a-, an-
(Greek: prefix; no, absence of, without, lack of; not)
These prefixes are normally used with elements of Greek origin, a- is used before consonants and an- is used before vowels.
It affects the meanings of hundreds of words.
There are too many words that use these prefix elements to list all of them on this site; however, there are significant examples listed in this and the other units where they exist.
An adermia is defined as an acquired absence of the skin or a specified area of skin.
Adiadochokinesis involves the inability to stop one movement and then to follow it immediately with another motion in the opposite direction.
2. The inability to perform rapid alternating movements of one or more of the body's extremities: Adiadochocinesis is sometimes requested by physicians during physical examinations so they can determine if the patient has any neurological problems.3. Etymology: a highly contrived word that is composed of the Greek a-, "without" + diadochos, "successive" + kinesis, "motion".
So, adiadochokinesis is a neurological sign of the inability to perform rapid alternating movements; such as, pronation (turning the hand so the palm faces downward or backward) and supination (having the palm of the hand facing upward).
2. An abnormal avoidance of drinking: As people age, they have a tendency to have adipsia and so they are less likely to notice their thirst and may not drink sufficient fluids when they are needed.