Bradykinesia is an umbrella term describing a slowness of movement, while hypokinesia specifically refers to a reduction in the amplitude or size of movements. Bradykinesia encompasses more than just slowness; it includes hypokinesia and akinesia.
Here's a breakdown of the key differences:
| Feature | Bradykinesia | Hypokinesia |
|---|---|---|
| Definition | Slowness of movement. Includes slowness, reduced amplitude and difficulty initiating movement. | Decreased amplitude or size of movement. |
| Scope | A broader concept incorporating hypokinesia & akinesia. | A specific component of bradykinesia. |
| Manifestation | Slower execution of movements, hesitant starts, and smaller movements. | Smaller handwriting (micrographia), reduced facial expression, quiet voice. |
Examples:
- A person with bradykinesia might take a long time to button a shirt, have difficulty initiating the movement, and make smaller, less fluid motions while doing so.
- A person with hypokinesia might exhibit reduced arm swing while walking, a quieter voice than usual, or smaller handwriting.
In Summary:
Think of bradykinesia as the overall slowness and difficulty with movement. Hypokinesia is one aspect of that, focusing specifically on the smaller size of the movements. The reference states, "Bradykinesia is a complex consisting of slowness of movement (also called bradykinesia), hypokinesia (small or decreasing amplitude movement), and akinesia (inability to initiate movement)."
