminology, the words don't mean much and can be confusing.

Below I share 5 medical terms associated with Alzheimer's disease and what they mean. You may notice that all of these terms start with the letter "A." In Greek, when the prefix is "a-" it means "not" or "without," so each of these words describes a function that can be diminished or lost with Alzheimer's disease pathology.

Anomia

• A- (Greek prefix): Meaning "without" or "not"
• Onoma/Onyma (Greek root): Meaning "name" (the same root found in words like onomatopoeia)
• Literal meaning: without a name

With anomia, it is not a loss of intelligence, memory of what an object is called, or vocabulary — it is when a person knows what they want to say but struggles to pull the word out of their brain's internal dictionary. They will often substitute with filler words like "that thing," "stuff," or "that guy." It can be described as having a word "right at the tip of the tongue" frequently, disrupting normal conversation. You may sometimes see the word aphasia used in relation to speech, but that is an umbrella term for any language disorder originating in the brain, whereas anomia specifically refers to the inability to retrieve names or words.

Apraxia

• A- / An- (Greek prefix): Meaning "not," "without," or "absence of"
• Praxis (Greek root): Meaning "action," "doing," "practice," or "exercise." This root comes from the Greek verb prassein, meaning "to do" or "to act" (the same root that gives us words like practice and pragmatic)
• Literal meaning: without action

Apraxia is characterized by the inability to perform purposeful, learned, and familiar movements, even though the person has the physical capacity and willingness to do them. It is not caused by muscle weakness, paralysis, or lack of coordination. Instead, it is a breakdown in the brain's ability to sequence and perform a motor movement command. The individual knows how they want to move and the muscles are capable of the movement, but the brain struggles to deliver the message to the body of how to execute it.

Agnosia

• A- (Greek prefix): Meaning "not," "without," or "absence of"
• Gnosia (Greek root): Derived from the Greek word gnōsis, meaning "knowledge" or "to know" (the same root found in words like diagnosis, prognosis, and gnostic)
• Literal meaning: lack of knowledge or ignorance

  This does not speak to a loss of intelligence, but an inability to recognize something that would be considered common. "Common" is the important distinction as many of us wouldn't be able to name a highly specific tool used by a mechanical engineer, but should be able to name pieces of sporting equipment, cooking utensils, or household objects.

  Agnosia can impact specific senses; a person may see a common object but be unable to recognize or name it. They may be unable to recognize or name the familiar faces of family or friends, a condition called prosopagnosia. It can also occur with sound recognition, or as tactile agnosia, where a common object like a coin is placed in their hand but they cannot identify it by touch alone.

  Amnesia

  • A- (Greek prefix): Meaning "not," "without," or "absence of"
  • Mnesia (Greek root): Derived from the Greek word mnēsis, meaning "memory" or "remembrance," from the root verb mnaomai, "to remember" (the same root that gives us words like mnemonic, a memory aid)
  • Literal meaning: forgetfulness or without memory

  There are multiple types and variations of amnesia, but generally speaking, it relates to being unable to recall facts or events. In Alzheimer's disease, it is common for an individual to recall previous events and memories — like their childhood or early adult years — but be unable to recall recent events, like where they went the day before or what they had for breakfast.

  Aphasia

  • A- (Greek prefix): Meaning "not," "without," or "absence of"
  • Phasia (Greek root): Derived from the Greek word phasis, meaning "speech," "utterance," or "expression."
  • Literal meaning: speechless or without speech

  Mentioned above because it is related to anomia, but rather than impacting just the retrieval of a specific word, aphasia can affect the processing of language, the understanding of what is being said, or the physical production of a known word. This can be described as having a word at the

  tip of the tongue, where the person knows exactly what they want to say but has a hard time physically producing speech. It can also manifest as someone believing they are speaking a cohesive sentence, when in reality it comes out as gibberish to the listener. Additionally, with aphasia a person may have difficulty processing what is said to them. They may hear just fine, but if given directions, cannot understand or process the information well enough to follow them.

  While the "tip of the tongue" experience can look similar across these terms, aphasia specifically reflects a breakdown in the brain's language system itself — not just word retrieval (anomia) or the physical sequencing of speech-related movement (apraxia).

  A Simplified Example

  • Anomia: You cannot find the word for the toothbrush.
  • Aphasia: You cannot communicate about the toothbrush (speaking, writing, or understanding the word).
  • Apraxia: You cannot physically sequence your hand and mouth muscles to use the toothbrush on command.
  • Agnosia: You pick up the toothbrush, but have no idea what it is until you taste the toothpaste or feel it brush against your teeth.
  • Amnesia: You cannot remember if you brushed your teeth this morning or not.

  These changes in brain function may occur with neurodegenerative processes like Alzheimer's disease, but they don't all need to be present for a diagnosis, and no single change is indicative of Alzheimer's disease. It is important to monitor changes, especially as you age, and to speak with a practitioner if you notice these differences in yourself or a loved one. The sooner cognitive changes are identified and addressed, the better the chances of using neuroplasticity for better brain health outcomes.